Nocturnal blood pressure rather than night-to-day blood pressure ratio is related to arterial stiffening in untreated young and middle-aged adults with non-dipper hypertension

Little is known about nocturnal blood pressure (BP) or night-to-day BP ratio, which is a more specific determinant of arterial stiffness in subjects with non-dipper hypertension? This study aims to investigate the correlation of nocturnal BP and brachial-ankle pulse wave velocity (ba PWV), an index of arterial stiffness in untreated young and middle-aged adults with non-dipper hypertension. A cross-sectional analysis of baseline parameters of the NARRAS trial was performed. Twenty-four hour ambulatory BP measurements, ba PWV and routine clinical data collection were performed in all patients. The relationship of 24-h ambulatory BP profiles, biochemical measures as well as demographic parameters and ba PWV were analyzed using Pearson's correlation and multiple stepwise regression analysis. A total of 77 patients (mean age 47.0 +/- 11.7 years) with non-dipper hypertension were included. Age, height, weight and nocturnal systolic BP were related to ba PWV in Pearson's correlation analysis. In stepwise regression analysis, age (beta = 10.57, 95% confidence interval (CI): 6.099-15.042, p < 0.001) and weight (beta = -3.835, 95% CI: -7.658--0.013, p = 0.049) are related to ba PWV. Nocturnal systolic BP (beta = 8.662, 95% CI: 2.511-14.814, p = 0.006) was the independent predictors of ba PWV, even after night-to-day systolic BP ratio or 24-h ambulatory BP profile were taken into account. Nocturnal systolic BP rather than night-to-day systolic BP ratio appears to be a more specific determinant for arterial stiffness, as assessed by ba PWV in young and middle-aged adults with non-dipper hypertension. 24-h ambulatory BP measurements are essential for cardiovascular risk evaluation.