Exercise restores impaired resistance vessel function in hypothalamic hypoestrogenic premenopausal women in association with increased resting cardiac output and decreased systemic vascular resistance

Objectives: To determine the hemodynamic effects of an acute bout of exercise on previous findings of impaired resistance vessel function in physically active premenopausal women with hypothalamic hypoestrogenemia (ExHH). Methods: Two groups of similarly trained recreationally active premenopausal women were studied: ExHH (n=12; aged 25±1 years; body mass index 20.3±0.7 kg/m2; mean±SEM), and eumenorrheic ovulatory women (ExOv; n=14; 24±1years; 21.4±0.5 kg/m2). Blood pressure (BP), heart rate (HR), stroke volume (SV), cardiac output (CO), total peripheral resistance (TPR; 2D echocardiography) and resting and peak-ischemic calf blood flow (CBF; plethysmography) were assessed at baseline and 60 minutes after 45 minutes of moderate aerobic exercise. Results: In ExHH, baseline HR (47±2 beats/min), systolic BP (90±2 mmHg) and CO (3.4±0.1 L/min) were lower (p<0.05) than in ExOv (54±2 beats/min; 101±1 mmHg; 4.1±0.1 L/min; respectively). Resting and peak-ischemic CBF were also lower (p<0.05) in ExHH (1.5±0.1 and 20.5±1.5 ml/100ml/min) than ExOv women (2.4±0.2 and 28.8±2.9 ml/100ml/min). Conversely, TPR was higher (p<0.05) in ExHH (1606±69 dynes/sec/cm5) than eumenorrheic women (1400±47 dynes/sec/cm5). Post-exercise: HR and CO were increased (p<0.05), and TPR decreased (p<0.05) in both groups. However, in ExHH, HR (58±2 beats/min) and CO (3.90±0.1 L/min) remained lower (p<0.05) and TPR (1365±65 dynes/sec/cm5) higher (p<0.05) than in ExOv women. Resting CBF was increased (p<0.05) to a similar value (3.3±0.2 ml/100ml/min; overall mean) in both groups. Peak CBF was increased (p<0.05) in ExHH only (26.4±2.0 ml/100ml/min). Using pooled data, CO was positively, and TPR inversely, associated (p