Estimated versus measured aortic stiffness: implications of diabetes, chronic kidney disease, sex and height

Abstract

Background: Aortic stiffness is measured by carotid–femoral pulse wave velocity (PWV), but it can also be estimated (ePWV) based on age and brachial mean arterial pressure (MAP). However, diabetes mellitus and/or chronic kidney disease (DM/CKD) may cause more pronounced damage to the arterial wall, changing the pressure and PWV relationship. Furthermore, sex and height could affect PWV through their relationship to the arterial diameter and path length. The aim of the present study was to quantify the extent to which DM/CKD, sex and height affect the validity of ePWV in predicting PWV. Methods: This cross-sectional study evaluated PWV in adult participants at high risk of aortic stiffness, using Complior and the second derivative transit time algorithm (PWV2nd). PWV2nd was converted into intersecting tangent PWV (PWVITc), and ePWV was calculated using the Reference Values for Arterial Stiffness Collaboration formulas. Results: Among 825 patients (62% males), the mean age was 60 ± 17 years, 34% had diabetes mellitus, 69% had CKD, and 24% did not have DM/CKD. MAP, ePWV, PWV2nd, and PWVITc were, respectively, 96 ± 14 mmHg, 9.8 (8.1–11.8) m/s, 9.5 (7.8–11.9) m/s and 11.3 (8.8–15.9) m/s. There was a significant interaction between DM/CKD, sex, and the predictive value of ePWV. Increasing height lowered the intercept but did not affect the slope of the relationship between estimated and measured PWVs. Conclusion: These findings suggest that the current ePWV equations do not accurately predict PWV in patients with DM/CKD, and that sex and height should also be considered in the future ePWV equations.