Lack of sleep alters hormones, ...( Chronic sleep loss can reduce the cap...),Health

Chronic sleep loss can reduce the capacity of even young adults to perform basic metabolic functions such as processing and storing carbohydrates or regulating hormone secretion, report researchers from the University of Chicago Medical Center in the October 23 issue of The Lancet. Cutting back from the standard eight down to four hours of sleep each night produced striking changes in glucose tolerance and endocrine function -- changes that resembled the effects of advanced age or the early stages of diabetes -- after less than one week.

Although many studies have examined the short-term effects of acute, total sleep deprivation on the brain, this is the first to investigate the impact of chronic, partial sleep loss on the body by evaluating the metabolism and hormone secretion of subjects subjected to sleep restriction and after sleep recovery.

"We found that the metabolic and endocrine changes resulting from a significant sleep debt mimic many of the hallmarks of aging," said Eve Van Cauter, Ph.D., professor of medicine at the University of Chicago and director of the study. "We suspect that chronic sleep loss may not only hasten the onset but could also increase the severity of age-related ailments such as diabetes, hypertension, obesity and memory loss."

Cutting back on sleep is an extremely common response to the time pressures of modern industrial societies. The average night's sleep decreased from about nine hours in 1910 to about 7.5 hours in 1975, a trend that continues. Millions of shift workers average less than five hours per work day. Previous studies, however, have measured only the cognitive consequences of sleep loss.

Van Cauter and colleagues Karine Spiegel and Rachel Leproult chose to focus instead on the physiologic effects of sleep loss, how sleep deprivation altered basic bodily functions such regulating blood-sugar levels, storing away energy from food and th
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Contact: John Easton
jeaston@mcis.bsd.uchicago.edu
773-702-6241
University of Chicago Medical Center
21-Oct-1999