Long-term estrogen deficiency lowers regional blood flow, resting systolic blood pressure, and heart rate in exercising premenopausal women

Abstract

The cardiovascular consequences of hypoestrogenism in premenopausal women are unclear. Accordingly, the influence of menstrual status and endogenous estrogen (E₂) exposure on blood pressure (BP), heart rate (HR), and calf blood flow in young (18–35 yr) regularly exercising premenopausal women with exercise-associated menstrual aberrations was investigated. Across consecutive menstrual cycles, daily urinary ovarian steroid levels were analyzed, and the area under the curve was calculated to determine menstrual status and E₂exposure. BP, HR, blood flow, vascular conductance, and resistance were measured at baseline and following ischemic calf exercise. Exercising subjects consisted of 14 ovulatory (ExOv), 10 short-term (anovulatory and ≤100 days amenorrhea; ST-E₂Def), and 8 long-term (>100 days amenorrhea; LT-E₂Def) E₂-deficient women. Nine sedentary ovulatory subjects (SedOv) were also studied. All groups were similar in age (24.8 ± 0.7 yr), height (164.8 ± 1.3 cm), weight (57.9 ± 0.9 kg), and body mass index (21.3 ± 0.3 kg/m²). E₂-deficient groups had lower ( P < 0.002) E₂exposure compared with ovulatory groups. Resting systolic BP, HR, blood flow, and vascular conductance were lower ( P < 0.05) and vascular resistance higher ( P < 0.05) in LT-E₂Def compared with both ovulatory groups. Peak ischemic blood flow, vascular conductance, and HR were also lower ( P < 0.05) and vascular resistance higher ( P < 0.05) in LT-E₂Def compared with all other groups. Our findings show that exercising women with long-term E₂deficiency have impaired regional blood flow and lower systolic BP and HR compared with exercising and sedentary ovulatory women. These cardiovascular alterations represent markers of altered vascular function and autonomic regulation of which the long-term effects remain unknown.