Posts Tagged ‘dementia’

Poor Sleep May Add to Dementia

Older men with sleep disturbances appear more likely to have brain changes associated with dementia, according to a new study, adding to evidence that poor sleep may play a role in mental decline.

“These findings suggest that low blood oxygen levels and reduced slow wave sleep may contribute to the processes that lead to cognitive decline and dementia,” said lead author Rebecca P. Gelber, MD, DrPH, of the VA Pacific Islands Health Care System and the Pacific Health Research and Education Institute in Honolulu.

Dr. Gelber and colleagues conducted a prospective cohort study of 167 Japanese American men, mean age 84 years, in Honolulu who underwent at-home sleep studies in 1999–2000.

All of the men were monitored until they died an average of 6.4 years later.

Autopsies were conducted on their brains to look for microinfarcts (tiny abnormalities in brain tissue), loss of brain cells, the plaques and tangles associated with Alzheimer disease, and Lewy bodies found in Lewy body dementia.

Loss of brain cells was more common in men who spent less time in slow wave, or deep, sleep (sleep that is important in processing new memories and remembering facts) than in those who spent more time in slow wave sleep.

People tend to spend less time in slow wave sleep as they age, the researchers noted.

Loss of brain cells also is associated with Alzheimer disease and dementia.

LOW OXYGEN LEVELS LEAD TO BRAIN CHANGES

The researchers divided the participants into 4 groups based on the percentage of time spent with lower than normal blood oxygen levels during sleep.

The lowest group spent 13% of their time or less with low oxygen levels, and the highest group spent 72% to 99% of the night with low oxygen levels.

Microinfarcts in the brain were seen almost 4 times as frequently in the one-fourth of men with the lowest oxygen levels during sleep than in men who had the highest oxygen levels.

There was no association between the sleep measures and the level of plaques and tangles.

The researchers noted that the causes of low oxygen levels during sleep were unclear and that brain changes could have occurred before the sleep tests.

Previous studies also have shown a link between sleep stages and dementia.

But this is the first study to show that certain sleep features are related to brain changes, Dr. Gelber noted.

“More research is needed to determine how slow wave sleep may play a restorative role in brain function and whether preventing low blood oxygen levels may reduce the risk of dementia,” she said.

Although the study did not actually show that sleep apnea per se is related to brain changes, Dr. Gelber noted that a previous study showed that use of a continuous positive airway pressure machine for obstructive sleep apnea may improve cognition, even after dementia has developed.

The researchers published their results on December 10, 2014 in the online issue of Neurology.

Healthy Behaviors Trim Dementia, Chronic Diseases

Five healthy behaviors — regular exercise; no smoking; and maintaining a low body weight, a healthy diet, and low alcohol intake — appear to reduce the risk of dementia and several chronic diseases significantly, according to a 35-year study that monitored men’s health habits.

The men who consistently engaged in 4 or 5 of these behaviors experienced a 60% reduction in dementia and cognitive decline — with exercise being the strongest mitigating factor — as well as 70% fewer instances of diabetes mellitus, heart disease, and stroke, compared with persons who engaged in none of them.

“Undoubtedly, these protective behaviors affect a host of biological mechanisms.

Separating out relationships between the 5 behaviors and the 4 disease outcomes we examined would be an enormous, and probably a rather fruitless, task.

It would not be helpful to the overall aim of promoting healthy lifestyles to dissect out and promote individual behaviors.

People should be urged to adopt a healthy lifestyle as a complete package,” said lead author Peter Elwood, DSc, MD of the Cochrane Institute of Primary Care and Public Health at Cardiff University.

Dr. Elwood and colleagues presented their results in the December 9, 2013 issue of PLoS One.

Researchers have known for some time that what is good for the heart is good for the head, Dr. Elwood pointed out, noting that the study provides more evidence that healthy living could significantly reduce the chances of developing dementia.

The Caerphilly Cohort Study recorded the healthy behaviors of 2235 men aged 45 to 59 years in Caerphilly, South Wales.

An important aim of the study was to examine the relationships among healthy lifestyles, chronic disease, and cognitive decline over a 35-year period.

The researchers also monitored changes in the take-up of healthy behaviors.

“The size of reduction in the instance of disease owing to these simple healthy steps is of enormous importance in an aging population,” said Dr. Elwood.

“What the research shows is that following a healthy lifestyle confers surprisingly large benefits to health. Healthy behaviors have a far more beneficial effect than any medical treatment or preventative procedure.”

However, Dr. Elwood pointed out, “our study showed that over 30 years health promotion had no detectable effect upon the prevalence of healthy living.”

Despite increasing knowledge of the relevance of lifestyle to health and to survival, the proportion of the adult Welsh population following all 5 healthy behaviors was, and remains, under 1%.

The prevalence of all 5 healthy behaviors is estimated to be only 3% in large, primary prevention studies in the United States.

“Clearly there is an urgent need for new strategies in health promotion to be developed and evaluated,” Dr. Elwood said.

He suggested that rather than talk to their patients about the benefits of a healthy lifestyle in rather vague terms, physicians should speak in precise, quantitative terms, saying something like: “People who live a truly active lifestyle experience 60% fewer heart attacks, 70% less diabetes, and a 60% reduction in dementia.

Furthermore, those who follow a healthy lifestyle and still get a disease or dementia get it when they are about 12 years older.”

Is Screening for Pre-dementia a Good Idea?

Does screening for minor memory changes wrongly label persons with dementia? Yes, say some experts, who worry there is not enough good evidence yet to screen for pre-dementia.

Minor memory changes, often called pre-dementia or mild cognitive impairment (MCI), are arguably an inevitable consequence of aging.

Although up to 15% of those with MCI will progress to dementia each year, more than half of them will not progress.

Many in whom dementia develops do not meet definitions of MCI before diagnosis.

Pre-dementia was included in a new set of diagnostic guidelines for Alzheimer disease issued in May 2011 by 3 consensus groups organized by the National Institute on Aging and the Alzheimer’s Association.

For the first time, the guidelines included biomarkers — such as functional MRI and PET scans, amyloid imaging, and cerebrospinal fluid analysis — specifically for MCI and preclinical phases of the disease.

“The people with preclinical Alzheimer disease have at most mild impairments in their cognition.

They span a spectrum defined at one end as being cognitively normal to, at the other end, needing more time to do their usual, everyday tasks—and even unable to do some of life’s harder tasks, like tax preparation—but they’re not demented,” said Jason Karlawish, MD, Professor of Medicine and Medical Ethics and Health Policy at the Perelman School of Medicine at the University of Pennsylvania.

Dr Karlawish led a recent survey of Alzheimer researchers who agreed that amyloid test results could be released to research participants, if guidance and counseling were put in place.

“For a person with MCI, the benefits of learning amyloid imaging results include an accurate diagnosis of the cause of cognitive impairment,” said Dr Karlawish.

“This, in turn, can motivate a person to adopt brain-healthy behaviors, trimming a medication list that often includes a host of symptomatic medications for anxiety and depression and cognitive impairment, and planning for the future.”

However, Dr Karlawish thinks that the concept of preclinical Alzheimer disease is not yet ready for practice.

“It remains a diagnosis in the shadows between research and clinical care,” he said.

“For now, someone who is labeled being amyloid positive can enroll in a clinical trial to test a drug that targets brain amyloid.”

One such trial will start later this year.

The Anti-Amyloid in Asymptomatic Alzheimer’s disease Study will assign 1000 cognitively normal, amyloid imaging-positive, older adults to a drug that clears amyloid or a placebo.

Screening for Minor Memory Changes

The drive to screen older persons for minor memory changes is leading to unnecessary investigation and potentially harmful treatment, according to experts from around the world who gathered at the recent “Preventing Overdiagnosis” conference in New Hampshire.

A team of specialists from Australia and the United Kingdom said that an expansion of the diagnosis of dementia will end up including up to two-thirds of persons older than 80 years and up to one-fourth of non-demented older persons being labeled with dementia.

With no drugs available to prevent the progression of dementia or to treat MCI, once patients are labeled, they may be vulnerable to untested therapies, say the specialists.

Perhaps our aging population has become a commercial opportunity to develop screening, early diagnostic tests, and medicines marketed to maintain cognition for a condition that is just part of the normal aging process.

Tai Chi May Delay Onset of Alzheimer’s Disease

As an unprecedented number of Americans approach old age, there is a growing concern about the loss of cognitive function that is often attributed to aging.

By around age 70 1 in 6 people have mild cognitive decline.

Mild cognitive decline is considered an intermediate state between the cognitive changes of aging and the earliest clinical features of dementia, particularly Alzheimer’s disease.

The good news is that due to your brain’s plasticity you may be able to improve your cognitive function and offset age-related decline through exercise, stress reduction, learning new tasks, staying socially active, and learning how to focus better — all integral elements of Tai Chi training.

“A body of studies on Tai Chi and cognitive function lend support to the promise of Tai Chi for your brain and mind’s health,” says Peter Wayne, PhD, Assistant Professor of Medicine, Harvard Medical School Director of Research, Osher Center for Integrative Medicine Brigham and Women’s Hospital and Harvard Medical School, and author of The Harvard Medical School Guide to Tai Chi.

This ancient form of slow, meditative exercise helps to create mental activity, and scientists believe it may be possible to delay the onset of Alzheimer’s disease.

November is National Alzheimer’s Disease Awareness Month, and although there is no cure for the disease, a study published in the June issue of the Journal of Alzheimer’s Disease revealed that elderly people practicing Tai Chi just three times a week can boost brain volume and improve memory and thinking.

Scientists from the University of South Florida and Fudan University in Shanghai found increases in brain volume and improvements on tests of memory and thinking in Chinese seniors who practiced Tai Chi three times a week.

The 8-month randomized controlled trial compared those who practiced Tai Chi to a group who received no intervention.

The same trial showed increases in brain volume and more limited cognitive improvements in a group that participated in lively discussions three times per week over the same time period.

“The ability to reverse this trend with physical exercise and increased mental activity implies that it may be possible to delay the onset of dementia in older persons through interventions that have many physical and mental health benefits,” said lead author Dr. James Mortimer, professor of epidemiology at the University of South Florida College of Public Health.

Dr. Wayne notes that other randomized trials have evaluated Tai Chi in adults diagnosed with moderate levels of dementia.

In one large Chinese trial, a group assigned to Tai Chi showed greater improvements in cognitive performance after five months than a group assigned to a stretching and toning program, and fewer of those in the Tai Chi group progressed to dementia.

In a smaller study at the University of Illinois, a group of adults with dementia showed small increases in mental ability and self-esteem after 20 weeks of a combination of Tai Chi, cognitive behavioral therapies, and a support group as compared to an education group, who had slight losses of mental function.

“Interestingly, a follow-up companion study reported benefits of Tai Chi training to the caregivers of people with dementia,” says Dr. Wayne.

“Tai Chi may offer specific benefits to cognition, but more larger-scale trials that also include longer follow-up periods are needed to make stronger conclusions.”