Endothelin levels decrease after oral and nonoral estrogen in postmenopausal women with increased cardiovascular risk factors.
OBJECTIVE
To establish levels of plasma endothelin-1 in postmenopausal women with increased CV risk as compared with healthy premenopausal women and to measure the effects of different forms of estrogen replacement on plasma endothelin-1.


METHODS
Prospective randomized study.


METHODS
University of Southern California Medical Center.


METHODS
We studied 18 postmenopausal women (mean age 53.4 +/- 4.9 years) with total cholesterol levels > 240 mg/dL divided into those with and without hypertension as well as in 10 healthy premenopausal women.


METHODS
The postmenopausal women were randomized to receive oral estrone sulfate, transdermal E2, or placebo for 30 days.


METHODS
We measured the endothelin-1 levels and total cholesterol at baseline and after 30 days of estrogen treatment.


RESULTS
In the postmenopausal women, endothelin-1 was higher (4.58 +/- 0.46 pg/mL) compared with premenopausal levels (2.80 +/- 0.46 pg/mL). In hypertensive postmenopausal women, endothelin-1 was 5.56 +/- 0.44 pg/mL. After estrogen, plasma endothelin-1 values decreased from 5.38 +/- 0.66 to 4.82 +/- 0.9 pg/mL with oral estrone sulfate, 4.84 +/- 0.25 to 4.54 +/- 0.49 pg/mL with transdermal E2, and did not change after placebo 4.76 +/- 0.71 to 4.81 +/- 0.46 pg/mL. In evaluating hypertensive women alone with estrogen therapy, plasma endothelin-1 showed the greatest decrement from 5.39 +/- 0.49 to 4.4 +/- 0.59 pg/mL (18.4%). The decrease in endothelin-1 with estrogen, which was statistically significant for the entire group, did appear to be influenced by the route of administration. Baseline plasma endothelin-1 levels were correlated positively to plasma cholesterol levels with a correlation coefficient of 0.632.


CONCLUSIONS
These data provide another potential mechanism explaining the cardioprotective effects of hormone replacement therapy.
Wilcox
J G
JG
Department of Obstetrics and Gynecology, University of Southern California School of Medicine, Los Angeles, USA.
Hatch
I E
IE
Gentzschein
E
E
Stanczyk
F Z
FZ
Lobo
R A
RA
D000279:Administration, Cutaneous; D000284:Administration, Oral; D000328:Adult; D002318:Cardiovascular Diseases; D002784:Cholesterol / Q000097:blood; D019332:Endothelin-1 / Q000097:blood*; D015914:Estrogen Replacement Therapy; D004967:Estrogens / Q000627:therapeutic use*; D004970:Estrone / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000494:pharmacology; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood; D008875:Middle Aged; D017698:Postmenopause / Q000097:blood*; D017697:Premenopause / Q000097:blood; D011446:Prospective Studies; D012016:Reference Values; D012307:Risk Factors
D019332:Endothelin-1; D004967:Estrogens; D004970:Estrone; D002784:Cholesterol; C017296:estrone sulfate