Effects of CPAP on visceral adipose tissue in patients with obstructive sleep apnea: a meta-analysis

Purpose The efficacy of obstructive sleep apnea (OSA) treatment with continuous positive airway pressure (CPAP) on visceral adipose tissue (VAT) yielded conflicting results. This meta-analysis was performed to assess whether OSA treatment with CPAP could reduce VAT. Methods The PubMed, Cochrane Library, Embase, and Web of Science were searched before April 2019. Information on characteristics of study participants, pre- and post-CPAP treatment of VAT, and study design was utilized for analysis. Standardized mean difference (SMD) and 95% confidence interval (CI) were used to fully analyze the overall effects. Eleven studies were obtained and the meta-analysis was performed using RevMan v.5.2 and STATA 12.0. Results A total of 11 studies (16 cohorts) were pooled into meta-analysis, which included 398 patients. The value of VAT before and after CPAP treatment showed no change in OSA patients (SMD = − 0.02, 95% CI − 0.16 to 0.12, z = 0.24, p = 0.81). Subgroup analyses were further conducted, which revealed that age, gender distribution, baseline body mass index, daily duration, CPAP therapy duration, measure, sample size, and study design did not affect the results. Conclusions This meta-analysis revealed that CPAP therapy has no effect on VAT in OSA patients. Further large-scale, well-designed randomized controlled trials are required to address this issue.