Influence of sex on the relation between heart rate and aortic stiffness

Background Heart rate and aortic pulse wave velocity (PWV) are both cardiovascular risk factors. The aim of this study was to evaluate the influence of sex on the heart rate -PWV relationship in two populations of normotensive and hypertensive men and women. Patients and methods In a first study, steady-state data describing the heart rate-PWV relationship were determined in 558 normotensive men, 308 normotensive women, 323 hypertensive men and 93 hypertensive women. In a second study, the changes in blood pressure and PWV under atrial pacing at 60, 80 and 100 beats/min were investigated in 15 men and 15 women who were either normotensive or hypertensive. Results In women in study 1, 26.8% of PWV variance in normotensive patients and 15.4% of PWV variance in hypertensive patients was explained by a multiple regression including only age and systolic blood pressure as covariates. In men in study 1, 27% of PWV variance in normotensive patients and 28.5% of PWV variance in hypertensive patients was explained by a multiple regression including age, systolic blood pressure, weight, and also heart rate, as covariates. In study 2, atrial pacing in the overall population tended to decrease mean blood pressure (P = 0.05) and increase pulse pressure (P = 0.003), with no substantial change in PWV. However, when heart rate increased, PWV tended to decrease in women and to increase in men (interaction: P = 0.07). Conclusion Accelerated heart rate influences PWV in both normotensive and hypertensive men and, through this mechanism, could influence cardiovascular risk. However, heart rate does not influence PWV in women. (C) 2003 Lippincott Williams Wilkins.