The American Journal of Respiratory and Critical Care Medicine recently reported results of a study showing that effective treatment of sleep apnea with continuous positive airway pressure (CPAP) for 4 months significantly improved early signs of atherosclerosis in patients with severe Obstructive Sleep Apnea.

Researchers in Brazil enrolled 24 patients with severe obstructive sleep apnea who did not have any other known risk factors for atherosclerosis, such as high blood pressure, obesity, diabetes, smoking history, or high cholesterol, in a study to see the effect of treating the sleep apnea on atherosclerosis. Half of the patients received treatment with CPAP for 4 months. The other half did not. They examined the differences between the 2 groups before and after treatment on the muscle thickness and stiffness of the carotid artery, blood pressure, C-reactive protein (an inflammatory chemical identified in the blood, also associated with heart attacks), and stress hormones. They were all similar before treatment. In those patients who received CPAP, there was a significant decrease, in carotid artery muscle thickness and stiffness, and a significant decrease in C reactive protein and stress hormone levels. This occurred without change in weight, cholesterol level, or blood pressure in the 2 groups.

This is the best evidence to date that Obstructive Sleep Apnea can contribute to causation of atherosclerosis even in the absence of other contributing factors, and that treatment with CPAP can reverse it. The reversal is associated with the significant decrease in systemic inflammation and stress hormone levels. Furthermore, the effect was as or more powerful than that shown so far from lipid lowering medication.

Conclusions: While this is a preliminary study with a small number of patients, it is likely that treating Obstructive Sleep Apnea can prevent atherosclerosis and lower the risk of heart attacks and strokes. Obstructive Sleep Apnea appears to be a separate risk factor for atherosclerosis, joining the ranks of hypertension, diabetes, obesity, high cholesterol, and smoking. Since sleep apnea affects about 10% of adults (9% of middle aged females, 24% of middle aged males), this has major public health implications.

And since we have very effective treatment for sleep apnea, hopefully the medical community and the public will increase efforts to identify and treat the many among us who have sleep apnea.

Dr. Gofreed

January, 2008

Reference: Am J Respir Crit Care Med Vol 176 pp 706-712, 2007