By David Douglas
Reuters Health Information
In women with polycystic ovary syndrome (PCOS), obstructive sleep apnea is associated with insulin resistance, glucose intolerance and type 2 diabetes, according to a study from the University of Chicago.
“Our findings,” investigator Dr. David A. Ehrmann told Reuters Health, “suggest that the metabolic disturbances seen commonly among women with PCOS are due, at least in part, to the effects of sleep disordered breathing.”
“In the absence of obstructive sleep apnea,” he added, “metabolic disturbances in PCOS are modest and are not significantly different from those seen among obese women without PCOS.”
In the October issue of the Journal of Clinical and Endocrinological Metabolism, Dr. Ehrmann and colleagues describe their prospective study of 52 women with PCOS and 21 comparable women without the disorder.
With polysomnography, the team diagnosed obstructive sleep apnea in 29 women with PCOS (56%) and 4 controls (19%). After adjustment for risk factors, the PCOS patients with sleep apnea were more insulin resistant than those without apnea. Further, impaired glucose tolerance was observed in 16 of the 29 women (55%) with PCOS and sleep apnea versus only 6 of the 23 (26%) PCOS patients without sleep apnea.
“Insulin resistance and glucose tolerance were highly correlated with the presence and severity of obstructive sleep apnea,” the authors report.
They also found that in PCOS patients with normal glucose tolerance, sleep apnea was associated with an almost twofold higher fasting insulin level and homeostatic model assessment (HOMA) index.
Moreover, the severity of sleep apnea was a highly significant predictor of the fasting concentrations of glucose and insulin as well as 2-hour glucose concentration and HOMA index.
Dr. Ehrmann’s team is now “actively engaged in clinical studies designed to determine the direction of causality between obstructive sleep apnea and the metabolic disturbances characteristic of PCOS.”
J Clin Endocrinol Metab 2008;93:3878-3884.