J Appl Physiol (1985). 2016 Nov 10;:jap.00732.2016
Aging causes micro- and macrovascular endothelial dysfunction, as assessed by endothelium-dependent dilation (EDD), which can be prevented and reversed by habitual aerobic exercise (AE) in men. However, in estrogen-deficient postmenopausal women, whole forearm microvascular EDD hasn't been studied, and a beneficial effect of AE on macrovascular EDD hasn't been consistently shown. We assessed forearm blood flow in response to brachial artery infusions of acetylcholine (FBFACh), a measure of whole forearm microvascular EDD, and brachial artery flow-mediated dilation (FMD), a measure of macrovascular EDD, in 12 premenopausal sedentary women (Pre-S; 24±1 yrs; VO2max=37.5±1.6 ml/kg/min), 25 estrogen-deficient postmenopausal sedentary women (Post-S; 62±1 yrs; VO2max=24.7±0.9 ml/kg/min), and 16 estrogen-deficient postmenopausal AE-trained women (Post-AE; 59±1 yrs; VO2max=40.4±1.4 ml/kg/min). FBFACh was lower in Post-S and Post-AE compared with Pre-S women (135±9 and 116±17 vs.193±21 AUC, respectively, both P<0.008), whereas Post-S and Post-AE women weren't different (P=0.3). Brachial artery FMD was 34% (5.73±0.67%) and 45% (4.79±0.57%) lower in Post-S and Post-AE, respectively, vs. Pre-S women (8.69±0.95%, both P≤0.01), but not different between Post-S and Post-AE women (P=0.3). Post-AE women had lower circulating C-reactive protein and oxidized low-density lipoprotein compared with Post-S women (0.5±0.1 vs. 1.1±0.2 mg/L and 40±4 vs. 55±3 U/L, respectively, both P=0.01), but these markers weren't correlated to FBFACh (P=0.3) or brachial artery FMD (P=0.8). These findings are consistent with the idea that habitual AE doesn't protect against age/menopause-related whole forearm micro- and macrovascular endothelial dysfunction in healthy non-obese estrogen-deficient postmenopausal women, despite being associated with lower systemic markers of inflammation and oxidative stress.