Effects of Continuous Positive Airway Pressure on Surrogate, Intermediate, and Functional Cardiovascular Outcomes in Obstructive Sleep Apnea: An Umbrella Review of Systematic Reviews and Meta-Analyses

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• Picked for Biochemistry (medical) (top studies of the week, 30 August 2026).

Abstract

Background and Objectives: Obstructive sleep apnea (OSA) is a prevalent sleep-related breathing disorder associated with increased cardiovascular morbidity and mortality. Continuous positive airway pressure (CPAP) is the standard treatment for OSA; however, its effects on cardiovascular outcomes remain incompletely established. This umbrella review synthesized and critically appraised the evidence regarding the effects of CPAP on surrogate, intermediate, and functional cardiovascular outcomes in adults with OSA. Materials and Methods: An umbrella review of systematic reviews and meta-analyses evaluating CPAP therapy in adults with OSA was conducted. A comprehensive literature search was performed in PubMed, Embase, and the Cochrane Library from database inception to 28 February 2026. Eligible reviews assessed cardiovascular outcomes, including blood pressure, cardiac function, autonomic function, cardiovascular biomarkers, and functional cardiovascular measures. Methodological quality was evaluated using AMSTAR 2, and the certainty of evidence for the main outcomes was assessed using the GRADE framework. Results: Thirty-eight systematic reviews and meta-analyses were included. CPAP therapy was consistently associated with reductions in systolic blood pressure (mean difference [MD] -4.8 mmHg) and diastolic blood pressure (MD -3.0 mmHg), with additional improvements in 24 h ambulatory blood pressure. Favorable effects were also observed for left ventricular ejection fraction (MD 3.27), left ventricular diastolic function (weighted mean difference [WMD] 0.22), and sympathetic nervous system activity, reflected by lower circulating noradrenaline levels (standardized mean difference [SMD] -1.10) in randomized controlled trials. Improvements in BNP/NT-proBNP concentrations and New York Heart Association functional class were reported among patients with heart failure, whereas no significant effect was observed on body mass index. The certainty of evidence ranged from low to moderate, and methodological confidence of the included reviews was predominantly moderate, low, or critically low. Conclusions: CPAP therapy was associated with improvements in several surrogate, intermediate, and functional cardiovascular outcomes in adults with OSA, particularly blood pressure, left ventricular function, and sympathetic activity. However, the certainty of evidence ranged from low to moderate, and substantial heterogeneity and methodological limitations warrant cautious interpretation. Current evidence remains insufficient to demonstrate a consistent reduction in major adverse cardiovascular events or cardiovascular mortality. Further high-quality randomized controlled trials with longer follow-up are needed to clarify the long-term cardiovascular impact of CPAP therapy.

Abstract as published, via PubMed.