ROCHESTER, N.Y., March 5 (UPI) -- A U.S. study found stress led to significantly larger increases in a marker of inflammation in poor sleepers compared to good sleepers, researchers said.
Kathi L. Heffner, assistant professor of psychiatry at the University of Rochester Medical Center in New York, said inflammation is a marker associated with poor health outcomes and death.
"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 in a statement.
The study involved 45 women and 38 men with an average age of 61. The participants were evaluated for cognitive status and each participant completed a self-report of sleep quality, perceived stress, loneliness and medication use.
The participants were in good physical health, but 27 percent were categorized as poor sleepers.
On the day of the study, the participants were given a series of tests of verbal and working memory, a battery of questions that served as the stressor. The blood was studied for levels of interleukin-6 a protein primarily produced at sites of inflammation.
The study published in the American Journal of Geriatric Psychiatry found poor sleepers reported more depressive symptoms, more loneliness and more global perceived stress relative to good sleepers. They also had as much as four times the level of interleukin-6, which increases the risk for illness and death in older adults, the study said.