Effect of CPAP on Weight and Local Adiposity in Adults with Obstructive Sleep Apnea: A Meta-Analysis

Evidence suggests that continuous positive airway pressure (CPAP) treatment promotes weight gain in obstructive sleep apnea (OSA) patients. It is unclear whether weight gain is influenced by CPAP adherence or comorbid disorders. To examine the CPAP effects on body mass index (BMI) and local adiposity，and the potential moderators of CPAP effects on BMI in OSA patients. We searched PubMed/Medline, Embase and Cochrane through to December 2019. Randomized controlled trials (RCTs) of CPAP versus controls with ≥4 weeks treatment were included. A total of 39 RCTs with 6954 subjects were included. In intention-to-treat analysis, BMI increased significantly after CPAP treatment compared to controls (WMD=0.148 kg/m2, 95% CI=0.04-0.26, P=0.001). In studies demonstrating an increase in BMI, waist and neck circumferences were also significantly increased. Subgroup-analyses revealed that increased BMI was attributable to CPAP use of ≤5 hours/night (WMD=0.231), but not in those with CPAP use of >5 hours/night (WMD=0.001, between-group P-value=0.049). Furthermore, BMI increased significantly in patients without cardiovascular disease (CVD, WMD=0.200), whereas decreased significantly in those with CVD at baseline (WMD=-0.188, between-group P-value