Effects of estrogen plus progesterone on hemodynamic and vascular reactivity in hypertensive postmenopausal women.

• AIMS: To investigate the medium-term effects of estrogen plus progesterone therapy (EPT) on vascular reactivity, endothelial function and hemodynamic responses in 20 hypertensive postmenopausal women. METHODS: This randomized, double-blind, cross-over, placebo-controlled study investigates the effect of 6 months of EPT (conjugated equine estrogen plus medroxyprogesterone). Blood pressure (office and ambulatory), heart rate and heart rate variability (HRV) were measured at baseline and following EPT/placebo treatment. In eight women, we used a wire-myograph to assess endothelial function and contractile response of subcutaneous arteries to transmural nerve stimulation (TNS) and exogenous noradrenaline. RESULTS: EPT decreased vascular reactivity to cumulative TNS compared with baseline (p<0.01) and placebo (p<0.05). Moreover, EPT diminished sensitivity to exogenous noradrenaline (p<0.05). Although EPT reinforced response to acetylcholine, we observed no difference in maximal relaxation induced by substance P or acetylcholine. EPT did not affect ambulatory blood pressure, heart rate or HRV. CONCLUSIONS: Oral combined medium-term EPT reduces adrenergic reactivity in subcutaneous arteries from treated hypertensive postmenopausal women. EPT might act postjunctionally at the adrenergic vascular receptor level. In the present study, EPT neither reduces sympathetic activity nor increases vagal tone, and thus does not support an effect on the central hemodynamic system.

Nyckelord

Acetylcholine

pharmacology

Arteries

drug effects

Blood Pressure

drug effects

Cross-Over Studies

Double-Blind Method

Estrogens

administration & dosage

pharmacology

Estrogens

Conjugated (USP)

administration & dosage

pharmacology

therapeutic use

Female

Heart Rate

drug effects

Hemodynamics

drug effects

Humans

Hypertension

drug therapy

Medroxyprogesterone

pharmacology

Middle Aged

Norepinephrine

pharmacology

Progesterone

pharmacology

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