Blood Pressure Trajectories and Cardiovascular Risk in Obstructive Sleep Apnea: A Dual-Cohort Analysis.

Abstract

This study primarily examined longitudinal systolic blood pressure trajectories in untreated obstructive sleep apnea (OSA) and their association with cardiovascular risk. A complementary analysis in the independent trial evaluated longitudinal blood pressure change after CPAP treatment. Data were obtained from the observational Sleep Heart Health Study (SHHS) and the interventional Apnea Positive Pressure Long-term Efficacy Study (APPLES). Participants with OSA who were not receiving antihypertensive treatment were included. Group-based trajectory modelling was used to identify SBP patterns over time, cardiovascular risk was assessed using Kaplan-Meier and Cox proportional hazards analyses, and CPAP-related SBP changes were evaluated using linear mixed-effects models. During a 10-year follow-up of 624 untreated patients with OSA, three SBP trajectories were identified: stable (87.0%), falling (5.9%), and rising (7.1%). Compared with the stable trajectory, the rising SBP group had a significantly higher risk of cardiovascular events (adjusted hazard ratio [HR] 2.84, 95% confidence interval [CI] 2.13-3.78; p < 0.001). CPAP therapy was associated with a reduced risk of cardiovascular events (adjusted HR 0.62, 95% CI 0.45-0.84; p = 0.002). Supplementary adherence analyses suggested more sustained SBP reduction with higher nightly CPAP use, and restricted cubic spline analysis indicated a steeper decline above 5.59 h/night. These findings suggest that rising SBP trajectories identify patients with OSA at highest cardiovascular risk, while CPAP use was associated with lower cardiovascular event risk in the observational SHHS comparison and modest SBP reduction in the complementary APPLES analysis. Trial Registration: SHHS (NCT00005275) and APPLES (NCT00051363).