Relationship between sleep-disordered breathing and central systolic blood pressure in a community-based population: the Toon Health Study

Sleep-disordered breathing (SDB) is linked with brachial blood pressure. Although central systolic blood pressure (cSBP) is a better predictor of cardiovascular diseases than is brachial blood pressure, the association between SDB and cSBP is not fully understood. This cross-sectional study included 1484 participants without cardiovascular diseases who were enrolled in the Toon Health Study between 2009 and 2012. The respiratory disturbance index (RDI) was estimated with a one-night sleep test using an airflow monitor. Participants were grouped into three categories according to RDI level: mild (<10 events/h), moderate (10 to <20 events/h), and severe (>= 20 events/h). The cSBP was measured using a noninvasive automated tonometer. Multivariable-adjusted cSBP means for the mild, moderate, and severe RDI categories were, respectively, 116.0, 118.0, and 120.7 mm Hg (p for trend = 0.02) for men and 111.8, 113.7, and 111.7 mm Hg (p for trend = 0.59) for women. The association for men was no longer significant after adjusting for BMI. When stratified by BMI (<22 or >= 22 kg/m(2)), the RDI was associated with cSBP among men with BMI >= 22 kg/m(2), and this association was of borderline significance. Augmentation index, pulse pressure amplification, and brachial blood pressure were not significantly associated with the RDI. Higher RDI values were associated with increased multivariable-adjusted cSBP means among men. This association was more evident among those with BMI >= 22 kg/m(2). In conclusion, we found that the RDI was associated with cSBP among men, and this association was independent of confounding variables among individuals above the ideal weight.