If You Don't Snooze, You Lose

Immune system weakened by sleep problems that cause increase in inflammation

(RxWiki News) If you're not getting enough good quality sleep, it's not just your energy that might be lagging. Your immune system likely isn't holding up well to stress either.

A new study reveals that poor sleepers have higher levels of a specific protein associated with inflammation in the body when they're under stress - and that inflammation puts them at a higher risk for health problems ranging from general illness to heart attack, stroke, diabetes and psychiatric problems.

"Ask your doctor for help if you're not getting enough quality sleep."

Kathi Heffner, Ph.D., assistant professor of psychiatry at the University of Rochester Medical Center, led the study, which evaluated 45 healthy women and 38 healthy men with an average age of 61.

The participants were evaluated for their cognitive status and then filled out a questionnaire on their sleep quality, stress, loneliness and use of medication. Based on their responses, about 27 percent of the participants were classified as poor sleepers.

For the actual study, the men and women underwent a series of verbal and short-term memory tests which were intended to cause them stress. Over an hour's time, researchers took blood samples from the participants five times, starting from just before the tests began.

The researchers analyzed the blood for its amount of interleukin-6 (IL-6), a protein made at sites of inflammation.

The participants classified as poor sleepers had the same levels of IL-6 as the good sleepers during the first blood draw, though they had reported higher levels of depression, loneliness and perceived overall stress.

The amount of IL-6 increased for all the participants during the testing, but the levels jumped about four times higher in the poor sleepers - high enough to increase their risk of disease or death.

The link between these IL-6 levels and poor sleep remained even after the researchers took into account other factors that could weaken the immune system, such as the levels of stress, loneliness and depression the participants had been asked about.

According to Heffner, the poor sleepers and good sleepers performed equally well on the tests, but the poor sleepers were in generally worse moods afterward.

“This study offers more evidence that better sleep not only can improve overall well-being but also may help prevent poor physiological and psychological outcomes associated with inflammation,” Heffner said.

The older people get, the more inflammation occurs in their bodies and the weaker their immune systems tends to get. Higher levels of inflammation mean higher risks for health problems like cardiovascular disease, diabetes and mental illness.

"Our study suggests that, for healthy people, it all comes down to sleep and what poor sleep may be doing to our physiological stress response, our fight or flight response,” Heffner said.

In other words, good health isn't sufficient protection against the higher risks for illness if a person isn't getting sufficient sleep as well.

“There are a lot of sleep problems among older adults,” Heffner said. “Older adults do not have to sleep poorly. We can intervene on sleep problems in older adulthood. Helping an elderly person become a better sleeper may reduce the risk of poor outcomes associated with inflammation.”

The study was funded partly by a grant from the National Institute of Aging and appeared online February in the American Journal of Geriatric Psychiatry.

Review Date: 
March 3, 2012