Aortic Stiffness Is Associated With Higher Nighttime Ambulatory Blood Pressure in Middle-Aged and Older Adults

Abstract

Purpose: The objective of this study was to determine the relationship between aortic stiffening and brachial and central ambulatory blood pressure (AMBP) in a nonclinical sample of middle-aged and older adults (MA/O). We hypothesized aortic stiffness would be positively associated with 24-hr, daytime, and nighttime brachial and central AMBP. Methods: Fifty-one participants aged ≥50 yr (21 males and 30 females, mean age 63.4 ± 9.0 yr) with a body mass index <35 kg/m2 who also had a resting brachial blood pressure (BP) <160/100 mmHg with or without BP medications were recruited for this cross-sectional analysis. All participants underwent measures of aortic stiffness (carotid-femoral pulse wave velocity [cfPWV]) and 24-hr AMBP monitoring. Bivariate correlations assessed the relationship between cfPWV, brachial, and central AMBP. Partial correlations were used to independently adjust for traditional cardiovascular disease (CVD) risk factors including age, sex, waist circumference, glucose, and augmentation index normalized to heart rate 75 bpm, a surrogate measure of arterial stiffness, and in a multivariable combined model. Results: Nighttime brachial systolic BP (r = 0.31) and central systolic BP (r = 0.30) were correlated with cfPWV in the multivariable combined model (P≤ .05). Nighttime brachial pulse pressure and central pulse pressure were correlated with cfPWV after independently adjusting for all CVD risk factors (P≤ .05, all) but not when combined in the multivariable model (P> .05). Conclusions: Higher nighttime brachial and central AMBP with older age are related, in part, to greater aortic stiffening. Therefore, interventions to lower or prevent aortic stiffening may also lower nighttime BP in MA/O adults to lower CVD risk.