Blood pressure and hemodynamics in postmenopausal women during estradiol-17 beta substitution

Blood pressure, central hemodynamics and peripheral blood flow were measured at rest in 20 normotensive and 20 hypertensive postmenopausal women during cyclic placebo/estradiol-17 beta treatment. Micronized estradiol-17 beta was given in daily doses of 2 mg and 4 mg. Corresponding measurements were also performed during exercise in 10 borderline hypertensive subjects given estradiol-17 beta substitution in 2 mg daily doses for three months. In addition, electrocardiograms and changes in various hematological parameters were evaluated both at rest and during exercise. Cardiac output was determined by the isotope 113mIn radiocardiographic method, and peripheral blood flow was measured using the vena-occlusion plethysmograph. The serum estrone, estradiol, FSH, LH and prolactin concentrations were determined by radioimmunoassay. Estradiol-17 beta substitution decreased the systolic and diastolic blood pressure in normotensive, hypertensive and borderline hypertensive postmenopausal women. The blood pressure of the hypertensive subjects decreased on average more than the blood pressure of the normotensive subjects. A statistically significant correlation was observed between the increase in serum estrone concentration and the decrease in systolic and diastolic blood pressures produced by the 4 mg daily doses of estradiol-17 beta in the hypertensive subjects. In the borderline hypertensive subjects systolic blood pressure was lower during estradiol-17 beta substitution than before treatment even when measured during exercise. No dose-dependent effect was observed in connection with the decrease in blood pressure. Irrespective of the pretreatment blood pressure levels, heart rate decreased during estradiol-17 beta substitution. The change was most marked in hypertensive and borderline hypertensive women. Estradiol-17 beta treatment did not influence heart rate during exercise. There was a statistically significant correlation between the decrease in resting heart rate and the increase in serum estrone concentration produced by the 4 mg daily doses of estradiol-17 beta in the normotensive subjects. Estradiol-17 beta substitution caused an increase in the blood volume in all groups of postmenopausal women. Estradiol-17 beta substitution with the 2 mg daily dose produced an increase in blood volume, which correlated significantly with the rise in both serum estrone and serum estradiol concentrations. This correlation was observed in both normotensive and hypertensive women. Cardiac output increased in the normotensive test subjects but decreased in the hypertensive and borderline hypertensive subjects.(ABSTRACT TRUNCATED AT 400 WORDS)