Sex-specific effects of habitual aerobic exercise on brachial artery flow-mediated dilation in middle-aged and older adults

Abstract

Brachial artery flow-mediated dilation (FMD) is impaired with aging and is associated with increased risk for cardiovascular disease (CVD). We determined if regular aerobic exercise improves brachial artery FMD in middle-aged/older (MA/O) men and postmenopausal women. In sedentary MA/O adults (age 55 – 79 years) without CVD, 8 weeks of brisk walking (6 days/week for ~50 min/day; randomized, controlled design) increased treadmill time ~20% in both MA/O men (n=11) and postmenopausal women (n=15) (P<0.01), without altering body composition or circulating CVD risk factors. Brachial artery FMD increased > 50% in the MA/O men (4.6 ± 0.6 to 7.1 ± 0.6%, P < 0.01), but did not change in the postmenopausal women (5.1 ± 0.8 vs. 5.4 ± 0.7%, P = 0.50). No changes occurred in the non-exercising controls. In a separate cross-sectional study (n =167), brachial artery FMD was ~50% greater in endurance exercise-trained (6.4 ± 0.4%, n = 45) vs. sedentary (4.3 ± 0.3%, n = 60) MA/O men (P < 0.001), whereas there were no differences between endurance-trained (5.3 ± 0.7%, n = 20) and sedentary (5.6 ± 0.5%, n = 42) postmenopausal women (P = 0.70). Brachial artery lumen diameter, peak hyperemic shear rate and endothelium independent dilation did not differ with exercise intervention or in the endurance-exercise vs. sedentary groups. Regular aerobic exercise is consistently associated with enhanced brachial artery FMD in MA/O men, but not in postmenopausal women. Some postmenopausal women without CVD may be less responsive to habitual aerobic exercise than MA/O men.

Early Postmenopausal Phase Is Associated With Reduced Prostacyclin-Induced Vasodilation That Is Reversed by Exercise Training

“…28 Collectively, these findings indicate that estrogen status plays a key permissive role in the adaptive response of the vasculature to exercise training in women. However, the studies in which beneficial vascular effects of exercise training were not observed in late postmenopausal women were characterized by low to moderate exercise intensities, 15,28 whereas high-intensity aerobic training such as that introduced in the current study has been shown to be associated with improvements in vascular function. 29 As this latter training modality has superior cardiovascular effects compared with moderate intensity exercise in patients with heart failure, 30 it may be that exercise intensity is an essential factor for reversing vascular dysfunction in postmenopausal women.…”

“…In a study on middle-aged and older adults, regular physical activity was found to improve flow-mediated dilation in previously sedentary men but not in late postmenopausal women. 15 In another study, flow-mediated dilation was increased in late postmenopausal women who had undergone 12 weeks of estradiol therapy before initiation of exercise training and continued treatment throughout the intervention period, whereas flow-mediated dilation did not change in the women receiving placebo. 28 Collectively, these findings indicate that estrogen status plays a key permissive role in the adaptive response of the vasculature to exercise training in women.…”

“…15,16 Estradiol supplementation has been found to counteract this detrimental consequence of the menopausal transition, 16 suggesting that estrogen status plays an import regulatory role in the improvement of endothelial function with exercise training. Along these lines, the beneficial effects of estrogen supplementation in terms of atherosclerosis and cardiovascular disease are most pronounced during the peri-and early postmenopausal years when estrogen receptors (ERs) or other compensatory mechanisms may function.…”

Drug Treatment of Hypertension: Focus on Vascular Health

“…In clinical studies, aerobic exercise improves brachial artery flow-mediated dilatation in older males and females with low oestrogen but not women treated with oestrogen supplementation 184,187,188 . This suggests that oestrogen may be permissively involved in the beneficial effects of aerobic exercise on endothelial function in women 184 .…”

Phase I/II randomized trial of aerobic exercise in Parkinson disease in a community setting

“…Using continuous electronic heart rate and speed monitoring, we were able to show dose-response relationships in improving aerobic fitness. Similar to community-based studies of self-administered aerobic walking exercise in healthy people, 33 our intervention was conducted in a real-life environment, and is likely to generalize to community dwelling, independently ambulating patients with PD without significant comorbidities.…”