Impact of continuous positive airway pressure therapy on renin-angiotensin-aldosterone system in obstructive sleep apnea: an updated systematic review and meta-analysis.

PURPOSE: While continuous positive airway pressure (CPAP) reduces cardiovascular risk in obstructive sleep apnea (OSA), its effects on renin–angiotensin–aldosterone system (RAAS) modulation remain controversial. This meta-analysis investigates CPAP's differential impacts on RAAS components and identifies responsive patient subgroups. METHODS: Sixteen studies were included in the systematic review and eight (231 patients) in the meta-analysis. Primary outcomes included plasma aldosterone concentration (PAC), plasma renin activity (PRA), and angiotensin II (AngII) changes. Subgroup analyses examined age, BMI, and CPAP duration thresholds, with meta-regression assessing moderating factors. RESULTS: CPAP significantly reduced PAC (d + of -0.72, 95% CI -1.39 to -0.05, p = 0.036), though statistical significance was attenuated in adjusted models, and improved daytime hemodynamics: systolic BP (d + -0.81), diastolic BP (d + -1.30), and heart rate (d + -1.61). Notably, patients < 50 years showed marked PAC reduction (d + -1.12, 95% CI -1.88 to -0.35), as did those with CPAP adherence ≥ 3 months (d + -0.88, 95% CI -1.86 to 0.09). No significant changes occurred in PRA (p = 0.917), plasma renin concentration (p = 0.463), or AngII (p = 0.058) in the overall cohort. Meta-regression revealed no significant associations between age, BMI, or CPAP duration and RAAS changes (all p > 0.05). CONCLUSION: CPAP demonstrates selective RAAS modulation – significantly lowering PAC – alongside pronounced hemodynamic benefits, even though overall renin and AngII levels did not change significantly. Younger patients (< 50 years) and those maintaining ≥ 3 months therapy show aldosterone responsiveness, suggesting duration-dependent physiological effects. These findings highlight CPAP's potential role in targeted RAAS modulation and underscore the need for personalized treatment strategies in OSA management.