The association between arterial compliance, as assessed by PTC1 and PTC2 from radial artery waveforms, and age, sex, and race/ethnicity

Background:There is limited literature on differences in arterial compliance, as assessed from arterial pressure waveforms, with age, sex, and race/ethnicity. PTC1 and PTC2 are indices of arterial compliance, which are derived from a Windkessel model of the waveform, relatively easy to obtain, and associated with cardiovascular disease.Method:PTC1 and PTC2 were computed from radial artery waveforms from participants of the Multi-Ethnic Study of Atherosclerosis at baseline and again 10 years later. We evaluated the association of PTC1, PTC2, and 10-year change in PTC1 and PTC2 with age, sex, and race/ethnicity.Results:Among 6245 participants in 2000-2002 (mean±SD of age was 62±10 years; 52% female; 38% White, 12% Chinese, 27% Black, and 23% Hispanic/Latino), means±SDs for PTC1 and PTC2 were 394±334 and 94±46ms. After adjustment for cardiovascular disease risk factors, mean PTC2 was 1.1ms (95% confidence interval: 1.0, 1.2) lower (arterial stiffness was greater) per year older age, was 22ms (19, 24) lower for females, and varied by race/ethnicity (P<0.001; e.g., 5ms lower for Blacks compared with Whites), although the differences were smaller at older ages (P<0.001 for age-sex, P<0.001 for age-race/ethnicity interactions). Among 3701 participants with repeat measurements in 2010-2012, arteries had stiffened (mean±SD 10-year decrease in PTC2: 13±46ms) consistent with cross-sectional age-Trend and tended to stiffen less for females and Blacks consistent with cross-sectional age-interactions.Conclusion:Differences in arterial compliance by age, sex, and race/ethnicity lend support to identify and act on societal factors that may drive health disparities.