Effects of estrogen plus progesterone on hemodynamic and vascular reactivity in hypertensive postmenopausal women.
OBJECTIVE
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.
Brandin
Lisa M
LM
Institute of Medicine, Department of Emergency and Cardiovascular Medicine, Sahlgrenska University Hospital, Sahlgrenska Academy, Göteborg University, Sweden.
Gustafsson
Helena
H
Ghanoum
Bachar
B
Milsom
Ian
I
Manhem
Karin
K
D000109:Acetylcholine / Q000494:pharmacology; D001158:Arteries / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004967:Estrogens / Q000008:administration & dosage / Q000494:pharmacology; D004966:Estrogens, Conjugated (USP) / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D006973:Hypertension / Q000188:drug therapy; D008525:Medroxyprogesterone / Q000494:pharmacology; D008875:Middle Aged; D009638:Norepinephrine / Q000494:pharmacology*; D011374:Progesterone / Q000494:pharmacology*
D004967:Estrogens; D004966:Estrogens, Conjugated (USP); D011374:Progesterone; D008525:Medroxyprogesterone; D000109:Acetylcholine; D009638:Norepinephrine