Obstructive sleep apnea syndrome is associated with significantly higher blood pressure variability in patientsSleep apnea is linked to higher blood pressure variability

BackgroundObstructive sleep apnea syndrome (OSAS) is associated with increased cardiovascular risk, but its relationship with blood pressure variability (BPV), an independent predictor of adverse outcomes, remains incompletely defined. This meta-analysis aimed to evaluate the association between OSAS and BPV assessed by ambulatory blood pressure monitoring (ABPM).MethodsPubMed, Embase, Web of Science, Wanfang, and CNKI were systematically searched for observational studies comparing BPV between adults with OSAS and non-OSAS controls. BPV was evaluated based on standard deviation of systolic (SBP) and diastolic blood pressure (DBP) derived from 24-h ABPM, including nighttime, daytime, and 24-h periods, as reported in the original studies. Random-effects models were used to pool mean differences (MDs) with 95% confidence intervals (CIs).ResultsEleven studies comprising 17 datasets (1,261 patients with OSAS and 826 controls) were included. Compared with controls, OSAS was associated with significantly higher BPV across all periods. Nighttime BPV showed the largest differences (SBP: MD 1.89 mmHg, 95% CI 1.07–2.70; DBP: MD 1.93 mmHg, 95% CI 1.17–2.69), followed by 24-h BPV (SBP: MD 1.77 mmHg, 95% CI 0.80–2.75; DBP: MD 1.17 mmHg, 95% CI 0.47–1.87) and daytime BPV (SBP: MD 1.17 mmHg, 95% CI 0.35–1.99; DBP: MD 0.61 mmHg, 95% CI 0.26–0.96). Subgroup analyses suggested a trend toward increasing BPV with greater OSAS severity, with statistically significant differences observed only for nighttime DBP variability (p = 0.003). Meta-regression analyses showed that mean age, proportion of men, and mean body mass index were not significant modifiers of any BPV outcome (all p > 0.05). According to the GRADE framework, the certainty of evidence ranged from low to very low.ConclusionOSAS is associated with increased BPV, particularly during nighttime. Although a trend toward greater BPV with increasing OSAS severity was observed, the certainty of evidence ranged from low to very low, and substantial between-study heterogeneity warrants cautious interpretation of the findings.Systematic review registrationCRD420261395221.