Objectives: The aim of this study was to examine the effect of three different doses of aerobic exercise training (corresponding to approximately 50%, 100% and 150% of the National Institutes of Health consensus guidelines) on endothelial function in sedentary obese postmenopausal women with elevated blood pressure. Aerobic exercise training improves endothelial function in individuals with cardiovascular risk; however, it is unknown whether these adaptations occur in a dose-dependent manner.
Methods: Obese postmenopausal women (n=155) with elevated blood pressure (systolic blood pressure between 120 and 159.0 mm Hg) were randomly assigned to one of four groups: 4, 8 or 12 kilocalories per kilogram of energy expenditure per week (kcal/kg/week) or a non-exercise control group for 6 months. Endothelial function was assessed via flow-mediated dilation (FMD) at baseline and post-intervention.
Results: After exercise training, there was a similar improvement (1.02-1.5%) in FMD in all three exercise groups (p<0.05) compared with control (-0.5%). Change in FMD after exercise training was significantly correlated with FMD at baseline (r= -0.35, p<0.001). Post hoc analyses found a significant improvement in FMD in exercisers (all exercise groups combined) with endothelial dysfunction (FMD < 5.5%) at baseline (1.8%, 95% CI: 1.17 to 2.38; p<0.001) compared with exercisers with normal endothelial function (FMD ≥ 5.5%) (-1.2%; 95% CI: -1.17 to 0.69; p=0.60).
Conclusions: Aerobic exercise training was associated with improved FMD in postmenopausal women with elevated blood pressure. In addition, exercise training may be more efficacious in improving endothelial function in postmenopausal women with endothelial dysfunction than individuals with normal endothelial function at baseline.