The efficacy of bariatric surgery on pulmonary function and sleep architecture of patients with obstructive sleep apnea and co-morbid obesity: a systematic review and meta-analysis

Obstructive sleep apnea (OSA) is highly prevalent in patients with morbid obesity. There is a growing interest in the role of bariatric surgery in OSA management. This study aims to evaluate the therapeutic efficacy of bariatric surgery on changes in pulmonary function and sleep architecture. Studies of patients with OSA that underwent bariatric surgery were searched in 4 different databases (PubMed, Cochrane, Web of Science, and Embase) until October 31, 2022. We identified studies evaluating the efficacy of surgical intervention on primary outcomes (body mass index [BMI] and apnea-hypopnea index [AHI]) and secondary outcomes such as forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), FEV1/FVC, oxygen desaturation index (ODI), T90, mean oxygen saturation (SpO2), nadirSpO2, sleep efficiency (SE), N1%, N2%, N3%, rapid eye movement (REM%), arousal index, Epworth sleepiness scale (ESS), neck circumference, waist circumference, and weight. A total of 24 eligible studies were finally chosen. Risk of bias assessed through funnel plots was collected and analyzed via random effects meta-analyses. There were significant reductions in BMI and AHI after bariatric surgery induced weight loss. Accordingly, improvement in FVC, meanSpO2, nadirSpO2, SE, N3%, REM%, and ESS were observed compared with baseline. Patients with OSA also exhibit lower ODI, T90, arousal index, neck circumference, waist circumference, and weight after treatment. Bariatric surgery has beneficial effects on patients with OSA and obesity, particularly with morbid obesity. Surgical weight loss significantly eliminates apnea-hypopnea events, reduces weight, increases oxygen saturation, N3 and REM sleep stage, reduces sleep fragmentation, and improves pulmonary functions with augmented FVC.