Reference values for local arterial stiffness. Part A: carotid artery

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

Reference values for local arterial stiffness. Part B: femoral artery

Carotid-femoral pulse wave velocity (PWV) is considered the gold standard measure of arterial stiffness, representing mainly aortic stiffness. As compared with the elastic carotid and aorta, the more muscular femoral artery may be differently associated with cardiovascular risk factors (CV-RFs), or, as shown in a recent study, provide additional predictive information beyond carotid-femoral PWV. Still, clinical application is hampered by the absence of reference values. Therefore, our aim was to establish age and sex-specific reference values for femoral stiffness in healthy individuals and to investigate the associations with CV-RFs

Reference intervals for common carotid intima-medi thickness measured with echotracking: Relation with risk factors

Aims Common carotid artery intima-media thickness (CCIMT) is widely used as a surrogate marker of atherosclerosis, given its predictive association with cardiovascular disease (CVD). The interpretation of CCIMT values has been hampered by the absence of reference values, however. We therefore aimed to establish reference intervals of CCIMT, obtained using the probably most accurate method at present (i.e. echotracking), to help interpretation of these measures. Methods and results We combined CCIMT data obtained by echotracking on 24 871 individuals (53% men; age range 15-101 years) from 24 research centres worldwide. Individuals without CVD, cardiovascular risk factors (CV-RFs), and BP-, lipid-, and/or glucose-lowering medication constituted a healthy sub-population (n 1/4 4234) used to establish sex-specific equations for percentiles of CCIMT across age. With these equations, we generated CCIMT Z-scores in different reference subpopulations, thereby allowing for a standardized comparison between observed and predicted ('normal') values from individuals of the same age and sex. In the sub-population without CVD and treatment (n 1/4 14 609), and in men and women, respectively, CCIMT Z-scores were independently associated with systolic blood pressure [standardized bs 0.19 (95% CI: 0.16-0.22) and 0.18 (0.15-0.21)], smoking [0.25 (0.19-0.31) and 0.11 (0.04-0.18)], diabetes [0.19 (0.05-0.33) and 0.19 (0.02-0.36)], total-to-HDL cholesterol ratio [0.07 (0.04-0.10) and 0.05 (0.02-0.09)], and body mass index [0.14 (0.12-0.17) and 0.07 (0.04-0.10)]. Conclusion We estimated age- and sex-specific percentiles of CCIMT in a healthy population and assessed the association of CVRFs with CCIMT Z-scores, which enables comparison of IMT values for (patient) groups with different cardiovascular risk profiles, helping interpretation of such measures obtained both in research and clinical settings. © 2012 The Author All rights reserved