Medical News

Blood test could provide an early arthritis warning

Medical News - Mon, 03/23/2015 - 17:50

"Arthritis breakthrough as new test diagnoses condition up to a decade earlier," the Mail Online reports. The test measures proteins linked with arthritis.

The study aimed to see whether a blood test could be developed that could distinguish between different types of early stage arthritis.

The study included groups of people with established diagnoses, including those diagnosed with early-stage osteoarthritis (so-called "wear and tear arthritis") and rheumatoid arthritis (caused by the immune system).

It then measured and compared levels of different proteins in their blood.

Overall, it found that looking at a combination of the levels of three proteins in the blood could distinguish between the different types of early-stage arthritis. This suggested such a test could have promise.

This is still early-stage research. Further study needs to look at whether this test is reliable for identifying and distinguishing between the different forms of early-stage arthritis in practice.

Most importantly, it needs to be seen whether use of the test leads to earlier treatment, and whether this leads to an improvement in patient outcomes.

 

Where did the story come from?

The study was carried out by researchers from the University of Warwick and other institutions in the UK. No sources of funding were reported. Some of the authors have a patent based on this work.

The study was published in the peer-reviewed scientific journal Scientific Reports.

The Mail’s headline is premature, as we do not know how accurate this test will prove to be on further study or whether it would be introduced. The subheadings saying “There is currently no test, meaning some patients are only diagnosed when disease is so progressed that surgery is the only option” is also a little overdramatic and inaccurate. This reporting makes it sound like osteoarthritis currently has no diagnosis and management pathways in place, which is not the case. Osteoarthritis is usually diagnosed based on a person’s symptoms, examination findings and X-ray findings.

 

What kind of research was this?

This was laboratory research, which aimed to develop a blood test to allow the detection and differentiation between different types of early-stage arthritis.

Blood tests are already used to help diagnose or exclude certain types of arthritis, such as rheumatoid arthritis, which is linked to having particular proteins and inflammatory markers in the blood. However, osteoarthritis (OA) has no diagnostic blood test. OA is a degenerative joint condition, where the cartilage covering the ends of the bones becomes worn and thin, causing symptoms including pain, stiffness, swelling and crunching feelings in the joints.

It is currently diagnosed based on a combination of a person’s symptoms and findings from a clinical examination. X-rays can also detect characteristic changes to the joints, though these are often not present in early stages of the disease.

This study aimed to look at if there were any biochemical markers that could be detected in the blood that would help diagnose early-stage OA and distinguish it from other types of arthritis. Ideally, a diagnosis could be made before any of the more advanced joint changes set in, which could be detected by X-ray.

 

What did the research involve?

This study included groups of people (181 people in all) with different established diagnoses:

  • advanced OA
  • early OA
  • advanced rheumatoid arthritis (RA)
  • early RA
  • early non-RA inflammatory arthritis – people with early symptoms of an inflammatory arthritis, but not having the diagnostic features of RA
  • a healthy control group with no joint problems

The researchers took blood samples from these people and samples of the fluid in the joints (synovial fluid) from those with early-stage arthritis. They used advanced laboratory techniques to measure the amount of different proteins in these fluids. They particularly looked at the amount of:

  • anti–cyclic citrullinated peptide (CCP) antibodies – a marker for RA
  • citrullinated protein – a marker for inflammation
  • hydroxyproline – a building block that is part of the protein collagen – a structural protein found in cartilage and bone

They compared the levels of these markers in people from the different groups. They also assessed whether looking for a particular combination of levels of these markers would allow them to tell the different groups apart.

 

What were the basic results?

The researchers found that compared to healthy controls, blood levels of citrullinated proteins were increased in people with early OA and early RA. Generally, people with early arthritis tended to have higher levels of these proteins in the blood, while in advanced disease, levels were lower in the blood and higher in the joint fluid.

Levels of citrullinated proteins were not increased in people with other non-RA early-stage inflammatory arthritis.

Anti–CCP antibodies were found mainly in the blood of people with early RA.

Compared to health controls, increased levels of hydroxyproline were found in people with early OA and early non-RA, but not in people with early RA.

The researchers found that looking at the levels of all three proteins enabled them to discriminate between people with early OA, early RA, other non-RA early inflammatory arthritis, and healthy joints. This combination test correctly identified:

  • 73% of people with early OA
  • 57% of people with early RA
  • 25% of people with non-RA early inflammatory arthritis
  • 41% of people with healthy joints

The test also correctly identified:

  • 87% of people who did not have early OA
  • 91% of people who did not have early RA
  • 76% of people who did not have non-RA early inflammatory arthritis
  • 75% of people who did not have healthy joints

 

How did the researchers interpret the results?

The researchers say their study provides a novel biochemical blood test that could be used for the diagnosis and discrimination of early-stage arthritis. They say that this could help to support improved treatment and patient outcomes.

 

Conclusion

This laboratory study suggests that for people presenting with early joint symptoms, examining blood levels of a combination of proteins could help to distinguish people who have early-stage OA from those who have early-stage RA or other inflammatory arthritis. 

However, this study is in the early stages and so far has only looked at relatively small samples of people with confirmed diagnoses of these different conditions. A lot of further work needs to be done to examine the accuracy of such a blood test, and to see whether it could reliably identify and distinguish between people with these conditions presenting to doctors in real world practice. These studies should assess whether it offers an improvement on the current approach to diagnosis based on symptoms, clinical examination, imaging findings and other blood tests currently used – such as measurement of inflammatory markers, rheumatoid factor, or anti-CCP antibodies.

Even if such studies find that the test performs well, it is likely that it would not replace all other diagnostic tests, instead being used in combination with other methods, especially as it performed better at detecting some forms of arthritis than others.

Most importantly, it also needs to be seen whether using this blood test as a diagnostic method would actually lead to improved disease outcomes for people with arthritis, as suggested in the news reports.

While several of the risk factors associated with OA are unavoidable (e.g. increasing age, female gender, previous joint damage or abnormalities), maintaining a healthy weight and staying active could help prevent onset of the disease. RA is an autoimmune disease (where the body’s own immune cells attack the joints) with no established cause. However, smoking is associated with the development of the condition.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Arthritis breakthrough as new test diagnoses condition up to a decade earlier - with just a single drop of blood. Mail Online, March 22 2015

DISCOVERY of proteins could lead to diagnosis of arthritis up to ten years before symptoms. Daily Express, March 22 2015

Links To Science

Ahmed U, Anwar A, Savage RS, et al. Biomarkers of early stage osteoarthritis, rheumatoid arthritis and musculoskeletal health. Scientific Reports. Published online March 19 2015

Categories: Medical News

Climate change 'might bring rise in UK mosquito-borne diseases'

Medical News - Mon, 03/23/2015 - 14:00

"Mosquitoes heading for warmer UK," Sky News reports after a new review predicted climate change will make the UK a more hospitable environment for disease-carrying mosquitoes and ticks, leading to an outbreak of conditions normally seen in more tropical climates.

In the review, two authors searched the literature to identify evidence looking at the effect climate change in Europe could have on diseases carried by mosquitoes or other insects, such as ticks.

Mosquitoes thrive in warm and wet environments, so a rise in the average temperature could make the UK a more attractive destination. This could then lead to an increase in three diseases – malaria, dengue fever and chikungunya (a viral infection with symptoms similar to malaria) – in the UK by as early as 2030.

A review of this kind can only provide an estimate and cannot predict the future with 100% accuracy. However, it does show the potential public health dangers that could arise from climate change: a rise in the average temperature by just a few degrees centigrade could have a range of unpredictable effects on our environment.

Where did the story come from?

This study was written by two researchers from the Emergency Response Department, Public Health England (PHE), Porton Down. PHE is the NHS body responsible for protecting and improving public health in England.

One of the researchers received partial finding from the National Institute for Health Research's Health Protection Research Unit.

The study was published in the peer-reviewed medical journal Lancet Infectious Diseases.

What kind of research was this?

This was a literature review, where the researchers identified and discussed research on the effect climate change could have on the risk of vector-borne disease in the UK. Vector-borne disease is disease carried by a non-human organism (such as mosquitoes or ticks) that is then transmitted to humans.

The researchers searched literature databases to identify any published papers that had looked at vector-borne disease in Europe, and focused on reports that were potentially relevant to the UK.

They present a discussion of the issue and the evidence they identified. They also make various recommendations on monitoring and studying these vector-borne diseases, including how they are impacted by weather and climate.

The researchers clearly state that the views expressed in the article are theirs and "not necessarily those of the National Health Service, the NIHR, the Department of Health, or PHE".

What do the researchers say about mosquito-borne disease and climate change?

Insects regulate their body temperature by taking in heat from the environment. This means that increases in temperature could help them survive and incubate, thereby spreading any disease-causing organisms they carry, such as parasites, bacteria and viruses.

The researchers present evidence that has looked at the effects that 2C, 4C or 6C rises in average temperature could have on vectors carrying the following pathogens:

Of these pathogens, some (but not all) of the most extreme modelling scenarios suggest malaria could be present in the UK as early as 2030.

Climate assessment has suggested one type of mosquito that spreads dengue fever and chikungunya could theoretically live in warmer parts of the UK, and that by 2030 the climate could be even more well suited to this mosquito.

What do they say about malaria?

The researchers explain how malaria was regularly found in certain parts of the UK in the 1800s. The UK still has several species of mosquito capable of carrying the malaria parasite, albeit the less severe kind (Plasmodium vivax).

However, the researchers say rising summer temperatures could also support the development of the more severe malaria parasite (Plasmodium falciparum).

One group of researchers have modelled the effect climate change could have on P. falciparum. They estimate there will be between 1.5C and 5C increases in temperature between 2030 and 2100. Sustained transmission of the malaria parasite is still unlikely at these temperatures.

However, one of the most extreme model scenarios they looked at suggested there could be sustained transmission of the parasite (lasting at least one month of the year) in southern England by 2080 or, to a lesser extent, even as early as 2030.  

But, as the researchers say, antimalarial drugs and the UK health system should be able to minimise transmission.

What do they say about dengue fever and chikungunya?

The researchers say that since 1990, five different tropical species of mosquito have become adapted to the temperate climate of Europe. These species are potential vectors of the tropical diseases dengue, chikungunya and yellow fever.

In the past decade, there have been cases where one of these tropical mosquito species has been implicated in outbreaks of chikungunya and dengue in southern France, Italy and Croatia.

Climate change is predicted to permit the expansion of this species across Europe, including the south of the UK.

If these mosquitoes do become established in the UK, people with dengue or chikungunya who travel to the UK would then be a source of infection for the established mosquitoes.

Ongoing transmission would then depend on the local climate conditions controlling mosquito populations.

Two models suggested that by 2030-50, the climate in southern England could be more suitable for one species of mosquito that carries chikungunya and dengue.

Models also predicted transmission periods of one month to be possible in London by 2041, and one to three months of activity possible in southern England by 2071-2100.

What do the researchers conclude?

The researchers make the following recommendations about how the potential threat from vector-borne disease could be managed:

  • Continue to enhance UK surveillance of endemic and non-native vectors.
  • Improve understanding of the effect of climate change and develop strategies to deal with changing public health risks in a changing environment (such as wetland management).
  • Better understand the effect of extreme weather events (such as flooding and drought) on the risk of infectious disease, and work with environmental organisations to develop management plans to prepare for a disease outbreak resulting from an extreme event.
  • Develop improved models that incorporate the many drivers for change (such as climate and land use) for a range of vector-borne diseases.
  • Continue to work collaboratively across Europe sharing data on vector-borne diseases and risk assessment.
Conclusion

Overall, this review provides insights into how climate change might lead to the transmission of tropical diseases in what are currently temperate parts of the world, such as the UK. Predicting what may happen in the future can help countries make sure they are prepared for such an eventuality.

This review was informed by a search for relevant literature, but may not have captured or included all relevant studies. Most of the studies were modelling studies, which are reliant on various assumptions that may or may not turn out to be correct.

It's not possible to say with any certainty what will occur in the future. The authors also note that climate change is not the only factor affecting vector-borne diseases.

Many other factors are equally important, such as socioeconomic development and changes in how land is used. This adds to the difficulty in predicting exactly how much climate change might impact these diseases.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Mosquitoes Heading For Warmer UK - Experts. Sky News, March 23 2015

Mosquitoes 'could bring exotic diseases to UK'. BBC News, March 23 2015

Plague of mosquitos carrying deadly diseases is headed for Britain, scientists warn. The Daily Telegraph, March 23 2015

Warmer weather means mosquitoes carrying killer diseases including dengue fever 'could be in the UK by 2030'. Mail Online, March 22 2015

Links To Science

Medlock JM, Leach SA. Effect of climate change on vector-borne disease risk in the UK. The Lancet Infectious Diseases. March 23 2015. (Article not yet online)

Categories: Medical News

Research casts doubt on aspartame sensitivity

Medical News - Fri, 03/20/2015 - 13:31

"Sweetener linked to cancer is safe to use," reports the Mail Online.

Aspartame – a commonly used artificial sweetener – has been dogged by controversy, despite being deemed safe by food regulators in the UK, EU and US.

Some believe they are sensitive to the sweetener. Anecdotal reports suggest it can cause headaches and stomach upsets.

This study recruited 48 "aspartame-sensitive" individuals and tested whether giving them a cereal bar with or without aspartame would elicit the suspect symptoms. The study was a gold-standard double blind randomised controlled trial (RCT), meaning neither the participants nor those analysing the results knew which bar they had eaten. This made it a fairer and more rigorous test.

It showed that there was no difference in the symptoms reported after eating the aspartame-laced bar compared with the normal bar.

This provides evidence that aspartame fears may not be warranted in some people who believe they are sensitive to the ingredient. However, the study may have failed to recruit those most fearful of the sweetener, so we can’t rule out aspartame-related symptoms in this group.

This study also can’t tell us whether regular aspartame consumption may have any health effects in the longer term.

To find out more, read "The truth about aspartame".

 

Where did the story come from?

The study was carried out by researchers from the University of Hull, the Food Standards Agency (FSA), Imperial College London, University College Dublin, Institute of Food Research (UK) and Weill Cornell Medical College, Qatar.

It was funded by the Food Standards Agency.

The study was published open-access in the peer-reviewed medical journal PLOS One. This means it is free to view and download this aspartame research.

The Mail Online reported the story accurately. However, in stating that aspartame does not cause harm, it would be better to make clear that this study has only looked at short-term effects. This study also had nothing to do with verifying aspartame’s safety in regards to cancer, despite what the headlines may lead you to believe.

 

What kind of research was this?

This was a double-blind randomised control crossover study looking at whether aspartame causes any harmful symptoms in people who report sensitivity to it.

Aspartame is a commonly used artificial sweetener that is around 200 times sweeter than normal sugar. Since its introduction in the 1980s, there have been concerns over whether aspartame is safe. There are many anecdotal reports of it causing stomach upsets, headaches and other problems. However, this concern doesn’t match the evidence.

Aspartame has been approved as a safe food ingredient after assessment of the evidence by regulators in the UK, EU and US, all of which have independently assessed the best available evidence. Despite the regulatory assurance, some people report they are sensitive to aspartame and are convinced that it causes them problems. The current study wanted to investigate this "aspartame-sensitive" group, to see if the claims were true.

A double blind RCT like this is the gold standard of single study research. It is one of the best ways to investigate whether aspartame is affecting people who report being sensitive to it. Neither the study participants nor those analysing the results knew whether they were consuming aspartame. This helps to eliminate bias caused by pre-conceived ideas of whether it is harmful or not. The only thing more convincing in the evidence stakes than an RCT like this is a meta-analysis of many of them.

 

What did the research involve?

Researchers gave 48 UK adults who said they were sensitive to aspartame two cereal bars, at least one week apart. One of the bars was laced with 100mg aspartame. This is equivalent, the researchers say, to the amount found in a can of diet fizzy drink. The other was a normal cereal bar. After eating each bar, standard questionnaires were used to assess psychological condition, and 14 symptoms were rated repeatedly over the next four hours. Blood samples were also taken immediately after eating and four hours later – the same was done for urine samples, but at four-, 12-, and 24-hour intervals.

One of the cereal bars was laced with aspartame and one was not. However, neither the participant nor the person analysing the results knew which was which, making the test more objective and eliminating many sources of bias.

Individuals volunteering were classified as "aspartame-sensitive" if they reported suffering one or more symptoms on multiple occasions, and as a consequence were actively avoiding consumption of any aspartame in their diet.

A further 48 people who didn’t report aspartame sensitivity (controls) repeated the same experiment under the same conditions. This group was chosen to match the characteristics of the aspartame-sensitive group in terms of age and gender. The aspartame-sensitive group had 21 men and 31 women; the control group had 23 men and 26 women. The groups did not differ significantly for age (around 50), weight, BMI, waist or hip circumference.

The 14 aspartame sensitivity symptoms assessed were:

  • headache
  • mood swings 
  • hot or flushed 
  • nausea 
  • tiredness 
  • dizziness
  • nasal congestion 
  • visual problems 
  • tingling
  • bloating 
  • hunger 
  • thirst 
  • happiness
  • arousal

The researchers’ main analysis looked for differences in symptoms after eating the aspartame-laced bar in those reporting aspartame sensitivity, compared with those reporting no sensitivity.

 

What were the basic results?

The main finding was that none of the rated symptoms differed between aspartame and control bars, or between sensitive and control participants.

They also found aspartame and control bars affected levels of chemicals in the blood (GLP-1, GIP, tyrosine and phenylalanine levels) equally in both aspartame-sensitive and non-sensitive subjects.

However, there were intriguing differences between the aspartame-sensitive group and the aspartame non-sensitive group. For example, the aspartame-sensitive people rated more symptoms, particularly in the first test session, whether this was after eating the placebo bar or the aspartame bar.

The two groups also differed psychologically in how they handled feelings and perceived stress.

 

How did the researchers interpret the results?

The authors’ conclusion was firm: "Using a comprehensive battery of psychological tests, biochemistry and state of the art metabonomics, there was no evidence of any acute adverse responses to aspartame.

"This independent study gives reassurance to both regulatory bodies and the public that acute ingestion of aspartame does not have any detectable psychological or metabolic effects in humans."

 

Conclusion

This study shows that an aspartame-laced cereal bar caused no more adverse symptoms than a bar without aspartame in a group or people who said they were sensitive to aspartame. It also had no more adverse symptoms in a control group of people who did not think they were sensitive to aspartame.

The effects were monitored up to four hours after eating. This provides compelling evidence that aspartame doesn’t cause any short-term symptoms, even in people who think they are particularly susceptible to it, and report avoiding it as a result.

Limitations with the study include some missing symptom data, because not everyone was able to complete the ratings scale after eating the bars. However, you might expect someone with symptoms to fill it in, so not filling it in might signal a lack of symptoms. The sample size of around 90 participants was also relatively small. A larger sample size would have increased the conviction of the results.

The study authors reported problems recruiting participants, which brings us to the biggest limitation to consider. They anticipated 48 aspartame-sensitive people would be recruited within a year, but it took 2.5 years, despite high-level media coverage. A lot more non-aspartame-sensitive people (147 individuals) initially volunteered for the study before just one aspartame-sensitive individual participated. The researchers say this may reflect their genuine fear of aspartame consumption. Consequently, the 48 who participated may not be representative of the population of people who believe they are aspartame-sensitive, but it was impossible to recruit those most fearful, as they avoid taking part.

A further limitation is that the study looked only at short-term effects and cannot exclude the possibility of long-term, cumulative effects of aspartame on biological parameters and on a person’s psychological state. The dose given was also reported to be smaller than the daily intake of many individuals, but was greater than the intake at which the people reporting aspartame sensitivity believe they suffer symptoms.

Overall, this study provides evidence that aspartame fears may not be warranted in some people who believe they are sensitive to the ingredient. However, the study probably failed to recruit those most fearful of the sweetener. We don’t know if this group have symptoms caused by aspartame.

The conclusions of this study, and aspartame’s approval by food safety agencies in the US, UK and EU, provide quite robust reassurance that aspartame is safe for the vast majority of people. As with any ingredient, you can’t say for sure that some individuals won’t react badly to it. However, the findings from this study suggest this may be a perception of harm that is not necessarily borne out when tested rigorously.

The FSA website says that in December 2013, the European Food Safety Authority (EFSA) published an opinion on aspartame: "following a full risk assessment after undertaking a rigorous review of all available scientific research on aspartame and its breakdown products, including both animal and human studies. The EFSA opinion concluded that aspartame and its breakdown products are safe for human consumption at current levels of exposure".

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Controversial sweetener aspartame found in fizzy drinks and diet products 'does NOT cause harm', report declares. Mail Online, March 20 2015

Links To Science

Sathyapalan T, et al. Aspartame Sensitivity? A Double Blind Randomised Crossover Study. PLOS One. Published Match 18 2015

Categories: Medical News

Are half of all children's teeth really rotten?

Medical News - Fri, 03/20/2015 - 13:30

"Rotten teeth are secret reason why teens don't smile," revealed The Times today.

The Daily Mirror expressed shock over revelations that, "More than a quarter of British children are afraid to smile because they have such bad tooth decay".

It explained how "poverty and sugar" were to blame after evidence has emerged that the poorest in British society are "twice as likely" to suffer from oral disease.

Public Health England's director of dental public health, Dr Sandra White, said the survey highlighted "the need to urgently reduce the amount of sugary snacks and drinks in our children's diets".

She went on: "Fluoride is indisputable in preventing tooth decay, and by brushing teeth using fluoride toothpaste and also introducing water fluoridation where needed, we can significantly improve our children's dental health."

Quoted in The Independent, Professor Damien Walmsley, scientific adviser to the British Dental Association, said: "These inequalities [between rich and poor] are persistent, but avoidable, and both parents and government must accept their share of responsibility."

What is the basis for these current reports?

These figures were revealed in the latest of five large-scale Children's Dental Health Surveys covering England, Wales and Northern Ireland. These surveys have been carried out every 10 years since 1973 to monitor the oral health of the nation.

The new survey report outlines changes in oral health since the last survey in 2003, and provides information on the distribution and severity of oral diseases and conditions in 2013.

The latest survey gives estimates of the dental health of 5-, 8-, 12- and 15-year-olds using data collected on a random sample of children by NHS dentists and nurses at dental examinations in schools.

Information on the children's experiences, perceptions and behaviours relevant to their oral health was collected from parents and 12- and 15-year-old children using self-completion questionnaires.

What did it find?

There was some good news. There were reductions in the extent and severity of tooth decay present in the permanent teeth of 12- and 15-year-olds overall in England, Wales and Northern Ireland in the last 10 years (2003 to 2013).

Decay was found in around a third of 12-year-olds (down from 43% in 2003) and half of 15-year-olds (46%, reduced from 56% in 2003). Around a third of 5-year-olds and almost half of 8-year-olds were found to have decay in their milk teeth.

However, large proportions of children continue to be affected by poor oral health. This directly affects their lives in significant and serious ways, such as not wanting to smile or problems eating food.

Children from poor families (judged by eligibility for free school meals) were more likely to have oral disease than other children of the same age:

  • a fifth (21%) of the 5-year-olds from poor backgrounds had severe or extensive tooth decay, compared with 11% of 5-year-olds whose families were richer
  • a quarter (26%) of the 15-year-olds from poor backgrounds had severe or extensive tooth decay, compared with 12% of 15-year-olds who were not eligible for free school meals

Oral health affected the health and wellbeing of older children and their families, too:

  • a fifth of 12- and 15-year-olds (22% and 19% respectively) reported experiencing difficulty eating in the past three months
  • more than a third (35%) of 12-year-olds and more than a quarter (28%) of 15-year-olds reported being embarrassed to smile or laugh because of the condition of their teeth
  • 58% of 12-year-olds and 45% of 15-year-olds reported that their daily life had been affected by problems with their teeth and mouth in the past three months

The majority of older children were positive about their oral health. About half of 12-year-olds (51%) and 60% of 15-year-olds were satisfied with the appearance of their teeth.

However, problems with oral health were common, and these impacted on children and their families:

  • a fifth of 12- and 15-year-olds (22% and 19% respectively) reported having difficulty eating in the past three months, and 35% of 12-year-olds and 28% of 15-year-olds reported being embarrassed to smile or laugh because of the condition of their teeth
  • nearly a quarter (23%) of the parents of 15-year-olds said they had taken time off work in the last six months because of their child's oral health, and 7% of parents of 5-year-olds said this

Severe or extensive decay was seen in around one in seven of the 5- and 15-year-old children (13% and 15% respectively).

How does this news affect me?

This study is a stark reminder to children, young people and parents of the importance of good oral health from the time a baby gets their first milk teeth. Poor oral health can have a significant impact on a person's life.

Today's report does not suggest or endorse ways to combat the issues raised, but we have covered stories in the past that offer potential solutions for discussion.

These include adding fluoride to water to prevent tooth decay, more consistent advice on how to brush teeth, and teaching and supervising tooth brushing in schools.

Read more about preventing tooth decay.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Half of children have tooth decay - with poverty and sugar blamed for epidemic. Daily Mirror, March 19 2015

Nearly half British children and teenagers have tooth decay. The Independent, March 19 2015

Almost HALF of eight year olds and a third of five year olds have fillings or missing teeth because of decay. Daily Mail, March 19 2015

'Half of eight-year-olds have tooth decay'. BBC News, March 19 2015

Half of children have tooth decay, national survey finds. The Times, March 19 2015

Categories: Medical News

Following UK dietary advice may cut heart disease risk

Medical News - Thu, 03/19/2015 - 16:00

"Sensible diet cuts heart attack risk in months," The Times reports after a randomised controlled trial found evidence that following current UK diet guidelines can reduce cardiovascular disease risk factors such as blood pressure and cholesterol levels.

We know that being a healthy weight and not smoking can help lower the risk of cardiovascular diseases such as heart attacks and strokes, but the evidence that healthy people benefit from low-salt, low-fat diets is weaker.

One of this study's strengths is its randomised design, which is actually uncommon with diet studies. This helps reduce the possibility that other factors influenced the results. Limitations include the fact this was a small study (165 participants) carried out over a relatively short time period.

Blood pressure and cholesterol measures are good indicators of the chances of someone having a heart attack or stroke, but not as reliable as waiting to see whether people in the study actually did so. It would be difficult (and possibly unethical) to do a dietary study that lasted long enough to show these outcomes.

The study suggests that if healthy middle-aged people follow current UK dietary recommendations, there may well be benefits, but we can't be sure of the size of the protective effect.

Where did the story come from?

The study was carried out by researchers from King's College London and was funded by the UK Food Standards Agency, the Department of Health, and the National Institute for Health Research.

It was published in the peer-reviewed medical journal The American Journal of Clinical Nutrition. It has been published on an open access basis, so it is free to read online.

A number of the authors have worked, or are currently working, for food manufacturers and medical companies, which could represent a conflict of interest.

The UK media reported the study with enthusiasm, with the Daily Mirror describing fruit and veg as a "lifesaver".

The Guardian did a good job of reporting the different outcomes, but did not report that some of the key measures did not show any improvement.

But none of the papers questioned how the overall "one-third" reduction figure mentioned by the researchers was calculated.

What kind of research was this?

This was a randomised controlled trial that compared the effects of following two types of diet.

One was based on a nutritionally balanced standard UK diet. The other included current UK nutritional guidelines, which recommend reduced salt, saturated fat and sugar intake, and an increased consumption of oily fish, fruit, wholegrain and vegetables.

Randomised controlled trials are a good way of comparing the true effects of a treatment or diet. However, the 12-week study could only look at the effects the diets had on markers such as blood pressure and cholesterol levels, but not long-term outcomes such as heart disease and stroke.

What did the research involve?

The researchers recruited 165 healthy non-smoking UK volunteers aged 40 to 70. They all had health checks at the start of the study, and were then split randomly into two groups. One group was asked to follow a standard UK diet while the others followed a diet based on healthy eating guidelines.

After 12 weeks, the health checks were repeated and the researchers looked for differences in blood pressure, cholesterol and other measures of heart attack risk that could have been caused by the different diets.

People selected to be in the study had an average risk of having a heart attack or stroke in the next 10 years.

The researchers ensured health check measurements, such as blood pressure, were reliable by using 24-hour blood pressure monitors rather than just taking one-off measurements.

Volunteers also had urine tests throughout the study so the researchers could estimate how well they were sticking to their allotted diets by checking their nutrient levels.

The dietary guidelines group were given dietary advice to help them reach the salt, fat, sugar and other targets in the healthy guidelines, and were advised to choose low-fat dairy products and lean cuts of meat.

The standard group were advised to eat a balanced "British" diet with no salt or sugar restrictions, based on bread, pasta and rice, potatoes with meat, limited oily fish, and wholegrain cereals. They were asked to eat full-fat dairy products.

Both groups were asked to limit their intake of sweets, cakes, biscuits and crisps, and to drink alcohol within safe limits.

Before the study began, the researchers agreed to look for three main outcomes, which they said would indicate an important change in people's heart attack risk. These were:

  • a reduction in daytime systolic blood pressure of 4mmHg (the higher blood pressure figure, which shows the pressure of the blood when it is pumped out of the heart)
  • a 5% change in the ratio of total cholesterol to HDL (or "good") cholesterol
  • a 1% reduction in blood vessel stiffness (flow mediated dilation)

While they reported on many other outcomes in the study, these are the key ones to look at. The researchers reported the effects of treatment as the comparison between the diet groups at the end of the study, adjusted to take account of differences between the participants before the study began.

However, it is not clear from the study how the researchers calculated the overall reduction in risk of having a heart attack or stroke from all the changes combined.

What were the basic results?

The main result was that people who followed healthy dietary recommendations reduced their daytime blood pressure measurement by an average of 4.2mmHg compared with the standard diet group, which was more than the researchers had hoped.

However, the average change in cholesterol ratio was less than expected – 4%, below the hoped-for 5%. There was no significant difference in change in blood vessel stiffness.

The people following the dietary recommendations lost weight compared with the standard diet group (average difference 1.9kg), even though that was not the intention of the study.

How did the researchers interpret the results?

The researchers said the change in blood pressure was "remarkable" and would "suggest" a reduction in the risk of having a fatal stroke of 54%, as well as a 39% drop in the risk of getting heart disease, for people following the healthy diet, depending on age.

They attribute about half of the drop in blood pressure to the effect of eating less salt. They say the change in cholesterol levels for the dietary guidelines group, although "modest compared with drugs such as statins", would still reduce the risk of heart disease by about 6%.

They concluded that, "selecting a diet consistent with current dietary guidelines compared with a traditional United Kingdom dietary pattern" would be likely to cut the chances of having a heart attack or stroke for people in the general population by 30% based on previous research.

Conclusion

This study showed that following dietary recommendations closely for 12 weeks can reduce blood pressure by a significant amount, which is likely to cut the chances of having a heart attack or stroke for an average healthy middle-aged person. The diet also affects cholesterol levels, but the overall effect of this may be modest.

The study appears to have been carefully conducted to avoid biasing the results. The researchers gave butter or margarine spread and cooking oil to people in both groups, for example, and asked everyone to fill out food diaries, as well as taking urine samples for nutrient analysis.

This may have improved the chances of people sticking to the diet they were allocated to. The methods used to analyse blood pressure and other health checks were rigorous and likely to produce reliable results.

However, it is disappointing that the study report is not clear about how the researchers reached the headline figure of a one-third drop in the risk of a heart attack or stroke.

The report includes much detail about changes to individual risk factors, such as different ways to measure cholesterol, but does not explain how the researchers calculated the overall risk reduction.

That said, this is a well-conducted study that offers good-quality evidence of the effects of following the current UK dietary recommendations.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Sensible diet cuts heart attack risk in months. The Times, March 19 2015

Diet with more fruit, fish and nuts cuts heart attack risk, say researchers. The Guardian, March 18 2015

Healthy diet means heart attack risk reduction says study. ITV News, March 19 2015

Links To Science

Reidlinger DP, Darzi J, Hall WL, et al. How effective are current dietary guidelines for cardiovascular disease prevention in healthy middle-aged and older men and women? A randomized controlled trial. The American Journal of Clinical Nutrition. Published online March 18 2015

Categories: Medical News

New blood test could help prevent antibiotic misuse

Medical News - Thu, 03/19/2015 - 14:40

"A new blood test can help doctors tease out whether an infection is caused by a bacteria or a virus within two hours," BBC News reports. The test, which looks at protein pathways in the blood, could help to appropriately target the use of both antibiotics and antivirals.

In many cases, it is unclear whether a person’s symptoms are being caused by a viral or bacterial infection, and current testing can take up to several days to find out.

In cases of severe illness, antibiotics are usually prescribed while waiting for the results, and this can contribute to antibiotic resistance.

Israeli-based researchers who developed the test used 1,002 children and adults who had been admitted to hospital. The test was good at distinguishing between viral and bacterial infections, and separating people with and without an infectious disease.

However, it needs to be used by a greater number people, to test its effectiveness, and has not yet been used to influence treatment. Further research, including randomised controlled trials, will be required before it could be used in a clinical setting.

Where did the story come from?

The study was carried out by researchers from several institutes and medical centres in Israel. It was funded by MeMed, a company based in Israel that designs and manufactures diagnostic tests. Most of the researchers were employed by MeMed and some reported owning stock options with the company.

The study was published in the peer-reviewed medical journal PLOS One. It is published on an open-access basis, so is free to read online.

The research was accurately reported by BBC News.

What kind of research was this?

This was a laboratory study, which used blood samples from a cohort of patients admitted to hospital. It aimed to develop a blood test that could distinguish between viral and bacterial infections.

Overuse or incorrect use of antibiotics leads to the inadvertent selection of bacteria that have resistance to them. Over time, the resistant bacteria can become more common, making the drugs less useful.

This is causing global concern, as infections that have been easy to treat with antibiotics may now emerge as serious, life-threatening conditions. This can happen by people being given "broad spectrum antibiotics". This happens when an infection is suspected, but before any microbiological results can show the exact type of infection. This means that some people will be given the wrong antibiotic, too many antibiotics or an antibiotic for illness caused by viruses, which will be ineffective.

Current tests that can be speedily obtained when an infection is suspected include non-specific markers of infection and the number of different white blood cells. These cells are specialised to fight different types of infections, with neutrophils mainly fighting bacteria and lymphocytes mainly fighting viruses. However, the interpretation of these tests is not straightforward, as both can be increased in each type of infection.

The researchers wanted to develop a test that could show whether the infection is from a bacteria or virus, so that fewer

What did the research involve?

The researchers took blood samples from 30 people and measured a number of proteins that are produced by the immune system in response to bacterial or viral infections. They used this information to create a blood test that measured these proteins. They then tested how accurate it was in 1,002 children and adults admitted to hospital with or without a suspected infection.

They used a systematic literature review to identify 600 proteins that can increase during bacterial and viral infections. Using samples from 20 to 30 people, half of whom had a viral infection and half a bacterial infection, they whittled down the number of proteins that are distinctly raised in each type of infection to 86. They then looked at the level of these proteins in 100 people, half with each infection, and found that 17 of the proteins were the most useful. Using statistical programmes, they chose three proteins for their final test. These were:

  • CRP (C-Reactive Protein) – a protein that increases in response to tissue injury, infection and inflammation; this is routinely used in clinical practice
  • IP-10 (Interferon gamma-induced protein-10)
  • TRAIL (Tumour necrosis factor [TNF] related apoptosis-inducing ligand)

The researchers then used the test on blood samples from children and adults from two medical centres who were suspected of having an infection due to a fever of over 37.5C developing within 12 days of the onset of symptoms. A control group consisted of people who were not suspected of having an infection – such as people with suspected trauma, stroke or heart attack – or healthy people.

People were excluded who had:

  • evidence of acute infection in the previous two weeks
  • immune deficiency from birth
  • immunosuppressant treatment
  • cancer
  • HIV
  • hepatitis B or C

After all usual test results were obtained, a panel of three clinicians individually reviewed the clinical notes and test results, and recorded whether each person had a bacterial infection, viral infection, no infection, or that it was unclear. The three doctors made their assessment independently and were not told what the other doctors had decided, and did not know the result of the test in development. They compared findings from this expert panel with the results of their blood test.

What were the basic results?

A total of 765 participants were diagnosed with either a viral infection, bacterial infection or no infection. Additionally, there were 98 people who did not have a clear diagnosis.

The test was good at distinguishing between viral and bacterial infections, and separating people with and without an infectious disease. The test remained robust regardless of where the infection was, such as in the lungs or the gut, or variables such as age.

Results were not clearly presented for the 98 people without a firm clinical diagnosis.

How did the researchers interpret the results?

The researchers concluded that "the accurate differential diagnosis provided by this novel combination of viral- and bacterial-induced proteins has the potential to improve management of patients with acute infections and reduce antibiotic misuse".

Conclusion

This new test shows promising results in distinguishing between viral and bacterial infections. This is important because of increasing antibacterial resistance and could help doctors to tailor treatment quicker when someone is admitted with a suspected infection.

At present, distinguishing between different types of infections is complex and relies on symptoms, signs, a variety of clinical tests and clinical judgement. One of these tests is the CRP, which is used as an indicator of the severity of infection or inflammation, and is often used to monitor this over time. It is surprising that it has been used as one of the determinants in this new test, as it is considered to be a non-specific marker of inflammation or infection and increases in both viral and bacterial infections.

While the results of the study are positive, it’s important to realise that the test is not ready to be used on the general population. It will need to be tested on larger groups of people to confirm its accuracy. In addition, studies will need to show that it delivers benefits to patients in the way it is hoped – for example, finding out whether using this test leads to more accurate prescribing of antibiotics, less antibiotics being prescribed, or speeds up the process of diagnosing infection. Further research along these lines, including randomised controlled trials, will be required before it could be used in the clinical setting.

Although the test appeared to be good at distinguishing between viral and bacterial infections, it is unclear what results were obtained for people who did not end up with a clear diagnosis using the best existing methods. We do not know if the new test gave a result for these people or was inconclusive. This group doesn’t appear to benefit from the old or new testing methods, so will need to be explored in the next phases of research.

You can help slow down antibiotic resistance by always completing a course of prescribed antibiotics, even if you feel well before the end of the suggested course of treatment. Remember: antibiotics are not effective against colds, most sore throats and flu.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Rapid blood test to 'cut antibiotic use'. BBC News, March 19 2015

Links To Science

Oved K, Cohen A, Boico O, et al. A Novel Host-Proteome Signature for Distinguishing between Acute Bacterial and Viral Infections. PLOS One. Published online March 18 2015

Categories: Medical News

Damage to 'heart health' may start in childhood

Medical News - Wed, 03/18/2015 - 15:30

"Children are suffering damage to their hearts as early as 12 due to poor diets," the Mail Online reports.

A US study has found high levels of known risk factors for heart disease in children. The study has not shown the direct effect these risks have in this age group, but it has raised concerns that they may affect the heart from childhood.

The study looked at four related risk factors known to contribute towards heart disease in adults:

They are:

Researchers surveyed 8,961 children and found that less than 1% of children aged two to 11 ate a healthy diet. Nearly a third of the children were overweight or obese.

80% of the children only met one of the five elements considered to be part of an "ideal" diet:

  • four or five portions of fruit and vegetables a day
  • fish twice a week
  • low salt
  • low added sugar in drinks
  • regular wholegrains

While heart damage in later life was not directly assessed in this study, it does highlight the need for further health promotion strategies. Heart disease has now overtaken cancer as the leading cause of death in developed countries.

While it is not clear to what extent these US findings relate to the UK population, the UK is in the midst of its own obesity epidemic. The latest figures suggest that the UK is now the "fat man of (Western) Europe", with one in four British adults now obese.

 

Where did the story come from?

The study was carried out by researchers from Northwest University in Chicago, the University of North Carolina at Chapel Hill and the University of Colorado School of Medicine. No external funding was reported.

The study was published in the peer-reviewed medical journal Circulation: Cardiovascular Quality and Outcomes.

On the whole, the Mail Online reported the story well, but there were some inaccuracies. The headline that stated damage to the heart starts before the age of 12 was not confirmed by the study. While it is likely that the increased cholesterol, BMI, poor diet and high blood pressure in this age group may be bad for the heart, the study did not directly check for any damage to the heart. They did point out some of the limitations of the study – specifically, using adult dietary recommendations for children and not adjusting this for the amount of exercise they take.

 

What kind of research was this?

This was a cross-sectional study, which measured how common risk factors for cardiovascular disease are in childhood.

Cardiovascular diseases (which affect the heart and blood vessels) are the leading cause of death globally. There are several known risk factors for cardiovascular disease, which are smoking, high blood pressure, obesity, high cholesterol, diabetes, low levels of physical activity and poor diet. Previous research has shown that managing these risk factors from adolescence is associated with reduced risk of cardiovascular disease.

This research aimed to provide a national reference point for these risk factors in children under the age of 12 in the US. This will help researchers to assess how successful future strategies are in tackling childhood obesity, by looking for changes in these measures over time.

 

What did the research involve?

The researchers used information from a large US study called The National Health and Nutrition Examination Survey (NHANES). These surveys collect data from adults and children across the US every two years, using a home interview and a health examination.

This study looked at four cardiovascular risk factors for 8,961 children who had participated between 2003 and 2010. These were:

  • diet
  • cholesterol level
  • blood pressure
  • BMI

Dietary intake was assessed by two interviews with the child’s carer (parent or guardian) and recorded dietary intake over the previous 24 hours. An "ideal diet" was considered to meet the following five criteria:

  • 4.5 or more cups of fruit and vegetables per day
  • two or more servings of fish per week
  • three or more servings of wholegrains per day
  • less than 1.5 grams of salt per day
  • less than 450 calories of added sugar in drinks per week

This broadly matches current UK recommendations for a healthy diet for children.

Children were then classified into three groups, according to how many of these criteria they fulfilled:

  • "ideal diet" – meeting four or five criteria
  • "intermediate diet" – meeting two or three criteria
  • "poor diet" – meeting none or one of the criteria

Similarly, they also classed the children’s other measurements (such as BMI, blood pressure and cholesterol) as "ideal", "intermediate" or "poor", based on standard criteria.

 

What were the basic results?

The main results were:

  • 99.9% of children did not have an ideal healthy diet, with most (over 80%) having a poor diet
  • 38% did not have an ideal cholesterol level
  • about 8% did not have ideal blood pressure
  • about 30% of children did not have an ideal BMI (were overweight or obese)

When combining the results for children aged eight to 11:

  • no children had ideal levels for all four cardiovascular health measures (diet, cholesterol, BMI and blood pressure)
  • 39% of boys and 38% of girls had three ideal measures
  • all children had ideal levels for at least one measure

 

How did the researchers interpret the results?

The researchers concluded that "with the exception of diet rated as intermediate or poor for nearly all children, the majority of children observed from ages two to 11 years had ideal CVH [cardiovascular health] for BMI, total cholesterol and blood pressure, thereby starting life with generally favourable CVH metrics". However, they are concerned about the rise in obesity and the effect this has on cardiovascular health. They say that "promoting the recommended dietary habits, physical activity as part of daily life, and arresting the growing trend of obesity are keys to achieving more favourable CVH metrics and long-term freedom from cardiovascular disease".

 

Conclusion

This large US survey has found high rates of poor diet, as well as overweight and obesity in children, some of whom also had high blood pressure and cholesterol. The data was collected over a number of years, and should be nationally representative, but may not be representative of each year individually.

Other limitations acknowledged by the researchers include the following:

  • Potential inaccuracies in parental reporting of the children’s diet over the previous 24 hours. This could be due to poor recall or being unaware of food the child consumed outside of the home.
  • An average ideal dietary intake for adults was used, rather than individual estimates of the required dietary intake per child according to their level of energy expenditure, height, weight, growth rate and age.
  • Some children participated in each of the two-yearly surveys, so their results will be included at each age group. This may have affected the results.
  • The survey did not collect data on smoking or secondhand smoke exposure, physical activity level or type 2 diabetes.

While the study did not directly assess heart damage, as might be assumed from the news coverage, it does suggest that children in the US frequently have risk factors for developing cardiovascular disease. It is not clear whether the results are representative of what might be seen in the UK, but it is known that overweight and obesity are becoming more common.

Overall, the study highlights the need for measures to encourage healthy diet and lifestyle from an early age. Installing healthy habits at a young age may make it more likely that said habits will persist into adulthood.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Damage to the heart can start before the age of 12 if young people have a poor diet. Mail Online, March 18 2015

Links To Science

Ning H, Labarthe DR, Shay CM, et al. Status of Cardiovascular Health in US Children Up to 11 Years of Age - The National Health and Nutrition Examination Surveys 2003–2010. Circulation: Cardiovascular Quality and Outcomes. Published online March 17 2015

Categories: Medical News

Breastfed babies 'grow up to be brainier and richer'

Medical News - Wed, 03/18/2015 - 15:00

"Breastfed babies grow up smarter and richer, study shows," The Daily Telegraph reports. A study from Brazil that tracked participants for 30 years found a significant association between breastfeeding and higher IQ and income in later life.

This study followed almost 3,500 infants from birth to adulthood in Brazil. It found babies who were breastfed longer had higher IQs at the age of 30, as well as higher incomes. The authors say this is the first study to directly assess the impact of breastfeeding on income.

Another novel feature of the study was that the majority of the mothers were from low-income backgrounds. Studies in developed countries, such as the UK, may be skewed by the fact there is a trend for breastfeeding mothers to come from medium- to higher-income backgrounds.

The study used a good design and had a relatively high follow-up of participants (almost 60%) given how long it was. Although factors other than breastfeeding may have been influencing the results, the researchers did try to reduce their impact by making adjustments. The results for income may also not be as representative of more developed countries.

While it's difficult to conclusively state that breastfeeding itself definitely directly caused all of the differences seen, overall this research supports the view that breastfeeding can potentially benefit children long-term.

Current UK advice is that exclusive breastfeeding for around the first six months of life provides a range of health benefits for babies

Where did the story come from?

The study was carried out by researchers from the Federal University of Pelotas and the Catholic University of Pelotas in Brazil.

It was funded by the Wellcome Trust, the International Development Research Center (Canada), CNPq, FAPERGS, and the Brazilian Ministry of Health.

The study was published in the peer-reviewed medical journal Lancet Global Health on an open-access basis, so it is free to read online or download as a PDF.

The majority of the UK media provided a very balanced report of this study, noting the results and their implications, as well as the study's limitations.

What kind of research was this?

This was a prospective cohort study looking at whether breastfeeding was associated with higher IQ and income in adulthood. The short-term benefits of breastfeeding on a baby's immunity are well known.

The researchers also report that a meta-analysis of observational studies and two randomised controlled trials (RCT), which looked at the promotion of breastfeeding or compared breast milk versus formula in preterm babies, found longer-term benefits on IQ in childhood and adolescence.

There have been fewer studies looking at the effect on IQ in adults, all from developed high-income countries, but none looking at income.

Although two out of these three studies found a link with higher IQ, there is concern that this may at least in part be related to the fact that mothers of higher socioeconomic status in these countries tend to breastfeed for longer.

In the UK, women from a middle or upper class background are more likely to breastfeed than women from a working class background, so the researchers wanted to look at the link in a lower-income country (Brazil) where this pattern does not exist.

This is likely to be the best study design for assessing this question, as randomised controlled trials allocating babies to be breastfed or not are unlikely to be unethical.

As with all observational studies, the main limitation is that factors other than the one of interest (breastfeeding in this case) could be having an impact on the results, such as socioeconomic status.

Researchers can reduce the impact of these factors (confounders) by using statistical methods to take them into account in their analyses.

In this study, they also chose to analyse a population where a major confounder was thought to have less impact. There may still be some residual effect of these or other unmeasured factors, however.

What did the research involve?

The researchers recruited 5,914 babies born in 1982 in Pelotas, Brazil and their mothers, and recorded whether the babies were breastfed or not. They then followed them up and assessed their IQ, educational achievements and income as 30 year olds in 2013.

The researchers invited all mothers of babies born in five maternity hospitals in Pelotas in 1982 and who lived in the city to take part in their study, and almost all agreed.

When the babies were infants (19 months or 3.5 years old) the researchers recorded how long they were breastfed and whether they were mainly breastfed (that is, without foods other than breast milk, teas or water).

Researchers who did not know about the participants' breastfeeding history assessed their IQ using a standard test when they reached about 30 years of age. They also recorded the highest level of education participants had reached and their income in the previous month.

The researchers then compared outcomes in those who were breastfed longer against those who were breastfed for a shorter period of time or not at all.

They took into account a large range of potential confounders assessed around the time of the baby's birth (such as maternal smoking in pregnancy, family income, and baby's gestational age at birth) and during infancy (household assets). 

What were the basic results?

The researchers were able to follow-up and analyse data for 59% (3,493 individuals) of the participants they recruited.

About a fifth of babies (21%) were breastfed for less than a month, about half (49%) were breastfed for between one and six months, and the rest (about 30%) for longer than this. Most babies were mainly breastfed for up to four months, with only 12% mainly breastfed for four months or longer.

Longer duration of any breastfeeding or mainly being breastfed was associated with higher levels of education, adult IQ and income.

For example, compared with those who were breastfed for less than one month, those who had received any breastfeeding for a year or longer had:

  • IQ scores 3.76 points higher on average (95% confidence interval [CI] 2.20 to 5.33)
  • 0.91 more years of education on average (95% CI 0.42 to 1.40)
  • a higher than average monthly income (95% CI 93.8 to 588.3) – this was equivalent to around an extra 30% of the average income in Brazil

The researchers carried out a statistical analysis that suggested the difference seen in income with longer breastfeeding was largely a result of differences in IQ.

How did the researchers interpret the results?

The researchers concluded that, "Breastfeeding is associated with improved performance in intelligence tests 30 years later, and might have an important effect in real life by increasing educational attainment and income in adulthood."

Conclusion

This large long-term study found an association between being breastfed for longer and subsequent educational attainment, IQ and income at the age of 30 in participants from Brazil.

The authors say this is the first study to directly assess the impact of breastfeeding on income. The study used a good design and had a relatively high follow-up of participants (almost 60%) given its duration.

However, there are some points to note:

  • As with all observational studies, factors other than breastfeeding may have been influencing the results. The researchers did try to reduce their impact by making statistical adjustments, but some residual impact may remain.
  • There was less awareness of the benefits of breastfeeding in Brazil when the study started, so less association with socioeconomic status and education was expected. However, researchers did find that women who had the least, as well as the most, education and those with a higher family income tended to breastfeed more, although the differences tended to be small (less than 10% difference in frequency of breastfeeding at six months).
  • The results for IQ support those seen in higher-income countries, but there have not been any direct assessments of the effect of breastfeeding on income in these countries so far, and these may differ from lower-income countries.

While it's difficult to conclusively state that breastfeeding itself definitely directly caused all of the differences seen in this study, this research supports the belief that breastfeeding potentially has long-term benefits.

Breastfeeding is known to bring health benefits, and current UK advice is that this can be achieved through exclusive breastfeeding for around the first six months of life.

However, as experts noted on the BBC News website, breastfeeding is only one of many factors that can contribute to a child's outcomes, and not all mothers are able to breastfeed.

For more advice on breastfeeding, visit the NHS Choices Pregnancy and baby guide.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Breast-fed babies grow up smarter and richer, study shows. The Daily Telegraph, March 18 2015

The longer babies breastfeed, the more they achieve in life – major study. The Guardian, March 18 2015

Breastfeeding 'linked to higher IQ'. BBC News, March 18 2015

Longer breastfeeding 'boosts IQ'. Daily Mail, March 18 2015

Breastfeeding 'linked to success and higher IQ'. The Independent, March 18 2015

Breastfed babies earn more as adults. The Times, March 18 2015

Links To Science

Victoria CG, Horta BL, de Mola CL, et al. Association between breastfeeding and intelligence, educational attainment, and income at 30 years of age: a prospective birth cohort study from Brazil. The Lancet Global Health. Published online March 18 2015

Categories: Medical News

Obese people 'underestimate how much sugar they eat'

Medical News - Tue, 03/17/2015 - 14:30

"Obese people are 'in denial' about the amount of sugar they eat," the Mail Online reports. Researchers looking into the link between sugar consumption and obesity found a "huge gap" between overweight people's self-reported sugar consumption and the reality, according to the news story.

Researchers assessed the self-reported sugar consumption (based on food diaries) and sugar levels in urine samples in about 1,700 people in Norfolk. After three years, they had their body mass index (BMI) measured.

The researchers found those whose urine test suggested they actually consumed the most sugar were more likely to be overweight after three years compared with those who consumed the least. However, the opposite was true for self-reported sugar intake.

The specific role of sugar (rather than calorie intake as a whole) in obesity is unclear, and previous studies have had inconsistent results.

One limitation of this study is that the spot-check urinary sugar test may not be representative of sugar intake over the whole study period. Also, the results may be affected by factors not taken into account by the analyses.

Although the news story focuses on the suggestion that overweight people are "in denial" about what they eat, this study itself did not attempt to explain the discrepancy between diet diaries and urine sugar measurements.

Overall, the main conclusion of this study is that more objective measures, rather than subjective diet-based records, may help future studies to better disentangle the effects of sugar on outcomes such as being overweight. 

Where did the story come from?

The study was carried out by researchers from the universities of Reading and Cambridge in the UK and Arizona State University in the US.

It was funded by the World Cancer Research Fund, Cancer Research UK, and the Medical Research Council.

The study was published in the peer-reviewed medical journal Public Health Nutrition. It is available on an open-access basis, so is available to download for free.

The Mail focuses on the suggestion that overweight people are "in denial" about what they eat. But this study did not assess why the discrepancies between diet diaries and urine sugar measurements exist. It also does not question some potential problems with the urine tests, which could undermine the results.

What kind of research was this?

This was a prospective cohort study, part of the European Prospective Investigation into Cancer and Nutrition (EPIC), a long-running investigation. It aimed to see whether people who ate more sugar were more likely to be overweight using two different ways of measuring sugar intake.

Observational studies assessing whether total sugar intake is linked to obesity have had conflicting findings. Such studies usually ask people to report what they eat using food frequency questionnaires or a food diary, and then use this information to calculate sugar intake.

However, there is concern that people under-report their food intake. Therefore, the researchers in this study used both food diaries and an objective measure (the level of sugar in urine) to assess sugar intake. They wanted to see if there was any difference in results with the two approaches.

The main limitation of observational studies such as this is that it is difficult to prove that a single factor, such as a particular type of food, directly causes an outcome such as being overweight. This is because other differences between people may be affecting the results.

However, it would not be ethical to expose people to potentially unhealthy diets in a long-term randomised controlled trial, so this type of observational study is the best practical way of assessing the link between diet and weight.

What did the research involve?

Researchers recruited adults aged 39 to 79 in Norfolk in the UK. They took measurements including their body mass index (BMI), lifestyle information, and tested their urine for sugar levels. Participants were also asked to record their diet over seven days.

Three years later, the participants were invited back and measured again for BMI and waist circumference. Researchers looked for links between people's sugar levels as shown in urine samples, the amount of sugar they reported eating based on their diet records, and whether they were overweight at this three-year assessment.

The entire EPIC study included more than 70,000 people, but researchers took a single urine sample from around 6,000 people as a "spot check" biomarker on sugar levels.

These single spot check samples measured recent sugar intake, and may be a less reliable measure of overall sugar intake than the more expensive and difficult test of collecting urine over a 24-hour period for analysis.

Almost 2,500 people did not come back for the second health check, and 1,367 people's urine tests were either not possible to analyse or the results were outside the standard range and so discarded.

This means only 1,734 of the original sample could be included in the final analysis. Because the people finally included were not randomly selected, it's possible that their results are not representative of all the people in the study.

The researchers ranked both the urine sugar results and sugar based on the dietary record results into five groups, from lowest to highest sugar intake. The specific sugar they were assessing was sucrose, found in normal table sugar.

For the analyses of people's self-reported sugar intake based on dietary record, the researchers took into account how many calories each person ate so this did not affect the analysis.

They then looked at how well the two types of sugar consumption measurement compared, and how likely people at the five different levels of sugar consumption were to be overweight or obese after three years, based on their BMI and waist circumference.

What were the basic results?

Results showed a striking difference between the urine sugar measurements and the sugar intake based on the diet diaries.

People who had the highest levels of sugar in their urine were more likely to be overweight after three years than those with the lowest levels.

The reverse was true when researchers looked at the people whose diet diaries suggested they ate the most sugar relative to their overall calorie intake compared with the least.

Using the urine sugar measurement, 71% of people with the highest concentration were overweight three years later, compared to 58% of people with the lowest concentration.

This meant that having the highest urinary levels of sugar was associated with a 54% increase in the odds of being overweight or obese after three years (odds ratio [OR] 1.54, 95% confidence interval [CI] 1.12 to 2.12).

Using people's seven-day diet diaries, 61% of people who said they ate the most sugar relative to their overall calorie intake were overweight, compared to 73% of people who said they ate the least sugar.

This meant those who reported the highest sugar intake relative to their overall calorie intake were 44% less likely to be overweight or obese after three years (OR 0.56, 95% CI 0.40 to 0.77).

How did the researchers interpret the results?

The researchers conclude that, "Sucrose measured by objective biomarker, but not self-reported sucrose intake, is positively associated with BMI."

They say there are "several possible reasons" for the discrepancies between the methods used to assess sugar intake. They admit the spot check urinary sugar marker may have disadvantages, but conclude that under-reporting of foods with high sugar content, particularly among those who are overweight or obese, may be a contributing factor.

As a result, they say future researchers looking at sugar as part of diet should consider using an "objective biomarker" such as urinary sugar, rather than relying on people's own estimates of what they have consumed.

Conclusion

This study has found conflicting associations between an objective measure of sugar intake and a subjective measure of sugar intake based on food diaries, and the risk of a person becoming overweight.

While more sugar in urine samples was associated with a greater risk of becoming overweight, consuming more sugar (based on food diary records) was actually associated with a reduced risk.

If the urine biomarker is a more accurate reflection of sugar consumed than diet diaries, then this research may explain why some previous diet studies have failed to show a link between sugar and being overweight.

However, there are some limitations to consider with the urine biomarker. Because the test used was a one-off snapshot of sugar intake, it can only show us how much sugar was in the person's urine at the time they were tested. Similar to a short-term food diary, we don't know whether that is representative of their sugar consumption over time.

The urine test is also not able to measure very high or very low sugar levels. The analyses of urine sugar levels did not adjust for overall calorie intake, while those for self-reported sugar intake did. It would have been interesting to see whether the association between urinary sugar levels remained once calorie intake was taken into account.

The current study did not assess why the dietary records and urinary measures of sugar differed. It also did not assess whether the discrepancies were larger among people who were overweight or obese at the start of the study – only how these measures were related to the outcomes at the end.

So it is not possible to say from this study alone that people who were overweight or obese had greater discrepancies between what they reported eating and their urinary sugar measurements.

However, the authors report that other studies have shown overweight people, especially women, are prone to under-reporting diet, particularly between-meal snacks.

As with all observational studies, it is difficult to rule out that factors other than those being assessed might be having an effect on the results. The researchers adjusted their analyses for age and gender, and say that results "did not change materially" after they adjusted the figures to take account of people's physical activity levels.

The results do not appear to have been adjusted to take account of other factors, such as people's level of education, income or other components of their diet, which may have an effect on weight.

The effect of sugar on health, independent of calorie intake, is still being debated by health organisations. If the findings of the current study are correct, using objective measures of sugar intake could help assess its effect on obesity and more widely on health. 

 

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Obese people are 'in denial over how much sugar they eat': Huge gap exists between how much fat people think they consume and the reality, landmark study warns. Mail Online, March 16 2015

Links To Science

Kuhnlea GC, Tasevska N, Lentjes MA et al. Association between sucrose intake and risk of overweight and obesity in a prospective sub-cohort of the European Prospective Investigation into Cancer in Norfolk. The journal Public Health Nutrition. Published online February 2015

Categories: Medical News

Could epilepsy drug help treat Alzheimer's disease?

Medical News - Tue, 03/17/2015 - 13:37

A drug commonly used to treat epilepsy could help "slow down" the progress of Alzheimer's disease, reports The Daily Express. According to the news story, the drug levetiracetam was shown to "help restore brain function and memory". 

The story is based on a study analysing the short-term effect of the drug in 54 people with mild cognitive impairment (MCI). This is where people have problems with their memory and are at an increased risk of developing dementia, including Alzheimer's disease.

Dementia is a common condition that affects about 800,000 people in the UK. Most types of dementia cannot be cured.

Researchers found people with the condition showed overactivity in one part of the brain during one memory test involving image recognition.

This overactivity and performance on the test was better when participants had been taking 125mg of levetiracetam twice a day for two weeks, compared with when they had taken inactive "dummy" capsules.

This study was small, short-term and showed improvement on a single memory test. It is not possible to say from this study whether continuing to take the drug would reduce a person's chances of developing dementia.

Larger and longer-term trials would be needed to assess this. For now, levetiracetam remains a prescription-only medication that is only licensed for the treatment of epilepsy.

Where did the story come from?

The study was carried out by researchers from the Johns Hopkins University, and was funded by the US National Institutes of Health. It was published in the peer-reviewed medical journal NeuroImage: Clinical.

The Daily Express' headline, "Epilepsy drug found to slow down slide into Alzheimer's", overstates the findings of this study. It did not assess whether the drug affected a person's risk of Alzheimer's disease.

The study actually focused on how the drug affected short-term performance on one memory test in people with a specific type of MCI.

The news story also refers to "younger victims", but it is not clear what this means – the participants in this study were, on average, aged in their 70s.

What kind of research was this?

The main part of this study was a crossover randomised controlled trial looking at the effect of the anti-epileptic drug levetiracetam on brain function in people with amnestic mild cognitive impairment (aMCI). This type of study design is suitable if testing a drug or intervention that does not have lasting effects. 

The researchers report that previous studies have suggested people with aMCI have more activity in one part of one area of the brain (the dentate gyrus/CA3 region of the hippocampus) during certain memory tasks relating to recognising patterns.

Levetiracetam had been shown to reduce activity in these areas in animal research, so the researchers wanted to test whether low doses could reduce this excess activity and improve performance in memory tests in people with aMCI.

MCI is a decline in cognitive abilities (such as memory and thinking) that is greater than normal, but not severe enough to be classed as dementia. aMCI mainly affects a person's memory. A person with MCI is at an increased risk of developing dementia, including Alzheimer's disease.

What did the research involve?

The researchers recruited 69 people with aMCI and 24 controls (people of similar ages who did not have the condition). They gave levetiracetam to the people with aMCI and then tested their cognitive ability and monitored their brain activity with a brain scan (MRI).

They then repeated these tests with identical-looking dummy pills (placebo) and compared the results. They also compared the results with those of the controls taking the dummy pills.

All participants completed standard cognitive tests, such as the mini-mental status exam and other verbal and memory tests, as well as brain scans, at the start of the study.

Those with aMCI had to meet specific criteria – such as impaired memory, but without problems carrying out their daily activities – but not meet criteria for dementia. The control participants were tested to make sure they did not have MCI or dementia.

People with aMCI were randomly allocated to have either the levetiracetam test first and then the placebo test four weeks later, or the other way around. This aims to make sure that the order the tests were carried out does not affect the outcomes of the study.

In each test, participants took the capsules twice a day for two weeks before doing the cognitive test while having a brain scan. The researchers used three different doses of levetiracetam in their study (62.5mg, 125mg or 250mg, twice a day).

The cognitive test called the "three-judgement memory task" involved being shown pictures of common objects, such as a frying pan, beach ball, or a piece of luggage, shown one after the other.

Some of the pictures in the sequence were identical, some were similar but not identical (for example, different coloured beach balls), and most were unique pictures with no similar pictures shown.

The participants were asked whether each picture was new, identical to the one they had seen before, or similar to the one they had seen before. During the test, their brains were scanned using MRI to see which parts of the brain were active.

The researchers were able to analyse data from 54 people with aMCI and 17 controls, as some people dropped out of the study or did not have useable data – for example, if they moved too much while the brain scans were being taken.

What were the basic results?

After taking a placebo, people with aMCI tended to incorrectly identify more items as identical to ones they had seen before than control participants on the three-judgement memory task.

They identified fewer items as being similar to ones shown before compared with the control participants. This suggested people with aMCI were not as good at discriminating between items that were just similar to ones they had seen before and those that were identical.

When people with aMCI had been taking 62.5mg or 125mg of levetiracetam twice a day, they performed better on the three-judgement memory task than when they took placebo.

They correctly identified more items as being similar and fewer items incorrectly as similar, and performed similar to the controls. The highest dose of levetiracetam (250mg twice a day) did not improve test performance in people with aMCI.

Brain scans showed that when people with aMCI who had been taking placebo recognised identical items, they showed more activity in one area within a part of the brain called the hippocampus than controls recognising a match.

Taking 125mg of levetiracetam twice a day reduced this activity compared with placebo, but the lower and higher doses of levetiracetam did not.

The researchers say levetiracetam did not affect the performance of people with aMCI on standard neuropsychological tests. Results on these tests were not reported in detail.

How did the researchers interpret the results?

The researchers concluded that people with aMCI have overactivity of the dentate gyrus/CA3 region of the hippocampus during an image recognition memory task. Low doses of the epilepsy drug levetiracetam reduced this activity and improved performance on the tasks.

Conclusion

This small-scale study found that low doses of the epilepsy drug levetiracetam improved performance on an image recognition task for people with aMCI. This condition causes memory problems, and people who have it are at an increased risk of developing dementia.

While the news reporting has focused on the potential for levetiracetam to slow the onset of dementia, this is not something the research has assessed or focused on.

It instead focused on the short-term impact of the drug on a single test of memory, plus brain activity. There was reported to be no impact on other neuropsychological tests, which appeared to include other memory tests.

It's also important to note that the effect of taking the drug for two weeks was not lasting. It is not possible to say from this study whether continuing to take the drug would reduce a person's chances of developing dementia. Larger and longer-term trials would be needed to assess this. 

The researchers noted that they only looked at very specific brain areas, and this will not capture wider changes in brain networks.

Testing an existing drug that already has approval for treating another condition means that we already know it is safe enough for use in humans. This can mean that human trials can get started more quickly than if a completely new drug was being tested.

However, the benefits and risks still need to be weighed up for each new condition a drug is used for.

For now, levetiracetam remains a prescription-only medication that is only licensed for the treatment of epilepsy.

Analysis by Bazian. Edited by NHS ChoicesFollow Behind the Headlines on TwitterJoin the Healthy Evidence forum.

Links To The Headlines

Epilepsy drug found to slow down slide into Alzheimer's, study finds. Daily Express, March 14 2015

Links To Science

Bakker A, et al. Response of the medial temporal lobe network in amnestic mild cognitive impairment to therapeutic intervention assessed by fMRI and memory task performance. NeuroImage: Clinical. Published February 21 2015

Categories: Medical News

All teens should be vaccinated against rare strain of meningitis

Medical News - Mon, 03/16/2015 - 15:00

"A vaccination for meningitis is to be offered to all 14-18 year-olds in England and Wales, after a spike in a rare strain of the disease," The Guardian reports. The strain – meningitis W (MenW) – is described as rare, but life-threatening.

There has been a year-on-year increase in the number of meningitis cases caused by MenW since 2009, and infection has been associated with particularly severe disease and high fatality rates in teenagers and young adults. The increasing trend looks set to continue unless action is taken, so the government’s Joint Committee on Vaccination and Immunisation (JCVI), the body that advises on vaccination for England and Wales, has advised that immunisation against MenW should be routinely offered to all 14 to 18 year-olds.

 

What is meningitis?

Meningitis means inflammation (-itis) of the membrane (meninges) that covers the brain and spinal cord. It can be caused by infection with bacteria or viruses, but bacterial infection causes the most severe illness. The most common type of bacterial meningitis is meningococcal, caused by the bacteria Neisseria meningitidis. There are six main types of this bacterium – A, B, C, W, X and Y – with group B responsible for the majority of cases to date (over 90%).

Meningitis can cause different symptoms in different people, including:

  • fever with cold hands and feet
  • vomiting
  • severe headache
  • stiff neck
  • dislike of bright lights
  • tiredness
  • drowsiness
  • confusion
  • agitation
  • in some cases, convulsions or seizures

In babies, the soft spot on their head (fontanelle) may bulge. If infection spreads to the bloodstream (septicaemia), this can cause a non-blanching rash. This appears because the toxins released from the bacteria cause damage to the blood vessels, causing them to bleed.

Meningitis is a life-threatening medical emergency and requires immediate medical attention if suspected.

 

How many cases of MenW have there been?

Since 2009, Public Health England (PHE) reports a steady rise in the number of cases of meningitis caused by a particularly virulent W strain of meningitis. There were 22 cases in 2009, rising to 117 cases in 2014. In January 2015 alone, there were 34 confirmed cases in England, compared to 18 in January 2014, and nine in January 2013.

Andrew Pollard, Chair of JCVI, said: "We have seen an increase in MenW cases this winter, caused by a highly aggressive strain of the bug. We reviewed the outbreak in detail at JCVI and concluded that this increase was likely to continue in future years, unless action is taken. We have therefore advised the Department of Health to implement a vaccination programme for teenagers as soon as possible, which we believe will have a substantial impact on the disease and protect the public’s health."

 

When will the MenW vaccine be introduced?

The JCVI advises that immunisation against MenW should be offered to all 14 to 18 year-olds.

There is a quadrivalent MenACWY conjugate vaccine currently available that can give protection against MenW. However, this vaccine is currently not included in the UK’s immunisation schedule. It has, to date, only been recommended for groups at increased risk, including those with splenic dysfunction or who are travelling to certain parts of the world.

There doesn’t appear to be a set date for the introduction of the vaccine, but the Department of Health says it accepts JCVI’s advice on routine introduction of the vaccine and is now planning the implementation of a combined MenACWY immunisation programme.

John Watson, Deputy Chief Medical Officer for England, says on the PHE website: "We accept JCVI’s advice for an immunisation programme to combat this devastating disease. We are working with NHS England, PHE and the vaccine manufacturer to develop a plan to tackle the rising number of MenW cases."

Until the vaccine is introduced, remaining vigilant to the signs and symptoms of the disease will be the best form of protection.

As Dr Shamez Ladhani, Paediatric Infectious Disease Consultant at PHE, advises: "Meningococcal group W disease is a rare but life-threatening infection in children and adults. It’s crucial that we all remain alert to the signs and symptoms of the disease, and seek urgent medical attention if there is any concern. The disease develops rapidly ... be aware of all signs and symptoms – and don’t wait for a rash to develop before seeking urgent medical attention."

PHE is also reminding health professionals to be aware of the increase in MenW disease and to keep a high index of suspicion for this strain of the disease, across all age groups.

 

What other meningitis vaccines are currently available?

The current NHS immunisation programme offers protection against various other bacterial causes of meningitis.

The meningitis C vaccine is given as part of the childhood immunisation programme, with a routine booster jab given at ages 13 to 15 years. For non-vaccinated children and adults, like those going to university, they can also receive a single catch-up booster. Two decades ago meningitis C was responsible for a number of severe cases and deaths, particularly among adolescents and young adults at college. Introduction of the meningitis C vaccine in 1999 caused a big fall in the number of cases caused by this bacterium.

A new meningitis B vaccine was introduced last year, and the JCVI also recommended this is given as part of the child immunisation programme. However, there are still some cost-effectiveness issues to be resolved before it is routinely offered. There are also no current plans for this to be given as a booster jab in adolescence or young adulthood.

Protection against other non-meningococcal bacterial causes of meningitis is also given through the routine child immunisation programme. These are:  

  • the MMR vaccine
  • the 5-in-1 vaccine – which provides protection against diphtheria, tetanus, whooping cough (pertussis), polio and Hib (Haemophilus influenzae type b)
  • the pneumococcal vaccine

Regardless of immunisation status, as PHE advises, being vigilant to possible signs and symptoms of meningitis is the best protection against this potentially life-threatening disease.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Meningitis vaccine to be offered to teenagers between 14 and 18. The Guardian, March 13 2015

Over three million teenagers to be vaccinated against 'virulent' new Meningitis strain. The Independent, March 13 2015

Jabs drive to combat new deadly strain of meningitis after a number of cases rise by 431%. Mail Online, March 14 2015

All UK teenagers 'should be vaccinated' against aggressive meningitis strain. The Daily Telegraph, March 13 2015

Meningitis vaccine plan after steep rise in new strain. BBC News, March 13 2015

Links To Science

Public Health England. Meningococcal group W (MenW) immunisation advised for 14 to 18 year-olds (Press Release). March 13 2015

Categories: Medical News

Does light at night pose a health risk?

Medical News - Mon, 03/16/2015 - 03:00

"Britons should fit blackout blinds and ban electronic gadgets from the bedroom to avert the risk of diseases such as cancer," the Mail Online warns.

This alarmist advice is prompted by a review looking at the theory that electrical light at night disrupts our normal body block and could therefore pose a risk to our health.  

In the review, researchers looked at various studies, including research linking night-shift work with breast or colon cancer, and light levels in the bedroom being linked to depression and obesity.

As the authors of this review acknowledge, the main problem with this type of evidence is that much of it is circumstantial, and may be influenced by bias and confounding from other factors.

Another drawback is this study does not appear to be systematic. The researchers provide no methods for how they identified the studies they discuss, and we do not know that all relevant studies have been included.

This effectively makes the review an opinion piece, albeit with lashings of supporting evidence. This means there is the risk that the authors have cherry-picked evidence that backs up their claims, while ignoring research that doesn't fit in with their theories.

The potentially large public health impact of even a small increase in disease risk linked with light at night seems worthy of further study. But this study doesn't prove that light at night harms our health.

Regardless, getting a good night's sleep is important. Read more about how to have a restful night.

 

Where did the story come from?

This opinion piece was written by two researchers from the University of Connecticut and Yale University in the US, and was jointly funded by the two universities.

It was published in the peer-reviewed Philosophical Transactions B on an open-access basis, so it is free to read online or download as a PDF.

The Mail appears to have taken the study at face value, recommending that Britons need to use blackout blinds on their windows, and clearly hasn't considered some of the drawbacks of this particular piece of research.

Because this wasn't a systematic review, we can't be certain that the studies used to inform the authors' conclusions are representative of the literature on the subject, and could also be of questionable quality. 

 

What kind of research was this?

This was an evidence-informed opinion piece, or narrative review, where the researchers discussed the theory that electrical light, especially at night, disrupts our normal body block. They consider whether this poses a risk to our health.

This narrative discussion is referenced throughout, but no methods are provided. It does not appear to be a systematic review, where researchers search all the available evidence to identify studies related to the issue of the effects that electrical light may have on the body clock.

This means we do not know that all the relevant studies related to this issue have been identified. As such, this review must largely be considered to be an article outlining the researchers' opinions, as informed by the evidence they looked at.

 

What do the researchers discuss?

The researchers present sleep deprivation or disruption at night as a result of exposure to electrical light as being a burden of modern life.

While they say light at night has been linked to sleep disruption, "What has not been 'proven' is that electric light at night causally increases risk of cancer, or obesity, or diabetes, or depression."

They say these links are plausible given that disturbed sleep can have an effect on cellular processes and DNA repair. The problem, they say, is that much of the evidence linking disturbed sleep and light at night to these diseases is circumstantial. They then describe what this circumstantial evidence looks like.

 

What do they say about light at night and disease risk?

The researchers discuss the issue of light at night and disease risk, supported by various studies.

They first discuss studies that have linked night-shift work in women with an increased risk of breast cancer, thought to possibly be a result of the influence of melatonin on oestrogen levels.

Melatonin is a sleep hormone, while high oestrogen levels are linked to breast cancer development.

Similarly, a handful of studies have linked shift work or sleep disruption with bowel cancer in both sexes, and with prostate cancer in men, as discussed in our special report on shift working and health last year.

But the researchers fail to mention that these studies may be influenced by various confounders.

The International Agency for Research on Cancer (IARC) currently defines the confidence that something may cause cancer as:

  • 1 – human carcinogen
  • 2a – probable carcinogen
  • 2b – possible carcinogen
  • 3 – inadequate evidence
  • 4 – probably not a carcinogen

In 2007 the IARC classified shift work that involves circadian disruption as a class 2a probable carcinogen, putting it in a category alongside anabolic steroids, vinyl fluoride and mustard gas.

This categorisation was based on a "compelling animal model", but limited epidemiological studies, where signs were consistent with a causal relationship but probably influenced by bias and confounding.

The researchers then discuss other observational studies linking light level in the bedroom (either self-reported or measured) with depression and obesity risk.

They acknowledge a risk of bias and confounding in these studies, but say that, "If these reported associations are causal, then there would be obvious and easy interventions, such as to use black-out shades and elimination of all light sources in the bedroom, no matter how minute."

The researchers go on to present other small experimental studies where participants were exposed to different amounts of light at night. The effects on body chemicals were then measured, including the sleep chemical melatonin.

Some of the broad conclusions were:

  • blue light has the greatest effect upon sleep disruption; red the least
  • there is a dose-response relationship
  • light exposure during the day influences night-time sensitivity
  • individuals have different levels of sensitivity to light
  • even through closed eyelids, a very bright light can suppress melatonin levels

The researchers go on to discuss the possible effect light has on genes involved in the control of the body clock, and how these could potentially be linked to cancer.

 

How did the researchers interpret the results?

In response to their overall question of whether electrical light exposure at night is a risk factor for our health, the researchers say this "cannot yet be answered with assurance, but is important to ask".

They say that, "It must be stressed that there is ample evidence for the disruptive effect of electric light on physiology in short-term experiments in humans.

"There is some epidemiologic evidence on the long-term impact on disease, but this evidence is not yet adequate to render a verdict."

However, they stress this is "an urgent issue given the increasing pervasiveness of electric lighting in our built environment."

 

Conclusion

This opinion piece discusses the evidence related to whether exposure to electrical light night is a health risk.

Much of the article considers various experimental studies where small numbers of participants were exposed to different light levels at night, as well as observational studies reportedly linking night-shift work with cancer, including breast and colon cancer.

The researchers also identified some studies linking self-reported or measured light in the bedroom with depression and obesity.

But this study has two prominent limitations. It does not appear to have been a systematic review. No methods are provided, and we do not know whether the researchers have searched the entire global literature on the subject to identify all relevant studies.

We also do not know whether studies linking light at night with disease could have been preferentially discussed as examples, while other studies that did not find any links were either not identified or not discussed in this review.

As such, this review must largely be considered to be the opinion of the researchers as informed by the evidence they looked at.

The second limitation is the strength and quality of the evidence linking light exposure at night to disease.

Most of the experimental studies discussed, where people were exposed to different light levels at night, were very small (one included 12 people, another eight).

These results are specific to the small sample included. This means they may be heavily biased and confounded by the characteristics of the participants, and therefore not apply to wider populations.

The small sample size may also fail to identify any real differences because of a lack of statistical power.

And just measuring body chemicals after a couple of nights of artificially manipulated light levels may not give us reliable evidence of health effects that would be seen with longer-term patterns.

Much of the evidence looked at is also circumstantial and based on observational studies. Though the design and quality of these underlying studies was not examined as part of this appraisal, it is likely the studies may be subject to various sources of bias or confounding, making it difficult to establish direct cause and effect.

The IARC study reportedly classified shift work that involves circadian disruption as a probable carcinogen. But the organisation acknowledged that this is based on limited epidemiological studies that may have been influenced by bias and confounding factors.

Overall, the possible links between electrical light exposure at night and disease is definitely worthy of further study. But, for now, people should not be overly alarmed by these findings and feel the need to rush out to buy blackout blinds for their bedroom windows.

That said, creating a calming environment in your bedroom, free from visual and audio distractions, can enhance the quality of your sleep.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Cancer warning over lights in the bedroom: Fit blackout blinds and ban gadgets to avert disease, say experts. Mail Online, March 16 2015

Links To Science

Stevens RG, Zhu Y. Electric light, particularly at night, disrupts human circadian rhythmicity: is that a problem? Philosophical Transactions B. Published online March 16 2015

Categories: Medical News

Do people with depression perceive time differently?

Medical News - Fri, 03/13/2015 - 14:00

"How depression affects our sense of time: Hours drag on and even stand still," is the somewhat over-hyped headline from the Mail Online.

As the old saying goes – Time flies when you’re having fun. So does the reverse also ring true? Does feeling depressed slow down your perception of time? Two German researchers tried to find out.

They pooled the results of previous studies, which lead to 433 depressed people being compared with 485 non-depressed people. The results tentatively suggest that some people with depression may perceive time as going more slowly than those without.

No difference was found in their ability to estimate actual time durations in tests (for example, trying to judge when a minute had passed).

The study has a number of limitations, meaning we should be cautious in assuming that the findings are reliable. Their statistical methods, for example, made it more likely to find a statistically significant result by chance and they noted that using other methods would have wiped out any differences between the groups.

The clinical implications of this potential time perception difference are also unclear. Can knowing that people with depression perceive time as progressing slowly help their care or support?

The study provides little in the way of answers, but may stimulate useful debate.

 

Where did the story come from?

The study was carried out by researchers from Johannes Gutenberg-Universität Mainz, Germany, who report receiving no external funding for the work.

The study was published in the peer-reviewed Journal of Affective Disorders.

The Mail Online reported the story at face value and did not discuss any of its limitations. Its choice of headline, "Hours drag on and even stand still", is an exaggeration of the findings.

It included interviews with the study authors, who said their results confirmed anecdotal reports from hospital and private practice staff that: "depressed patients feel that their time only creeps forward slowly or is passing in slow motion". Anecdotal reports, while interesting, are not evidence.

 

What kind of research was this?

This was a meta-analysis pooling the results of studies looking at time perception of people with depression.

The study authors say that "depressive patients frequently report to perceive time as going by very slowly", but previous studies on the topic have given inconsistent results. They wanted to pool the past results to see if there was any overall effect. This pooling of many independent studies is called a meta-analysis.

A meta-analysis is an appropriate and potentially powerful way of studying the issue. However, the meta-analysis is only as good as the studies feeding it.

 

What did the research involve?

The team pooled the results from 16 individual studies in which 433 depressed people (cases) and 485 non-depressed people (controls) participated. The main analysis looked for differences in measures of time perception between the two groups.

To identify as much relevant material as possible, the researchers searched for published evidence online (using a Web of Science search) and called for unpublished information to be submitted by more than 100 experts in the field.

Studies were only included if they were in adults, had a control group of non-depressed people, had diagnosed depression using standardised criteria, and had sufficient statistical information to enable the pooling of estimates.

In the included studies, the participants were asked to estimate the duration of periods of time.

For example, they were asked to estimate the length of a film in minutes, press a button for five seconds, or discriminate the duration of two sounds. Studies measured time durations ranging from the ultra-short (less than a second) to the long (greater than 10 minutes).

They were also asked about their perception of whether time flowed quickly or slowly. This typically used visual scales, requiring the participant to mark a point on a line ranging from very fast to very slow.

 

What were the basic results?

The main results showed that people with depression were no different than people without at judging time duration.

However, the subjective perception of how time flowed did differ between the groups. People with depression perceived time as going more slowly than those without.

In effect, this meant that both groups could estimate time to the same accuracy, but the people with depression perceived the time to be passing much more slowly.

 

How did the researchers interpret the results?

The team concluded: "Depression has medium effects on the subjective flow of time, whereas duration judgments basically remain unaffected."

 

Conclusion

Having compared 433 depressed people with 485 non-depressed people, the study suggests that some people with depression perceive time as going more slowly than those without. No difference was found in their ability to actually estimate duration of time on testing, but people with depression rated time generally as flowing more slowly.

People with low mood often have associated feelings of little enjoyment in daily life and normal activities, and feelings of being hopeless or helpless. As such, the idea that they may perceive time as passing by more slowly seems plausible, and point to a possible phenomenon to be investigated further. However, the findings do not prove this outright. The study authors themselves advised caution when interpreting the findings. For example, the results weren’t able to take account of any influence of the use of medications or treatments for depression, such as psychotherapy. These could potentially influence time perception.

More importantly, their use of statistical methods made it more likely to find a statistically significant result by chance. They note that by using other methods, none of their findings would have reached statistical significance.

The clinical implications of this time perception are also unclear. Can knowing that people with depression perceive time as progressing slowly help their care or support?

As a result, it would be beneficial to see more robust research in this area before believing this is a widespread occurrence, and a clearer rationale for its importance.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

How depression affects our sense of time: Hours drag on and even stand still for those battling the condition, study reveals. Mail Online, March 12 2015

Links To Science

Thönes S, Oberfeld D. Time perception in depression: A meta-analysis. Journal of Affective Disorders. Published online January 14 2015

Categories: Medical News

Loneliness 'increases risk of premature death'

Medical News - Fri, 03/13/2015 - 13:31

"Loneliness as big a killer as obesity and as dangerous as heavy smoking," the Daily Express reports. Researchers pooled the results of previous studies, estimating that loneliness can increase the risk of premature death by around 30%.

The headline follows a new analysis of more than 3.4 million participants, which showed evidence that people who feel, or are, socially isolated or live alone are at about a 30% higher risk of early death.

The study has many strengths: its large sample size, adjustment for initial health status, and use of prospective studies being the main three. This provided some evidence that the isolation was causing ill health, rather than the other way round, but we can't be certain.

Causation bias could still be a factor in some cases – in other words, people with a chronic disease are less likely to socialise with others. This makes it difficult to nail down cause and effect.

The results of this study remind us that health has a strong social element and is not merely physical. Connecting with others can improve both mental and physical wellbeing.

 

Where did the story come from?

The study was carried out by researchers from Brigham Young University in the US and was funded by grants from the same university.

It was published in the peer-reviewed journal, Association for Psychological Science.

The UK media generally covered the study accurately. Many news sources based their reporting on an assertion made by the lead author, Julianne Holt-Lunstad, who said the harmful effects of loneliness are akin to the harm caused by smoking, obesity or alcohol misuse.

Professor Holt-Lunstad was quoted in the Daily Mail as saying that, "The effect is comparable to obesity, something that public health takes very seriously ... we need to start taking our social relationships more seriously."

This assertion appears to be based on a previous study carried out by Professor Holt-Lunstad published in 2010. We were not able to appraise this study, so we cannot comment on the accuracy of this comparison. The 2010 research was published in the online journal PLOS One.

 

What kind of research was this?

This was a systematic review and meta-analysis investigating whether loneliness, social isolation, or living alone affects your chances of dying early.

The researchers say there are many lifestyle and environmental factors that increase our risk of dying early, such as smoking, being inactive and air pollution.

However, they say much less attention is paid to social factors, despite evidence they may carry an equal or greater influence on early death.

This study wanted to be the first to quantify the influence of loneliness and social isolation on early death.

 

What did the research involve?

The researchers searched online databases for studies reporting numerical data on deaths affected by loneliness, social isolation, or living alone. They then pooled all the studies to calculate the overall effect.

The literature search included relevant studies published between January 1980 and February 2014. These were identified using the online databases MEDLINE, CINAHL, PsycINFO, Social Work Abstracts, and Google Scholar.

Loneliness and social isolation were defined objectively and subjectively:

  • social isolation (objective) – pervasive lack of social contact or communication, participation in social activities, or having a confidant (example measure: Social Isolation Scale or Social Network Index)
  • living alone (objective) – living alone versus living with others (example measure: answer to a yes/no question on living alone)
  • loneliness (subjective) – feelings of isolation, disconnectedness and not belonging (example measure: University of California, Los Angeles Loneliness Scale)

Some studies made no adjustment for potential confounders. Others controlled for just a few variables (partial adjustment), usually age and gender.

A final group adjusted for several factors (fully adjusted), such as measures relevant to depression, socioeconomic status, health status, physical activity, smoking, gender and age.

Sensibly, the researchers presented separate results for the different categories of adjustment to see to what extent the results were potentially influenced by the confounders.

The bigger studies counted more towards the meta-analysis than the smaller ones – a "weighted" effect size.

 

What were the basic results?

In total, the study analysed 70 independent prospective studies containing more than 3.4 million participants followed for an average of seven years. Overall, the researchers found social isolation resulted in a higher likelihood of death, whether measured objectively or subjectively.

Pooling the best studies – those with full adjustment for confounding – showed the increased likelihood of death was 26% for reported loneliness, 29% for social isolation, and 32% for living alone. All were statistically significant increases compared with those reporting less loneliness or social isolation.

The researchers found no differences between measures of objective and subjective social isolation, and the results remained consistent across gender, length of follow-up and world region.

However, initial health status influenced the findings, as did participant age. For example, social deficits were more predictive of death in people under the age of 65 than over 65.

 

How did the researchers interpret the results?

The researchers said that, "Substantial evidence now indicates that individuals lacking social connections (both objective and subjective social isolation) are at risk for premature mortality.

"The risk associated with social isolation and loneliness is comparable with well-established risk factors for mortality, including those identified by the US Department of Health and Human Services (physical activity, obesity, substance abuse, responsible sexual behaviour, mental health, injury and violence, environmental quality, immunisation, and access to health care)."

They say there is mounting evidence that social isolation and loneliness are increasing in society, so it would be prudent to add social isolation and loneliness to lists of public health concerns.

 

Conclusion

This meta-analysis of more than 3.4 million participants indicates social isolation, living alone and loneliness are linked with about a 30% higher risk of early death.

The study has many strengths, including its huge sample size, adjustment for initial health status, and use of prospective studies.

This provided some evidence that the isolation was causing ill health, rather than the other way round, but we can't be certain. Poor health can lead to loneliness and social isolation and vice versa, so cause and effect are tricky to nail down.

The researchers believe the study of the effects of loneliness and social isolation is currently at the stage that research into the risks of obesity was decades ago. They have identified a problem and predict it will increase in years to come.

The findings also challenge assumptions. The study team said that, "The data should make researchers call into question the assumption that social isolation among older adults places them at greater risk compared with social isolation among younger adults [who may be at risk of alcohol and drug misuse, as well as suicide].

"Using the aggregate data, we found the opposite to be the case. Middle-age adults were at greater risk of mortality when lonely or living alone than when older adults experienced those same circumstances."

The results of this study remind us all that psychosocial and emotional feelings can be just as relevant to our overall health and wellbeing as physical factors. Read more about how how connecting with others can improve wellbeing and find out how to overcome feelings of loneliness.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Loneliness as big a killer as obesity and as dangerous as heavy smoking. Daily Express, March 12 2015

How loneliness leads to an early grave: Feeling alone 'shortens lifespan as much as obesity'. Mail Online, March 12 2015

Links To Science

Holt-Lunstad J, Smith TB, Baker M, et al. Loneliness and Social Isolation as Risk Factors for Mortality - A Meta-Analytic Review. Perspectives on Psychology. Published online March 11 2015

Categories: Medical News

Ebola risk remains low as medic flown home

Medical News - Thu, 03/12/2015 - 19:40

A UK military healthcare worker who was infected with Ebola in Sierra Leone has been flown home and is being treated at the Royal Free Hospital in London.

Four other healthcare workers who had been in contact with the infected person are also being assessed. Two were flown home on the same flight as the infected worker and are now being monitored at the Royal Free. The others are to be assessed at the Royal Victoria Infirmary in Newcastle-upon-Tyne. None of the four has been diagnosed with Ebola.

The latest case follows that of Glasgow nurse Pauline Cafferkey, who was found to have Ebola after arriving in Glasgow from Sierra Leone in December 2014. She recovered after specialist care at the Royal Free Hospital and was discharged.

Ms Cafferkey remains the only case confirmed in the UK, and the risk to the general public is very low. Ebola can be transmitted only by direct contact with the blood or bodily fluids of an infected person.

The UK has well-established and practised infection control procedures for dealing with cases of imported infectious disease, and these will be strictly followed to minimise the risk of transmission.

Professor Dame Sally Davies, Chief Medical Officer, said: "The UK has robust, well-developed and well-tested systems for managing Ebola virus disease. All appropriate infection control procedures have, and will continue to be, strictly followed to minimise any risk of transmission. UK hospitals have a proven record of dealing with imported infectious diseases."

More than 24,200 cases of Ebola have been confirmed in West Africa, with over 9,900 deaths – a mortality rate of around 40%.

Outbreaks of Ebola are nothing new, but health professionals are concerned about the size of the current outbreak.

What is Ebola?

Ebola is a virus that can be spread through blood and bodily fluids. The virus originated in the West African rainforest and is thought to have spread to humans by handling or butchering infected animals.

Once the virus enters the body it can replicate very quickly, causing a range of increasingly harmful symptoms, including internal bleeding. Left untreated, it can have a mortality rate as high as 90%.

 

What are the symptoms of Ebola virus?

An infected person will typically develop a fever, headache, joint and muscle pain, sore throat, and intense muscle weakness. These symptoms start suddenly 2 to 21 days after becoming infected.

Diarrhoea, vomiting, a rash, stomach pain, and impaired kidney and liver function follow. The infected person may then bleed internally, as well as from the ears, eyes and mouth.

 

How is the Ebola virus spread?

People can become infected with the Ebola virus if they come into contact with the blood, body secretions or organs of an infected person.

Some traditional African burial rituals may have played a part in its spread. The Ebola virus can survive for several days outside the body, including on the skin of an infected person.

In parts of Africa, it is common for mourners to touch the skin of the deceased. A person then only needs to touch their mouth to become infected.

Other ways people can catch the virus include:

  • touching the soiled clothing of an infected person and then touching their mouth
  • having sex with an infected person without using a condom – the virus can be present in semen for as long as seven weeks after an infected person has recovered
  • handling unsterilised needles or medical equipment that have been used on the infected person
  • handling infected animals or coming into contact with their bodily fluids

A person is infectious as long as their blood and secretions contain the virus.

Ebola virus is generally not spread through routine social contact, such as shaking hands with patients without symptoms.

The virus is not airborne, so it's not as infectious as diseases such as the flu – you'd need to get close to it to catch it.

 

Who's at risk from Ebola?

Anyone who has close contact with an infected person or handles samples from patients is at risk of becoming infected. Hospital workers, laboratory workers and family members are at greatest risk.

 

How is Ebola diagnosed?

It's difficult to know if a patient is infected with Ebola virus in the early stages. The early symptoms of Ebola, such as fever, headache and muscle pain, are similar to those of many other diseases.

But health workers are on standby to act quickly. If anyone in the UK develops the above symptoms and has potentially been in close contact with the virus, they will be admitted to hospital and will most likely be quarantined.

Samples of blood or body fluid can be sent to a laboratory to be tested for the presence of Ebola virus, and a diagnosis can be made rapidly. If the result is negative, doctors will test for other diseases, such as malaria, typhoid fever and cholera.

 

What are the treatments for Ebola?

There's currently no specific treatment or cure for the Ebola virus, although potential new vaccines and drug therapies are being developed and tested.

Patients need to be treated in isolation in intensive care. Dehydration is common, so fluids may be given intravenously (directly into a vein).

Blood oxygen levels and blood pressure will be maintained at the correct level, and the body organs supported while the patient recovers.

 

What is the risk of Ebola in the UK?

The risk to the UK is thought to be very low, and, while someone with the virus can bring it to the UK, the risk of it spreading is very low.

Ebola virus is not airborne, so there is no credible risk of a swine flu-like global pandemic.

You cannot catch Ebola by travelling on a plane with someone who is infected, unless you come into very close physical contact with them – for example, by kissing them.

 

What precautions are being taken?

Public Health England (PHE), the body responsible for public health in England, has told health professionals about the situation in West Africa and asked for vigilance about unexplained illness in people who have visited the affected area.

PHE has provided advice for humanitarian workers planning to work in affected areas. It is also working with people from Sierra Leone living in England.

Advice has been issued to immigration removal centres on carrying out health assessments for people who may have been in Ebola outbreak areas within the preceding 21 days.

Dr Brian McCloskey, PHE's director of global health, said: "The risk to UK travellers and people working in these countries of contracting Ebola is very low.

"People who have returned from affected areas, who have a sudden onset of symptoms such as fever, headache, sore throat and general malaise [sense of feeling unwell] within three weeks of their return should immediately seek medical assistance." 

Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Scottish Ebola patient transferred to London hospital – live updates. The Guardian, December 30 2014

Ebola healthcare worker transferred to London unit. BBC News, December 30 2014

Ebola patient transferred to London's Royal Free Hospital. The Daily Telegraph, December 30 2014

Nurse With Ebola To Arrive At London Hospital. Sky News, December 30 2014

Two more patients being tested for Ebola at UK hospitals. Daily Express, December 30 2014

Race to find hundreds of BA passengers who came into contact with UK nurse who brought Ebola back to Britain – but why did TWO screenings fail to spot her condition? Mail Online, December 30 2014

Categories: Medical News

Ultrasound 'breakthrough' in treating Alzheimer's - in mice

Medical News - Thu, 03/12/2015 - 15:00

"Alzheimer's breakthrough as ultrasound successfully treats disease in mice," The Guardian reports.

New research found high-energy sound waves helped remove abnormal clumps of proteins from the brains of mice, and also improved their memory.

The mice used in this study were genetically engineered to produce amyloid plaques – abnormal clumps of protein fragment amyloid-β typically found in the brains of people with Alzheimer's disease.

There was a 50% reduction in plaques in mice whose brains were exposed to ultrasound once a week for five to seven weeks.

Memory also improved to the extent that the mice were able to negotiate a maze as well as healthy mice after the treatment. They were also better able to avoid a section of a spinning wheel that would give them an electric shock.

While the treated mice appeared to be unharmed, with no obvious tissue damage, human brains are much more complex. Ultrasound could damage brain function in ways that we cannot predict.

The current study used mice that have plaques, but not the other two main brain features of Alzheimer's: cell damage and loss of neural connections. Both these differences limit our certainty of how well the findings represent what would happen in humans. Therefore, further animal studies are needed.

 

Where did the story come from?

The study was carried out by researchers from the University of Queensland in Australia and was funded by the estate of Dr Clem Jones AO, the Australian Research Council, and the National Health and Medical Research Council of Australia.

The study was published in the peer-reviewed journal Science Translational Medicine.

The Guardian reported the story accurately and indicated that this is very early stage research, with human trials unlikely to occur for several years. It was encouraging that the newspaper's headline made it clear that the study was on mice, rather than humans.

 

What kind of research was this?

This was an animal study, which aimed to see if ultrasound showed potential for use as a treatment for Alzheimer's disease.

When ultrasound of the brain is combined with an injection of tiny spheres (microbubbles) into the blood, it temporarily makes it easier for substances to cross the blood-brain barrier (the membrane that separates the two). This might help the removal of amyloid-β from the brain and stop the build-up of plaques.

Alzheimer's disease is the most common form of dementia. The cause is unknown, but there are three main features of the disease in the brain. They are:

  • a build-up of amyloid plaques, which are deposits of a protein fragment called amyloid-β
  • neurofibrillary tangles, which are abnormal collections of a protein called tau in the nerve cells
  • loss of connections between the nerves

Previous research has aimed to reduce the amyloid plaques using drugs to decrease the production of amyloid-β or increase its removal by the immune system. Drugs used in both ways have had side effects.

Here, the researchers wanted to see if ultrasound could be used to reduce the amyloid plaques and whether this improved memory. A mouse model of Alzheimer's disease was used for their experiments.

Animal models are used for the early testing of potential treatments for the human form of the disease. These tests are essential for assessing the potential beneficial effects and safety of these treatments before they are used in humans.

However, there are differences between species, and between disease models and the actual human disease. This means results in animal models may not perfectly represent what will happen in humans.

Alzheimer's is a complex disease, and there are several mouse models of this condition, each with slightly different features of the disease. The mouse model used in this study developed amyloid plaques, but not neurofibrillary tangles or loss of connections between the nerves.

 

What did the research involve?

Twenty mice genetically engineered to develop amyloid plaques in their brains were given either five sessions of ultrasound over six weeks, or sham (placebo) treatment.

The sham treatment involved receiving the microbubble injection and being placed under the ultrasound machine, but not receiving any ultrasound. Both groups were then assessed for their spatial working memory using a maze.

The researchers compared 20 mice with amyloid plaques and 10 normal mice using the active place avoidance task. This involves mice getting an electric shock if they enter a particular zone in a rotating arena. Mice with amyloid plaques did not learn to avoid this area as well as control mice with no plaques.

The amyloid mice were then put into two groups. One group received ultrasound every week for seven weeks, and the other group had a sham treatment. The mice were then retested in the active place avoidance task.

After these tests, their brains were inspected for amyloid plaques. The researchers also carried out various tests to see how ultrasound might be having an effect on plaques.

 

What were the basic results?

The mice with amyloid plaques did not perform as well on the maze task as healthy mice. However, ultrasound restored the ability of the mice to negotiate the maze to the same level as normal mice.

When the researchers compared the brains of the two groups of mice, they found ultrasound reduced the amount of amyloid plaques by over half.

Mice treated with ultrasound weekly for seven weeks learned to avoid electric shocks in the active place avoidance task better than mice given sham treatment, indicating that their memory had improved. They also had half the amount of amyloid plaques in their brains as the untreated mice.

Ultrasound appeared to have stimulated microglial cells (brain support cells that get rid of waste) to engulf the amyloid-β to reduce the plaques. The treatment did not appear to cause any tissue damage.

 

How did the researchers interpret the results?

The researchers concluded that repeated ultrasound to the entire mouse brain reduced the amyloid plaques and improved the memory of the mice.

They say this has the potential to treat conditions such as Alzheimer's disease, though there are many hurdles to overcome.

 

Conclusion

This animal study found a technique using ultrasound directed at the brain reduces the number of amyloid plaques in mice. These mice were genetically engineered to develop these plaques, one of the key brain features of Alzheimer's disease.

There are two other features of Alzheimer's disease that these mice did not have: neurofibrillary tangles and loss of nerve connections.

As it is unknown how these features inter-relate, or if one causes another, this model has certain limitations.

However, the results did show that by reducing the amount of amyloid plaques, the memory and spatial awareness of the mice improved.

While mice studies can give us an indication of how a treatment may affect humans, they are only indications, as there are inherent differences between the species, and between the model and the actual human disease.

Although we can study the mice's ability to negotiate a maze and avoid electric shocks, it is more difficult to assess higher and more complex human brain functions that are affected in Alzheimer's, such as language and personality.

The authors pointed out several important differences between this mouse study and the ability to use the technique in humans:

  • The human brain is much larger, and the skull thicker, so the ultrasound would need to be stronger to penetrate all areas of the brain. This could have negative consequences, such as causing damage to healthy brain tissue.
  • There are concerns that the level of immune response that might be activated in the human brain could be too high. To counter this, the researchers suggest the potential treatment regimen could focus on giving ultrasound to smaller sections at a time.
  • The mice in the study already had plaques when the ultrasound was started. The researchers do not know at what point of Alzheimer's disease it would be appropriate to start treating humans. They are concerned that if they gave ultrasound to people with very early Alzheimer's disease when there are few amyloid plaques, it may damage brain tissue.
  • The study did not look at the long-term effects of the treatment.

Further animal studies will now be required, progressing to primates, before any human trials can take place.

The cause of Alzheimer's disease is not known, but you can reduce the risk of developing the condition by adopting a healthy lifestyle, including maintaining a healthy weight, not smoking, taking regular physical exercise, and drinking alcohol in moderation.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Alzheimer's breakthrough as ultrasound successfully treats disease in mice. The Guardian, March 12 2015

Links To Science

Leinenga G, Götz J. Scanning ultrasound removes amyloid-β and restores memory in an Alzheimer's disease mouse model. Science Translational Medicine. Published Online March 11 2015

Categories: Medical News

Diet, exercise and brain training may help keep the mind 'sharp'

Medical News - Thu, 03/12/2015 - 14:30

"Dancing, doing Sudoku and eating fish and fruit may be the way to stave off … mental decline," The Guardian reports. A Finnish study suggests a combination of a healthy dietexercise and brain training may help stave off mental decline in the elderly.

The study looked at whether a combined programme of guidance on healthy eating, exercise, brain training and the management of risk factors such as high blood pressure (associated with vascular dementia) could have an effect on dementia risk and cognitive function.

Half of the 1,260 people in this two-year study were randomly allocated to receive this programme, while the other half acted as a control group, receiving only regular health advice. All participants were given standard tests to measure their brain function at the start, and at 12 and 24 months.

Researchers found that overall, scores measuring brain function in the group who received the programme were 25% higher than in the control group. For a part of the test called "executive functioning" (the brain's ability to organise and regulate thought processes), scores in the intervention group were 83% higher.

While the results of this well-conducted study are certainly encouraging, it's worth pointing out that the study does not look at whether people developed dementia in the longer term.

Most experts agree that a healthy diet, exercise and an active social life with plenty of interests may help reduce the risk of dementia.

 

Where did the story come from?

The study was carried out by researchers from several institutes in Scandinavia, including the Karolinska Institutet in Sweden, the Finnish National Institute for Health and Welfare, and the University of Eastern Finland.

It was funded by a number of different academic centres, including the Academy of Finland, La Carita Foundation, Alzheimer Association, Alzheimer's Research and Prevention Foundation, Juho Vainio Foundation, Novo Nordisk Foundation, Finnish Social Insurance Institution, Ministry of Education and Culture, Salama bint Hamdan Al Nahyan Foundation, and Axa Research Fund, EVO grants, Swedish Research Council, Swedish Research Council for Health, Working Life, and Welfare and af Jochnick Foundation.

The study was published in the peer-reviewed medical journal The Lancet.

The study was widely covered in the UK media. Most coverage was fair, although many papers reported that the study showed how lifestyle interventions can reduce the risk of dementia. This was incorrect – the study looked only at cognitive performance in people at risk of dementia.

A study with a much longer follow-up would be required to see if the interventions used in the study were effective in preventing dementia.

Reports also tended to only concentrate on the lifestyle interventions in the study and not the medical management. One of the interventions involved doctors and nurses monitoring risk factors for dementia, such as blood pressure and body mass index (BMI), with advice where needed for people to get medication from their GP.

It is possible some people found to be at risk – because, for example, they had high blood pressure – were prescribed medication by a physician and it was this that led to the improvement in cognitive function.

 

What kind of research was this?

This was a double blind randomised controlled trial (RCT) looking at whether a comprehensive programme of healthy eating, exercise, brain training and management of risk factors could have an effect on mental function in older people at risk of dementia. An RCT is the best kind of study to find out whether an intervention is effective.

The researchers say previous observational studies have suggested a link between cognitive function in older people and factors such as diet, fitness and heart health.

They say their study is the first large RCT looking at an intensive programme addressing whether a combination of interventions might help prevent cognitive decline in elderly people at risk of dementia.

 

What did the research involve?

Older adults at risk of dementia were randomised to receive either an intervention that addressed their diet, exercise, cognitive training and cardiovascular risk monitoring, or general health advice. After two years, the participants were compared using a range of cognitive assessments.

Researchers recruited 1,260 people aged 60 to 77. To be eligible, participants had to have a dementia risk score of six points or higher. This is a validated score based on age, sex, education, blood pressure, body mass index (BMI), total blood cholesterol levels, and physical activity. The score ranges from 0 to15 points.

Participants also had to have average cognitive function of slightly lower than expected for their age. This was established by cognitive screening using validated tests.

Anyone with previously diagnosed or suspected dementia was excluded. People with other major disorders, such as major depression, cancer, or severe loss of vision or hearing, were also excluded.

Participants were randomly assigned either into the intervention group or to a control group.

All participants had their blood pressure, weight, BMI, and hip and waist circumference measured at the start of the study, and again at 6, 12 and 24 months.

All participants (control and intervention group) met the study physician at screening and at 24 months for a detailed medical history and physical examination.

At baseline, the study nurse gave all participants oral and written information and advice on healthy diet and physical, cognitive, and social activities beneficial for the management of cardiovascular risk factors and disability prevention.

Blood samples were collected four times during the study: at baseline and at 6, 12, and 24 months. Laboratory test results were mailed to all participants, together with general written information about the clinical significance of the measurements and advice to contact primary health care if needed.

The control group received regular health advice.

The intervention group additionally received an intensive programme comprising four interventions.

Diet

The diet advice was based on Finnish nutritional recommendations. This was tailored to individual participants, but generally included high consumption of fruit and vegetables, consumption of wholegrain cereals and low-fat milk and meat products, limiting sugar intake to less than 50g a day, use of vegetable margarine and rapeseed oil instead of butter, and at least two portions of fish a week.

Exercise

The physical exercise programme followed international guidelines. It consisted of individually tailored programmes for progressive muscle strength (one to three times a week) and aerobic exercise (two to five times a week), using activities preferred by each participant. Aerobic group exercise was also provided.

Cognitive training

There were group and individual sessions, which included advice on age-related cognitive changes, memory and reasoning strategies, and individual computer-based cognitive training, conducted in two periods of six months each.

Medical management

Management of metabolic and cardiovascular risk factors for dementia was based on national guidelines. This included regular meetings with the study nurse or doctor for measurements of blood pressure, weight and BMI, hip and waist circumference, physical examinations, and recommendations for lifestyle management. Study doctors did not prescribe medication, but recommended participants contact their own doctor if needed.

Participants underwent a cognitive assessment using standard neuropsychological tests called the neurological test battery (NTB) at baseline and at 12 and 24 months. The test measures factors such as executive functioning, processing speed and memory. 

Researchers looked at any changes in people's cognitive performance over the course of the study, as measured by an NTB total score, with higher scores suggesting better performance.

They also looked at various scores on individual tests. They assessed participation in the intervention group with self reports at 12 and 24 months and recorded their attendance throughout the trial.

 

What were the basic results?

In total, 153 people (12%) dropped out of the trial.

People in the intervention group had 25% higher overall NTB scores after 24 months compared with the control group.

Improvement in other areas, such as executive function, was 83% higher in the intervention group, and 150% higher in processing speed. However, the intervention appeared to have no effect on people's memory.

Forty-six participants in the intervention group and six in the control group suffered side effects; the most common adverse event was musculoskeletal pain (32 individuals in the intervention versus none in the control group).

Self-reported adherence to the programme was high.

 

How did the researchers interpret the results?

The researchers say their findings support the effectiveness of a "multi-domain" approach for elderly people at risk of dementia. They will be investigating possible mechanisms whereby the intervention might affect brain function.

 

Conclusion

This RCT suggests a combination of advice on lifestyle, group activities, individual sessions and monitoring of risk factors appear to improve mental ability in elderly people at risk of dementia.

Whether it will have an effect on the development of dementia in such a population is uncertain, but the participants will be followed for at least seven years to determine whether the improved mental scores seen here are followed by reduced levels of dementia.

The trial was done in Finland and its results may not be applicable elsewhere, although the interventions included, such as diet and exercise, are similar to other countries' recommendations.

This study shows that a combined approach is beneficial. What is not clear is how active the clinical management of cardiovascular risk factors was in each group. Both groups were given health advice, but the intervention group were monitored more regularly for risk factors such as high blood pressure.

Though the study physicians did not prescribe medication, the participants were informed of results so they could seek advice from their GP. We do not know how many people in each group sought treatment for high blood pressure or cholesterol, and this could have affected the results.

All in all, it seems this study provides further evidence of the benefits of a healthy lifestyle. 

A good rule is that what is good for the heart, such as regular exercise and a healthy diet, is also good for the brain. It may also be useful to regard your brain as a type of muscle. If you don't exercise it regularly, it may well weaken.

Not all cases of dementia are preventable, but there are steps you can take to reduce your risk.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Dancing, Sudoku, fish and fruit – the keys to a mentally alert old age. The Guardian, March 12 2015

How diet, exercise and social activity can delay dementia: Study finds living a healthy lifestyle can boost brainpower by a quarter. Daily Mail, March 12 2015

Proof that dementia risk can be reduced by improving lifestyle. The Independent, March 12 2015

Want to know how to ward off dementia? We have the tips on how you can. Daily Mirror, March 12 2015

Links To Science

Ngandu T, Lehtisalo J, Solomon A, et al. A 2 year multidomain intervention of diet, exercise, cognitive training, and vascular risk monitoring versus control to prevent cognitive decline in at-risk elderly people (FINGER): a randomised controlled trial. The Lancet. Published online March 11 2015

Categories: Medical News

Autism-related genes linked to cognitive ability

Medical News - Wed, 03/11/2015 - 15:00

"Autism is linked to higher intelligence," the Mail Online reports. A new study found evidence that certain genetic variations associated with autistic spectrum disorder (ASD) were linked to greater cognitive ability in non-autistic individuals.

Researchers looked at the DNA of more than 10,000 people in the general population in Scotland and Australia. The study aimed to see whether genetic variations associated with ASD are associated with improved cognitive ability in the general population. They carried out a similar assessment for variants associated with attention deficit hyperactivity disorder (ADHD).

They found that individuals carrying more of the genetic variations associated with ASD had slightly higher overall cognitive scores. No consistent link was found between ADHD-associated variants and improved cognitive performance.

The most important thing to know about these results is that the effect seen was very small. Less than 0.5% of the difference seen in people’s cognitive scores was explained by how many of the ASD-linked genetic variants they carried. These findings would need to be replicated in other, larger, samples to be confirmed.

These findings do not currently have any obvious practical implications for individuals.

 

Where did the story come from?

The study was carried out by researchers from the University of Edinburgh and other research centres in the UK and Australia. The study received its main funding from the Chief Scientist Office of the Scottish Government Health Directorates and the Scottish Funding Council, Age UK and the Biotechnology and Biological Sciences Research Council (BBSRC), and the researchers and centres had various other sources of funding.

The study was published in the peer-reviewed journal Molecular Psychiatry.

The Mail Online's reporting could give readers the impression the improvement in cognitive ability seen by the researchers is much more impressive than it actually was.

It is only towards the end of the article that the website provides a quote from one of researchers pointing out that the variants only provided a "small intellectual advantage".

 

What kind of research was this?

This was a cross sectional study looking at whether genetic variations associated with autism spectrum disorders (ASD) or attention deficit hyperactivity disorder (ADHD) are associated with cognitive ability in the general population.

The researchers report that individuals with ADHD and ASD often have cognitive difficulties, although the relationship is more complex for ASD. The researchers say that some studies have found better cognitive functioning on some tests in individuals with ASD than controls.

While some diseases, such as cystic fibrosis, are caused by mutations in a single gene, the genetic contribution to other conditions such as ASD and ADHD is more complex and not fully understood. Rather than a single gene, variations in a large number of genes are thought to each contribute to increasing a person’s risk. These genetic variations are common in the population, and most people who carry them will not have ASD or ADHD. Cognitive ability also appears to have a complex genetic component.

The researchers in the current study wanted to see whether the genetic variants that have been linked to ASD or ADHD are linked to cognitive ability in the general population. If so, this might suggest that the same genes are contributing to ASD and ADHD, as well as cognitive function.

 

What did the research involve?

The researchers analysed the DNA of 9,863 Scottish individuals, who had also completed cognitive tests. They looked for a range of common genetic variations that have been found to be linked with ASD or ADHD. They analysed whether the number of these variations a person had was related to their cognitive performance.

The participants were taking part in the Generation Scotland: Scottish Family Health Study. The participants completed four cognitive tests:

  • the Mill Hill vocabulary scale junior and senior synonym test – where participants are asked to explain the meaning of certain words
  • a test of verbal declarative memory (logical memory) – where participants are asked to recall a series of previous learned facts and events
  • the Wechsler digit symbol substitution task – where participants are given a list of digit-symbol pairs (such as # = 14) and then translate a list of symbols into digits as fast as possible
  • a verbal fluency test – where participants are asked to say as many words from a category in a given time – such as "how many animals beginning with the letter E can you name in 60 seconds"

The researchers combined the results of these tests, to obtain a measure of performance across them all. For each participant, the researchers calculated a genetic "risk score" based on how many of the ASD or ADHD-linked genetic variants they had. They then carried out statistical analyses to see if there were links between a person’s genetic "risk score" and cognitive performance. They took into account people’s age and gender in the analyses.

The researchers also repeated their analyses on two other samples of people – one from Scotland (1,522 people) and one from Australia (921 people) – to see if they got the same results. This second Scottish sample had cognitive tests in childhood and old age, and the Australian sample had cognitive tests in adolescence. Different cognitive tests were used in the three samples.

 

What were the basic results?

The researchers found that having a higher genetic risk score for ASD was linked with having a slightly higher overall cognitive performance score in their large Scottish sample. A higher genetic risk score for ASD was also linked with having a slightly higher score on three of the four individual cognitive tests (logical memory, vocabulary test and verbal fluency test). A one unit increase in genetic risk score was associated with between a 0.04 and 0.07 unit increase in each of these scores. These were small effects, and variation in the genetic risk score accounted for less than 0.5% of the variation in people’s scores.

The researchers found similar associations between genetic risk score for ASD and different cognitive tests in the Australian sample, but did not find associations for their second, smaller Scottish sample.

When looking at the genetic risk score for ADHD, the researchers found no associations with cognitive performance in the main Scottish sample or the Australian sample. There was an association between higher genetic risk score for ADHD and slightly lower IQ score at age 11 in the second (smaller) Scottish sample. A one unit increase in genetic risk score was associated with a 0.08 unit reduction in this score. Other measures of cognitive performance in this study did not show consistent associations with ADHD genetic risk score.

 

How did the researchers interpret the results?

The researchers concluded that their findings suggest common genetic variants linked to ASD are also associated with general cognitive ability in general population.

 

Conclusion

This study has found some small associations between common genetic variations linked to ASD and cognitive performance in the general population.

Even where an association was found between genetic risk score and cognitive performance, the effect was very small. Less than 0.5% of the variability in people’s cognitive scores in the main study sample was explained by their ASD genetic risk score.

The link between ASD genetic risk score and cognitive performance were only found in two of the three population samples assessed. This may be due to different age groups of participants, or to different cognitive tests being used. There was even less consistency in findings relating to ADHD genetic risk score. Ideally these findings need to be replicated in other, larger, samples to confirm them.

The study is likely to be of interest to researchers, but does not have any obvious practical implications for individuals.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Autism IS linked to higher intelligence: People with genes related to the condition 'scored better in mental ability tests'. Mail Online, March 11 2015

Links To Science

Clarke TK, Lupton MK, Fernandez-Pujals AM, et al. Common polygenic risk for autism spectrum disorder (ASD) is associated with cognitive ability in the general population. Molecular Psychiatry. Published online March 10 2015

Categories: Medical News

Genetic high cholesterol 'may help protect against type 2 diabetes'

Medical News - Wed, 03/11/2015 - 14:30

"High cholesterol LOWERS the risk of diabetes," is the Daily Mail's rather misleading headline, going on to say that, "New study reveals why taking statins may be harmful".

But this study looked at familial hypercholesterolemia (FH) and not at the more common form of high cholesterol, which is associated with a high-fat diet.

FH is caused by an abnormal gene that affects how much cholesterol is absorbed by cells (cholesterol uptake). People with FH usually require lifelong statin treatments. Statins are drugs that help reduce cholesterol levels, which can reduce the risk of serious complications of the condition, such as a heart attack.

As greater cholesterol uptake by cells has been linked to increased type 2 diabetes risk, the researchers expected that diabetes may be less common in people with FH.  

The researchers studied 60,000 relatives of people with FH who were having a DNA test to see if they also had the condition. They compared how common type 2 diabetes was in those found to have the condition and those who were unaffected.

Overall, they found diabetes was slightly less common in those diagnosed with FH (1.75%) compared with those who did not have the condition (2.93%).

These findings certainly do not suggest that high cholesterol is good for you and taking statins is bad. Statins could potentially be lifesaving – without treatment, high circulating cholesterol levels could put people at a very high risk of heart attacks or strokes.

 

Where did the story come from?

The study was carried out by researchers from the Academic Medical Centre in the Netherlands.

The individual researchers in this study received various research grants, including those from the Netherlands Organisation for Scientific Research, the Cardiovascular Research Initiative and the European Union.

The study was published in the peer-reviewed medical journal JAMA.

The Daily Mail's headline, which claimed that "High cholesterol LOWERS the risk of diabetes: New study reveals why taking statins may be harmful", is misleading and arguably irresponsible.

This study specifically looked at people with a genetic condition that leads to raised cholesterol levels. It found they were less likely to have type 2 diabetes than their unaffected relatives.

The findings suggest poor cellular uptake of cholesterol could confer a lower risk of type 2 diabetes. But the biological link is not confirmed at this stage and requires further study.

As statins increase the cellular uptake of cholesterol, the Mail suggested they could therefore be harmful. But this study has not actually examined the effects of statins. 

The headline should have made it clear, as the researcher quoted in the article said, that statins have a "clear overall benefit" in high-risk patients.

 

What kind of research was this?

This was a cross sectional study aiming to look at the link between familial hypercholesterolemia and type 2 diabetes.

Familial hypercholesterolemia (FH) is a genetic condition where a person has very high cholesterol levels (both total cholesterol and LDL, or "bad" cholesterol) as the result of an abnormal gene.

People with FH have a high risk of cardiovascular disease from a young age and usually require lifelong statin treatment following diagnosis.

About 1 in 500 people in the general population have FH. If you have a parent with the condition, you have a one in two chance of having FH.

This study included people who had relatives with FH who were being screened by DNA testing to see if they also had the abnormal gene.

The researchers say the risk of type 2 diabetes has been found to be increased in statin users. This is believed to be the result of statins increasing the amount of LDL cholesterol receptors on body cells, causing an increased uptake of cholesterol.

People with FH have problems with cholesterol regulation and uptake, and in the majority of cases this is caused by an abnormality of the LDL receptor gene. As their body cells – including the insulin-producing cells of the pancreas – have decreased cholesterol uptake, the researchers therefore expected this might decrease their diabetes risk.

The researchers aimed to look at how common diabetes was in the relatives of people with FH who were screened in the Netherlands. They wanted to see whether prevalence differed between relatives who were also found to have the condition and those found to be unaffected.

 

What did the research involve?

The research included 63,320 first-degree relatives (parents, siblings or children) of people with FH. These people had DNA testing in the Netherlands between 1994 and 2014 to see if they also had the condition.

They also had their blood cholesterol levels measured. People were considered to have FH if they had one of the mutations known to cause the condition.

The main outcome the researchers looked at was whether a person had type 2 diabetes, as defined by self-report on a questionnaire.

They examined the difference in type 2 diabetes prevalence between those found to have FH and their unaffected relatives. They adjusted their analyses for the following potential confounders:

  • age
  • body mass index (BMI)
  • HDL ("good") cholesterol levels
  • triglycerides (another fat) levels
  • statin use
  • smoking
  • cardiovascular disease

 

What were the basic results?

Of the 63,320 relatives tested, 40% were found to have FH, and 60% were found to be unaffected and not carrying an FH mutation. Of those found to have FH, 86% had a mutation of the LDL receptor gene and others had less common mutations.

People with FH tended to be younger, have a lower BMI, higher "bad" LDL cholesterol but lower "good" HDL cholesterol, smoked less, and had greater statin use.

The overall prevalence of type 2 diabetes was 1.75% in people with FH (440 of 25,137) and 2.93% in unaffected relatives (1,119 of 38,183). This was a significant difference, calculating that people with FH had 38% reduced odds of type 2 diabetes (odds ratio [OR] 0.62, 95% confidence interval [CI] 0.55 to 0.69).

Repeating the analysis after adjusting for confounders still found that type 2 diabetes prevalence was lower in people with FH (1.44%) compared with unaffected relatives (3.26%), which was a significant difference (OR 0.49, 95% CI 0.41 to 0.58).

 

How did the researchers interpret the results?

The researchers concluded that, "In a cross-sectional analysis in the Netherlands, the prevalence of type 2 diabetes among patients with familial hypercholesterolemia was significantly lower than among unaffected relatives."

They say that if this finding is confirmed in further studies, it would raise the possibility that the transport of cholesterol into cells via the LDL receptor could be directly contributing to type 2 diabetes.

 

Conclusion

This cross sectional study included 60,000 first-degree relatives of people with FH who were undergoing genetic testing in the Netherlands to see if they also had the condition.

It compared the prevalence of type 2 diabetes between those relatives found to have the condition and those found to be unaffected. Overall, it found that those affected had lower prevalence of type 2 diabetes than those who were unaffected.

Compared with those who were unaffected, people with FH tended to have a lower BMI, higher LDL cholesterol, be less likely to be smokers, and more likely to be using statins at the time they were diagnosed.

This suggests they could have been taking statins and making healthy lifestyle changes as they already knew they had higher cholesterol, even before this was confirmed to be genetic FH.

However, their lower prevalence of type 2 diabetes was still found to be significantly lower than those without FH, even after adjustment for statin use and these healthier lifestyle factors.

This suggests, as the researchers propose, that the genetic abnormality in cholesterol regulation and cellular uptake – including the insulin-producing cells of the pancreas – could make people with FH less likely to develop type 2 diabetes.

But these results do not suggest high cholesterol is good for you and taking statins is bad, which is a simplistic interpretation of this study.

If the link is caused by the cellular uptake of cholesterol, statins may increase this process and could therefore potentially lead to a small increase in risk of type 2 diabetes.

Other research has also linked statin use with type 2 diabetes, as we discussed in September 2014. However, any potential risk must be weighed up against the benefits of statins in terms of reducing cardiovascular risk.

For people with FH, statins can really be viewed as a potentially lifesaving treatment – without these drugs, high circulating cholesterol levels put these people at a very high risk of cardiovascular disease at a young age.

Even for people who have raised cholesterol without having the genetic condition FH, the benefits of statins in terms of reducing cardiovascular risk are likely to outweigh any small increase in diabetes risk.

Overall, this study suggests the transport of cholesterol into cells via the LDL receptor may be linked with type 2 diabetes risk. But further study is needed to determine whether this is actually the case.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

High cholesterol LOWERS the risk of diabetes: New study reveals why taking statins may be harmful. Daily Mail, March 10 2015

Links To Science

Besseling J, Kastelein JJP, Defesche JC, et al. Association Between Familial Hypercholesterolemia and Prevalence of Type 2 Diabetes Mellitus. JAMA. Published online March 10 2015

Categories: Medical News

HRT review finds increased risk of blood clots and stroke

Medical News - Tue, 03/10/2015 - 15:00

"Women on HRT pills should be aware that there is a small chance of an increased risk of blood clots and possibly stroke," BBC News reports.

This story is based on an update of a review on the effects of hormone replacement therapy (HRT) on the risk of heart and blood vessel diseases (cardiovascular diseases).

The updated results supported their previous findings that HRT did not reduce the risk of deaths from any cause or from cardiovascular causes during follow-up. However, it did increase the risk of stroke and blood clots (for example deep vein thrombosis – DVT).

Researchers estimated that for every 1,000 women taking HRT, an extra six would experience stroke and an extra eight would experience a blood clot.

The review is robust and the trials of good quality. Still, there are some important points to note. The trials did include different doses and types of oral HRT given over different time periods, but results may not be representative of each of these individually. Also, the women were, on average, about 60 years old at the start of the trials, so results may not be representative of women who start taking HRT at a younger age.

If you are receiving HRT and are concerned, or are considering it, you should discuss your individual risk factors (such as a family history of clotting or stroke), as well as potential benefits, with your GP.

 

Where did the story come from?

The study was carried out by researchers from the University of Oxford and other research centres in the UK and Spain. They were carrying out the review for the Cochrane Collaboration – an international independent network of researchers and professionals, as well as patients and carers, which produces and updates a library of systematic reviews on a wide range of healthcare questions. The Cochrane Collaboration does not accept commercial or conflicted funding.

The study in question was published in the Cochrane Library – an online resource that is free to access.

The UK media generally covered this story well, giving balanced viewpoints from the authors of the review.

What they don’t mention is that the previous version of the review had similar findings, so the results are not unexpected.

 

What kind of research was this?

This was a systematic review of randomised controlled trials (RCTs), assessing whether HRT affects postmenopausal women’s risks of cardiovascular (heart) disease. Observational studies had suggested that women taking HRT were at lower risk of death or heart disease events during follow up. However, later RCTs had contradicted these findings. Some research has suggested that HRT might only reduce cardiovascular risk if it is started soon after the menopause starts.

A systematic review is the best way of assessing what the existing research says about any given question. They aim to use transparent, rigorous and unbiased methods to identify as much of the relevant evidence as possible, to assess its quality, and to analyse and interpret their findings.

Over time, new research evidence is published, so Cochrane reviews are regularly updated to incorporate new evidence and see if conclusions change as a result. The current publication updated the previous version of this review from 2013. The previous version found that HRT did not reduce the risk of heart problems, but did increase risk of stroke and blood clotting events.

 

What did the research involve?

The researchers searched multiple literature databases to identify RCTs comparing the effects of HRT versus a dummy pill (placebo) or no treatment. They selected those RCTs that met their inclusion criteria, assessed their quality, and pooled their results in a meta-analysis.

The researchers only included RCTs in women followed up for at least six months. HRT had to be given orally – trials of HRT patches, creams etc. were excluded. HRT could contain oestrogen alone or oestrogen plus a progestogen.

The main outcomes the researchers were interested in were death from any cause, death from a heart-related (cardiovascular) cause, non-fatal heart attack, stroke or chest pain (angina). They were also interested in blood clots, either in the lungs (pulmonary embolism) or DVT.

The results of the trials were analysed using standard meta-analytical techniques.

 

What were the basic results?

The searches identified six relevant RCTs published since the review was last published. This brought the total number of RCTs to 19, featuring 40,410 postmenopausal women. Nine RCTs included relatively healthy women, the majority of whom were not known to have heart disease, and 10 RCTs included women with known heart disease. The RCTs assessed various types and doses of HRT, for different lengths of time (seven months to 10 years). The RCTs were generally of good quality.

Meta-analysis of the trials found that HRT did not affect women’s risk of death from any cause or death from cardiovascular disease during follow up, or of non-fatal heart attacks, compared to placebo or no treatment. Similar results were obtained if trials in women with and without heart disease were analysed separately.

HRT increased risk of stroke compared to placebo or no treatment – with an extra six women per 1,000 experiencing stroke with HRT. On average, across the studies, about 31 women per 1,000 taking HRT experienced stroke during follow-up, compared to 25 women per 1,000 not taking HRT. This meant that for every 165 women taking HRT, there would be one extra stroke over an average of about four years. The overall quality of the evidence on this outcome was rated as high.

HRT also increased risk of blood clot (venous thromboembolism) – with an extra eight women per 1,000, on average, experiencing clots with HRT. On average across the studies, about 19 women per 1,000 taking HRT experienced clots during follow-up, compared to 10 women per 1,000 not taking HRT. The overall quality of the evidence on this outcome was rated as moderate.

If the women were split by when they started taking HRT, results in the group of women who started taking HRT more than 10 years after menopause started were similar to the overall results above.

However, HRT reduced risk of death during follow-up in the women who started taking it less than 10 years after menopause started (relative risk (RR) 0.70, 95% confidence interval (CI) 0.52 to 0.95).

HRT also reduced risk of death from heart disease or non-fatal heart attack in these women (RR 0.52, 95% CI 0.29 to 0.96). The risk of stroke was not significantly affected by HRT in this group, but the risk of blood clots was still increased (RR 1.74, 95% CI 1.11 to 2.73). These analyses did not include as many women as the overall analyses (only about 8,000-9,000), and relied largely on one trial.

 

How did the researchers interpret the results?

The researchers concluded that their findings
"provide strong evidence that treatment with hormone therapy in post-menopausal women overall … has little if any benefit and causes an increase in the risk of stroke and venous thromboembolic events".

 

Conclusion

This updated Cochrane review has found that oral HRT increases risk of stroke and blood clots, and does not appear to reduce overall risk of cardiovascular disease or death during follow-up.

More exploratory analyses suggested that HRT might reduce risk of death from heart disease or non-fatal heart attack if it was started within 10 years of menopause, but this finding needs further confirmation.

The review was carried out using robust methods and the trials were of good quality. Its findings are in line with the previous version of the review, and also with other reviews.

There are some points to note:

  • This review specifically looked at the effects of HRT on the risk of heart and vascular disease. It did not assess the effects of HRT on women’s menopausal symptoms or quality of life.
  • Although there were 19 trials included, three large trials (two testing combined HRT) had the greatest impact on the analyses. The authors note that there is debate about whether the results of these trials apply to all types of HRT, and all women receiving HRT.
  • The trials did include different doses and types of HRT, but results may not be representative of each of these individually. The review did not assess non-oral HRT; therefore, results may not apply to this form of HRT.
  • The women were, on average, about 60 years old at the start of the trials. Many women would start HRT at a younger age than this, soon after the start of the menopause, to counteract menopausal symptoms.

Overall, the review supports previous findings.

When prescribing any medicine, it is important to consider the balance of benefits and harms for the individual. If you are receiving HRT and are concerned, or are considering it, you may find it useful to discuss individual risk factors with your GP, such as whether you have an increased risk of developing a blood clot or stroke. This will help you to weigh your risks against the benefits HRT can bring, especially if your menopausal symptoms are particularly severe.

The UK MHRA notes that HRT does relieve menopausal symptoms, and suggests that for all women taking HRT, the lowest effective dose should be used for the shortest time.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

HRT linked to clots - and possibly stroke - study finds. BBC News, March 10 2015

HRT could halve the risk of heart disease, Oxford University research suggests. The Daily Telegraph, March 10 2015

Taking HRT in your 50s ‘cuts risk of premature death and heart disease’. Mail Online, March 10 2015

Women on HRT ‘face an increased risk of stroke' according to new review. Daily Express, March 10 2015

Links To Science

Boardman HMP, Hartley L, Eisinga A, et al. Hormone therapy for preventing cardiovascular disease in post-menopausal women. Cochrane Database of Systematic Reviews. Updated March 2015

Categories: Medical News