Arterial properties, such as carotid distention and intima-media thickness (IMT) are important markers of arterial stiffness and atherosclerotic disease and have been shown to predict cardiovascular events. However, the application of these measurements in clinical practice has been hampered by the absence of reference values. The aim of the present study is to establish reference and normal values for carotid stiffness and IMT.

Measurements of carotid wall thickness and function obtained by an echo tracking system (Walltrack and ArtLab, Esaote, Maastricht, Netherlands) are available for individuals from several combined European (n ∼9000) and Chinese (n ∼1500) cohort studies. After pooling, data will be analysed in order to obtain normal values of carotid stiffness and IMT as estimated in the ‘normal population’, which will be constituted from those selected individuals with no acquired cardiovascular risk factors (i.e. diabetes, use of antihypertensive and/or lipid lowering medication, dyslipidaemia, smoking) or overt cardiovascular disease and optimal blood pressure values. Other populations with one or more risk factors will serve to scale stiffness and IMT between populations and to obtain reference values. A special attention will be focused on bringing correspondence between echo tracking and image analysis techniques to allow for conversion, and carotid stiffness values calculated from central pressure and/or brachial pressure.

The study is currently ongoing, which enables presentation of the exact design. Definitive results are expected for Artery 2011.