Effects of continuous positive airway pressure therapy on inflammatory markers in patients with obstructive sleep apnea: a meta-analysis of randomized controlled trials.

Objective: In this meta-analysis, we provide the findings of randomized controlled trials on the levels of inflammatory markers in patients with obstructive sleep apnea (OSA) receiving continuous positive airway pressure (CPAP).

Methods: Literature published in the PubMed, Web of Science, Embase and Cochrane databases up to May 21, 2024, was comprehensively searched, and inclusion and exclusion criteria were developed. Pooled estimates of CPAP therapy were analyzed via the standardized mean difference (SMD). This meta-analysis follows the PRISMA 2020 guidelines and is registered with PROSPERO (ID CRD42024548588).

Results: A total of 15 studies were included, each reporting data on one or more inflammatory markers, as follows: 10 studies on C-reactive protein (CRP), 12 studies on interleukin-6 (IL-6), 3 studies on interleukin-8 (IL-8), and 9 studies on tumor necrosis factor-α (TNF-α). The results revealed that the SMDs (95% confidence intervals [CIs]) for CRP, IL-6, IL-8 and TNF-α levels before and after CPAP treatment were 0.88 (95% CI 0.28-1.48), 0.58 (95% CI 0.12-1.05), 0.20 (95% CI 0.39-0.80) and 0.17 (95% CI 0.05-0.29), separately.

Conclusion: CPAP therapy used for a certain duration can lower CRP, IL-6 and TNF-α levels in OSA patients, and there are substantial differences observed in the various inflammatory indicators. To confirm the usefulness of these biomarkers in evaluating CPAP therapy for cardiovascular risk reduction among OSA patients, more randomized controlled trials (RCTs) have to be carried out in the future.