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

Background: Obstructive 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.

Methods: Prospective bariatric patients were referred for polysomnography if they scored >or=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.

Results: Of 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

Conclusions: OSA 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.