Effect of continuous positive airway pressure on leptin levels in patients with obstructive sleep apnea: a meta-analysis

Continuous positive airway pressure (CPAP) is an effective treatment for obstructive sleep apnea hypopnea syndrome (OSAHS), but previous studies assessing the effect of CPAP on leptin in patients with OSAHS yielded conflicting results. In this study, we conducted a meta-analysis to determine whether CPAP therapy could reduce serum leptin levels.Databases of PubMed, Elsevier, and SCI were thoroughly searched by 2 independent reviewers.RevMan (version 5.2) was used for data synthesis. Weighted mean difference (WMD) before and after CPAP therapy was calculated to estimate the effects of CPAP therapy.A total of 11 studies involving 413 participants were included. Meta-analysis showed that the total WMD for leptin levels was 1.44 units (95% confidence interval: 1.11-1.77, P.01) before and after CPAP therapy. Subgroup analysis exhibited that leptin was decreased within 3 days after the therapy, and it was further reduced within 1 to 3 months and beyond.The results of our meta-analysis showed that CPAP could significantly reduce leptin levels in OSAHS patients without concomitant weight loss.