REPRODUCIBILITY OF ARTERIAL COMPLIANCE AND CAROTID WALL THICKNESS MEASUREMENTS IN NORMAL SUBJECTS

1. Non-invasive techniques to measure indices of arterial function and wall thickness are frequently used as surrogate markers of cardiovasc ular disease. Reproducibility of measurements of arterial compliance h as been infrequently reported and little is known about the interrelat ionships of the various indices in vivo. 2. The present study was desi gned to assess reproducibility and interrelationships of indices of sy stemic arterial compliance, pulse wave velocity, carotid compliance an d intima-media thickness (IMT). 3. Fifty healthy volunteers (20 male a nd 30 female; aged 20-70 years, mean 46.5 years), participated in the present study. Each subject was studied on two occasions by the same i nvestigators, using an identical protocol at an interval of 1-5 weeks (mean 2.5 weeks) without lifestyle change. 4. There were no significan t differences between visits for any recorded general data, except res ting blood pressure, which was lower on the second occasion. There wer e no systematic differences within each pair over the range of measure ments for any of the variables. Bland-Altman plots of repeatability of changes in indices showed that the mean values between visits were no t significantly different. All indices of central arterial compliance were significantly related to age and IMT. 5. Thus, under controlled e xperimental conditions, there was satisfactory repeatability of measur ements of indices of both intrinsic and functional arterial mechanical properties (central and carotid arterial compliance and IMT), This ty pe of information will permit the construction of sample size tables f or clinical trials using these indices. 6. Central arterial compliance may be an important determinant of IMT.