Sleep Apnea and Risk of Deep Vein Thrombosis: A Non-randomized, Pair-matched Cohort Study

BACKGROUND: Patients with sleep apnea have been reported to be associated with increased prevalence of deep vein thrombosis (DVT) in some papers, which were criticized for either a small sample size or lack of a prospective control. Our study strived to explore the relationship of sleep apnea and the subsequent development of DVT using a nationwide, population-based database. METHODS: From 2000 to 2007, we identified a study cohort consisting of newly diagnosed sleep apnea cases in the National Health Insurance Research Database. A control cohort without sleep apnea, matched for age, sex, comorbidities, major operation, and fractures, was selected for comparison. The 2 cohorts were followed-up, and we observed the occurrence of DVT by registry of DVT diagnosis. RESULTS: Of the 10,185 sampled patients (5680 sleep apnea patients vs. 4505 control), 40 (0.39%) cases developed DVT during a mean follow-up period of 3.56 years, including 30 (0.53%) from the sleep apnea cohort and 10 (0.22 %) from the control group. Subjects with sleep apnea experienced a 3.113-fold (95% confidence interval, 1.516-6.390; P = .002) increase in incident DVT, which was independent of age, sex, and comorbidities. Kaplan-Meier analysis also revealed the tendency of sleep apnea patients toward DVT development (log-rank test, P = .001). The risk of DVT was even higher in sleep apnea cases who needed continuous positive airway pressure treatment (hazard ratio 9.575; 95% confidence interval, 3.181-28.818; P < .001). CONCLUSION: Sleep apnea may be an independent risk factor for DVT. (C) 2012 Elsevier Inc. All rights reserved. The American Journal of Medicine (2012) 125, 374-380