High aerobic capacity does not attenuate aortic stiffness in hypertensive subjects.

BACKGROUND

It is unknown whether increased physical fitness reduces aortic stiffness in hypertensive individuals. The purpose of this cross-sectional study was to examine, in a cohort of community-dwelling subjects with no history of cardiac events, differences in the impact of aerobic capacity on aortic stiffness between normotensive and hypertensive subjects.

METHODS

The study sample included 275 subjects representing a large age range (21-85 years). Of these, 61 subjects (hypertensive cohort) were either hypertensive at enrollment or were taking antihypertensive medication. The remaining 214 subjects (normotensive cohort) had no history of hypertension. The study protocol included maximal cardiopulmonary exercise testing (determination of maximal oxygen consumption, or VO2max) and measurement of aortic wave velocity (AWV) using a novel magnetic resonance-based method.

RESULTS

Overall, the hypertensive cohort exhibited significantly elevated AWV in comparison to a subset of normotensives matched for age, sex, and aerobic fitness. Each cohort was then subdivided according to the percentage of predicted VO2max achieved (< 100% = "unfit," > or = 100% = "fit"). Differences between subgroups were assessed by unpaired t test. In the normotensive cohort, AWV was significantly lower in the fit versus the unfit subgroup. However, in the hypertensive cohort, AWV was not significantly different between fit and unfit subgroups nor between treated and untreated subgroups.

CONCLUSION

Unlike the situation in healthy normotensive subjects, higher peak aerobic capacity is not associated with lower aortic stiffness in hypertensive individuals.