Non-invasive measures of common carotid artery properties, such as diameter, distension and local pulse pressure, have been widely used to determine carotid stiffness (CS), which is associated with cardiovascular disease (CVD). The interpretation of CS values measured across different age, sex and risk groups has been hampered by the absence of reference values, however. We therefore aimed to establish reference intervals of CS (obtained by echotracking) to help interpretation of these measures both in research and clinical settings.

We combined CS data on 10,749 individuals (53% men; age range 15–99 years) from 13 research centres worldwide. Individuals without CVD, cardiovascular risk factors and who were not on blood pressure- and/or lipid-lowering medication constituted the ‘normal’ healthy sub-population (n=2,281), which will be used to establish equations for percentiles of CS across age. With these equations we further plan to generate CS Z-scores in different sub-populations thereby allowing for a standardized comparison between observed and predicted (normal) values from individuals of the same age. The independent associations of known cardiovascular risk factors will then be assessed with multiple linear regression analyses, using these Z-scores as outcome variables.

The exact results are expected by the time of Artery 12. We hope to estimate age-specific percentiles of CS in a healthy population and to assess the associations of cardiovascular risk factors with CS Z-scores, which will enable comparison of CS values for (patient) groups with different cardiovascular risk profiles, helping interpretation of such measures when obtained both in research and clinical settings.