Obstructive Sleep Apnea Risk and Stroke among Blacks with Metabolic Syndrome: Results from Metabolic Syndrome Outcome (MetSO) Registry.

Abstract

Introduction: The American Stroke Association estimates that stroke is the fifth leading cause of death in the United States. According to the Center for Disease Control and Prevention someone in the United States has a stoke every 40 seconds, affecting more than 795,000 people of which 140,000 result in death [1]. Emerging evidence suggests that obstructive sleep apnea (OSA) is a strong risk factor for stroke. This study using The Metabolic Syndrome Outcome (MetSO) registry explored whether blacks at risk for obstructive sleep apnea (OSA) are at greater risk for a stroke.

Method: The present study utilized data from the MetSO study, an NIH-funded cohort study of blacks with metabolic syndrome (MetS). Patients were diagnosed with MetS using standard criteria articulated in the joint interim statement for harmonizing the MetS. The study assessed OSA risk using the Apnea Risk Evaluation System (ARES); defining high risk as a total ARES score ≥6. Data was coded and analyzed by an experienced statistician using SPSS 20.0.

Results: A total of 1035 participants were screened for MetS in the MetSO registry. During the data collection period 875 participants were enrolled during the time of analysis. The average age of the sample was 62±14 years (range: 20-97); 71% were female, and all were of black race/ethnicity. Seventy-one percent reported finishing high school, and 43% reported annual income <10K. Descriptive analyses showed 93% of the participants were diagnosed with hypertension; 61%, diabetes; 72%, dyslipidemia; 90% were overweight/obese; 33% had a history of heart disease and 10% had a stroke history. Using the ARES screener, we estimated that 48% were at high risk for OSA. Logistic regression analysis, adjusting for age and gender, showed that patients at high risk for OSA had a nearly three-fold increase in the odds of having a stroke (OR = 2.79, 95% CI: 1.64-4.73).

Conclusion: In the MetSO registry, a cohort of blacks with MetS, the prevalence of stroke is greater than in the general US population. Blacks at risk for OSA are particularly vulnerable to experiencing a stroke.