Reference values for local arterial stiffness. Part A

Abstract

Objective: Non-invasive measures of common carotid artery properties, such as diameter and distension, and pulse pressure, have been widely used to determine carotid artery distensibility coefficient – a measure of carotid stiffness (stiffness ∼1/distensibility coefficient). Carotid stiffness has been associated with incident cardiovascular disease (CVD) and may therefore be a useful intermediate marker for CVD. We aimed to establish age and sex-specific reference intervals of carotid stiffness. Methods: We combined data on 22 708 individuals (age range 15–99 years, 54% men) from 24 research centres worldwide. Individuals without CVD and established cardiovascular risk factors constituted a healthy sub-population (n = 3601, 48% men) and were used to establish sex-specific equations for percentiles of carotid distensibility coefficient across age. Results: In the sub-population without CVD and treatment (n = 12 906, 52% men), carotid distensibility coefficient Z-scores based on these percentile equations were independently and negatively associated, in men and women, respectively, with diabetes {−0.28 [95% confidence interval (CI) −0.41; −0.15] and −0.27 (−0.43; −0.12)}, mean arterial pressure [−0.26 (−0.29; −0.24) and −0.32 (−0.35; −0.29)], total-to-high-density lipoprotein cholesterol ratio [−0.05 (−0.09; −0.02) and −0.05 (−0.11; 0.01)] and BMI [−0.06 (−0.09; −0.04) and −0.05 (−0.08; −0.02)], whereas these were positively associated with smoking [0.30 (0.24; 0.36) and 0.24 (0.18; 0.31)]. Conclusions: We estimated age and sex-specific percentiles of carotid stiffness in a healthy population and assessed the association between cardiovascular risk factors and carotid distensibility coefficient Z-scores, which enables comparison of carotid stiffness values between (patient) groups with different cardiovascular risk profiles, helping interpretation of such measures.