John G. Wilcox

Cardioprotective effects of individual conjugated equine estrogens through their possible modulation of insulin resistance and oxidation of low-density lipoprotein*

OBJECTIVE To examine the independent effects on insulin sensitivity and antioxidative activity of the three most prevalent constituents in Premarin (Wyeth-Ayerst Laboratories, Philadelphia, PA): estrone sulfate (E1S), 50%; equilin sulfate (EqS), 25%, and 17 alpha-dihydroequilin sulfate (17 alpha-ES), 15%. DESIGN Prospective randomized cross-over study. SETTING University of Southern California Medical Center. PATIENT(S) Eight healthy postmenopausal women, mean age 53 +/- 2 years, and mean body mass index, 26 +/- 2 kg/m2, were enrolled. INTERVENTION(S) Each woman received, in randomized succession, daily oral doses of 17 alpha-ES (0.2 mg), E1S (0.625 mg), and EqS (0.3 mg) for 30 days. MAIN OUTCOME MEASURE(S) Oxidation of low-density lipoprotein (LDL) by negatively charged LDL (LDL-) and lag phase duration and measured the plasma glucose disappearance after insulin administration (K(itt)). RESULT(S) All three estrogen preparations demonstrated antioxidant effects with E1S demonstrating the most significant changes, followed by EqS and 17 alpha-ES. Using E1S, LDL-levels decreased from a baseline of 3.91 +/- 0.9 to 2.05 +/- 0.32 mg/dL and the lag time increased from 24.5 +/- 6.0 to 87.8 +/- 11.8 minutes. Changes in insulin tolerance tests revealed improved insulin action with the various estrogens. With EqS, K(itt) increased from 3.1% +/- 0.3% to 4.3% +/- 0.3% glucose/min, was intermediate with E1S and was least with 17 alpha-ES. CONCLUSION(S) All three conjugated equine estrogens demonstrated antioxidant activity. Also, some improved insulin action was demonstrated. To our knowledge, this is the first in vivo study to examine the effects of these components which may help explain, in part, some of the cardioprotective properties ascribed to Premarin.

Resolution of hormonal markers of ectopic gestation : A randomized trial comparing single-dose intramuscular methotrexate with salpingostomy

Objective To evaluate resolution of serum hCG and progesterone in patients with ectopic pregnancy receiving singledose intramuscular (IM) methotrexate as compared with those undergoing laparoscopic salpingostomy. Methods In this prospective randomized clinical trial, 75 hemodynamically stable women with a diagnosis of ectopic pregnancy were randomized to treatment with single-dose IM methotrexate (1 mg/kg) or laparoscopic salpingostomy. All women had initial, day 4, and weekly serum hCG and progesterone measurements taken until hCG levels were less than 15 mIU/mL. Methotrexate therapy was repeated if posttreatment day 7 hCG levels did not decrease by 15%, as compared with day 4 levels. Success rate was defined as ectopic resolution without the need for the alternate mode of therapy. Results Thirty-eight women were randomized to treatment with methotrexate and 37 to laparoscopic salpingostomy. The mean (± standard deviation) time required for serum progesterone concentrations to decrease to less than 1.5 ng/mL was significantly less for laparoscopic salpingostomy than for treatment with methotrexate: 7.8 ± 1.7 and 17.6 ± 2.2 days, respectively (P < .01). Within each treatment group, serum progesterone levels resolved (less than 1.5 ng/mL) more rapidly than did hCG levels (less than 15 mIU/mL) (P < .01). No further treatment was required once serum progesterone levels had decreased to less than 1.5 ng/mL. Success rates were similar in both groups: 94.7% (36 of 38) for methotrexate and 91.4% (33 of 36) for laparoscopic salpingostomy. Mean time required for hCG concentrations to decrease to less than 15 mIU/mL was significantly less for laparoscopic salpingostomy than for methotrexate therapy: 20.2 ± 2.7 and 27.2 ± 2.3 days, respectively (P < .05). Additional methotrexate injections were required in 15.8% (6 of 38) of women randomized to methotrexate therapy. Initial serum hCG levels for patients receiving additional methotrexate doses were 4830 ± 1588 mIU/mL as compared with 2133 ± 393 mIU/mL for women receiving only one dose (P = .07). Conclusion Serum progesterone levels of less than 1.5 ng/mL are a good predictor of ectopic pregnancy resolution regardless of treatment, and because its return to normal values occurs more rapidly than that of hCG levels, serum progesterone may be a better marker for predicting successful treatment. Although laparoscopic salpingostomy leads to faster resolution of hormonal markers of ectopic gestation, methotrexate is equally successful for treating small unruptured ectopic pregnancies. Initial hCG levels may be a marker for women requiring additional doses of methotrexate.

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. DESIGN Prospective randomized study. SETTING University of Southern California Medical Center. PATIENT(S) 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. INTERVENTION(S) The postmenopausal women were randomized to receive oral estrone sulfate, transdermal E2, or placebo for 30 days. MAIN OUTCOME MEASURE(S) We measured the endothelin-1 levels and total cholesterol at baseline and after 30 days of estrogen treatment. RESULT(S) 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. CONCLUSION(S) These data provide another potential mechanism explaining the cardioprotective effects of hormone replacement therapy.

Biologic effects of 17α-dihydroequilin sulfate

Objective To determine the independent biologic effects of 17 α -dihydroequilin sulfate. Design Prospective randomized study. Setting University of Southern California Medical Center. Patient(s) Twenty-one postmenopausal women, mean age 50±2 (±SEM) years, and mean body mass index 27±2. Intervention(s) Women were randomized to receive daily oral doses of either 1.25mg of estrone sulfate (E 1 S), 0.2mg of 17 α -dihydroequilin sulfate, or a combination. Three blood and urine samples were obtained before and after 30 and 90days of treatment. Result(s) After 30 and 90days of treatment, E 1 S alone increased sex hormone-binding globulin (SHBG) levels significantly, 19.7%±6.0% and 61.3%±13.0%, whereas 17 α -dihydroe-quilin sulfate reduced SHBG levels, 20.8%±68% and 12.4%±7.5%, respectively. Nevertheless, the combination of E 1 S and 17 α -dihydroequilin sulfate significantly increased SHBG levels, 103%±27.9% and 98.2%±19.1%, compared with baseline at 30 and 90days. Fewer changes were evident with corticosteroid-binding globulin (CBG). After 90days of treatment, CBG levels significantly increased 30.9%±5.5% with E 1 S, decreased by 7.2%±5.0% with 17 α -dihydroequilin sulfate, and, with the combination, significantly increased by 10.5%±2.4% compared with baseline. Changes in lipids and lipoproteins were more variable. However, high-density-lipoprotein cholesterol increased significantly with E 1 S at 30 and 90days compared with baseline, 96.5%±39% and 91.5%±22.6%, and with the combination increased 66.4%±13.3% and 79.2%±24.4%, respectively. Fewer changes were evident with 17 α -dihydroequilin sulfate alone, decreasing 4.4%±22% and 2.6%±21.3%. Urinary ratios of bone collagen equivalents-creatinine and calcium-creatinine decreased in all three groups. However, the combination group resulted in a significantly greater percentage decrease in bone collagen equivalents-creatinine than with E 1 S alone. Conclusion(s) 17 α -Dihydroequilin sulfate could modify some of the first-pass effects of conjugated equine estrogens and act synergistically with other conjugated equine estrogens to reduce bone resorption.