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 : 6 on the Epworth Sleepiness Scale. The severity of OSA was categorized by the respiratory disturbance index (PLDI) 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 PLDI; 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. A I a median 11 months (6 to 42 months) after bariatric surgery, mean body mass index (BMI) was 38 +/- 1 kg/,(2) (P <. 01 vs 56 +/- 1 kg/m(2) 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 :fE.025). Male gender and increasing BMI correlated with increasing PLDI (P <. 01) by chi-square analysis. In a multivariate linear regression model adjusted for age and gender, preoperative BMI correlated with preoperative PLDI (r = 0.27; P <. 01). Conclusions. OSA is prevalent in at least 45 % of bariahic surgery patients. Preoperative BM[ correlates with the severity of OSA. Surgically induced weight loss significantly improves obesity-related OSA and parameters of sleep quality.