Racial differences in relation between carotid and radial augmentation index

Background: Augmented central artery wave reflection is a cardiovascular disease risk factor. Augmentation index (AI) obtained from peripheral artery waveforms provides qualitatively similar information to AI from central artery waveforms. Little information is available, however, regarding the influence of racial difference in association between central and peripheral AI. Methods: We studied 47 White adults (45 ± 17 yr, 20 women) and 94 age-matched Asian adults (45 ± 14 yr, 42 women). Results: The White group was significantly taller than the Asian group, whereas there were no significant group differences in blood pressure and heart rate. Carotid and radial AI tended to be lower in White compared with Asian adults (P < 0.10 for both). Such tendency disappeared when the difference in height was taken into account using ANCOVA (P = 0.84 and P = 0.77, respectively). Radial AI was strongly and positively correlated with carotid AI in White adults (r = 0.75, P < 0.0001) as well as in Asian adults (r = 0.82, P < 0.0001). The slope and intercept of linear regression line between radial and carotid AI of White adults were highly comparable with those of Asian adults. Conclusion: AI in the conveniently located peripheral vasculature may provide a surrogate measure of central AI irrespective of difference in race (e.g., Asian vs. White populations).