Objective evidence that bariatric surgery improves obesity-related obstructive sleep apnea

BackgroundObstructive sleep apnea (OSA) is associated with obesity. Our aim in this study is to report objective improvement of obesity-related OSA and sleep quality after bariatric surgery.MethodsProspective bariatric patients were referred for polysomnography if they scored ≥6 on the Epworth Sleepiness Scale. The severity of OSA was categorized by the respiratory disturbance index (RDI) as follows: absent, 0 to 5; mild, 6 to 20; moderate, 21 to 40; and severe, <40. Patients were referred for repeat polysomnography 6 to 12 months after bariatric surgery or when weight loss exceeded 75 lbs. Means were compared using paired t tests. Chi-square tests and linear regression models were used to assess associations between clinical parameters and RDI; P < .05 was considered statistically significant.ResultsOf 349 patients referred for polysomnography, 289 patients had severe (33%), moderate (18%), and mild (32%) OSA; 17% had no OSA. At a median of 11 months (6 to 42 months) after bariatric surgery, mean body mass index (BMI) was 38 ± 1 kg/m2 (P < .01 vs 56 ± 1 kg/m2 preoperatively) and the mean RDI decreased to 15 ± 2 (P < .01 vs 51 ± 4 preoperatively) in 101 patients who underwent postoperative polysomnography. In addition, minimum oxygen saturation, sleep efficiency, and rapid eye movement latency improved, and the requirement for continuous positive airway pressure was reduced (P ≤ .025). Male gender and increasing BMI correlated with increasing RDI (P < .01) by chi-square analysis. In a multivariate linear regression model adjusted for age and gender, preoperative BMI correlated with preoperative RDI (r = 0.27; P < .01).ConclusionsOSA is prevalent in at least 45% of bariatric surgery patients. Preoperative BMI correlates with the severity of OSA. Surgically induced weight loss significantly improves obesity-related OSA and parameters of sleep quality.