Cardiovascular Consequences of Estrogen Deficiency: Studies in Premenopausal Women

The influence of estrogen deficiency in physically active women with functional hypothalamic amenorrhea (ExFHA) on cardiovascular regulation is unknown. Three mechanistic studies compared cardiovascular responses to exercise and orthostatic stress in ExFHA women with responses in physically active (ExOv) and sedentary (SedOv) eumenorrheic ovulatory women. Measures included calf blood flow (BF), brachial artery (BA) endothelial dependent and independent function, shear rate (SR), vascular resistance (VR), blood pressure (BP), heart rate (HR), HR variability (HRV), muscle sympathetic nervous activity (MSNA), and serum renin-angiotensin-aldosterone system (RAAS) components. Study one examined the effects of a single bout of dynamic exercise on vascular function in ExFHA (n=12), ExOv (n=14), and SedOv (n=15) women. Pre-exercise, calf BF and BA endothelium-dependent flow-mediated vasodilation (FMD%) were lower (p0.05) to that observed in ovulatory women. FMD% and SR were augmented (p<0.05) post-exercise, but both remained lower (p<0.05) in ExFHA versus ovulatory women (p<0.05). Study two investigated neurohumoral (MSNA and RAAS) BP regulation during orthostatic stress in ExFHA (n=12) and ExOv (n=17) women. Baseline systolic BP was lower (p0.05) between the groups at baseline. However, during hypotensive stimuli, MSNA increased to a greater extent (p