Predictive Factors for Insufficient Weight Loss After Bariatric Surgery: Does Obstructive Sleep Apnea Influence Weight Loss?

Background: Important endpoints of bariatric surgery are weight loss and improvement of comorbidities, of which obstructive sleep apnea (OSA) is the highest accompanying comorbidity (70%). This study aimed to evaluate the influence of OSA on weight loss after bariatric surgery and to provide predictive factors for insufficient weight loss (defined as ≤50% excess weight loss (EWL)) at 1 year follow-up.
Methods: All consecutive patients, who underwent primary laparoscopic Roux-en-Y gastric bypass or laparoscopic sleeve gastrectomy between 2006 and 2014 were retrospectively reviewed. Patients with data on preoperative apnea-hypopnea index (AHI) and pre- and postoperative body mass index (BMI) were included. After surgery, the percentage excess weight loss (%EWL) and BMI changes were compared between preoperatively diagnosed OSA-, subdivided in mild, moderate, and severe OSA, and non-OSA patients. Multivariable logistic regression analysis evaluated predictive factors for ≤50% EWL.
Results: A total of 816 patients, 522 (64%) with and 294 (36%) without OSA, were included. After 1 year, OSA patients achieved less %EWL than non-OSA patients (65.5 SD 20.7 versus 70.3 SD 21.0; p < 0.01). The lowest %EWL was seen in severe OSA patients (61.7 SD 20.2). However, when adjusted for waist circumference, BMI, and age, no effect of OSA was seen on %EWL or changes in BMI. Although AHI, gender, age, BMI, type of surgery, and type II diabetes were predictive factors for ≤50% EWL (area under the curve 0.778), the AHI as variable was of little importance.
Conclusions: The presence of OSA does not individually impair weight loss after bariatric surgery.