To evaluate the association between obstructive sleep apnea syndrome (OSAS) and blood pressure variability (BPV) assessed by ambulatory blood pressure monitoring (ABPM).
Approach:
Study Selection: Systematic search of observational studies comparing BPV between adults with OSAS and non-OSAS controls across multiple databases.
Data Analysis: BPV evaluated based on standard deviation of systolic (SBP) and diastolic blood pressure (DBP) from 24-h ABPM. Random-effects models were used to pool mean differences (MDs) with 95% confidence intervals (CIs).
Key Findings:
OSAS was associated with significantly higher BPV across all periods compared to controls.
Nighttime BPV showed the largest differences (SBP: MD 1.89 mmHg; DBP: MD 1.93 mmHg).
Subgroup analyses indicated a trend toward increasing BPV with greater OSAS severity, statistically significant for nighttime DBP variability (p = 0.003).
Meta-regression analyses found mean age, proportion of men, and mean body mass index were not significant modifiers of BPV outcomes.
Interpretation:
The certainty of evidence ranged from low to very low, and substantial between-study heterogeneity warrants cautious interpretation of the findings.
Limitations:
The certainty of evidence ranged from low to very low.
Substantial heterogeneity between studies.
Conclusion:
OSAS is associated with increased BPV, particularly during nighttime.
