Differential impact of heart rate on arterial wall stiffness and thickness in young adults: The Bogalusa Heart Study.

Heart rate, a hemodynamic parameter, is an important determinant of arterial wall stiffness. However, information on the relationship of heart rate to arterial wall thickness is inconsistent. This study examined the influence of heart rate on arterial stiffness and thickness in Black and White young adults. The study cohort consisted of 255 Black and 659 White adults age 25 to 43 years enrolled in the Bogalusa Heart Study. Carotid artery intima-media thickness (IMT) was measured by B-mode ultrasound and aorta-femoral pulse wave velocity (af-PWV) by echo-Doppler. There was no difference in heart rate between Blacks and Whites. Males vs. females displayed lower heart rate and higher segmental and composite carotid IMT; Blacks vs. Whites had higher composite carotid IMT (0.83 mm vs. 0.80 mm, P < .01) and af-PWV (5.4 m/s vs. 5.2 m/s, P < .01). In a multivariate regression model adjusting for traditional cardiovascular risk variables, heart rate was independently associated with af-PWV (standardized regression coefficient: beta = .14, P = .01 for Blacks; beta = .06, P = .07 for Whites; beta = .09, P = .003 for total sample), but not with carotid IMT. These results indicate that heart rate plays differential roles in the development of arterial stiffness and subclinical atherosclerosis during young adulthood.