Factors associated with increased radial augmentation index in hypertensive individuals

Arterial stiffness is a variable predictor of morbidity and mortality and a possible marker of vascular injury. Its non-invasive assessment by radial tonometry and analysis of the augmentation index (r-AI) allows identifying patients exposed to higher cardiovascular risk.

To analyze the influence of r-AI on clinical-biochemical variables and its influence on the prevalence of target-organ damage in hypertensive patients.

140 consecutive hypertensive patients, followed-up in an outpatient clinic, were analyzed in a cross-sectional study. Blood pressure (BP) levels and r-AI were obtained by applanation tonometry of the radial artery (HEM-9000AI, Onrom). The patients were allocated into r-AI tertiles (r-AI < 85%; 85< r-AI < 97%; r-AI > 97%).

The sample was predominantly composed of women (56.4%), mean age of 61.7 ± 11.7 years and body mass index 29.6 ± 6.1 Kg/m². The highest tertile showed higher proportion of women (p = 0.001), higher systolic BP (p = 0.001) and pulse pressure (p = 0.014), and lower weight (p = 0.044), height (p < 0.001) and heart rate (p < 0.001). Multivariate analysis demonstrated that weight (β = -0.001, p = 0.017), heart rate (β = -0.001, p = 0.007) and central pressure (β = 0.015, p < 0.001) correlated independently with r-AI. In logistic regression analyses, the 3rd r-AI tertile was associated to lower levels of diabetes (DM) (OR = 0.41; 95% CI 0.17-0.97; p = 0.042).

This study demonstrated that weight, heart rate and central BP were independently related to r-AI.