Sleep Habits/Disorders | Vanguard Neurologist

Our Site Network	Dr. Perlmutter »	Vanguard Neurologist »	Perlmutter Health Center »

A Mysterious Link Between Sleeplessness and Heart Disease

January 10th, 2009

Dr. Perlmutter’s comment: Interestingly, we see the same link between sleeplessness and Alzheimer’s risk. I would suspect the mechanisms described below with reference to the heart are operative in the brain.

From nytimes.com

People who don’t get much sleep are more likely than those who do to develop calcifications in their coronary arteries, possibly raising their risk for heart disease, a new study has found.

The 495 participants in the study filled out sleep questionnaires and kept a log of their hours in bed. At night they also wore motion-sensing devices around their wrists that estimate the number of hours of actual sleep. At the beginning, none of the participants, who were ages 35 to 47, had evidence of coronary artery calcification.

Five years later, 27 percent of those who were sleeping less than five hours a night on average had developed coronary artery calcification for the first time, while only 6 percent of those who were sleeping seven hours or more had developed it. Among those who were sleeping between five and seven hours a night, 11 percent had developed coronary artery calcification, the study found.

After accounting for various other causes, the researchers concluded that one hour more of sleep per night was associated with a 33 percent decrease in the odds of calcification, comparable to the heart benefit gained by lowering one’s systolic blood pressure by 17 millimeters of mercury.

The study was published on Tuesday in the Journal of the American Medical Association. The data were drawn from the ongoing Coronary Artery Risk Development In Young Adults study.

Senior author Diane S. Lauderdale cautioned that the new report does not prove a cause-and-effect relationship between a lack of sleep and heart disease.

“It’s important to say that this is the first report and this does not yet prove the association is causal,” said Dr. Lauderdale, an associate professor of health studies at the University of Chicago Medical Center. “Until we know what the mechanism is — that it’s really a direct or a causal relationship — there is no point in making recommendations based on this.”

Although a number of studies have suggested that people who sleep less are at greater risk of heart disease and death, this is the first investigation to measure how much its subjects actually are sleeping, said Dr. Sanjay Patel, assistant professor of medicine at Case Western Reserve University and expert in sleep medicine. Patients’ own self-assessments can be very inaccurate, he added.

What isn’t clear is whether reduced sleep triggers physiological changes that increase heart disease risk, or whether a third, unrelated factor causes both changes, he said.

“It’s possible, for example, that people who are under more stress may be both sleeping less and at higher risk of heart disease,” Dr. Patel said.

If so, he added, “If we got those people to sleep more but they still were under a lot of stress, it wouldn’t change their risk of heart disease.”

Higher education levels are also associated with both a lower risk of heart disease and a tendency to get more sleep, said Dr. Lauderdale.

But it is also possible that lack of sleep leads to certain changes, like increasing blood levels of the stress hormone cortisol, which can raise the risk of coronary artery disease over time, Dr. Lauderdale said.

Another possible mechanism could be through the effect that sleep has on average blood pressure levels over a 24-hour period. Blood pressure usually dips when people are asleep, which could provide health benefits for those who get more sleep, Dr. Lauderdale suggested.

Babies gain weight with less sleep -

April 14th, 2008

From USATODAY.com

Infants and toddlers who slept fewer than 12 hours in a 24-hour period were twice as likely to be overweight than longer sleepers by the time they’re 3 years old, a study showed Monday.

The children most likely to be overweight were those who slept less than 12 hours and watched at least two hours of television a day, says the study in the Archives of Pediatric and Adolescent Medicine.

BETTER LIFE: TV time matters, too

Although previous research has linked inadequate sleep with weight gain in adults and older children and TV viewing and obesity in older children, the authors of the new study say theirs is the first to connect sleep and television viewing in infants to excess weight.

The researchers focused on 915 children in an ongoing Massachusetts study. When the children were 6 months old, their mothers were asked about their sleeping habits. When the children were ages 1 and 2, the mothers were asked about their sleep and television watching.

“One of the things we thought was that if children are sleeping less they might be watching more TV, and maybe that would explain the relationship between sleep and obesity,” says lead author Elsie Taveras, a Harvard pediatrician who runs the childhood obesity prevention clinic at Children’s Hospital Boston. “But that wasn’t the case.”

The children slept an average of 12.3 hours a day at age 6 months, 12.8 hours a day at 1 year and 12 hours a day at age 2. Some who slept more than 12 hours also watched more than two hours of TV a day, while some briefer sleepers didn’t.

Why less sleep in infancy and toddlerhood was linked to a greater chance of becoming overweight isn’t clear, says co-author Matthew Gillman, also a Harvard pediatrician. Gillman says some short-term experiments in adults suggest that “people whose sleep is curtailed do have hormone changes that tend to increase appetite.”

How lack of sleep may be bad for the brain

March 25th, 2008

FromLos Angeles Times

Both night-shift work and chronic sleep deprivation are increasingly implicated in mental and cognitive problems.

* Alzheimer’s risk: Abnormal insulin levels (common in shift workers and sleep-deprived people) may increase the risk for certain neurodegenerative disorders, such as Alzheimer’s disease, scientists at the University of Washington have found. Normally, insulin acts on the brain to promote learning and memory. However, insulin resistance may cause inflammation in the brain, a key process in the development of Alzheimer’s.

Children Who Sleep Less Weigh More

February 21st, 2008

Kids’ sleep patterns also vary by season, day, researchers report

From HealthScout

Children who get less than nine hours of sleep a night are more likely to be overweight or obese, new research shows.

Sleep-deprived kids also have more than a 3 percent increase in body fat on average compared to youngsters who sleep for more than nine hours nightly.

The researchers also reported that children’s sleep patterns vary by season and day. Children sleep fewer hours in the summer and on weekends, according to the study.

Researchers at the University of Auckland in New Zealand studied the sleep patterns of 591 seven-year-old children using actigraphy — a movement-based, noninvasive method used to study sleep-wake patterns and circadian rhythms. The children were assessed at birth, at one year of age, at three-and-a-half years and at seven years.

The team found that the children slept 10.1 hours on average. They slept fewer hours on weekend days than on weekdays, in the summer and when bedtime was set as after 9 p.m. They also slept fewer hours if they had no younger siblings.

In addition to increased weight and body fat, shorter sleep periods correlated with more emotional volatility, reported the research team.

“Sleep is important for health and well-being throughout life,” said lead author Ed Mitchell in a prepared statement. “Few studies have objectively measured sleep duration. In this large study of sleep in seven-year-olds, there was considerable variation in duration of sleep. Sleep duration was 40 minutes longer in winter than summer and was 31 minutes longer on weekdays than on the weekend. Short sleep duration was associated with a threefold increased risk of the child being overweight or obese. This effect was independent of physical activity or television watching. Attention to sleep in childhood may be an important strategy to reduce the obesity epidemic.”

The American Academy of Sleep Medicine recommends that children in preschool sleep between 11 and 13 hours a night and school-aged children between 10 and 11 hours of sleep a night.

The academy suggested that parents give their children an opportunity to get the recommended amount of sleep by keeping a consistent bedtime routine in a relaxed setting. Children may also sleep better if they have a parent to relate to before bed, instead of TV or video games. Food, drinks and medicines that contain caffeine are all enemies of sleep, according to the academy.

The study is published in the January issue of Sleep.

Sleep Disruptions May Up Diabetes Risk

January 14th, 2008

From washingtonpost.com

When Shakespeare called sleep the “chief nourisher of life’s feast,” he may have been well ahead of his time, medically at least. Researchers at the University of Chicago Medical Center report that disrupting sleep damages the body’s ability to regulate blood sugar levels, potentially raising the risk of developing type 2 diabetes.

More than 18 million Americans have diabetes and the most common form is type 2, in which the body either becomes resistant to insulin or doesn’t produce enough of it to regulate sugar in the bloodstream.

In a small experiment, researchers led by Dr. Esra Tasali, an assistant professor of medicine, found that disrupting the deepest sleep periods of volunteers rapidly resulted in reduction in their ability to regulate blood-sugar levels.

The findings are reported in Monday’s online edition of Proceedings of the National Academy of Sciences.

The researchers studied the sleep patterns of nine volunteers, five men and four women, all of normal weight, in good health and aged 20 to 31.

Normal sleep is divided into several stages, with the so-called slow-wave sleep considered the deepest.

Whenever the volunteers went into slow-wave sleep the researchers made noise _ enough to disturb the sleep though not to fully awaken them.

After just three days the ability of the volunteers to regulate blood sugar was reduced by 25 percent, the researchers reported.

Earlier studies have indicated that lack of sleep can reduce the ability to regulate sugar, and this report adds evidence that poor sleep quality is also a diabetes risk.

“This decrease in slow-wave sleep resembles the changes in sleep patterns caused by 40 years of aging,” Tasali said in a statement. Young adults spend 80 to 100 minutes per night in slow-wave sleep, while people over age 60 generally have less than 20 minutes. “In this experiment,” she said, “we gave people in their 20s the sleep of those in their 60s.”

“Since reduced amounts of deep sleep are typical of aging and of common obesity-related sleep disorders, such as obstructive sleep apnea, these results suggest that strategies to improve sleep quality, as well as quantity, may help to prevent or delay the onset of type 2 diabetes in populations at risk,” said co-author Dr. Eve Van Cauter, a professor of medicine.

___