Monday, February 27, 2017

What is high lipoprotein(a), and should I be concerned?

What is high lipoprotein(a), and should I be concerned?

A team of researchers from the Research Institute of the McGill University Health Center (RI-MUHC) found that elevations in a unusual form of cholesterol, called Lipoprotein(a) or Lp(a), as responsible for 1 in 14 heart attacks and 1 in 7 cases of aortic valve disease.

27 beb 2017--This form of cholesterol is not commonly screened for in Canada, so most people do not even know they are at risk. Although no specific treatments exist to lower Lp(a), new therapies are being developed, and in addition to this study, the researchers hope to demonstrate how lowering this form of cholesterol could have an important impact on the population.
"Approximately 20 per cent of individuals have high Lp (a), a form of cholesterol that is highly heritable and runs in families," says Dr. George Thanassoulis, who is a researcher at the RI-MUHC and principal author of the study.
"We hope that our work will raise awareness that individuals with high Lp(a) are at high risk of heart disease and hopefully stimulate the development and testing of new therapies."
The study Estimating the Population Impact of Lp(a) Lowering on the Incidence of Myocardial Infarction and Aortic Stenosis was co-written by Mehdi Afshar, Pia R. Kamstrup, Ken Williams, Allan D. Sniderman, Børge G. Nordestgaard and George Thanassoulis, and is published in the journal Arteriosclerosis, Thrombosis, and Vascular Biology.

Provided by McGill University Health Centre

Sunday, February 26, 2017

Dietary prebiotics improve sleep, buffer impacts of stress, says study

Credit: CC0 Public Domain
In recent years, reams of research papers have shed light on the health benefits of probiotics, the "good bacteria" found in fermented foods and dietary supplements. Now a first-of-its kind study by University of Colorado Boulder scientists suggests that lesser-known gut-health promoters called prebiotics - which serve as food for good bacteria inside the gut—can also have an impact, improving sleep and buffering the physiological impacts of stress.

26 feb 2017--"We found that dietary prebiotics can improve non-REM sleep, as well as REM sleep after a stressful event," said Robert Thompson, a post-doctoral researcher in the Department of Integrative Physiology and first author of the new study published in the journal Frontiers in Behavioral Neuroscience.
Prebiotics are dietary fibers found naturally in foods like chicory, artichokes, raw garlic, leeks and onions. When beneficial bacteria digest prebiotic fiber, they not only multiply, improving overall gut health, but they also release metabolic byproducts. Some research suggests these byproducts can influence brain function, explains lead author Monika Fleshner, a professor in the Department of Integrative Physiology.
For the study, the researchers fed 3-week-old male rats a diet of either standard chow or chow that included prebiotics. They then monitored the rats' body temperature, gut bacteria and sleep-wake cycles - using EEG, or brain activity testing—over time.
They found that the rats on the prebiotic diet spent more time in non-rapid-eye-movement (NREM) sleep, which is restful and restorative, than those on the non-prebiotic diet.
"Given that sufficient NREM sleep and proper nutrition can impact brain development and function and that sleep problems are common in early life, it is possible that a diet rich in prebiotics started in early life could help improve sleep, support the gut microbiota and promote optimal brain/psychological health," the authors wrote.
After being exposed to a stressor, the rats on the prebiotic diet also spent more time in rapid-eye-movement (REM) sleep. REM sleep is believed to be critical for promoting recovery from stress, with research showing that those who get more REM sleep post-trauma are less likely to suffer from post-traumatic stress disorder.
Stress has previously been shown to reduce healthy diversity of gut bacteria and to lead to a temporary flattening of natural fluctuations in body temperature.
But rats on the prebiotic diet were buffered from these impacts, maintaining a healthy and diverse gut microbiota and normal temperature fluctuations even after stress exposure.
Fleshner said it's far too early to recommend prebiotic supplements as a sleep aid. More studies are in the works to examine what role prebiotics can play in promoting sleep, or buffering stress in people.
But she does recommend loading up on healthy prebiotic fiber from food. "It can't hurt and it might help," she said.

More information: Robert S. Thompson et al, Dietary Prebiotics and Bioactive Milk Fractions Improve NREM Sleep, Enhance REM Sleep Rebound and Attenuate the Stress-Induced Decrease in Diurnal Temperature and Gut Microbial Alpha Diversity, Frontiers in Behavioral Neuroscience (2017). DOI: 10.3389/fnbeh.2016.00240

Provided by University of Colorado at Boulder

Saturday, February 25, 2017

The effects of drinking on the aging brain

Credit: Human Brain Project
Wisdom and grace come with age, but so do mental slowing and increased risk for dementia. As the elderly population continues to grow, preserving brain health to maintain independence and quality of life into older age is a pressing concern. Researchers have identified some unsurprising factors that reduce one's risk for cognitive decline, including education, exercise or a healthy diet. But a more controversial question that continues to perplex scientists is whether alcohol consumption might also stave off cognitive impairment with age.

The aging brain on alcohol

25 feb 2017--Anyone who's experienced the fatigue and brain fog that follow a night of heavy drinking doesn't need science to explain the dangers of excessive alcohol intake. These health risks may be especially impactful to the older brain, which is already particularly vulnerable to environmental stressors. However, in moderation, a glass of wine or beer may not only be harmless, but may in fact also confer resilience to the aging brain against cognitive decline. Numerous studies have reported that moderate drinking is associated with lower rates of dementia, better cognitive performance, and slower decline in memory and executive functions. Yet, not all studies support the notion that a nightcap can help keep the brain sharp into late life. These discrepant findings raise two obvious questions. First, why are some patterns of drinking neurobiologically healthy, while others are toxic? And second, how can we better identify drinking behaviors that promote the healthiest trajectories of cognitive aging?

Neuroprotective in moderation, neurotoxic in excess

In excess, alcohol works as a neurotoxin on may levels. Studies in animals have shown that binging on ethanol kills neurons and impairs neurogenesis–the birth of new neurons–in the hippocampus, a region critical to creating new memories. Furthermore, alcohol-induced dementia results from brain damage that occurs with prolonged alcohol abuse. The reasons for the observed benefits of alcohol are less clear. In contrast to binge drinking, moderate alcohol intake increases neurogenesis and may help combat oxidative stress to neurons. It's well documented that what's good for the heart is good for the brain, and indeed, vascular dysfunction often co-exists with or precipitates many forms of dementia. A prevailing theory is that the neuroprotective properties of drinking stem largely from their positive effects on cerebrovascular health. Alcohol can reduce risk for stroke and heart disease, lower blood pressure and increase HDL ("good") cholesterol. However, some evidence that wine is more strongly neuroprotective than other forms of alcohol suggests that resveratrol, a potent antioxidant found in red wine, may also play a role. Although resveratrol minimizes dementia pathology in animals, the extremely high doses required make it unlikely to be the primary source of neuroprotection from alcohol.

Unraveling healthy drinking patterns for the aging brain

For our aging population to reap the greatest benefit from alcohol, it will be essential to determine patterns of healthy drinking that are optimized for the individual. This will require, foremost, a comprehensive understanding of how alcohol distinctly affects you versus me based on our genetics, sex or lifestyle. For example, alcohol has been found to differentially influence brain structure and risk for dementia or cognitive impairment for those with and without the apolipoprotein E4 gene, a strong risk factor for Alzheimer's disease. Furthermore, studies have inconsistently reported sex differences in how drinking influences cognitive decline, which may be explained by differences in how men and women metabolize alcohol.
Despite overwhelming evidence that moderate alcohol intake can be healthy for the aging brain, there are striking incongruences across findings–which may be due to differences in study design or confounding factors­–that muddle our understanding of alcohol's benefits. 'Survival bias,' in which healthier individuals participate in studies for longer, is an unavoidable complication in longitudinal studies of aging. This could significantly skew results if unhealthy drinkers drop out early, leaving only "healthy" drinkers to be studied in very old age. Furthermore, most human studies on alcohol and brain aging rely on observed associations, which can be replete with confounding factors. For instance, it's known that drinkers tend to live more healthy lifestyles (e.g., they may exercise more or follow a Mediterranean diet), or may drink more often simply because they're more socially active, which alone is known to be brain-healthy. What's more, effects of alcohol on cognitive aging may depend on the type of alcohol consumed, how alcohol intake is measured, or the definition of "non-drinkers." Many studies group life-long abstainers together with quitters, who may avoid alcohol due to poor health or may have developed health problems from alcohol abuse. However, my postdoctoral adviser Linda McEvoy, who studies effects of alcohol on brain aging at UC San Diego, explains that "Randomized controlled trials offer a better alternative to more definitely answer the question of how moderate alcohol intake affects cognitive function. Such trials have demonstrated beneficial cardiometabolic effects in those randomized to drink moderate amounts of alcohol."

A prescription for alcohol?

Despite some uncertainties in the research so far, it appears that regular moderate drinking is unlikely to be hazardous to cognitive function and may even support healthy brain aging. Until we have further clarification, McEvoy offers some advice to those hoping to preserve brain health into late life: "If a person consumes alcohol, I would advise drinking moderate amounts of alcohol (one or two drinks) with dinner. If the person does not drink, I would not advise starting. Some individuals have a hard time controlling the amount they drink, and heavy drinking has detrimental effects on brain health and cognitive function."

More information: Elin Åberg et al. Moderate ethanol consumption increases hippocampal cell proliferation and neurogenesis in the adult mouse, The International Journal of Neuropsychopharmacology (2005). DOI: 10.1017/S1461145705005286

Kaarin J. Anstey et al. Alcohol Consumption as a Risk Factor for Dementia and Cognitive Decline: Meta-Analysis of Prospective Studies, The American Journal of Geriatric Psychiatry (2009). DOI: 10.1097/JGP.0b013e3181a2fd07

T. Anttila. Alcohol drinking in middle age and subsequent risk of mild cognitive impairment and dementia in old age: a prospective population based study, BMJ (2004). DOI: 10.1136/bmj.38181.418958.

BE May A Beydoun et al. Epidemiologic studies of modifiable factors associated with cognition and dementia: systematic review and meta-analysis, BMC Public Health (2014). DOI: 10.1186/1471-2458-14-643

B. J. K. Davis et al. The Alcohol Paradox: Light-to-Moderate Alcohol Consumption, Cognitive Function, and Brain Volume, The Journals of Gerontology Series A: Biological Sciences and Medical Sciences (2014). DOI: 10.1093/gerona/glu092

M. Ganguli et al. Alcohol consumption and cognitive function in late life: A longitudinal community study, Neurology (2005). DOI: 10.1212/01.wnl.0000180520.35181.24

L M Hines. Moderate alcohol consumption and coronary heart disease: a review, Postgraduate Medical Journal (2001). DOI: 10.1136/pmj.77.914.747

Kristin R. Krueger et al. Social Engagement and Cognitive Function in Old Age, Experimental Aging Research (2009). DOI: 10.1080/03610730802545028

Francesco Panza et al. Alcohol consumption in mild cognitive impairment and dementia: harmful or neuroprotective?, International Journal of Geriatric Psychiatry (2012). DOI: 10.1002/gps.3772

Nicole J Ridley et al. Alcohol-related dementia: an update of the evidence, Alzheimer's Research & Therapy (2013). DOI: 10.1186/alzrt157

Meir J. Stampfer et al. Effects of Moderate Alcohol Consumption on Cognitive Function in Women, New England Journal of Medicine (2005). DOI: 10.1056/NEJMoa041152

This story is republished courtesy of PLOS Blogs:

Provided by Public Library of Science

Friday, February 24, 2017

Alzheimer's drug prescribed 'off-label' for mild cognitive impairment could pose risk for some

old people
Credit: CC0 Public Domain
Donepezil, a medication that is approved to treat people with Alzheimer's disease, should not be prescribed for people with mild cognitive impairment without a genetic test. UCLA School of Nursing researchers discovered that for people who carry a specific genetic variation—the K-variant of butyrylcholinesterase, or BChE-K—donezpezil could accelerate cognitive decline.

24 feb 2017--Mild cognitive impairment is a transitional state between normal age-related changes in cognition and dementia. Because many people with the condition display symptoms similar to those caused by Alzheimer's disease, some physicians prescribe donepezil, which is marketed under the brand name Aricept and is the most-prescribed medication for Alzheimer's.
Donepezil was tested as a possible treatment for mild cognitive impairment in a large, federally funded study published in 2005, but it was not approved by the FDA. Still, doctors have often prescribed the drug "off-label"—meaning that it is not approved for that specific disorder—for their patients with mild cognitive impairment.
From data collected during the 2005 trial, the researchers looked at the association between BChE-K and changes in cognitive function. Using two tests that measure cognitive impairment, the Mini-Mental State Examination and the Clinical Dementia Rating Sum of Boxes, they found that people with the genetic variation who were treated with donepezil had greater changes in their scores than those who took placebos. They also found that those who took donepezil had a faster cognitive decline than those who took the placebo.
Physicians are increasingly using personalized medicine, including pharmacogenetics—the study of how genetics affect a person's response to a drug—to tailor their patients' care. The findings reinforce the importance of physicians discussing the possible benefits and risks of this treatment with their patients.

More information: Deleterious Effect of Butyrylcholinesterase K-Variant in Donepezil Treatment of Mild Cognitive Impairment. Journal of Alzheimer's

Provided by University of California, Los Angeles

Wednesday, February 22, 2017

How gut microbiome and diet can affect depression

Credit: CC0 Public Domain
An international group of researchers headed by André Carvalho has published in Psychotherapy and Psychosomatics a paper that provides new data and prospects for the links between the intestinal flora and several disorders, notably depression.

22 feb 2017--Persistent low-grade immune-inflammatory processes, oxidative and nitrosative stress, and hypothalamic-pituitary-adrenal axis activation are integral to the pathophysiology of major depressive disorder. The microbiome, intestinal compositional changes, and resultant bacterial translocation add a new element to the bidirectional interactions of the gut-brain axis. New evidence implicates these pathways in the onset of major depressive disorder. In addition, abnormalities in the gut-brain axis are associated with several chronic non-communicable disorders, which frequently co-occur in individuals with depression, including but not limited to irritable bowel syndrome, chronic fatigue syndrome, obesity, and type 2 diabetes mellitus.
The composition of the gut microbiota is influenced by several genetic and environmental factors (e.g. diet). Several lines of evidence indicate that gut-microbiota-diet interactions play a significant pathophysiological role in depression and related medical comorbidities. Gut dysbiosis and the leaky gut may influence several pathways implicated in the biology of major depressive disorder, including but not limited to immune activation, oxidative and nitrosative stress, and neuroplasticity cascades. However, methodological inconsistencies and limitations limit comparisons across studies.
Authors conclude that intestinal dysbiosis and the leaky gut may constitute a key pathophysiological link between depression and its medical comorbidities. This emerging literature opens relevant preventative and therapeutic perspectives.

More information: Anastasiya Slyepchenko et al. Gut Microbiota, Bacterial Translocation, and Interactions with Diet: Pathophysiological Links between Major Depressive Disorder and Non-Communicable Medical Comorbidities, Psychotherapy and Psychosomatics (2017). DOI: 10.1159/000448957

Provided by Journal of Psychotherapy and Psychosomatics

Monday, February 20, 2017

Bringing evidence to health screening debates

Bringing evidence to health screening debates
Gatsonis will speak at the AAAS Annual meeting about how large screening trails are structured to provide the best evidence, not only of accuracy but also for many other pertinent questions regarding patient care. 
Whether to screen? How often? At what age? At what cost?—seem to readily breed conflicting opinions and public confusion. What's needed is rigorously produced evidence. 

20 feb 2017--That's where Constantine Gatsonis, chair of the Department of Biostatistics at Brown University, comes in.
In a talk and panel discussion at the 2017 annual meeting of the American Association for the Advancement of Science on Sunday, Feb. 19, Gatsonis, a veteran researcher on many large cancer screening studies, will discuss how such trials are designed and conducted to ensure that researchers can evaluate not only the accuracy of a test, but also its cost-effectiveness, its effect on doctor and patient decision-making and its effect on health outcomes.
After all, screening is not just about detection, Gatsonis said, but about health. Patients definitely want their cancers found, but not all accurate, positive diagnoses should lead to treatment.
"There is a growing concern of this notion of over-diagnosis," he said. "Screening is finding small lesions that would not hurt you. Generally speaking with screening, especially as the modalities become more and more accurate and can see smaller and smaller things, the question is, is that good for you? It's not a foregone conclusion."
In his talk, "Evaluating the Impact of Diagnostic Modalities Used in Screening for Disease," and the panel, "Medical Decision-Making: To Screen or Not to Screen?" in Room 309 of Hynes Convention Center at 8 a.m., Gatsonis will outline how large studies and statistical analysis bring data to bear on the many questions that swirl around screenings.

Big questions, big studies

Definitive screening trials feature huge sample sizes to ensure the highest degree of certainty when comparing one method against another. But even when the sample is large and the question is straightforward, the answers won't always be obvious. Gatsonis was the lead statistician of the Digital Mammographic Imaging Screening Trial, which sought to compare the accuracy of digital vs. film mammograms for detecting breast cancer in a sample of more than 49,000 women. The primary paper from that study was published in the New England Journal of Medicine in 2005.
The two technologies turned out to have similar accuracy overall, but with a huge sample and carefully gathered data, the study was able to also show that digital mammography had significantly greater accuracy in women younger than 50 years, women with radiographically dense breasts, and premenopausal or perimenopausal women.
The evidence of some clear advantages gave digital mammography a strong foothold, Gatsonis said: "That study is the study that essentially put digital mammography in every hospital."
Well-structured, thoughtfully designed trials can answer multiple questions. Gatsonis was co-lead statistician for the National Lung Screening Trial, which produced the 2010 finding that among 53,454 current or former heavy smokers aged 55 to 74, those who received low-dose helical CT scans had a 20 percent lower risk of dying from lung cancer than participants who received chest X-rays. The study therefore answered the question of which screening method was better based on health outcomes.
The trial also kept track of costs and so was able to assess that CT screening was cost-effective, at least given certain specific assumptions. The study also gathered the data needed to analyze another pertinent question that isn't always asked: Did false positives—CT scans that inaccurately detected cancer—trouble patients? An analysis led by Gatsonis's Brown colleague Ilana Gareen found that such results did not cause serious concern, at least in part because the study's informed consent procedures were clear about the possibility of the unduly dire-seeming result.
Gatsonis is now leading the statistical side of a new breast cancer screening study, the Tomosynthesis Mammography Imaging Screening Trial, which will compare the 3D technology of tomosynthesis with standard, 2D digital mammography.
Rather than just assessing accuracy, the trial, which is set to begin recruiting a whopping total of 165,000 U.S. and Canadian women between the ages of 45 and 74, will also focus on a specific clinical outcome that will be readily apparent within four and a half years from their entry into the study. At that point the research team will assess in which group—tomosynthesis or digital mammography—it was more frequent for a woman to be diagnosed with an advanced, aggressive cancer. The data will help to discern the health impact of each kind of screening, without the team having to wait until there was a sufficient number of breast cancer deaths to allow for a comparison based on mortality.
"We're actually trying to bridge the span between accuracy and ultimate outcome," Gatsonis said, and "do so within a reasonably short study."
In addition to using this innovative endpoint for the primary comparison, the trial is promoting a new approach to screening, which incorporates knowledge of breast cancer risk factors and tailors screening to these factors. For example, Gatsonis said, postmenopausal women will be screened annually or biennially depending on their risk profile.
Big screening trials are expensive and logistically complicated. They generate massive amounts of data that must be expertly interpreted to accomplish their goals. But Gatsonis said that's all still better than the alternative of speculative opining.
"Nobody said screening is a simple process," he said.

Provided by Brown University

Sunday, February 19, 2017

New guideline provides clinical recommendations for specific insomnia drugs

A new clinical practice guideline is the first from the American Academy of Sleep Medicine to provide comprehensive, evidence-based analyses of individual agents commonly used in the treatment of chronic insomnia disorder.

19 feb 2017--The guideline, which is published in the Feb. 15 issue of the Journal of Clinical Sleep Medicine, provides recommendations to help clinicians choose a specific pharmacological agent for the treatment of chronic insomnia in adults, when such treatment is indicated. Developed by an expert task force and approved by the AASM board of directors, the guideline was based on a systematic literature review, meta-analyses, and assessment of the evidence using the GRADE methodology. A draft of the guideline was previously made available for public comment.
"The publication of this clinical practice guideline is an important step forward for the field of sleep medicine," said AASM President Ronald D. Chervin, MD, MS. "It further equips clinicians to provide high quality, patient-centered care for millions of people who suffer from chronic insomnia."
Although transient insomnia symptoms occur in 30 to 35 percent of the population, the full clinical syndrome of chronic insomnia disorder occurs in about 10 percent of people. The CDC has estimated that 4.1 percent of U.S. adults report having taken a prescription sleep aid in the past month, based on survey data collected from 2005 - 2010.
The clinical practice guideline includes 14 specific recommendations for individual agents, including prescription medications such as zolpidem and eszopiclone; over-the-counter medications such as diphenhydramine; and dietary supplements such as melatonin and valerian. Each recommendation suggests whether clinicians should or should not use the individual drug for sleep onset insomnia or sleep maintenance insomnia, versus no treatment. However, the guideline does not recommend one drug over another since few comparative efficacy studies have been conducted among these agents.
The authors noted that the data available to support these recommendations is often less than certain. As a result, the strength of each recommendation is classified as "weak," reflecting a lower degree of certainty in the appropriateness of the patient-care strategy. Therefore, clinicians must continue to exercise sound clinical judgment in their care for patients with chronic insomnia. Decisions should be based not only on these recommendations but also on a clinician's experience and the individual circumstances presented by the patient.
The guideline emphasizes that medications for chronic insomnia disorder should be considered mainly in patients who are unable to participate in cognitive behavioral therapy for insomnia (CBT-I), patients who still have symptoms after this therapy, or those who require a temporary adjunct to CBT-I. A clinical guideline previously published by the American Academy of Sleep Medicine indicates that CBT-I is an effective treatment that should be utilized as an initial intervention for chronic insomnia, and this position was reiterated by the AASM in a 2014 Choosing Wisely statement.
Anyone who is having trouble falling asleep or staying asleep should discuss the concern with a doctor. Help for an ongoing sleep problem is available from more than 2,500 sleep centers that are accredited by the American Academy of Sleep Medicine.

More information: Michael J. Sateia et al, Clinical Practice Guideline for the Pharmacologic Treatment of Chronic Insomnia in Adults: An American Academy of Sleep Medicine Clinical Practice Guideline, Journal of Clinical Sleep Medicine (2017). DOI: 10.5664/jcsm.6470

Provided by American Academy of Sleep Medicine

Saturday, February 18, 2017

Protein and carb intake post-exercise can benefit bone health, study finds

Protein and carb intake post-exercise can benefit bone health, study finds
The findings have the potential to influence athletes' dietary and training practices. Credit: Nottingham Trent University
Protein and carbohydrate intake after exercise can have a beneficial impact on bone health and could help to stave off serious injury among athletes, new research suggests.

18 feb 2017--A study led by sport scientists at Nottingham Trent University showed that drinking a protein and carbohydrate-rich solution after strenuous exercise helped decrease bone resorption – the breakdown of tissue in the bone.
It also had a small positive impact on bone formation, creating a better balance of bone turnover – which at high levels is also associated with bone loss and damage.
It is known that prolonged and intense exercise causes increased resorption of the bone – which is linked to the occurrence of debilitating stress fracture injuries in athletes. Such injuries can see athletes out of action for months, resulting in major losses in training time or missed competitions.
The researchers, writing in the journal Medicine & Science in Sports & Exercise, say the findings have the potential to influence athletes' dietary and training practices.
As part of the study male endurance runners ran on a treadmill until exhaustion – and had their blood collected before and after exercise, to measure the impact upon bone health biomarkers. Participants drank either a placebo or a protein and carbohydrate solution developed by the researchers.
The scientists found that the solution reduced concentrations of the b-CTX biomarker – which is released into the blood stream during bone resorption – whether it was ingested immediately or two hours after exercise.
Those who had the solution immediately after exercise also showed increases in P1NP, a blood biomarker for bone formation, four hours after exercise.
Previous work has looked at effects of nutrition before and during exercise, but this is not always practical and can lead to gastrointestinal discomfort.
A key benefit of drinking a solution in this context is that it is quick and easy for the athlete to ingest. It would probably take longer to see any similar benefit from eating protein and carbohydrate-rich food, due to the additional time taken for transit through the gut.
"Given that endurance athletes train multiple times a day, preventing bone loss and stress fracture injury is hugely important," said Craig Sale, Professor of Human Physiology in Nottingham Trent University's School of Science and Technology.
He said: "These athletes have minimal recovery time and rest days and are likely to suffer in terms of bone health, with increased risk of injury. These findings are important for those individuals because post-exercise intake, or training sessions, can be timed so that training occurs when bone resorption is at its lowest and bone formation at its highest."
Researcher Becky Townsend added: "Although the study was performed with elite athletes in mind, the data could also be used by sub-elite or recreational endurance athletes training just once a day.
"The data may also be useful for athletes that perform a variety of different training sessions; from long slow runs, to high-intensity interval type sessions, as all of these types of sessions include repetitive mechanical loading and cause increased physiological/hormonal responses.
"Although the carbohydrate and protein drink used in the study was individualised based on participant body weight, there are a number of similar carbohydrate and protein recovery drinks that are commercially available."
The study also involved the English Institute of Sport and Norwich Medical School at the University of East Anglia.
Dr Kevin Currell, Director of Science and Technical Development at the English Institute of Sport, said: "Working with Nottingham Trent University to find a simple intervention which could support elite athletes bone health has been an impactful partnership. This research has already been put into practice, and helped keep a number of athletes fit and healthy leading into Rio 2016."

More information: Rebecca Townsend et al. The Effect of Postexercise Carbohydrate and Protein Ingestion on Bone Metabolism, Medicine & Science in Sports & Exercise (2017). DOI: 10.1249/MSS.0000000000001211

Provided by Nottingham Trent University

Friday, February 17, 2017

Vitamin D protects against colds and flu, finds major global study

vitamin D
Credit: CC0 Public Domain
Vitamin D supplements protect against acute respiratory infections including colds and flu, according to a study led by Queen Mary University of London (QMUL).

17 feb 2017--The study provides the most robust evidence yet that vitamin D has benefits beyond bone and muscle health, and could have major implications for public health policy, including the fortification of foods with vitamin D to tackle high levels of deficiency in the UK.
The results, published in the BMJ, are based on a new analysis of raw data from around 11,000 participants in 25 clinical trials conducted in 14 countries including the UK, USA, Japan, India, Afghanistan, Belgium, Italy, Australia and Canada. Individually, these trials yielded conflicting results, with some reporting that vitamin D protected against respiratory infections, and others showing no effect.
Lead researcher Professor Adrian Martineau from QMUL said: "This major collaborative research effort has yielded the first definitive evidence that vitamin D really does protect against respiratory infections. Our analysis of pooled raw data from each of the 10,933 trial participants allowed us to address the thorny question of why vitamin D 'worked' in some trials, but not in others.
"The bottom line is that the protective effects of vitamin D supplementation are strongest in those who have the lowest vitamin D levels, and when supplementation is given daily or weekly rather than in more widely spaced doses.
"Vitamin D fortification of foods provides a steady, low-level intake of vitamin D that has virtually eliminated profound vitamin D deficiency in several countries. By demonstrating this new benefit of vitamin D, our study strengthens the case for introducing food fortification to improve vitamin D levels in countries such as the UK where profound vitamin D deficiency is common."
Vitamin D - the 'sunshine vitamin' - is thought to protect against respiratory infections by boosting levels of antimicrobial peptides - natural antibiotic-like substances - in the lungs. Results of the study fit with the observation that colds and 'flu are commonest in winter and spring, when levels of vitamin D are at their lowest. They may also explain why vitamin D protects against asthma attacks, which are commonly triggered by respiratory viruses.
Daily or weekly supplementation halved the risk of acute respiratory infection in people with the lowest baseline vitamin D levels, below 25 nanomoles per litre (nmol/L). However, people with higher baseline vitamin D levels also benefited, although the effect was more modest (10 per cent risk reduction). Overall, the reduction in risk of acute respiratory infection induced by vitamin D was on a par with the protective effect of injectable 'flu vaccine against 'flu-like illnesses.
Acute respiratory infections are a major cause of global morbidity and mortality. Upper respiratory infections such as colds and 'flu are the commonest reason for GP consultations and days off work. Acute lower respiratory infections such as pneumonia are less common, but caused an estimated 2.65 million deaths worldwide in 2013. Vitamin D supplementation is safe and inexpensive, so reductions in acute respiratory infections brought about by vitamin D supplementation could be highly cost-effective.

More information: Adrian R Martineau et al, Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data, BMJ (2017).DOI: 10.1136/bmj.i6583

Provided by Queen Mary, University of London

Tuesday, February 14, 2017

Review links albuminuria to cognitive impairment, dementia

Review links albuminuria to cognitive impairment, dementia
14 feb 2017—Albuminuria is associated with cognitive impairment, dementia, and cognitive decline, according to a review published online Feb. 2 in the Journal of the American Geriatrics Society.

Marios K. Georgakis, M.D., from the University of Athens in Greece, and colleagues conducted a systematic review to examine the correlation between albuminuria and cognitive impairment, dementia, and cognitive function. Data were included for 32 eligible studies.
The researchers found that albuminuria correlated with cognitive impairment, dementia, clinical Alzheimer's disease, and vascular dementia (odds ratios, 1.35, 1.35, 1.37, and 1.96, respectively). The significant effect persisted in longitudinal, population-based, and high-quality studies. In time-to-event analysis of prospective studies involving individuals without dementia at baseline, there was a significant association with incident dementia (risk ratio, 1.52). Subjects with albuminuria had worse global cognitive performance and accelerated cognitive decline (Hedge's g, −0.13 and −0.20, respectively); they also scored lower in executive function, processing speed, verbal fluency, and verbal memory.
"The stronger effects for vascular dementia and cognitive performance in domains primarily affected by microvascular disease support that the association could be mediated by shared microvascular pathology in the kidney and the brain," the authors write.

More information: Full Text (subscription or payment may be required)

Sunday, February 12, 2017

Hand-grip test can indicate decline in physical function of Parkinson's patients

Hand-grip test can indicate decline in physical function of Parkinson's patients
UBC researchers Jenn Jakobi, sitting, and Gareth Jones, right, review results from recent electromyography tests on patients with Parkinson's disease with their student researchers. Credit: UBC Okanagan
12 feb 2017--UBC researchers Jenn Jakobi and Gareth Jones, both Health and Exercise Sciences professors at UBC's Okanagan campus, recently completed a study that examined the methods used to monitor the progressive advancement of Parkinson's disease (PD)—a degenerative disease that affects the central nervous system.
The study compared results from electromyography assessments of leg and arm muscles to basic physical performance tests such as gait speed, balance and hand-grip strength. The results were surprising.
"It became very clear that the hand-grip test was one of the functional tests that proved to be a reliable and valuable test measure," says Jakobi. "The hand-grip test is an easy and conclusive way to test muscle strength decline in this group of people."
The study involved 23 men and women with PD and 14 people without the disease, all 50 years or older living independently in Kelowna. The participants wore a portable monitoring device to measure muscle activity with the device recording electrical activity of muscles in the arms and legs for approximately eight hours. Participants also underwent three physical function tests—hand-grip, gait and balance—each morning and afternoon.
Jones says the data gleaned from the three physical tests was as conclusive and as informative as the lengthy recordings of muscle activity. And the tests were easier for participants and those administering the experiments.
"The hand-grip dynamometer is a tool that is easily accessible, easy to use, and is reliable," says Jones. "In addition they are readily available to health professionals such as family doctors, community therapists and physiotherapists."
"It seems these devices have come full circle and are back being used by clinicians," adds Jakobi. "It's a tool that is ideal for Parkinson's patients as you can easily record a decline in an individual's physical strength and function as the disease progresses."
Patients with PD suffer symptoms like uncontrollable shaking, slowness of movement, and eventually difficulty with balance, coordination and walking. It's important for health care professionals to track early functional decline of Parkinson's patients, says Jakobi. In this way, individual health can be monitored and future falls related to the disease prevented.
According to Statistics Canada more than 67,000 Canadians are living with Parkinson's today, and it is mostly diagnosed in men over the age of 45.
The study was recently published in the journal Archives of Physical Medicine and Rehabilitation.

Provided by University of British Columbia

Friday, February 10, 2017

New data reveal aging experiences of LGBT Americans

A new supplemental issue of the journal The Gerontologist presents the findings of the largest national survey to date focused on the health and well-being of lesbian, gay, bisexual, and transgender (LGBT) older adults.

10feb 2017--The issue, titled "Aging with Pride: National Health, Aging, and Sexuality/Gender Study (NHAS)," provides cutting edge research, drawing upon the 2014 wave of data from the first national, longitudinal study of more than 2,400 diverse LGBT adults aged 50 to 100. This research was supported by a grant from the National Institute on Aging.
Karen I. Fredriksen-Goldsen, PhD, a professor in the University of Washington School of Social Work, served as editor for this journal issue, which contains 10 articles.
"These articles provide the opportunity to consider how social, historical, and environmental contexts influence the health and well-being of LGBT older adults as we move forward in aging-related research, services, and policies—especially if we are to understand the realities of older adulthood across diverse and vulnerable communities." said Fredriksen-Goldsen. "The insights gleaned from this study of aging among LGBT older adults can deepen our understanding of the richness, diversity, and resilience of lives across the life course."
Findings in the journal reveal that 2.4 percent of older adults in the U.S. currently self-identify as LGBT, accounting for 2.7 million adults aged 50 and older, including 1.1 million aged 65 and older.
Collectively, the articles cut across three major themes: risk and protective factors and life course events associated with health and quality of life among LGBT older adults; heterogeneity and subgroup differences in LGBT health and aging; and processes and mechanisms underlying health and quality of life of LGBT older adults. The authors address the intersection of health and well-being with such topics as race and ethnicity, HIV status, military service, marriage, social networks, and depression.
"LGBT older adults face disparities in health and well-being compared to heterosexual peers, including higher rates of disability, cardiovascular disease, depression and social isolation," Fredriksen-Golden said. "Discrimination, stigma, and lack of healthcare access is associated with these elevated disparities. It is important to understand that these communities are diverse, and unique groups face distinct challenges to their health."

Provided by The Gerontological Society of America

Thursday, February 09, 2017

Benefits for intensive BP lowering in older HTN patients

Benefits for intensive BP lowering in older HTN patients
For older patients with hypertension, intensive blood pressure (BP) lowering strategies are associated with reduced risk of certain cardiovascular events, according to research published in the Feb. 7 issue of the Journal of the American College of Cardiology.

09 feb 2017--Chirag Bavishi, M.D., M.P.H., from Mount Sinai St. Luke's & Mount Sinai West Hospitals in New York City, and colleagues examined data from four high-quality trials involving 10,857 older hypertension patients (aged ≥65 years) with a mean follow-up of 3.1 years.
The researchers found that, compared with standard BP lowering, intensive BP lowering correlated with significant reductions in major adverse cardiovascular events (MACE), cardiovascular mortality, and heart failure (pooled relative risks [RR], 0.71 [95 percent confidence interval (CI), 0.60 to 0.84], 0.67 [95 percent CI, 0.45 to 0.98], and 0.63 [95 percent CI, 0.43 to 0.99], respectively). There were no between-group differences in the rates of myocardial infarction or stroke. No significant between-group difference was seen in the incidence of serious adverse events or renal failure (RRs, 1.02 [95 percent CI, 0.94 to 1.09] and 1.81 [95 percent CI, 0.86 to 3.80], respectively). In a fixed effects model, results were largely similar except the risk of renal failure was increased with intensive BP-lowering therapy (RR, 2.03 [95 percent CI, 1.30 to 3.18]).
"When considering intensive BP control, clinicians should carefully weigh benefits against potential risks," the authors write.
Several authors disclosed financial ties to the pharmaceutical and medical technology industries.

More information: Full Text

Sunday, February 05, 2017

Zoster ups stroke risk in patients with autoimmune disease

Zoster ups stroke risk in patients with autoimmune disease
05 feb 2017—For patients with autoimmune diseases, the risk of stroke is increased in the few months subsequent to incident herpes zoster (HZ), according to a study published online Jan. 28 in Arthritis & Rheumatology.

Leonard H. Calabrese, D.O., from the Cleveland Clinic, and colleagues identified patients with autoimmune disease using Medicare data from Jan. 1, 2006, through Dec. 31, 2013. The authors examined whether the incidence of hospitalized stroke was increased immediately following HZ compared with incidence at later time points.
The researchers found that the crude incidence of stroke varied from 2.30 per 100 patient-years (95 percent confidence interval [CI], 0.96 to 5.52) within 90 days of HZ in patients who had HZ-related cranial nerve complications and did not receive treatment, to 0.87 per 100 patient-years (95 percent CI, 0.75 to 1.02) at 366 to 730 days for those who did not have complications and who received treatment. The overall incidence rate ratio (IRR) was 1.36 (95 percent CI, 1.10 to 1.68) for stroke in the first 90 days versus at 366 to 730 days after HZ, after multivariable adjustment for multiple stroke-related factors. Patients with zoster and cranial nerve complications had greater risk (IRR, 2.08; 95 percent CI, 0.99 to 4.36). The incidence of subsequent stroke was lower with prompt antiviral therapy (IRR, 0.83; 95 percent CI, 0.70 to 0.98).
"These data underscore the urgency of developing strategies for reducing the risk of varicella-zoster virus," the authors write.

More information: Full Text (subscription or payment may be required)

Wednesday, February 01, 2017

Air pollution may lead to dementia in older women

Air pollution may lead to dementia in older women
Tiny air pollution particles—the type that mainly comes from power plants and automobiles—may greatly increase the chance of dementia, including Alzheimer's disease, according to USC-led research.

01 feb 2017--Scientists and engineers found that older women who live in places with fine particulate matter exceeding the U.S. Environmental Protection Agency's standard are 81 percent more at risk for global cognitive decline and 92 percent more likely to develop dementia, including Alzheimer's.
If their findings hold up in the general population, air pollution could be responsible for about 21 percent of dementia cases, according to the study.
"Microscopic particles generated by fossil fuels get into our body directly through the nose into the brain," said University Professor Caleb Finch at the USC Leonard Davis School of Gerontology and co-senior author of the study. "Cells in the brain treat these particles as invaders and react with inflammatory responses, which over the course of time, appear to exacerbate and promote Alzheimer's disease.
"Although the link between air pollution and Alzheimer's disease is a new scientific frontier, we now have evidence that air pollution, like tobacco, is dangerous to the aging brain."
The adverse effects were stronger in women who had the APOE4 gene, a genetic variation that increases the risk for Alzheimer's.
"Our study—the first of its kind conducted in the U.S.—provides the inaugural scientific evidence of a critical Alzheimer's risk gene possibly interacting with air particles to accelerate brain aging," said Jiu-Chiuan Chen, co-senior author of the study and an associate professor of preventive medicine at the Keck School of Medicine of USC. "The experimental data showed that exposure of mice to air particles collected on the edge of USC damaged neurons in the hippocampus, the memory center that is vulnerable to both brain aging and Alzheimer's disease."
Their study, published Jan. 31 in the Nature journal Translational Psychiatry, adds to an emerging body of research from around the world that links air pollution to dementia. The offending pollutants—known as PM2.5—are fine, inhalable particles with diameters 2.5 micrometers or smaller. A human hair is about 70 micrometers in diameter, making it 30 times larger than the largest PM2.5.
The research was a collaboration between USC Davis, the Keck School of Medicine and the USC Viterbi School of Engineering.

Combining human data and lab experiments

The researchers analyzed data of 3,647 65- to 79-year-old women from the Women's Health Initiative Memory Study (WHIMS). These women lived across 48 states and did not have dementia when they enrolled.
The researchers adjusted for potential bias associated with geographic region, race or ethnic background, education, socioeconomic status, lifestyle and medical conditions.
Constantinos Sioutas, the Fred Champion Professor of Civil and Environmental Engineering at USC Viterbi, invented the technology to collect air particles for controlled exposure of mouse models.
USC scientists chronically exposed female mice carrying the APOE4 gene to nano-sized air pollution for 15 weeks. Compared to the control group, mice predisposed to Alzheimer's disease accumulated as much as 60 percent more amyloid plaque, the toxic clusters of protein fragments that further the progression of Alzheimer's.
"Our state-of-the-art aerosol technologies, called particle concentrators, essentially take the air of a typical urban area and convert it to the air of a freeway or a heavily polluted city like Beijing," said Sioutas, co-author of the study. "We then use these samples to test exposure and assess adverse neuro-developmental or neuro-degenerative health effects."
Worldwide, nearly 48 million people suffer from dementia, and there are 7.7 million new cases every year, according to the World Health Organization.
"Our study has global implications as pollution knows no borders," said Finch, holder of the ARCO/William F. Kieschnick Chair in the Neurobiology of Aging.
USC researchers and others in this field said more research is needed to confirm a causal relationship and to understand how air pollution enters and harms the brain. Accurate pollution monitors are important for this task.
Less than one-third of all counties in the United States have ozone or particle pollution monitors, according to the American Lung Association. Ambient monitoring data from the EPA are critical for scientists conducting research on air pollution and public health, Chen said.
"We analyzed data of high PM2.5 levels using standards the EPA set in 2012," Chen said. "We don't know whether the lower PM2.5 levels of recent years have provided a safe margin for older Americans, especially those at risk for dementia."
Six of the top 10 most polluted cities in the nation by PM2.5 are in California, including Los Angeles, Long Beach and Fresno, according to the American Lung Association.
Yet certain areas have seen cleaner air in recent decades. Reducing PM2.5 in the air we breathe coincides with fewer cases of dementia, the researchers pointed out, referencing the data of others.

The insidious effects of PM2.5

"Many studies have suggested that early life adversities may carry into later life and affect brain aging," Chen said. "If this is true, then maybe long-term exposure to air pollution that starts a downward spiral of neurodegenerative change in the brain could begin much earlier and rev up in later life."
In other studies, Chen and his colleagues linked long-term exposure to high PM2.5 levels to smaller gray and white matter volumes in important areas such as the frontal lobe, which carries out thinking, decision-making and planning.
For every 3.5 micrograms of PM2.5 per cubic meter of air, white matter (insulated nerve fibers that connect different brain regions) decreased by 6 cubic centimeters, according to one earlier study.
The new study in Translational Psychiatry examined only women and female mice. Future studies will include both sexes to evaluate generalizability to men as well as examine how PM2.5 interacts with cigarettes and other pollutants.
Finch and Chen in 2010 developed the AirPollBrain Network and have recruited 20 USC faculty into this new research area.

More information: Translational PsychiatryDOI: 10.1038/tp.2016.280

Provided by University of Southern California