Acute effects of transdermal estrogen on hemodynamic and vascular reactivity in elderly postmenopausal healthy women.
OBJECTIVE
The acute effects of estrogen on hemodynamic responses were studied with emphasis on the sympathoadrenal system and peripheral circulation.


METHODS
Eleven healthy postmenopausal women recruited from the population-based study BEDA were included in this randomized, double-blind, cross-over, placebo-controlled hypothesis-generating pilot study, where the effect of transdermal estrogen (17 beta-estradiol, 100 microg/24 h) was tested.


METHODS
Twenty-four hours after the patch with estrogen/placebo was attached, the blood pressure during rest and mental stress test was measured, together with blood samples for analysis of P-adrenaline and P-noradrenaline. Twenty-four-hour ambulatory registration of blood pressure and heart rate were recorded. Contractile properties and endothelial function of subcutaneous small arteries from gluteal biopsies were studied with the wire-myograph technique.


RESULTS
Estrogen treatment reduced both ambulatory systolic blood pressure (5 mmHg, P = 0.05), diastolic blood pressure (3 mmHg, P < 0.05) and heart rate (6-8 beats/min during morning hours, P < 0.01). Diastolic blood pressure during and after mental stress was significantly reduced after estrogen treatment (p < 0.01). The levels of P-adrenaline and P-noradrenaline were similar in both treatment protocols. The contractile properties of the arteries were not significantly influenced by estrogen. Substance P induced nitric oxide-dependent relaxation in both estrogen-treated and placebo-treated precontracted arteries. Acetylcholine, on the other hand, induced a non-nitric oxide, non-prostanoid-dependent hyperpolarization, which was inhibited by potassium-induced depolarization after placebo but not after estrogen treatment.


CONCLUSIONS
Acute administration of transdermal estrogen in clinically relevant doses modulates hemodynamics, probably by an altered parasympathetic balance, which might involve changes at the muscarinic receptor level.
Manhem
Karin
K
Clinical Experimental Research Laboratory, Heart and Lung Institute, Sahlgrenska University Hospital/Ostra, Sweden. Karin.Manheim@hjl.gu.se
Brandin
Lisa
L
Ghanoum
Bachar
B
Rosengren
Annika
A
Gustafsson
Helena
H
D000279:Administration, Cutaneous; D000368:Aged; D001158:Arteries / Q000502:physiology; D001794:Blood Pressure / Q000187:drug effects; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology; D004958:Estradiol / Q000008:administration & dosage*; D015914:Estrogen Replacement Therapy; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D010865:Pilot Projects; D017698:Postmenopause / Q000097:blood; D012016:Reference Values; D012867:Skin / Q000098:blood supply; D014661:Vasoconstriction / Q000187:drug effects; D014666:Vasomotor System / Q000187:drug effects*
D004958:Estradiol