Is mandatory screening for obstructive sleep apnea with polysomnography in all severely obese patients indicated?

The study aims to assess the risk factors for the presence and severity of obstructive sleep apnea (OSA) among severely obese patients evaluated for bariatric surgery. Polysomnography recordings were performed in consecutive patients undergoing Roux-en-Y gastric bypass from January 2004 to January 2007. Sleep apnea was noted as present or absent and graded from mild to severe according to the apnea/hypopnea index. Patient gender, age, weight, height, body mass index, neck circumference, and waist circumference were recorded. A total of 132 patients were included in the study group, and 85 patients had a confirmed diagnosis of OSA (64.4%). The prevalence of OSA was 55.7% in female and 77.4% in male. The prevalence of moderate or severe sleep apnea was higher in males (71.6%) than in females (31.6%). In OSA patients, body mass index (p = 0.020), neck circumference (p < 0.001), and age (p = 0.003) were higher as compared with obese patients without OSA, whereas no differences were found in waist circumference between groups. After multiple regression analysis, body mass index, age, and male gender were independent predictors of sleep apnea. In the female group, age greater than 49 years was the only significant predictor of moderate or severe OSA (odds ratio 5.42 (95% confidence interval 1.61-18.1); p = 0.006). Males and females with age greater than 49 years are at greatest risk for OSA. Preoperative sleep studies should be mandatory in this group of severely obese patients.