A new research study, which appeared in The Journal of Clinical Endocrinology & Metabolism, finds that chronic sleep deprivation may be part of America's obesity problem.   Author Eve van Cauter, Ph.D., a diabetes researcher with the University of Chicago, reports, “Sleep deprivation plays an important role in regulating our leptin levels and in controlling appetite.

 

Dr. Cauter explains that a lack of sleep can lower the “appetite control” hormone, leptin.  Leptin is a widely studied hormone, thought to be the source, or at least part of the answer, to controlling obesity. Produced by fat cells, our leptin levels tell the brain when the body does or doesn't need more food.  According to Dr. Cauter’s work, sleep deprivation triggers hormones which can lower leptin levels and other hormones that control metabolism are also triggered by sleep deprivation and may affect leptin levels.

 

During periods of sleep deprivation, “low leptin levels tell the brain there is a shortage of food which increases the appetite,” says van Cauter. "When leptin levels are higher, satiety levels are higher, which tells the brain that the body is getting enough food."  In their study, van Cauter's research group investigated sleep deprivation's effects more closely.

 

According to Stuart Menn, MD, Medical Director of Pacific Sleep Medicine (Palm Springs and Redlands) Sleep Centers, “we have long known that undiagnosed or untreated sleep disorders can have devastating effects on a number of health conditions.  This study demonstrates this problem in treating patients with obesity.”

 

Dr. Menn goes on to explain, “For example, the more obese the patient, the more likely he or she will suffer from Obstructive Sleep Apnea (OSA), as there have been numerous studies to demonstrate the relationship between OSA and obesity.  Unfortunately, it’s a vicious cycle.  The more obese, the more severe the OSA—and the more sever the OSA, the greater likelihood of obesity.”

 

“However,” Stuart Menn says, “at least we have a place to start.  If we can diagnose and treat the OSA, we can reduce the obesity by increasing the number of hours the patient is asleep.”

 

Dr. van Cauter states, "We think sleep deprivation probably signals a need for additional calories.  A larger study, involving more than 1,000 volunteers, showed a similar appetite control pattern."

 

Other studies have shown a relationship between body mass index (BMI, an indirect measure of body fat) and sleep deprivation.  Dr. van Cauter adds, “These consistently suggest that when sleep is under seven hours, BMI is higher.”

 

References: Van Cauter, E. The Journal of Clinical Endocrinology & Metabolism, November 2004; vol 89: pp 5762-5771. Eve van Cauter, PhD, University of Chicago. Satya P. Kalra, MD, professor of neuroscience, University of Florida, Gainesville.  Copyright ©1996-2005 WebMD Inc. All rights reserved.