Mediating effects of nocturnal blood pressure and morning surge on the contributions of arterial stiffness and sodium intake to morning blood pressure: A path analysis

Background. The aim of this study was to evaluate the mediating effects of nocturnal blood pressure (BP) and morning surge on the contribution of arterial stiffness and sodium intake to morning BP in a middle-aged general population. Methods. The study included 124 subjects aged 30-59 years, from rural Yeoju County, Gyeonggi Province, South Korea. Ambulatory BP monitoring, 24 h urinary sodium excretion (24 h UNa) and brachial-ankle pulse wave velocity (baPWV) measurements were performed in all subjects. Results. The mean ± SD age was 48.1 ± 8.2 years and the proportion of male subjects was 41.1%. After adjusting for covariates, morning systolic blood pressure (SBP) was significantly correlated with morning surge [coefficient = 0.761, 95% confidence interval (CI) 0.651-0.872, p