Effect of continuous positive airway pressure on endothelin-1 in patients with obstructive sleep apnea: a meta-analysis

PurposeObstructive sleep apnea (OSA) is related to endothelin-1 (ET-1). Continuous positive airway pressure (CPAP) is an effective therapy for OSA. However, the effectiveness of CPAP on ET-1 levels in patients with OSA yielded contradictory results. We conducted a meta-analysis to assess the effect of CPAP on ET-1 levels in OSA.MethodsThe Embase, and Cochrane Library and PubMed were searched before March, 2018. The overall effects were measured by the standardized mean difference (SMD) with a 95% confidence interval (CI). Ten studies were included and the meta-analysis was conducted using Stata 14.0.Results10 studies involving 375 patients were included in the meta-analysis. The result showed that there was a significant reduction in ET-1 levels in OSA patients before and after CPAP therapy (SMD = - 0.74, 95% CI = - 1.30 to - 0.17, z=2.56, p=0.01). Further, subgroup analysis demonstrated that Apnea-Hypopnea Index (AHI), CPAP therapy duration, and sample size also affected CPAP therapy.ConclusionsOur meta-analysis indicated that CPAP treatment among OSA patients was significantly was related to a decrease in ET-1 levels. Further prospective long-term studies with a larger number of patients are needed to evaluate and clarify this issue.