Heritability of arterial stiffness in black and white American youth and young adults

Background: Our objectives were to examine the heritability of arterial stiffness measured as pulse-wave velocity (PWV), and its dependence on ethnicity, gender, and blood pressure (BP). Methods: As part of the Georgia Cardiovascular Twin Study, we measured aorto-radial (radial) and aorto-dorsalis-pedis (foot) PWV in 702 twins (41% black; 49% male) aged 12 to 30 years (mean age, 17.7 +/- 3.3 years), including monozygotic and dizygotic pairs of the same as well as opposite gender. Ethnicity and gender effects on genetic and environmental contributions to PWV were estimated by genetic model fitting. Results: Diastolic BP was the most important hemodynamic predictor. The best-fitting models showed no ethnicity or gender differences in estimates of genetic and environmental influence, and indicated substantial heritabilities of 0.43 (95% confidence interval, 0.30 to 0.54) and 0.53 (95% confidence interval, 0.42 to 0.62) for radial and foot PWV, respectively. Over a quarter of these heritabilities (0.19 for radial PWV; 0.14 for foot PWV) could be attributed to genes that also influenced diastolic BP, as based on multivariate models. Conclusions: Individual differences in the arterial stiffness of youth and young adults are substantially heritable, and >25% of this heritability is explained by genes that also influence diastolic BP. Heritability estimates do not show any differences between blacks and whites or males and females.