Postmenopausal hormone therapy: new questions and the case for new clinical trials

Systematic review and meta-analysis of the effects of menopause hormone therapy on risk of Alzheimer's disease and dementia

Introduction

Despite a large preclinical literature demonstrating neuroprotective effects of estrogen, use of menopausal hormone therapy (HT) for Alzheimer's disease (AD) risk reduction has been controversial. Herein, we conducted a systematic review and meta-analysis of HT effects on AD and dementia risk.

Methods

Our systematic search yielded 6 RCT reports (21,065 treated and 20,997 placebo participants) and 45 observational reports (768,866 patient cases and 5.5 million controls). We used fixed and random effect meta-analysis to derive pooled relative risk (RR) and 95% confidence intervals (C.I.) from these studies.

Results

Randomized controlled trials conducted in postmenopausal women ages 65 and older show an increased risk of dementia with HT use compared with placebo [RR = 1.38, 95% C.I. 1.16-1.64, p < 0.001], driven by estrogen-plus-progestogen therapy (EPT) [RR = 1.64, 95% C.I. 1.20-2.25, p = 0.002] and no significant effects of estrogen-only therapy (ET) [RR = 1.19, 95% C.I. 0.92-1.54, p = 0.18]. Conversely, observational studies indicate a reduced risk of AD [RR = 0.78, 95% C.I. 0.64-0.95, p = 0.013] and all-cause dementia [RR = .81, 95% C.I. 0.70-0.94, p = 0.007] with HT use, with protective effects noted with ET [RR = 0.86, 95% C.I. 0.77-0.95, p = 0.002] but not with EPT [RR = 0.910, 95% C.I. 0.775-1.069, p = 0.251]. Stratified analysis of pooled estimates indicates a 32% reduced risk of dementia with midlife ET [RR = 0.685, 95% C.I. 0.513-0.915, p = 0.010] and non-significant reductions with midlife EPT [RR = 0.775, 95% C.I. 0.474-1.266, p = 0.309]. Late-life HT use was associated with increased risk, albeit not significant [EPT: RR = 1.323, 95% C.I. 0.979-1.789, p = 0.069; ET: RR = 1.066, 95% C.I. 0.996-1.140, p = 0.066].

Discussion

These findings support renewed research interest in evaluating midlife estrogen therapy for AD risk reduction.

Cardiometabolic health, menopausal estrogen therapy and the brain: How effects of estrogens diverge in healthy and unhealthy preclinical models of aging

Research in preclinical models indicates that estrogens are neuroprotective and positively impact cognitive aging. However, clinical data are equivocal as to the benefits of menopausal estrogen therapy to the brain and cognition. Pre-existing cardiometabolic disease may modulate mechanisms by which estrogens act, potentially reducing or reversing protections they provide against cognitive decline. In the current review we propose mechanisms by which cardiometabolic disease may alter estrogen effects, including both alterations in actions directly on brain memory systems and actions on cardiometabolic systems, which in turn impact brain memory systems. Consideration of mechanisms by which estrogen administration can exert differential effects dependent upon health phenotype is consistent with the move towards precision or personalized medicine, which aims to determine which treatment interventions will work for which individuals. Understanding effects of estrogens in both healthy and unhealthy models of aging is critical to optimizing the translational link between preclinical and clinical research.

Mortality and morbidity in ageing men: Biology, Lifestyle and Environment

Males live shorter lives than women in all countries. The universality of shorter male life expectancy is a 21st Century phenomena. It occurs with the decline in infectious diseases and the rise in cardiovascular diseases accounting for mortality. Male/female differences in morbidity are not as succinctly characterized. Men have a higher prevalence of lethal diseases, which is linked to their lower life expectancy. Women have more non-lethal conditions such as depression and arthritis; which may also be linked in part to longer survival. Men have better physical functioning and less disability which is partly explained by gender differences in diseases and also by their greater strength, size, and stamina. Gender differences in risk factors for disease have changed over time with the prevalence and treatment of risk as well as differential behavior by gender. Examination of what are seen as basic molecular and cellular measures related to aging indicates men age faster than women; however, even these basic biological measures result from a combination of biology, behavior, and social factors.

Evaluation of atherosclerosis-related biomarkers during perimenopause: A prospective cohort study in women with endometriosis

AIM

Endometriosis is linked to asymptomatic atherosclerosis and increases the risk of cardiovascular disease (CVD). Vascular function tests are used to assess atherosclerosis, an important indicator of CVD development. In this study, we aimed to evaluate atherosclerosis-related biomarkers, such as vascular function tests and laboratory data, in perimenopausal women with endometriosis.

METHODS

This prospective cohort study enrolled 207 women (≥40 years old) with endometriosis. Laboratory data, ankle brachial index (ABI), and cardio-ankle vascular index (CAVI) were evaluated.

RESULTS

The mean age, CAVI, and ABI of the participants at the initial examination were 45.02 years, 6.9 ± 0.6, and 1.07 ± 0.06, respectively. In multiple regression analysis, no factor was associated with CAVI, but ABI was significantly correlated with elevated total cholesterol (TC), low-density lipoprotein cholesterol, and estradiol (partial regression coefficient [β] = -0.00074, p = 0.017; β = -0.00075, p = 0.033; and β = -0.00022, p = 0.015, respectively). The annual rate of change in CAVI showed a positive correlation with TC and pentosidine and a negative correlation with history of hormone therapy. Neither correlation was strong. In a comparison of three groups classified by the annual rate of change in CAVI, the group with the severe change had a higher level of pentosidine. In adjusted multinomial logistic regression analysis, high pentosidine levels were a risk factor for increased rate of change in CAVI.

CONCLUSIONS

The association between CAVI and serum markers related to lipid metabolism and ovarian function was mild. Longitudinal analysis of CAVI showed an association with pentosidine, which may be helpful in assessing atherosclerosis risk in women with endometriosis during perimenopause.

Ovarian steroid hormones: A long overlooked but critical contributor to brain aging and Alzheimer's disease

Ovarian hormones, particularly 17β-estradiol, are involved in numerous neurophysiological and neurochemical processes, including those subserving cognitive function. Estradiol plays a key role in the neurobiology of aging, in part due to extensive interconnectivity of the neural and endocrine system. This aspect of aging is fundamental for women's brains as all women experience a drop in circulating estradiol levels in midlife, after menopause. Given the importance of estradiol for brain function, it is not surprising that up to 80% of peri-menopausal and post-menopausal women report neurological symptoms including changes in thermoregulation (vasomotor symptoms), mood, sleep, and cognitive performance. Preclinical evidence for neuroprotective effects of 17β-estradiol also indicate associations between menopause, cognitive aging, and Alzheimer's disease (AD), the most common cause of dementia affecting nearly twice more women than men. Brain imaging studies demonstrated that middle-aged women exhibit increased indicators of AD endophenotype as compared to men of the same age, with onset in perimenopause. Herein, we take a translational approach to illustrate the contribution of ovarian hormones in maintaining cognition in women, with evidence implicating menopause-related declines in 17β-estradiol in cognitive aging and AD risk. We will review research focused on the role of endogenous and exogenous estrogen exposure as a key underlying mechanism to neuropathological aging in women, with a focus on whether brain structure, function and neurochemistry respond to hormone treatment. While still in development, this research area offers a new sex-based perspective on brain aging and risk of AD, while also highlighting an urgent need for better integration between neurology, psychiatry, and women's health practices.

Endogenous and Exogenous Estrogen Exposures: How Women's Reproductive Health Can Drive Brain Aging and Inform Alzheimer's Prevention

After advanced age, female sex is the major risk factor for late-onset Alzheimer's disease (AD), the most common cause of dementia affecting over 24 million people worldwide. The prevalence of AD is higher in women than in men, with postmenopausal women accounting for over 60% of all those affected. While most research has focused on gender-combined risk, emerging data indicate sex and gender differences in AD pathophysiology, onset, and progression, which may help account for the higher prevalence in women. Notably, AD-related brain changes develop during a 10-20 year prodromal phase originating in midlife, thus proximate with the hormonal transitions of endocrine aging characteristic of the menopause transition in women. Preclinical evidence for neuroprotective effects of gonadal sex steroid hormones, especially 17β-estradiol, strongly argue for associations between female fertility, reproductive history, and AD risk. The level of gonadal hormones to which the female brain is exposed changes considerably across the lifespan, with relevance to AD risk. However, the neurobiological consequences of hormonal fluctuations, as well as that of hormone therapies, are yet to be fully understood. Epidemiological studies have yielded contrasting results of protective, deleterious and null effects of estrogen exposure on dementia risk. In contrast, brain imaging studies provide encouraging evidence for positive associations between greater cumulative lifetime estrogen exposure and lower AD risk in women, whereas estrogen deprivation is associated with negative consequences on brain structure, function, and biochemistry. Herein, we review the existing literature and evaluate the strength of observed associations between female-specific reproductive health factors and AD risk in women, with a focus on the role of endogenous and exogenous estrogen exposures as a key underlying mechanism. Chief among these variables are reproductive lifespan, menopause status, type of menopause (spontaneous vs. induced), number of pregnancies, and exposure to hormonal therapy, including hormonal contraceptives, hormonal therapy for menopause, and anti-estrogen treatment. As aging is the greatest risk factor for AD followed by female sex, understanding sex-specific biological pathways through which reproductive history modulates brain aging is crucial to inform preventative and therapeutic strategies for AD.

Postmortem mitochondrial membrane permeability transition assessment of apoptotic cell death in brain and liver of insulin resistant, ovariectomised rats

The adverse alterations in mitochondrial functions can affect neuronal function negatively, as they play a crucial role in neuronal plasticity and death. Direct measurements of mitochondrial activity, including membrane potential and ATP production, are not easily achieved in post-mortem brain and liver samples because most organ functions cease to work after death; in fact, with increasing post-mortem intervals (PMI), the brain and liver tissues deteriorate rapidly. Standard procedures of mitochondria isolation, protein determination expressed as BSA equivalent, and spectrophotometric assessment of pore opening at 540 nm were employed. Our results showed that (a) intact mitochondria may be isolated from rat brain and liver of these rats after storage in animal body (in situ) at -20 °C for 7 days (168 h, post-mortem), (b) some population of these mitochondria can still take up exogenous Ca2+ and (c) they can still resist osmotically induced large amplitude swelling in a suitable buffer. The need for mitochondrial purity, structural integrity and abundance for functional studies are common hindrances that can encumber mitochondrial research. Therefore, this study is significant to have shown that PMI up to 7 days did not extensively, diminish MMPT pore status in normal and diabetic, ovariectomised rats. This can be relevant for forensic data mining.

Dehydroepiandrosterone supplementation is not beneficial in the late postmenopausal period in diet-induced obese rats

AIMS

Dehydroepiandrosterone (DHEA) is an adrenal steroid hormone that is a precursor of sexual hormones. It is reduced during aging and is strongly associated with insulin resistance and obesity. There is evidence for beneficial effects of this steroid, in both human and animal models, during perimenopause. However, the impact of DHEA treatment during late postmenopause on glucose metabolism is not clearly documented. We tested the hypothesis that DHEA supplementation could improve insulin sensitivity in an ovariectomized obese rat model (OVX) that was fed a high-fat diet for 11 weeks.

MAIN METHODS

Female Wistar rats at 8 weeks of age were OVX or SHAM-operated. Eight weeks after the surgery, the animals were randomly treated with vehicle or DHEA for 3 weeks. Food intake, metabolic parameters and insulin sensitivity were evaluated.

KEY FINDINGS

Following the ovariectomy, increased body weight gain, adiposity index, and feeding efficiency were observed, despite there being no change in food and energy intake. The OVX rats also displayed glucose intolerance, insulin resistance, decreased insulin-induced IRS1/2 tyrosine phosphorylation in the skeletal muscle, and reduced serum VLDL-c and TAG levels. OVX rats treated with 10 mg/kg DHEA (OVX + DHEA) exhibited estradiol (E₂) serum levels similar to SHAM animals, with no change in uterus mass. DHEA treatment also resulted in an increase in energy intake.

SIGNIFICANCE

Despite the positive effects of DHEA supplementation observed in menopausal women and ovariectomized rats, a potential negative effect on glucose metabolism and insulin action in the late postmenopausal condition in diet-induced obese OVX rats are reported.

Menopausal hormone therapy: a better and safer future

Major advances in menopause hormone therapy (MHT) hold promise in the future of better and safer care for women at and after the menopause. The principal advances are: (1) the critical window or 'window of opportunity' in the 10 years or so after the menopause, during which the benefits of MHT in healthy women exceed any risks; (2) use of transdermal instead of oral administration of estrogen to reduce the risk of venous thromboembolism; (c) investigation of the use of oral micronized progesterone (MP) and vaginal MP to prevent endometrial hyperplasia and carcinoma without any increased risk of breast cancer and venous thromboembolism in postmenopausal women receiving estrogens; vaginal MP prevents endometrial proliferation in the short term but the long-term effects in MHT remain to be established; (4) investigation into the use of intrauterine levonorgestrel-releasing devices (LNG-IUDs), which are an attractive form of MHT in perimenopausal women, providing contraception and reducing uterine bleeding, although the risk of breast cancer with LNG-IUDs requires clarification. Women in the future can look forward to a symptom-free menopause and to safer and more beneficial MHT.

Prevention of Alzheimer's disease, cerebrovascular disease and dementia in women: the case for menopause hormone therapy

Alzheimer's disease, cerebrovascular disease and aging-related cognitive impairment and dementia (ARCID) increase in prevalence in women with advancing age. The development of Alzheimer's disease, cerebrovascular disease and ARCID may be postponed or prevented by protective measures including the active treatment of vascular risk factors and continuing exercise and healthy lifestyle from early- and mid-life onward. Bilateral oophorectomy before the natural menopause is associated with an increased incidence of ARCID and the increased risk is significantly reduced by estrogen therapy. Recent advances in menopause hormone therapy including transdermal estrogen therapy have favorably influenced the balance of benefits and risks. A case can be made for menopause hormone therapy in healthy postmenopausal women for 5-10 years starting during the menopausal transition (the 'window of opportunity'), together with all other protective measures, to delay or prevent the development of ARCID in later life.

Association of Mid-Life Changes in Body Size, Body Composition and Obesity Status with the Menopausal Transition

The mid-life period is a critical window for increases in body weight and changes in body composition. In this review, we summarize the clinical experience of the menopausal transition by obesity status, and examine the evidence regarding the menopausal transition and reproductive hormones effects on body weight, body composition, or fat distribution. Mid-life obesity is associated with a different menopausal experience including associations with menstrual cycle length prior to the final menstrual period (FMP), age at the FMP, and higher prevalence of vasomotor symptoms. The menopausal transition is associated with weight gain and increased central body fat distribution; the majority of evidence suggests that changes in weight are due to chronological aging whereas changes in body composition and fat distribution are primarily due to ovarian aging. Continuous and regular physical activity during mid-life may be an efficacious strategy to counteract the age-related and menopause-related changes in resting energy expenditure and to prevent weight gain and abdominal adiposity deposition.

Estrogen signaling in metabolic inflammation

There is extensive evidence supporting the interference of inflammatory activation with metabolism. Obesity, mainly visceral obesity, is associated with a low-grade inflammatory state, triggered by metabolic surplus where specialized metabolic cells such as adipocytes activate cellular stress initiating and sustaining the inflammatory program. The increasing prevalence of obesity, resulting in increased cardiometabolic risk and precipitating illness such as cardiovascular disease, type 2 diabetes, fatty liver, cirrhosis, and certain types of cancer, constitutes a good example of this association. The metabolic actions of estrogens have been studied extensively and there is also accumulating evidence that estrogens influence immune processes. However, the connection between these two fields of estrogen actions has been underacknowledged since little attention has been drawn towards the possible action of estrogens on the modulation of metabolism through their anti-inflammatory properties. In the present paper, we summarize knowledge on the modification inflammatory processes by estrogens with impact on metabolism and highlight major research questions on the field. Understanding the regulation of metabolic inflammation by estrogens may provide the basis for the development of therapeutic strategies to the management of metabolic dysfunctions.

17-β Oestradiol prevents cardiovascular dysfunction in post-menopausal metabolic syndrome by affecting SIRT1/AMPK/H3 acetylation

BACKGROUND AND PURPOSE

Oestrogen therapy is known to induce cardioprotection in post-menopausal metabolic syndrome (PMS). Hence, we investigated the effect of 17-β oestradiol (E2) on functional responses to angiotensin II and cardiovascular dysfunction in a rat model of PMS.

EXPERIMENTAL APPROACH

PMS was induced in ovariectomized rats by feeding a high-fat diet for 10 weeks. Isometric tension responses of aortic rings to angiotensin II were recorded using an isometric force transducer. TUNEL assay and immunoblotting was performed to assess apoptosis and protein expression respectively in PMS.

KEY RESULTS

Endothelial dysfunction in PMS was characterized by enhanced angiotensin II-induced contractile responses and impaired endothelial dependent vasodilatation. This was associated with an increased protein expression of AT1 receptors in the aorta and heart in PMS. PMS induced cardiac apoptosis by activating Bax and PARP protein expression. These changes were associated with a down-regulation in the expression of silent information regulation 2 homologue (SIRT1)/P-AMP-activated PK (AMPK) and increased H3 acetylation in aorta and heart. E2 partially suppressed angiotensin II-induced contractions, restored the protein expression of SIRT1/P-AMPK and suppressed H3 acetylation. The role of SIRT1/AMPK was further highlighted by administration of sirtinol and compound C (ex vivo), which enhanced angiotensin II contractile responses and ablated the protective effect of E2 on PMS.

CONCLUSION AND IMPLICATIONS

Our results provide novel mechanisms for PMS-induced cardiovascular dysfunction involving SIRT1/AMPK/ histone H3 acetylation, which was prevented by E2. The study suggests that therapies targeting SIRT1/AMPK/epigenetic modifications may be beneficial in reducing the risk of cardiovascular disorders.

Oophorectomy, estrogen, and dementia: a 2014 update

Current evidence suggests that estrogen may have beneficial, neutral, or detrimental effects on the brain depending on age, type of menopause (natural versus induced), or stage of menopause (early versus late), consistent with the timing hypothesis. Three studies have now compared women who underwent bilateral oophorectomy before menopause with referent women and consistently showed an increased risk of cognitive decline and dementia. These studies suggest a sizeable neuroprotective effect of estrogen naturally produced by the ovaries before age 50 years. In this article, we focus on neuroprotection as related to cognitive decline and dementia. Several case-control studies and cohort studies also showed neuroprotective effects in women who received estrogen treatment (ET) in the early postmenopausal stage (most commonly at ages 50-60 years). The majority of women in those observational studies had undergone natural menopause and were treated for the relief of menopausal symptoms. However, the clinical trials by the Women's Health Initiative showed that women who initiated ET alone or in combination with a progestin in the late postmenopausal stage (ages 65-79 years) experienced an increased risk of dementia and cognitive decline regardless of the type of menopause. Three observational studies have now formally tested the timing hypothesis, and showed that the neuroprotective or harmful effects of estrogen depend on age at the time of initiation of treatment and on stage of menopause. Therefore, women who undergo bilateral oophorectomy before the onset of menopause or women who experience premature or early natural menopause should be considered for hormonal treatment until the average age of natural menopause (around age 50 years). Recommendations for the use of ET by women who experience natural menopause at typical ages remain less certain, and more research is needed.

Rationale and design of the Kronos Early Estrogen Prevention Study (KEEPS) and the KEEPS Cognitive and Affective sub study (KEEPS Cog)

This manuscript describes the study design and rationalle for the Kronos Early Estrogen Prevention Study (KEEPS) and the KEEPS Cognitive and Affective ancillary study (KEEPS Cog). KEEPS is a multicenter, randomized, double-blinded, placebo-controlled trial, designed to test the hypothesis that low-dose hormone therapy (HT) initiated in recently postmenopausal women will reduce the progression of subclinical atherosclerosis as measured by carotid artery intima-media thickness (CIMT) and coronary artery calcification (CAC) over four years. The KEEPS Cog ancillary study was designed to assess potential estrogenic treatment effects on cognition and mood. We present the KEEPS trial in the context of issues raised by the Women's Health Initiative (WHI) and the Women's Health Initiative Memory Study (WHIMS). Here we also describe the most recent results and ongoing HT-related research studies designed to address similar issues. This article is part of a Special Issue entitled Hormone Therapy.

Estrogen and the brain: does estrogen treatment improve cognitive function?

In this paper we describe potential reasons for the discrepancies between data from basic sciences and observational studies and those of large treatment studies investigating the association between brain function and sex steroids. Observational studies which often showed positive associations between hormone use and cognition can be affected by 'recall bias' and 'healthy user bias', while outcomes of treatment studies were hypothesized to be modified by age at treatment, age at or type of menopause, health status, addition of a progestogen or type of estrogen treatment. However, meta-analyses of data from treatment studies negate many of these hypotheses showing at best mainly short-term (up to 6 months) positive effects of estrogen treatment on cognition regardless of age. This positive effect may reverse, particularly in older women with prolonged hormone treatment, which was predominantly seen after addition of progestogen. Medroxyprogesterone acetate seemed to have worse effects on cognition than other types of progestogen in these long-term studies. Estradiol with or without a progestogen was three times more likely to have positive effects on cognition than conjugated equine estrogens. However, two-thirds of studies showed no associations at all which may be an underestimate given the possibility of publication bias. We briefly review alternative treatments, such as testosterone and soy-derived supplements, but currently insufficient data are available for conclusive comments. Women who have undergone surgical menopause or who undergo natural menopause before age 47 may benefit most from hormone treatment and a special case may need to be made for this group. Long-term safety studies for this group are urgently needed.

A lack of ovarian function increases neuroinflammation in aged mice

Although several lines of evidence have indicated that menopause is associated with increased susceptibility to neurological disorders, the mechanisms involved in this phenomenon remain to be elucidated. Because neuroinflammation is a common feature of a number of brain diseases, we hypothesized that the cessation of ovarian functions and the consequent decrease in estrogen receptor (ER)-mediated antiinflammatory activity may represent a trigger for postmenopausal brain dysfunctions. The aim of the present study was to investigate the effects of aging and surgical menopause on the activity of ER in neuroinflammation. The present study shows that ER genes are expressed in the hippocampus, but ER transcriptional activity decreases significantly beginning at 12 months of age in intact and ovariectomized mice. With ovariectomy, we observe an age-dependent accumulation of mRNA encoding inflammatory mediators (e.g. TNFα, IL1β, and macrophage inflammatory protein-2) and changes in the morphology of astroglia and microglia. In addition, we show that aging itself is coupled with an exaggerated response to acute inflammatory stimuli with a major accumulation of TNFα, IL1β, macrophage inflammatory protein-2, and macrophage chemoattractant protein-1 mRNA in response to lipopolysaccharide administration. The response to acute inflammatory stimuli appears to be differentially modulated by the duration of hormone deprivation in 12-month-old mice. Taken together, the present results show that aging is associated with decreased ER activity, despite continuous ER synthesis, and that age-dependent neuroinflammation is strongly influenced by hormone deprivation.

Effects of oral estradiol and levonorgestrel on cardiovascular risk markers in postmenopausal women

PURPOSE

This study aimed at investigating changes in postmenopausal women's cardiovascular risk markers induced by hormone therapy regimens of low (1.0 mg) or ultra-low (0.5 mg) doses of micronized estradiol (mE(2)) and levonorgestrel (LNG).

METHODS

Three randomized placebo-controlled trials were reanalyzed with regard to changes in cardiovascular risk markers, such as serum lipids, lipoproteins, and coagulation parameters. Trial 1 (n = 210) was an 8-week study comparing the effects of 1.0 or 0.5 mg of unopposed mE(2) on menopausal symptoms. Trial 2 (n = 194) was a 24-week study comparing the effects of 1.0 mg of mE(2) combined with 10, 20, or 40 μg of LNG on endometrial safety. Trial 3 (n = 195) was a 52-week study comparing the effects of 1.0 or 0.5 mg mE(2) + 40 μg LNG on bone metabolism.

RESULTS

1.0 mg of unopposed mE(2) reduced low-density lipoprotein cholesterol (LDL-C) after as little as 8 weeks. 1.0 mg mE(2) for 24 weeks lowered the serum levels of total cholesterol (TC) and LDL-C, whereas the addition of LNG caused decreases in the levels of high-density lipoprotein cholesterol (HDL-C) and triglycerides (TG) in a dose-dependent fashion. 1.0 or 0.5 mg mE(2) + 40 μg LNG for 52 weeks also lowered the levels of TC, HDL-C, LDL-C, and TG. Both regimens slightly lowered antithrombin and Protein C activities within normal limits.

CONCLUSIONS

Hormone therapy using 1.0 or 0.5 mg of mE(2) and LNG lowers the serum levels of TC, HDL-C, LDL-C, and TG without significantly affecting coagulation/fibrinolysis parameters.

Are all estrogens created equal? A review of oral vs. transdermal therapy

BACKGROUND

To compare oral and transdermal delivery systems in domains of lipid effects; cardiovascular, inflammatory, and thrombotic effects; effect on insulin-like growth factor, insulin resistance, and metabolic syndrome; sexual effects; metabolic effects including weight; and effects on target organs bone, breast, and uterus.

METHODS

Review of the literature 1990-2010. Studies selected on basis of applicability, quality of data, and relationship to topic.

RESULTS

Data applicable to the comparisons of oral versus transdermal delivery systems for postmenopausal estrogen therapy were utilized to perform a review and formulate conclusions.

CONCLUSIONS

Significant differences appear to exist between oral and transdermal estrogens in terms of hormonal bioavailability and metabolism, with implications for clinical efficacy, potential side effects, and risk profile of different hormone therapy options, but neither results nor study designs are uniform. Bypassing hepatic metabolism appears to result in more stable serum estradiol levels without supraphysiologic concentrations in the liver. By avoiding first-pass metabolism, transdermal hormone therapy may have less pronounced effects on hepatic protein synthesis, such as inflammatory markers, markers of coagulation and fibrinolysis, and steroid binding proteins, while oral hormone therapy has more pronounced hyper-coagulant effects and increases synthesis of C-reactive protein and fibrinolytic markers. Both oral and transdermal delivery systems have beneficial effects on high-density lipoprotein cholesterol to low-density lipoprotein cholesterol ratios (oral>transdermal), while the transdermal system has more favorable effects on triglycerides. Incidence of metabolic syndrome and weight gain appears to be slightly lower with a transdermal delivery system. Oral estrogen's significant increase in hepatic sex hormone binding globulin production lowers testosterone availability compared with transdermal delivery, with clinically relevant effects on sexual vigor.

Menopausal hormone therapy: what we know now

OVERVIEW

This article describes the findings and limitations of the major research thus far on hormone therapy, particularly that of the Women's Health Initiative; examines practice recommendations; clarifies common terminology related to menopause and hormone therapy; and provides the implications for nurses. This is part one of a four-part series on postmenopausal health.

KEYWORDS

bioidentical hormones, combined estrogen and progestogen therapy, estrogen, estrogen therapy, hormone therapy, menopause, menopausal transition, postmenopause, progestin, progestogen, women's health, Women's Health Initiative.

Trends in menopausal hormone therapy use of US office-based physicians, 2000-2009

OBJECTIVE

The aim of this study was to evaluate recent trends and the adoption of practice recommendations for menopausal hormone therapy (MHT) use from 2001 to 2009 by formulation, dose, woman's age, and characteristics of physicians reporting MHT visits.

METHODS

The IMS Health (Plymouth Meeting PA) National Disease and Therapeutic Index physician survey data from 2001 to 2009 were analyzed for visits in which MHT use was reported by US office-based physicians. Estimated national volume of visits for which MHT use was reported.

RESULTS

MHT use declined each year since 2002. Systemic MHT use fell from 16.3 million (M) visits in 2001 to 6.1 M visits in 2009. Declines were greatest for women 60 years or older (64%) but were also substantial for women younger than 50 years (59%) and women 50 to 59 years old (60%). Women 60 years or older accounted for 37% of MHT use. Lower dose product use increased modestly, from 0.7 M (2001) to 1.3 M (2009), as did vaginal MHT use, from 1.8 M (2001) to 2.4 M (2009). Declines in continuing systemic MHT use (65%) were greater than for newly initiated MHT use (51%). Compared with other physicians, obstetrician/gynecologists changed their practices less, thereby increasing their overall share of total MHT visits from 72% (2001) to 82% (2009).

CONCLUSIONS

Total MHT use has steadily declined. Increased use of lower dose and vaginal products reflects clinical recommendations. Uptake of these products, however, has been modest, and substantial use of MHT continues in older women.

Gender differences of plaque characteristics in elderly patients with stable angina pectoris: an intravascular ultrasonic radiofrequency data analysis

The purpose of this study was to evaluate the relation between gender and plaque characteristics assessed by virtual histology-intravascular ultrasound (VH-IVUS) in patients with stable angina pectoris. Preinterventional VH-IVUS image was available for analysis in 88 men and 60 women patients. Women had significantly smaller vessel volume (12.7 ± 3.9 versus 14.5 ± 4.2 mm(3)/mm, P = .01) and smaller plaque volume (8.4 ± 3.5 versus 9.7 ± 3.5 mm(3)/mm, P = .04). However, these differences were no longer significant when corrected for body surface area (BSA). In VH-IVUS analysis, women had significantly higher dense calcium when corrected for BSA in the culprit lesion (volume: 0.32 ± 0.26 versus 0.44 ± 0.40 mm(3)/mm/BSA, P = .03; proportion: 8.2 ± 6.1 versus 11.2 ± 7.6%, P = .009). VH-IVUS analysis of plaque components in elderly patients with stable angina showed that women had higher calcium contents compared with men.

Oophorectomy, menopause, estrogen treatment, and cognitive aging: clinical evidence for a window of opportunity

The neuroprotective effects of estrogen have been demonstrated consistently in cellular and animal studies but the evidence in women remains conflicted. We explored the window of opportunity hypothesis in relation to cognitive aging and dementia. In particular, we reviewed existing literature, reanalyzed some of our data, and combined results graphically. Current evidence suggests that estrogen may have beneficial, neutral, or detrimental effects on the brain depending on age at the time of treatment, type of menopause (natural versus medically or surgically induced), or stage of menopause. The comparison of women who underwent bilateral oophorectomy with referent women provided evidence for a sizeable neuroprotective effect of estrogen before age 50 years. Several case-control studies and cohort studies also showed neuroprotective effects in women who received estrogen treatment (ET) in the early postmenopausal stage (most commonly at ages 50-60 years). The majority of women in those observational studies had undergone natural menopause and were treated for the relief of menopausal symptoms. However, recent clinical trials by the Women's Health Initiative showed that women who initiated ET alone or in combination with a progestin in the late postmenopausal stage (ages 65-79 years) experienced an increased risk of dementia and cognitive decline regardless of the type of menopause. The current conflicting data can be explained by the window of opportunity hypothesis suggesting that the neuroprotective effects of estrogen depend on age at the time of administration, type of menopause, and stage of menopause. Therefore, women who underwent bilateral oophorectomy before the onset of menopause or women who experienced premature or early natural menopause should be considered for hormonal treatment until approximately age 51 years.

Oophorectomy, menopause, estrogen, and cognitive aging: the timing hypothesis

BACKGROUND

The concept of neuroprotective effects of estrogen in women remains controversial.

OBJECTIVE

To explore the timing hypothesis in relation to cognitive aging and dementia.

METHODS

We reviewed existing literature, conducted some reanalyses, and combined results graphically.

RESULTS

Current evidence suggests that estrogen may have either protective effects or harmful effects on the brain depending on age, type of menopause (natural versus surgical), or stage of menopause. The comparison of women with ovarian conservation versus women who underwent bilateral oophorectomy provided evidence for a sizeable neuroprotective effect of estrogen in women in the premenopausal years (most commonly before age 50 years). Several case-control studies and cohort studies also showed a neuroprotective effect in women who received estrogen treatment in the early postmenopausal phase (most commonly at ages 50-60 years). However, recent clinical trials showed that women who initiated estrogen treatment in the late postmenopausal phase (ages 65-79 years) experienced an increased risk of dementia and cognitive decline.

CONCLUSION

The neuroprotective effects of estrogen depend on age, type of menopause, and stage of menopause (timing hypothesis).

Health correlates and mode of administration of hormones--are there any differences between parenteral and oral estrogen preparations?

OBJECTIVES

To investigate use-associated differences between parental and oral hormone therapy (HT) users in reference to HT non-users regarding self-rated general health status, quality of life, health service utilization, and selected chronic diseases.

METHODS

All cases of last-week medicine use were recorded among 2248 women aged 40-79 who participated in the German Health Interview and Examination Survey 1997-1999. 89 current parenteral HT users and 322 oral HT users were identified. Health correlates were compared between the two groups in reference to HT non-users.

RESULTS

Oral HT users had a poorer current health status as well as an impaired health status compared to the year before, were less satisfied with their health and life in general, and showed a lower quality of life regarding 'body pain' and 'vitality' in comparison with hormone non-users (all p<.05). Parenteral HT users showed no significant difference compared with HT non-users and oral HT users, respectively, in these health correlates except for a less satisfaction with health found in comparison with HT non-users (p=.002). Prevalences of cerebral-cardiovascular diseases were not different among women using parenteral or oral HT use. Parenteral HT users visited the offices of general practitioner and gynecologists more frequently than oral HT users as well as hormone non-users (all p<.05).

CONCLUSIONS

Oral HT use is associated with a negative assessment for health well-being whereas parenteral HT use shows largely a neutral effect. Further designated studies could clarify whether the mode of hormone administration consistently affects health-related quality of life and whether the mode of hormone treatment influences the choice of outpatient facilities for surveillance of therapy.

Increased cardiovascular mortality after early bilateral oophorectomy

OBJECTIVE

To investigate the mortality associated with cardiovascular diseases and the effect of estrogen treatment in women who underwent unilateral or bilateral oophorectomy before menopause.

DESIGN

We conducted a cohort study with long-term follow-up of women in Olmsted County, MN, who underwent either unilateral or bilateral oophorectomy before the onset of menopause from 1950 through 1987. Each member of the oophorectomy cohort was matched by age to a referent woman from the same population who had not undergone any oophorectomy. We studied the mortality associated with cardiovascular disease in a total of 1,274 women with unilateral oophorectomy, 1,091 women with bilateral oophorectomy, and 2,383 referent women.

RESULTS

Women who underwent unilateral oophorectomy experienced a reduced mortality associated with cardiovascular disease compared with referent women (hazard ratio [HR], 0.82; 95% CI, 0.67-0.99; P = 0.04). In contrast, women who underwent bilateral oophorectomy before age 45 years experienced an increased mortality associated with cardiovascular disease compared with referent women (HR, 1.44; 95% CI, 1.01-2.05; P = 0.04). Within this age stratum, the HR for mortality was significantly increased in women who were not treated with estrogen through age 45 years or longer (HR, 1.84; 95% CI, 1.27-2.68; P = 0.001) but not in women treated with estrogen (HR, 0.65; 95% CI, 0.30-1.41; P = 0.28; test of interaction, P = 0.01). Mortality was further increased after deaths associated with cerebrovascular causes were excluded.

CONCLUSIONS

Bilateral oophorectomy performed before age 45 years is associated with increased cardiovascular mortality, especially with cardiac mortality. However, estrogen treatment may reduce this risk.

Nonlinear association between serum testosterone levels and coronary artery disease in Iranian men

Previous studies have shown controversial results about the role of androgens in coronary artery disease (CAD). We performed this study to examine and compare the relationship between androgenic hormones and CAD using conventional linear statistical techniques as well as novel non-linear approaches. The study was conducted on 502 consecutive men who were referred for selective coronary angiography at Tehran Heart Center due to different indications. We studied the relationship between androgenic hormones and CAD by using the generalized linear models, generalized additive models, and neural networks. Free testosterone (fT), total testosterone (tT) and dehydroepiandrosterone sulfate levels in patients with significant CAD versus normal individuals were 6.69 +/- 3.20 pg/ml, 16.60 +/- 6.66 nm/l, and 113.38 +/- 72.9 microg/dl versus 7.12 +/- 3.58 pg/ml, 15.82 +/- 7.26 nm/l, and 109.03 +/- 68.19 microg/dl, respectively (P > 0.05). The Generalized linear models was unable to show any significant relationship between androgenic hormones and CAD, while generalized additive model and neural networks supported the significant effect of androgenic hormones on CAD. This finding suggests a nonlinear association of tT levels with CAD: lower levels have a preventive effect on CAD, whereas higher values increase the risk of CAD. Emphasizing the non-linearity of the variables may provide new insight into the possible explanation of the effect of androgenic hormones on CAD.

Cardiovascular effects of physiological and standard sex steroid replacement regimens in premature ovarian failure

Current hormone replacement therapy may not optimize cardiovascular health in women with premature ovarian failure. We compared the effects of physiological and standard sex steroid replacement regimens on cardiovascular health in these women. In an open-label, randomized, controlled crossover trial, 34 women with premature ovarian failure were randomly assigned to 4-week cycles of physiological (transdermal estradiol and vaginal progesterone) and standard (oral ethinylestradiol and norethisterone) therapy for 12 months. Cardiovascular health was assessed by 24-hour ambulatory blood pressure, arterial stiffness, and renal and humoral factors. Eighteen women (19 to 39 years of age) completed the 28-month protocol. Both regimens caused similar suppression of luteinizing hormone and follicle-stimulating hormone and provided symptom relief. In comparison with the standard regimen, physiological sex steroid replacement caused lower mean 24-hour systolic and diastolic blood pressures throughout the 12-month treatment period (ANOVA; P<or=0.0001 for both): systolic blood pressure was 7.3 mm Hg (95% CI: 2.5 to 12.0 mm Hg) and diastolic was 7.4 mm Hg (95% CI: 3.9 to 11.0 mm Hg) lower at 12 months. Although there were no differences in arterial stiffness, physiological sex steroid replacement reduced plasma angiotensin II (ANOVA; P=0.007) and serum creatinine (ANOVA; P=0.015) concentrations without altering plasma aldosterone concentrations. In comparison with a standard regimen, physiological sex steroid replacement in women with premature ovarian failure results in lower blood pressure, better renal function, and less activation of the renin-angiotensin system. These findings have major implications for the future cardiovascular health of young women who require long-term sex steroid replacement therapy.

Estrogen and mechanisms of vascular protection

Estrogen has antiinflammatory and vasoprotective effects when administered to young women or experimental animals that appear to be converted to proinflammatory and vasotoxic effects in older subjects, particularly those that have been hormone free for long periods. Clinical studies have raised many important questions about the vascular effects of estrogen that cannot easily be answered in human subjects. Here we review cellular/molecular mechanisms by which estrogen modulates injury-induced inflammation, growth factor expression, and oxidative stress in arteries and isolated vascular smooth muscle cells, with emphasis on the role of estrogen receptors and the nuclear factor-kappaB (NFkappaB) signaling pathway, as well as evidence that these protective mechanisms are lost in aging subjects.

Effects of isoflavones on the skin of postmenopausal women: a pilot study

OBJECTIVE

The aim of this study was to evaluate the effects of isoflavones on the skin of postmenopausal women.

DESIGN

A prospective study was performed with 30 postmenopausal women before and immediately after the end of treatment with 100 mg/day of an isoflavones-rich, concentrated soy extract for six months. A skin punch was performed in the gluteal region for sample collection before and immediately after the treatment program. Morphometric determination of epidermal thickness, the papillary index (wrinkling), and the amount of dermal elastic and collagen fibers was assessed. In addition, the number of blood vessels in the sample was also evaluated. The paired Student's t-test was used for statistical analysis (P < 0.05).

RESULTS

Isoflavone treatment resulted in a 9.46% increase in the thickness of the epidermis in 23 patients. In addition, the papillary index was reduced in 21 women. The papillary index was inversely proportional to skin wrinkling, i.e., there were a large number of papillae after treatment. The amount of collagen in the dermis was increased in 25 women (86.2%). In 22 women (75.8%) we observed that the number of elastic fibers increased. The number of dermal blood vessels was significantly increased in 21 women.

CONCLUSION

Our data show that the use of a concentrated, isoflavone-rich soy extract during six consecutive months caused significant increases in epithelial thickness, the number of elastic and collagen fibers, as well as the blood vessels.

Long-term effects of bilateral oophorectomy on brain aging: unanswered questions from the Mayo Clinic Cohort Study of Oophorectomy and Aging

In the Mayo Clinic Cohort Study of Oophorectomy and Aging, women who had both ovaries removed before reaching natural menopause experienced a long-term increased risk of parkinsonism, cognitive impairment or dementia, and depressive and anxiety symptoms. Here, we discuss five possible mechanistic interpretations of the observed associations; first, the associations may be non-causal because they result from the confounding effect of genetic variants or of other risk factors; second, the associations may be mediated by an abrupt reduction in levels of circulating estrogen; third, the associations may be mediated by an abrupt reduction in levels of circulating progesterone or testosterone; fourth, the associations may be mediated by an increased release of gonadotropins by the pituitary gland; and fifth, genetic variants may modify the hormonal effects of bilateral oophorectomy through simple or more complex interactions. Results from other studies are cited as evidence for or against each possible mechanism. These putative causal mechanisms are probably intertwined, and their clarification is a research priority.

Approach to the patient with menopausal symptoms

Many women experience menopausal symptoms during the menopausal transition and postmenopausal years. Hot flashes, the most common symptom, typically resolve after several years, but for 15-20% of women, they interfere with quality of life. For these women, estrogen therapy, the most effective treatment for hot flashes, should be considered. The decision to use hormone therapy involves balancing the potential benefits of hormone therapy against its potential risks. Accumulating data suggest that initiation of estrogen many years after menopause is associated with excess coronary risk, whereas initiation soon after menopause is not. Therefore, most now agree that short-term estrogen therapy, using the lowest effective estrogen dose, is a reasonable option for recently menopausal women with moderate to severe symptoms who are in good cardiovascular health. Short-term therapy is considered to be not more than 4-5 yr because symptoms diminish after several years, whereas the risk of breast cancer increases with longer duration of hormone therapy. A minority of women may need long-term therapy for severe, persistent vasomotor symptoms after stopping hormone therapy. However, these women should first undergo trials of nonhormonal options such as gabapentin, selective serotonin reuptake inhibitors, or serotonin norepinephrine reuptake inhibitors, returning to estrogen only if these alternatives are ineffective or cause significant side effects. Low-dose vaginal estrogens are highly effective for genitourinary atrophy symptoms, with minimal systemic absorption and endometrial effects.

Differential effects on visual and spatial recognition memory of a novel hormone therapy regimen of estrogen alone or combined with progesterone in older surgically menopausal monkeys

Building upon our initial studies in young adult surgically menopausal monkeys, this study examined the effects of a novel schedule of administration of estradiol therapy alone, or in combination with progesterone, on visual and spatial recognition memory in older monkeys. Monkeys were preoperatively trained on a delayed matching-to-sample task and a delayed response task. At the time of ovariectomy, monkeys began their hormonal treatments and were cognitively assessed at 2, 12 and 24 weeks following treatment initiation. A schedule of hormone administration was used that closely modeled the normal fluctuations of hormones during the course of a normal primate menstrual cycle. Monkeys receiving placebo had lower levels of accuracy than monkeys receiving estrogen therapies on the delayed matching-to-sample task that were not apparent until 12 weeks following initiation of therapy and were no longer detected at the 24-week assessment. There was no effect of hormone therapy on accuracy in the delayed response task at any of the postoperative assessments. In both tasks, monkeys treated with estrogen plus progesterone had longer choice response latencies, especially on trials in which they made errors; however these effects did not influence accuracy measures in these animals. Our findings indicate that visual recognition ability may be more sensitive than spatial recognition memory to this novel hormone therapy regimen, that treatment with estradiol plus progesterone was equivalent to that of estradiol alone, and that neither therapy had significant negative impact on memory profiles.

Trends in HRT and anti-osteoporosis medication prescribing in a European population after the WHI study

To assess the prescription patterns of anti-osteoporosis medications, three cross-sectional analyses were performed between 2004 and 2006. Women aged 50 and older were identified from the health insurance claims database of the Rhône-Alpes area. HRT prescriptions decreased while bisphosphonates and raloxifene prescriptions increased, respectively, in different age groups.

INTRODUCTION

The objective of this study was to assess the prescription patterns of hormone replacement therapy (HRT) and anti-osteoporosis medications (AOM) in post-menopausal French women since the WHI and the revision of the French clinical practice guidelines in 2004.

METHODS

Three cross-sectional analyses were performed between 2004 and 2006. Women aged 50 and older who had at least one claim for a prescription for HRT, bisphosphonates or raloxifene were identified from health insurance claims database of the Rhône-Alpes area.

RESULTS

A 39% decrease in the number of women who had HRT was observed (67,241 to 41,024). Twenty-one percent and 18% increases were observed, respectively, for bisphosphonates (39,192 to 47,395) and raloxifene (10,263 to 12,060). HRT and raloxifene were mainly prescribed to women aged 55 to 64 (58% and 39%, respectively), bisphosphonates to women aged 65 to 84 (70%). Ninety-eight percent of women had HRT prescribed by a gynaecologist or a general practitioner (GP). Most AOM were prescribed by a GP; 13% of women had AOM prescribed by a rheumatologist.

CONCLUSION

Prescriptions for HRT in post-menopausal French women have significantly decreased while bisphosphonates and raloxifene prescriptions have increased, respectively, in different age groups but to a lesser extent than the HRT decrease.

Estrogens in vascular biology and disease: where do we stand today?

PURPOSE OF REVIEW

Whereas hormone therapy may increase the risk of coronary heart disease and stroke in menopausal women, epidemiological studies (protection in premenopausal women) suggest and experimental studies (prevention of fatty streak development in animals) demonstrate a major atheroprotective action of estradiol. There is also evidence for a thrombogenic effect of oral estrogens. An understanding of the deleterious and beneficial effects of estrogens is thus required.

RECENT FINDINGS

The immuno-inflammatory system plays a key role in the development of fatty streak deposit as well as in the rupture of the atherosclerotic plaque. Whereas estradiol favors an anti-inflammatory effect in vitro (cultured cells), it rather elicits a pro-inflammatory response in vivo involving several subpopulations of the immuno-inflammatory system, which could contribute to plaque destabilization. Endothelium is another important target for estrogens, since estradiol potentiates endothelial nitric oxide and prostacyclin production. The respective actions of estrogens on these cell populations may be influenced by the timing of hormonal therapy initiation, hormone regimens, status of the vessel wall and expression of isoforms of estrogen receptors alpha and beta.

SUMMARY

A better understanding of the balance between the deleterious and beneficial effects of estrogens is required and should help to improve hormonal therapy safety and to optimize the prevention of cardiovascular disease after menopause.

New findings from non-linear longitudinal modelling of menopausal hormone changes

Changes in FSH and estradiol (E2) across the menopausal transition are clearly not linear. The present study utilizes data from 204 women who completed the 13-year prospective Melbourne Women's Midlife Health Project. E2, FSH, symptoms, self-rated health, mood, sexual function and coronary heart disease (CHD) risk were measured longitudinally. We presumed an s-shaped curve for each hormone and estimated five parameters for each hormone curve for each woman: baseline, final value, range, slope at inflexion point and age at inflexion point. These parameters were found to adequately estimate the curve for each hormone. The median age of transition observed for E2 occurs >1 year later than the median age of transition observed for FSH. FSH parameters did not affect any of the health outcomes analysed. Hot flushes, night sweats, sleeping problems, vaginal dryness and to a lesser extent self-rated health were highly significantly associated with E2 range and slope. Sexual response and CHD risk were highly significantly associated with final E2 level (post-menopausally). These findings have clinical relevance in identifying which symptoms will be triggered by steep transitions of E2 such as sudden withdrawal and which health parameters may require a maintenance level of E2.

SEX HORMONES AND THE CARDIOVASCULAR SYSTEM: EFFECTS ON ARTERIAL FUNCTION IN WOMEN

1. It has long been hypothesized that oestrogen may be cardioprotective. This hypothesis is supported by diverse and comprehensive mechanistic studies in animals and humans. Consistently, in observational studies, oestrogen use in post-menopausal women significantly reduced cardiovascular disease. Contrastingly, large interventional trials focusing on chronic disease prevention in older post-menopausal women have suggested neutral (oestrogen alone) or adverse (combined oestrogen/progestin preparations) cardiovascular effects. 2. The negative initial interpretation and extrapolation of the early randomized, controlled interventional trials, primarily the Women's Health Initiative, has recently been theoretically reconciled with the positive mechanistic and observational studies. As a new interventional literature emerges, it has been suggested that if oestrogen is used from menopause onwards it is likely to be protective, but if instituted after endothelial damage has occurred in an oestrogen-deficient post-menopausal state, the beneficial vessel wall effects are not observed and the procoagulant effects result in overall increased cardiovascular risk. 3. The present article reviews the literature on arterial function and oestrogen use in the setting of the early endothelial protection theory. This theory is generally supported by the data on oestrogen effects on arterial function. In general, in studies of premenopausal women the effects of oestrogen were positive, with similar benefits noted if oestrogen was used early after menopause. However, where hormone therapy was commenced some years after menopause, the beneficial effects on arterial function were not observed. In clinical practice, hormone therapy is primarily used at menopause for the treatment of menopausal symptoms. The data on arterial function reviewed herein, along with emerging interventional human studies, suggest that the cardiovascular effects of this practice are not adverse.

Distinct lipid/lipoprotein profiles and hormonal responsiveness in nine ethnic groups of postmenopausal Asian women: the Pan-Asia Menopause (PAM) study

BACKGROUND

Lipid/lipoprotein profiles, among other factors, are associated with risk of cardiovascular disease. Because cardiovascular disease varies in Asian countries, we hypothesized that lipid profiles differ in ethnic groups of postmenopausal Asian women. To add to the limited body of information currently available, we also investigated the effects of estrogen/progestin therapy on lipid/lipoprotein profiles in postmenopausal Asian women.

METHODS

The Pan-Asia Menopause (PAM) study was a prospective, randomized, double-blind clinical trial evaluating 1028 postmenopausal women at 22 investigational centers in 11 Asian countries/territories. Subjects were randomly assigned to one of three doses of continuous combined conjugated estrogens (CE)/medroxyprogesterone acetate (MPA): CE/MPA (in mg/day) = 0.625/2.5, 0.45/1.5 or 0.3/1.5. The treatment period, following baseline evaluations, consisted of six continuous 28-day cycles. Analysis of lipid profiles was a secondary objective of the PAM study. Total cholesterol, low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), very low density cholesterol (VLDC-C), triglycerides and lipoprotein(a) were analyzed at a central laboratory by state-of-the-art methods.

RESULTS

Mean concentrations of total cholesterol, LDL-C, VLDL-C and triglycerides differed significantly among the nine ethnic groups of postmenopausal women. This difference was independent of body mass index and age, two factors that also influenced lipid/lipoprotein profiles. Mean HDL-C concentrations also differed, but this difference was influenced by body mass index in a weak interaction. All three doses of CE/MPA significantly lowered total cholesterol. Treatment with the high and middle doses significantly lowered LDL-C, and increased HDL-C, VLDL-C and triglycerides. The high dose produced a significant decrease in lipoprotein(a).

CONCLUSIONS

The different lipid/lipoprotein profiles in the nine ethnic groups of postmenopausal Asian women evaluated here suggest a relationship to differences in the prevalence of cardiovascular disease reported for different regions in Asia. However, the reported prevalence data on cardiovascular disease morbidity and mortality in the regions corresponding to the nine ethnic groups are insufficient to allow qualitative comparisons with the lipid profiles shown in our study. The lipid/lipoprotein changes in response to estrogen/progestin therapy observed here are consistent with those reported for Western women.

Estrogen therapy and coronary-artery calcification

BACKGROUND

Calcified plaque in the coronary arteries is a marker for atheromatous-plaque burden and is predictive of future risk of cardiovascular events. We examined the relationship between estrogen therapy and coronary-artery calcium in the context of a randomized clinical trial.

METHODS

In our ancillary substudy of the Women's Health Initiative trial of conjugated equine estrogens (0.625 mg per day) as compared with placebo in women who had undergone hysterectomy, we performed computed tomography of the heart in 1064 women aged 50 to 59 years at randomization. Imaging was conducted at 28 of 40 centers after a mean of 7.4 years of treatment and 1.3 years after the trial was completed (8.7 years after randomization). Coronary-artery calcium (or Agatston) scores were measured at a central reading center without knowledge of randomization status.

RESULTS

The mean coronary-artery calcium score after trial completion was lower among women receiving estrogen (83.1) than among those receiving placebo (123.1) (P=0.02 by rank test). After adjustment for coronary risk factors, the multivariate odds ratios for coronary-artery calcium scores of more than 0, 10 or more, and 100 or more in the group receiving estrogen as compared with placebo were 0.78 (95% confidence interval, 0.58 to 1.04), 0.74 (0.55 to 0.99), and 0.69 (0.48 to 0.98), respectively. The corresponding odds ratios among women with at least 80% adherence to the study estrogen or placebo were 0.64 (P=0.01), 0.55 (P<0.001), and 0.46 (P=0.001). For coronary-artery calcium scores of more than 300 (vs. <10), the multivariate odds ratio was 0.58 (P=0.03) in an intention-to-treat analysis and 0.39 (P=0.004) among women with at least 80% adherence.

CONCLUSIONS

Among women 50 to 59 years old at enrollment, the calcified-plaque burden in the coronary arteries after trial completion was lower in women assigned to estrogen than in those assigned to placebo. However, estrogen has complex biologic effects and may influence the risk of cardiovascular events and other outcomes through multiple pathways. (ClinicalTrials.gov number, NCT00000611.)