Researchers find potential heart disease, sleep apnoea link

Researchers in Ohio have discovered a possible link between a common sleep disorder and heart disease, which is the leading cause of death responsible for 29 percent of people worldwide.

Sleep medicine and cardiovascular experts at The Ohio State University Medical Center wanted to see what would happen to fat cell secretion of certain substances when sleep apnea was simulated. While most of the substances secreted by fat cells have undesirable effects, others, such as a substance called adiponectin, may have the opposite action and even prevent atherosclerosis, the hardening of the arteries.

The findings, published in the journal Experimental and Clinical Endocrinology & Diabetes, showed that when fat cells were exposed to the repetitive dipping of oxygen levels, similar to that found in patients with obstructive sleep apnea, the secretion of adiponectin by the fat cells was decreased.

“Since adiponectin appears to prevent atherosclerosis, this finding could potentially explain why patients with obstructive sleep apnea are predisposed to develop heart disease,” said Dr. Ulysses Magalang, of the division of pulmonary, critical care, allergy and sleep medicine at Ohio State and director of its sleep medicine program.

Obstructive sleep apnea is a disorder, affecting approximately 12 million Americans, in which breathing is interrupted for brief periods during sleep. These repetitive disruptions of breathing lead to drops in oxygen levels, known as intermittent hypoxia.

“Further studies are necessary to determine exactly how intermittent hypoxia reduces the release of adiponectin by fat cells,” says Magalang, who is also principal investigator of the study.

(Source: Ohio State University Medical Center: Experimental and Clinical Endocrinology & Diabetes: November 2008.)