Indexes of aortic wave reflection are not augmented in estrogen-deficient physically active premenopausal women

Hypoestrogenemia due to menopause is associated with increased cardiovascular disease risk, in part due to elevated indexes of aortic wave reflection (AWRI) and central (aortic) blood pressure. We sought to investigate whether AWRI and central blood pressure are also augmented in hypoestrogenic exercise-trained premenopausal women with functional hypothalamic amenorrhea (ExFHA).

In age- (pooled mean ± SEM, 24 ± 1 years), BMI- (21 ± 1 kg/m² ), and cardiorespiratory fitness-matched (45 ± 2 ml/kg/min) eumenorrheic ovulatory (ExOv; n = 11) and ExFHA women (n = 10), we assessed aortic blood pressure and waveform characteristics (augmentation index and wave reflection amplitude) obtained from radial pressure waves (applanation tonometry). Doppler ultrasound determined cardiac output (CO) and total peripheral resistance (TPR). Measures were recorded before and 1 hour after 45 minutes of moderate intensity exercise to determine the influence of exercise-induced increases in nitric oxide.

Pre-exercise, AIx75, central systolic BP (SBPc), and CO were lower (P < .05) and TPR higher (P < .05) in ExFHA. Post-exercise, AIx75 was unchanged (P > .05) in ExFHA but was lowered (P < .05) in ExOv. Both groups demonstrated increased CO, and lowered SBPc and TPR, yet TPR remained higher (P < .05), and CO and SBPc lower (P < .05) in ExFHA.

Despite hypoestrogenemia, functional compliance of the central arteries and central BP is not augmented, yet TPR is higher, in ExFHA versus ExOv. An acute bout of dynamic exercise did not alter AIx75 in ExFHA, suggesting blunted vascular responsiveness to exercise-induced increases in nitric oxide, possibly due to augmented vascular tone. These findings have relevance in understanding the vascular consequences of hypoestrogenemia during the premenopausal years.