Effect of continuous positive airway pressure on cognitive impairment associated with obstructive sleep apnea: A systematic review and meta-analysis of randomized controlled trials

To evaluate the effects of continuous positive airway pressure (CPAP) therapy on cognitive impairments associated with obstructive sleep apnea (OSA). We systematically searched PubMed, Web of Science, EMBASE, and Cochrane Library for literature from their inception to June 26, 2025. Eligible randomized controlled trials (RCTs) included adults with OSA treated with CPAP, assessing daytime sleepiness, cognitive performance, mood, fatigue, and adherence. 17 RCTs involving 2,372 participants were included. CPAP therapy significantly improved daytime sleepiness (weighted mean difference [WMD] = -2.15; 95% confidence intervals [CI]: -2.96, -1.33), processing speed (WMD = 0.25; 95% CI: 0.07, 0.43), visual search (standardized mean difference [SMD] = -0.30; 95% CI: -0.58, -0.01), and anxiety (WMD = -0.81; 95% CI: -1.45, -0.17). With an average nightly usage of 4.99 hours (95% CI: 4.69, 5.30). CPAP therapy significantly improved daytime sleepiness, processing speed, visual search, and anxiety in patients with OSA.