Postmenopausal hormone therapy. Is it useful for coronary prevention?

Hormone Therapy and Selective Estrogen Receptor Modulators for Prevention of Coronary Heart Disease in Postmenopausal Women

Coronary heart disease is the leading cause of morbidity and mortality in women older than the age of 50 in the United States today. Traditional cardiovascular risk factors (hyperlipidemia, glucose intolerance, and hypertension) are more clearly associated with significant cardiovascular risk after menopause. The increased incidence of cardiovascular events in postmenopausal women and the evidence that cardiovascular disease on average manifests a decade later in women compared with men suggests that estrogen deficiency may predispose women to a higher cardiovascular risk. Numerous biologic mechanisms have been proposed that relate use of hormone therapy (HT) to improved lipid profiles, insulin sensitivity, and vascular reactivity. Early observational trials in the last 2 decades showed a significant decrease in cardiovascular events. Recently published randomized clinical trial results, however, have led to uncertainty about the earlier established cardiovascular benefits of HT. To complicate issues further, alternative estrogenlike compounds, selective estrogen receptor modulators, are being introduced that appear to convey similar cardiovascular benefit and notably less cancer risk than HT. The newly released randomized trials on hormone and nonhormonal agents are reviewed.

The medicalization of menopause: critique and consequences

Menopause is in the process of becoming medicalized. Midlife and older women are being told that natural menopause is actually a deficiency condition requiring replacement hormones to maintain health and increase longevity. The three major diseases that are being linked with the lower estrogen levels of midlife and older women are heart disease, osteoporosis and, most recently, Alzheimer's disease. Primary prevention of these diseases is the rationale used for urging healthy women to take long-term hormones. Although there have been many challenges to these links and warnings against the widespread use of hormones, they have been either ignored or trivialized. In this article, the author examines mortality and morbidity statistics across and within nations and over time, critiques the major arguments used to support the notion that menopause places women at an increased risk of disease and that exogenous hormones reduce this risk, and discusses the adverse consequences of defining all midlife and older women as hormonally deficient and in need of medical intervention.

Venous endothelial function in postmenopausal women after six months of tibolone therapy

STUDY OBJECTIVE

To test venous endothelial function in long-term climateric therapy with tibolone.

DESIGN

Measurement of dorsal hand-vein diameter by venous occlusion plethysmography during infusion of norepinephrine (NE), bradykinin (BK), NG-monomethyl L-arginine (L-NMMA) and sodium nitroprusside (SNP).

SETTING

Plethysmography and Menopause Units. University Hospital Valdecilla. Santander. Spain.

PATIENTS

Eleven postmenopausal women having continuous treatment with oral tibolone (2.5 mg/day) for 6 months.

INTERVENTIONS

Three plethysmography studies were made: at baseline, and at three and six months of treatment.

MAIN OUTCOME MEASURES

Dorsal hand-vein diameter measured by venous occlusion plethysmography during infusion of NE, BK, L-NMMA and SNP.

RESULTS

(a) Baseline study: maximum dilation with BK was 54.2+/-10.2%. (b) Three-month study: BK dilation of 71.5+/-11.9%, with a significant increase of 17.3% (P=0.019) compared with baseline. (c) Six-month study: BK dilation of 77.5+/-11.9%, with a significant increase 23.3% (P=0.002) compared with baseline. Maximal vasodilation was reached with SNP in the three studies and L-NMMA infusion has a similar vasoconstrictor response in the three studies.

CONCLUSIONS

Long-term climateric therapy with tibolone improves vein endothelium-dependent vasodilation suggesting a positive impact of this drug on endothelial function.

Heart disease in women. Gender-specific statistics and prevention strategies for a population at risk

For decades, coronary artery disease (CAD) was thought to be primarily a disease of middle-aged men, in whom most research was conducted. But CAD afflicts a diverse patient population, and a major subset of those patients--women--present special diagnostic and therapeutic challenges for the primary care physician. In this article, Dr Rosenfeld provides an overview of CAD in women and discusses its causes and risk factors, prevention strategies, and gender-specific characteristics. She also examines the effect of gender-biased research on the views of both patients and physicians.

Effects on serum lipid profiles of continuous 17beta-estradiol, intermittent norgestimate regimens versus continuous combined 17beta-estradiol/norethisterone acetate hormone replacement therapy

OBJECTIVE

To compare the effects of a daily oral 1-mg dose of continuous 17beta-estradiol (E2) plus intermittent (3 days off, 3 days on) norgestimate (NGM) 90 microg (n = 221), an oral 2-mg dose of continuous E2 plus intermittent NGM 180 microg (n = 219), and an oral 2-mg dose of continuous E2 plus continuous norethisterone acetate (NETA) 1 mg (n = 217) on blood lipids and lipoproteins in postmenopausal women.

BACKGROUND

The present study was undertaken because some progestins have adverse effects on lipid profiles, thereby negating the favorable effects of estrogens.

METHODS

This was a multicenter, randomized, parallel-group trial that focused primarily on the 2 marketed regimens--E2 1 mg/NGM 90 microg and E2/NETA. Both subjects and investigators were blinded to the intermittent regimens; the continuous combined regimen was administered open-label. After a minimum 12-hour overnight fast, blood samples were collected at baseline and during months 7 and 12 to determine lipid and lipoprotein concentrations using validated methods.

RESULTS

E2 1 mg/NGM 90 microg was associated with significant (ie, the 95% CI did not include 0) increases in high-density lipoprotein cholesterol (HDL-C) (6.8% [95% CI = 4.7%, 9.0%] and 4.8% [2.3%, 7.2%] at months 7 and 12, respectively) and high-density lipoprotein 2 cholesterol (HDL2-C) (10.8% [6.2%, 15.3%] and 24.1% [18.9%, 29.4%]) concentrations, and decreases in total cholesterol (-7.7% [-9.0%, -6.3%] and -9.2% [-10.5%, -7.9%]), low-density lipoprotein cholesterol (-14.3% [-16.3%, -12.4%] and -14.9% [-16.7%, -13.2%]), and lipoprotein(a) (-30.6% [-41.4%, -20.0%] at month 12) concentrations. A significant difference (P < 0.001 by analysis of variance) between the E2 1-mg/NGM 90-microg and NETA regimens was seen for HDL-C and HDL2-C concentrations, which were elevated in subjects receiving E2 1 mg/NGM 90 microg but reduced (-9.1% [-11.1%, -7.1%] and -12.3% [-14.3%, -10.3%] for HDL-C at months 7 and 12, respectively; -14.2% [-18.0%, -10.4%] and -2.5% [-7.8%, +2.8%] for HDL2-C at months 7 and 12, respectively) in those receiving E2/NETA.

CONCLUSIONS

In the present study, continuous E2 1 mg/NGM 90 microg was associated with beneficial effects on lipids and lipoproteins in healthy postmenopausal women, effects that were greater at least for HDL-C and HDL2-C than those observed with continuous combined E2/NETA. The applicability of the study results to women with preexisting cardiovascular disease or dyslipidemia, or those who are overweight, remains to be investigated.

Vascular actions of estrogen and Alzheimer's disease

Women are two to three times more likely to develop late-onset Alzheimer's disease (AD) than age-matched men. A large number of observational reports and a few randomized clinical trials have indicated that estrogen replacement therapy (ERT) may retard the development and severity of dementia in postmenopausal women. A chronic inflammatory reaction mediated by abnormal deposition of proteins such as amyloid-beta (A beta) is central to the pathology of AD. We investigated the effect of low doses of conjugated estrogen (Premarin) in an animal model of A beta-induced vascular disruption and inflammatory reaction. Estrogen prevented vascular deposition of A beta, endothelial and vessel wall disruption with plasma leakage, platelet and mast cell activation, and characteristic features of an inflammatory reaction: adhesion and transmigration of leukocytes. The beneficial effect was lost when estrogen treatment was discontinued. This novel protective effect of estrogen against A beta-induced vascular dysfunction may contribute to the therapeutic efficacy of estrogen in AD and coronary vascular disease.

A novel intermittent regimen of norgestimate to preserve the beneficial effects of 17beta-estradiol on lipid and lipoprotein profiles

OBJECTIVE

This study was undertaken to evaluate the effects of 3 dosage levels of intermittent norgestimate plus a constant dose of 17beta-estradiol on blood lipid and lipoprotein concentrations in 236 postmenopausal women.

STUDY DESIGN

In this multicenter, double-blind, parallel-group trial the subjects were randomly assigned to receive 1 mg estradiol daily or 1 mg estradiol daily plus intermittent (3 days off and 3 days on) doses of 30 microg, 90 microg, or 180 microg norgestimate for 360 days.

RESULTS

The regimens of 1 mg estradiol plus 30 microg norgestimate and 1 mg estradiol plus 90 microg norgestimate increased concentrations of high-density lipoprotein cholesterol, HDL(2) high-density lipoprotein cholesterol, HDL(3) high-density lipoprotein cholesterol (except the regimen of 1 mg estradiol plus 30 microg norgestimate at 7 months), and apolipoprotein apo A-I. They decreased total cholesterol concentration, low-density lipoprotein cholesterol concentration, low-density lipoprotein/high-density lipoprotein ratio, apolipoprotein apo B concentration, and Lp(a) lipoprotein concentration, and they attenuated estradiol-induced increases in triglyceride concentrations. In contrast, the regimen of 1 mg estradiol plus 180 microg norgestimate reduced concentrations of high-density lipoprotein cholesterol, high-density lipoprotein HDL(3) cholesterol, and apolipoprotein apo A-I at 7 months and increased the low-density lipoprotein/high-density lipoprotein ratio at 7 months.

CONCLUSIONS

An intermittent regimen of norgestimate at 30 or 90 microg daily administered for 3 days off followed by 3 days on preserved the beneficial lipid and lipoprotein changes induced by continuous therapy with 1 mg 17beta-estradiol daily; however, 180 microg norgestimate did not do so.

Endogenous androgens and carotid intimal-medial thickness in women

The influence of endogenous androgens on atherosclerotic disease in women is unknown. In this study involving 101 pre- and post-menopausal females, we evaluated the relationship between serum androgen levels and both carotid artery intimal-medial thickness (IMT) and major cardiovascular risk factors. In addition to evaluation of blood pressure, body mass index, and waist-to-hip ratio, serum dehydroepiandrosterone sulfate (DHEA-S), androstenedione (A), total testosterone (TTS), free testosterone (FTS), insulin, cholesterol (total and high density lipoproteins), triglycerides, and glucose were measured. All women underwent carotid ultrasonography. Spearman correlation coefficients showed that serum DHEA-S and A levels were negatively related (P < 0.03-0.0004) to several IMT measures. Higher tertiles of DHEA-S, A, and FTS corresponded to significantly lower measures of carotid thickness. DHEA-S, and all androgens were inversely related to age (P < 0.03 or less), showing no unfavorable association with major cardiovascular risk factors. In contrast, serum DHEA-S was negatively associated with WHR (P < 0.02), while A was negatively associated with body mass index (P < 0.02). Stepwise multiple regression analysis indicated that A and FTS showed an inverse association with IMT measures (P < 0.05-0.001). In conclusion, our data indicate that in women serum DHEA-S and androgens decline with age and that normal hormonal levels are not associated with major cardiovascular risk factors. They also show that higher DHEA-S and androgen concentrations are related to lower carotid wall thickness; for A this association is independent of cardiovascular risk factors. Our results suggest that, in the physiological range, DHEA-S and androgens in women are correlated with lower risk of carotid artery atherosclerosis.

Hormone and nonhormone therapy for the maintenance of postmenopausal health: the need for randomized controlled trials of estrogen and raloxifene

Multiple health benefits have been postulated for the long-term use of hormone therapy in postmenopausal women, most notably for prevention of osteoporotic fractures and coronary heart disease, as well as several risks, including cancer of the breast and uterus and venous thromboembolism. Cardiovascular disease is the most common cause of death among postmenopausal women. If real, the reduction in risk of coronary heart disease by hormone use suggested by observational studies would likely outweigh the risks. The decision to initiate and maintain hormone therapy is complicated by uncertainties about estrogen's true benefits and risks. Raloxifene, a selective estrogen receptor modulator (SERM), appears to have many of the benefits of estrogen without the cancer risks. It is not known if SERMs can provide significant cardiovascular protection. This article reviews the relation of use of postmenopausal hormones and raloxifene to women's health and addresses the need for large randomized trials to quantify the effect of both postmenopausal estrogen and raloxifene on cardiovascular health.