Cardiovascular responses to dynamic exercise in postmenopausal women

Abstract

Previous studies strongly indicate that the arterial baroreflex plays an important role in cardiovascular responses to dynamic exercise. However, the effect of arterial baroreflex on the hemodynamic responses to dynamic exercise is not well understood after menopause. Therefore, we investigated the cardiovascular responses during cycle exercise (30 W and 60 W) in healthy premenopausal and postmenopausal women. Thirty premenopausal and postmenopausal women were instrumented to measure heart rate (HR), cardiac output (CO) and mean arterial pressure (MAP). MAP was significantly increased with exercise intensity in postmenopausal women, while there was no difference in premenopausal women. CO, HR, total vascular conductance (TVC) and stroke volume increased with increasing workloads in both premenopausal and postmenopausal women. However, TVC was significantly lower after menopause at moderate workload compared to the premenopausal women (107.3±13.4 vs. 91.4±5.2 mm/min/Hg). The results indicate that higher MAP after menopause occurred due to combining increase in CO as well as substantial decrease in peripheral vascular conductance. We conclude that menopause altered normal cardiovascular responses to graded dynamic exercise. Additionally, after menopause significantly a higher increase in arterial blood pressure may be due to a depression in arterial baroreflex function during exercise.