The association between atrial fibrillation and stroke in patients with obstructive sleep apnea: A population-based case-control study

Background: Obstructive sleep apnea (OSA) has been shown to be an independent risk factor for ischemic stroke and may increase the risk of atrial fibrillation (AF) by up to fourfold. Given these relationships, it is possible that OSA may provide a link between stroke and AF. A case-control study was conducted to examine the association between AF and stroke in patients with OSA. Methods: Olmsted County, MN, USA, residents with a new diagnosis of OSA based on polysomnography (PSG) between 2005 and 2010 (N = 2980) who suffered a first-time ischemic stroke during the same period were identified as cases. Controls with no history of stroke were randomly chosen from the same database. Univariate and multiple logistic regression analyses were performed with age, gender, body mass index (BMI), smoking, hypertension, hyperlipidemia, diabetes mellitus, apnea-hypopnea index (AHI) and coronary artery disease (CAD) as co-variates, with the diagnosis of AF as the variable of interest. Results: A total of 108 subjects were studied. Mean age of cases (n = 34) was 73 +/- 12 years and 53% were men. Among controls (n = 74), mean age was 61 +/- 16 years and 55% were male. On univariate analyses, AF was significantly more common in the cases than among controls (50.0% vs 10.8%, p < 0.01). On multivariate regression analyses, the association between AF and stroke was significant after controlling for age, BMI, coronary artery disease, hypertension, diabetes mellitus, hyperlipidemia and smoking status (corrected odds ratio (OR): 5.34; 95% confidence interval (CI): 1.79-17.29). Conclusions: Patients with OSA who had a stroke had higher rates of AF even after accounting for potential confounders. (C) 2012 Elsevier B.V. All rights reserved.