Sleep Restriction Undermines Health. Does It Also Promote Obesity?

Does sleep deprivation cause metabolic changes that set up a chronic inflammatory response, suppress the immune system, and leave one at risk for obesity and related diseases?

The Medical College of Wisconsin has been awarded a four-year, $1.16 million grant from the National Heart, Lung and Blood Institute to expand the work of faculty research team members who are leaders in the field of advancing our understanding of the medical implications of inadequate sleep.

In work conducted at the Medical College and the Clement J. Zablocki VA Medical Center, Carol Everson, PhD, Medical College of Wisconsin Associate Professor of Neurology, and her team have shown that sleep restriction in the rat model leads to metabolic disturbance, dramatic increases in food consumption, and decreased leptin, a hormonal signal secreted from fat cells that is important in regulating appetite and fat deposition.

These changes, among others, point to yet unknown alterations in the regulation of the cells that make up visceral fat, which is increasingly recognized as an important and active endocrine organ. Aside from storing energy, it plays a role in a variety of biological processes, including immune function.

Current studies are focused on changes to how dietary fat is handled and how fat tissue is remodeled during and after repeated chronic sleep restriction. The team is also looking at the extent to which signals secreted by fat cells may be modulating the immune system in favor of an inflammatory state. Functional changes due to hormones, inflammatory molecules and obesity are known to be important elements in the development of several disease states.

"The body is expected to make adjustments over time to surfeits and deficits of basic biological requirements, such as food and sleep" said Dr. Everson.

"It has long been generally understood that sleep abnormalities are linked to disease progression and shortened longevity, but the specific reasons why this is so have been elusive. We are working to replace speculation with tangible medical evidence of the changes to organs and cells to explain why sleep restriction undermines health and impedes recuperation."

Also contributing to these studies are Medical College colleagues Ahmed Kissebah, MD, PhD, Professor of Medicine and Director of the Obesity Research Center; and Natalia Markelova, MD, Assistant Professor of Pathology.

MCW Health News presents up-to-date information on patient care and medical research by the physicians of the Medical College of Wisconsin.