Most health care professionals are aware of the cardiovascular consequences of sleep apnea. Less known are the serious consequences of sleep apnea on ischemic stroke. A new study shows that Obstructive Sleep Apnea (OSA) can significantly increase the risk for stroke as well. According to the study, the incidence rate of having an ischemic stroke nearly triples in men 40 and older with moderate to severe untreated OSA. OSA-related stressors are suspected to alter cerebral tissue oxygenation, blood flow and/or vascular autoregulation, and consequently, contribute to stroke risk.

The data, collected over an eight-year span on a large, geographically diverse population, was part of a longitudinal cohort study of 5422 patients in the Sleep Heart Health Study. The results were recently published in the American Journal of Respiratory and Critical Care Medicine, and revealed that men with an apnea + hypopnea index (AHI) of 20 or greater breathing stoppages per hour of sleep had almost three times the risk of developing a future stroke. Indeed, the incidence of ischemic stroke for men increased 6% with every unit increase in baseline AHI from 5 to 25. Surprisingly, increased risk of stroke in women was observed only when the AHI was 25 or more. Unlike men, stroke risk in women was significantly associated with diabetes, hypertension medication use and smoking. Potential explanations for the discrepancy between genders may be attributed to the different influence sex hormones may play on vascular function.

If you are a health care professional, screening your patients with a brief sleep history or incorporating sleep questionnaires in your practice to identify patients at risk for OSA can have significant health benefits, particularly for those at higher risk for cardiovascular events such as stroke or myocardial infarction. Prevention, as always, is the best course of action, and data have consistently shown that treating OSA can significantly improve a patient’s cardiovascular risk profile.