Habitual Aerobic Exercise Does Not Significantly Influence Age‐related Microvascular Endothelial Dysfunction in Healthy Estrogen‐deficient Postmenopausal Women

Abstract

Aging causes macro‐ and microvascular endothelial dysfunction, as assessed by endothelium‐dependent dilation (EDD), which can be prevented and reversed by habitual aerobic exercise (AE) in men. However, a beneficial effect of AE on macrovascular EDD has not been consistently shown in estrogen‐deficient postmenopausal women, and microvascular EDD has not been assessed. We determined forearm blood flow in response to incremental brachial artery infusion of acetylcholine (FBFACh), a measure of microvascular EDD, and brachial artery flow‐mediated dilation (FMD), an assessment of macrovascular EDD, in 8 premenopausal sedentary (PrS; 25.5±2 yrs; VO2max = 36.9±2.6 ml/kg/min), 28 estrogen‐deficient postmenopausal sedentary (PoS; 61.8±1 yrs; VO2max = 24.5±0.9 ml/kg/min), and 7 estrogen‐deficient postmenopausal trained (PoT; 58.6±2 yrs; VO2max = 40.6±2.4 ml/kg/min) women. Peak and area under the curve (AUC) FBFACh was lower in PoS vs. PrS (19.5±1.2 vs. 29.9 ml/100 ml tissue/min and 133.4±8.8 vs. 211.5±28.7 AUC, respectively, P<0.05) women. In PoT, peak and AUC FBFACh was lower than PrS, but not different from PoS (20.1 ml/100 ml tissue/min and 102.8±21.8 AUC, respectively, P<0.05 and P>0.05, respectively) women. FMD was 28% and 42% lower in PoS and PoT, respectively, vs. PrS women, and there was no difference in FMD between PoS and PoT (P>0.05) women. These findings suggest that habitual AE does not protect against age‐related macro‐ and microvascular endothelial dysfunction in estrogen‐deficient postmenopausal women.