Hemodynamic after-effects of acute dynamic exercise in sedentary normotensive postmenopausal women

Abstract

To determine, in sedentary normotensive postmenopausal women, the after-effects of exercise on systemic and regional hemodynamics, and whether changes in total peripheral conductance after exercise relate to changes in brachial artery flow-mediated vasodilation (FMD). In 13 sedentary postmenopausal women, the blood pressure (BP), cardiac output, total peripheral resistance and total peripheral conductance, calf vascular resistance and FMD were measured during baseline rest, and again commencing 45 min after treadmill exercise. Fourteen premenopausal women completed the identical protocol to obtain reference values for the after-effects of exercise in healthy females. In postmenopausal women, exercise was followed by falls in systolic BP (P < 0.01) and diastolic BP (P < 0.001). BP did not fall after exercise in premenopausal women. In both groups the cardiac output (P < 0.01) increased and the calf vascular resistance (P < 0.01) and total peripheral resistance (P < 0.05) decreased after exercise, but resistance fell more (P < 0.05) in postmenopausal women. Baseline FMD was greater in premenopausal women (12.1 +/- 1.5 versus 5.3 +/- 1.3%, P < 0.01), and similar before and after exercise, whereas prior exercise nearly doubled the FMD of postmenopausal women (to 9.9 +/- 1.4%, P < 0.01). These increases in FMD correlated with baseline values (r = -0.75, P < 0.01) and with relative changes in total peripheral conductance (r = 0.72, P < 0.02). The latter relationship was absent in premenopausal women (r = -0.29). In postmenopausal women, acute dynamic exercise elicits sustained increases in FMD that could facilitate post-exercise hypotension in this population. These observations reinforce the concept of exercise as an important non-pharmacological intervention to modify cardiovascular risk in postmenopausal women.