Effect of postmenopausal hormone therapy on glucose and insulin concentrations. PEPI Investigators. Postmenopausal Estrogen/Progestin Interventions

Diabetes and Menopause

During menopause, women's body composition, sex hormone profile, and metabolic profile may change dramatically. In this review, we summarize studies examining whether the menopausal transition and physiologic factors characterizing the transition are associated with increased risk of diabetes. We review the evidence for estrogen therapy and diabetes risk and studies examining the relationship between diabetes and menarche, which represents an extension of the reproductive life span at the opposite end of the age spectrum. Although studied less extensively, the presence of type 1 or type 2 diabetes may increase the risk of ovarian failure, and we review this literature. In conclusion, we note that the evidence linking menopausal sex hormone changes with increased diabetes risk is weak, although rapid changes as observed with oophorectomy may increase risk. Further studies should investigate the contradictory effects of estrogen therapy upon hepatic and glucose metabolism in mid-life women.

Estrogen receptor alpha and beta in health and disease

Estrogen receptors alpha (ERα) and beta (ERβ) are transcription factors that are involved in the regulation of many complex physiological processes in humans. Abnormal ER signaling leads to development of a variety of diseases, such as cancer, metabolic and cardiovascular disease, neurodegeneration, inflammation, and osteoporosis. This review provides an overview and update on ERα and ERβ in health and disease with focus on their role in cancer and metabolic disease and in the context of recent years' success in providing genome wide data on ER function. Furthermore, potential clinical applications and challenges are also discussed.

Estradiol regulates insulin signaling and inflammation in adipose tissue

BACKGROUND

Obesity-associated low-grade inflammation at white adipose tissue (WAT) leads to metabolic defects. Sex steroid hormone estrogen may be protective against high-fat diet (HFD)-induced obesity and insulin resistance. This has been tested by many previous studies utilizing rodent models of ovariectomy (OVX) and/or treatment of estradiol (E2), the major biologically active form of estrogen. Body weight and adiposity are increased by OVX and reduced following E2 treatment, however. Thus, the protective roles of E2 may be secondary effects to the changes in body weight and adiposity. We hypothesize that E2 directly prevents inflammation and maintains insulin sensitivity in WAT independent of energy status using mice with similar body weights and adiposity.

MATERIALS AND METHODS

Four groups of female C57BL/6 mice were used, including sham-operated mice treated with vehicle for E2 and fed with either a low-fat diet (LFD; Sham-Veh-LFD) or a HFD (Sham-Veh-HFD), and HFD-fed OVX mice treated with either vehicle (OVX-Veh-HFD) or E2 (OVX-E2-HFD). Body weight and abdominal parametrial WAT mass, insulin signaling, and expression levels of genes related to low-grade inflammation in WAT were compared between these groups pair-fed with equal amounts of calories for a period of 4 days.

RESULTS

Body weights and WAT mass were similar in all four groups. OVX-Veh-HFD mice had impaired insulin signaling associated with rapid activation of inflammation, whereas OVX-E2-HFD group maintained insulin sensitivity without showing inflammation in WAT.

CONCLUSIONS

E2 directly contributed to the maintenance of insulin sensitivity during the early phase of development of metabolic dysfunction, possibly via preventing low-grade inflammation in WAT.

Short-Term Estrogen Replacement Effects on Insulin Sensitivity and Glucose Tolerance in At-Risk Cats for Feline Diabetes Mellitus

Male domestic cats that are neutered and overweight are at an increased risk for developing a type-2-like diabetes mellitus. Beneficial effects of 17β-estradiol (E2) on glucose homeostasis may be lost with neutering and thereby account for increased diabetes risk. To evaluate this, adult male neutered overweight cats (n=6) were given daily E2 (1.0 μg/kg) or vehicle (Vh; ethanol, 1.0μL/kg) in a single crossover trial of 14-day periods with a 7-day washout. The E2 and Vh were voluntarily ingested on food. The E2 dosage was determined in a pre-trial to significantly and transiently reduce food intake with no measurable change in plasma E2 concentration. During treatments, physical activity was assessed with collar-mounted accelerometers on days 9-11, and tests of intravenous insulin tolerance and intravenous glucose tolerance were conducted on days 13 and 14, respectively. Over the 14 days, E2 compared to Vh treatment reduced (p=0.03) food intake (- 22%) but not enough to significantly reduce body weight; activity counts were not significantly changed. With E2 compared to Vh treatment, the late-phase plasma insulin response of the glucose tolerance test was less (p=0.03) by 31%, while glucose tolerance and insulin sensitivity indexes were not significantly changed. The results indicate that oral E2 at a dosage that moderately affects food intake may reduce insulin requirement for achieving glucose homeostasis in neutered male cats. Further investigation is needed to identify the mechanism underlying the E2 effect.

Molecular Mechanisms and Therapeutic Effects of (-)-Epicatechin and Other Polyphenols in Cancer, Inflammation, Diabetes, and Neurodegeneration

With recent insight into the mechanisms involved in diseases, such as cardiovascular disease, cancer, stroke, neurodegenerative diseases, and diabetes, more efficient modes of treatment are now being assessed. Traditional medicine including the use of natural products is widely practiced around the world, assuming that certain natural products contain the healing properties that may in fact have a preventative role in many of the diseases plaguing the human population. This paper reviews the biological effects of a group of natural compounds called polyphenols, including apigenin, epigallocatechin gallate, genistein, and (-)-epicatechin, with a focus on the latter. (-)-Epicatechin has several unique features responsible for a variety of its effects. One of these is its ability to interact with and neutralize reactive oxygen species (ROS) in the cell. (-)-Epicatechin also modulates cell signaling including the MAP kinase pathway, which is involved in cell proliferation. Mutations in this pathway are often associated with malignancies, and the use of (-)-epicatechin holds promise as a preventative agent and as an adjunct for chemotherapy and radiation therapy to improve outcome. This paper discusses the potential of some phenolic compounds to maintain, protect, and possibly reinstate health.

Estrogens protect male mice from obesity complications and influence glucocorticoid metabolism

BACKGROUND

Although the prevalence of obesity is higher among women than men, they are somewhat protected from the associated cardiometabolic consequences. The increase in cardiovascular disease risk seen after the menopause suggests a role for estrogens. There is also growing evidence for the importance of estrogen on body fat and metabolism in males. We hypothesized that that estrogen administration would ameliorate the adverse effects of obesity on metabolic parameters in males.

METHODS

Male and female C57Bl/6 mice were fed control or obesogenic (DIO) diets from 5 weeks of age until adulthood. Glucose tolerance testing was performed at 13 weeks of age. Mice were killed at 15 weeks of age and liver and adipose tissue were collected for analysis of gene expression. A second cohort of male mice underwent the same experimental design with the addition of estradiol pellet implantation or sham surgery at 6 weeks.

RESULTS

DIO males had greater mesenteric adipose deposition and more severe increases in plasma glucose, insulin and lipids than females. Treatment of males with estradiol from 6 weeks of age prevented DIO-induced increases in adipose tissue mass and alterations in glucose-insulin homeostasis. We also identified sex differences in the transcript levels and activity of hepatic and adipose glucocorticoid metabolizing enzymes. Estrogen treatment feminized the pattern of DIO-induced changes in glucocorticoid metabolism, rendering males similar to females.

CONCLUSIONS

Thus, DIO induces sex-specific changes in glucose-insulin homeostasis, which are ameliorated in males treated with estrogen, highlighting the importance of sex steroids in metabolism. Given that altered peripheral glucocorticoid metabolism has been observed in rodent and human obesity, our results also suggest that sexually dimorphic expression and activity of glucocorticoid metabolizing enzymes may have a role in the differential metabolic responses to obesity in males and females.

Hormone therapy for preventing cardiovascular disease in post-menopausal women

BACKGROUND

Evidence from systematic reviews of observational studies suggests that hormone therapy may have beneficial effects in reducing the incidence of cardiovascular disease events in post-menopausal women, however the results of randomised controlled trials (RCTs) have had mixed results. This is an updated version of a Cochrane review published in 2013.

OBJECTIVES

To assess the effects of hormone therapy for the prevention of cardiovascular disease in post-menopausal women, and whether there are differential effects between use in primary or secondary prevention. Secondary aims were to undertake exploratory analyses to (i) assess the impact of time since menopause that treatment was commenced (≥ 10 years versus < 10 years), and where these data were not available, use age of trial participants at baseline as a proxy (≥ 60 years of age versus < 60 years of age); and (ii) assess the effects of length of time on treatment.

SEARCH METHODS

We searched the following databases on 25 February 2014: Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE and LILACS. We also searched research and trials registers, and conducted reference checking of relevant studies and related systematic reviews to identify additional studies.

SELECTION CRITERIA

RCTs of women comparing orally administered hormone therapy with placebo or a no treatment control, with a minimum of six months follow-up.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study quality and extracted data. We calculated risk ratios (RRs) with 95% confidence intervals (CIs) for each outcome. We combined results using random effects meta-analyses, and undertook further analyses to assess the effects of treatment as primary or secondary prevention, and whether treatment was commenced more than or less than 10 years after menopause.

MAIN RESULTS

We identified six new trials through this update. Therefore the review includes 19 trials with a total of 40,410 post-menopausal women. On the whole, study quality was good and generally at low risk of bias; the findings are dominated by the three largest trials. We found high quality evidence that hormone therapy in both primary and secondary prevention conferred no protective effects for all-cause mortality, cardiovascular death, non-fatal myocardial infarction, angina, or revascularisation. However, there was an increased risk of stroke in those in the hormone therapy arm for combined primary and secondary prevention (RR 1.24, 95% CI 1.10 to 1.41). Venous thromboembolic events were increased (RR 1.92, 95% CI 1.36 to 2.69), as were pulmonary emboli (RR 1.81, 95% CI 1.32 to 2.48) on hormone therapy relative to placebo.The absolute risk increase for stroke was 6 per 1000 women (number needed to treat for an additional harmful outcome (NNTH) = 165; mean length of follow-up: 4.21 years (range: 2.0 to 7.1)); for venous thromboembolism 8 per 1000 women (NNTH = 118; mean length of follow-up: 5.95 years (range: 1.0 to 7.1)); and for pulmonary embolism 4 per 1000 (NNTH = 242; mean length of follow-up: 3.13 years (range: 1.0 to 7.1)).We performed subgroup analyses according to when treatment was started in relation to the menopause. Those who started hormone therapy less than 10 years after the menopause had lower mortality (RR 0.70, 95% CI 0.52 to 0.95, moderate quality evidence) and coronary heart disease (composite of death from cardiovascular causes and non-fatal myocardial infarction) (RR 0.52, 95% CI 0.29 to 0.96; moderate quality evidence), though they were still at increased risk of venous thromboembolism (RR 1.74, 95% CI 1.11 to 2.73, high quality evidence) compared to placebo or no treatment. There was no strong evidence of effect on risk of stroke in this group. In those who started treatment more than 10 years after the menopause there was high quality evidence that it had little effect on death or coronary heart disease between groups but there was an increased risk of stroke (RR 1.21, 95% CI 1.06 to 1.38, high quality evidence) and venous thromboembolism (RR 1.96, 95% CI 1.37 to 2.80, high quality evidence).

AUTHORS' CONCLUSIONS

Our review findings provide strong evidence that treatment with hormone therapy in post-menopausal women overall, for either primary or secondary prevention of cardiovascular disease events has little if any benefit and causes an increase in the risk of stroke and venous thromboembolic events.

Comparison of the effects of fetal hypothyroidism on glucose tolerance in male and female rat offspring

Thyroid hormones are vital for survival of mammalian species and play critical roles in growth, development, and metabolism. Both fetal hypothyroidism and sex can affect carbohydrate metabolism during adult life. This study aims to assess carbohydrate metabolism in male and female offspring born from mothers who were hypothyroid during pregnancy. Pregnant rats were divided into two groups; the controls consumed water and the hypothyroid group received water containing 0.025 % 6-propyl-2-thiouracial throughout gestation. The intravenous glucose tolerance test (0.5 g/kg glucose) was carried out in 3-month-old offspring. Findings showed that compared to controls, male fetal hypothyroid rats during adulthood had glucose intolerance (area under the curve: 446.4 ± 9.7 vs. 486.4 ± 8.8, p < 0.01 in control and fetal hypothyroid groups, respectively) whereas females had improved glucose tolerance (478.1 ± 7.0 vs. 455.9 ± 8.5, p < 0.01). In conclusion, sex could modulate the effects of fetal hypothyroidism on glucose tolerance in rats.

Bone as an endocrine organ relevant to diabetes

There are well-established associations between diabetes and fracture risk and yet the mechanism underlying these associations are controversial. Guided by a series of mouse studies, a specific form of the bone protein, osteocalcin, was proposed to be the mechanistic link between these two chronic diseases. Translation to humans initially appeared elusive in part because serum concentrations of osteocalcin are a biomarker of bone turnover and not necessarily specific to the biology of this protein. The suitability of the mouse model for the study of osteocalcin as a therapeutic target also appears ambiguous. With greater discrimination of the different forms of osteocalcin present in circulation and inclusion of multiple measures of bone turnover, evidence currently does not support osteocalcin as a protein critical to the diabetes and fracture association in humans.

Memory Impairment in Estrogen Receptor α Knockout Mice Through Accumulation of Amyloid-β Peptides

Estrogen has been known to reduce the development of Alzheimer’s disease (AD). However, exact mechanisms are not clear. We investigated whether estrogen can increase amyloid-beta (Aβ) degradation and affects Aβ-induced memory impairment in an estrogen deficiency model. Estrogen receptor alpha (ERα) knockout mice and wild-type mice were intracerebroventricular (ICV) infused with Aβ (300 pmol) for 2 weeks. Cognitive function was then assessed by the Morris water maze test and passive avoidance test. In addition, Western blot analysis, immunostaining, immunofluorescence staining, ELISA, and enzyme activity assays were used to examine the degree of Aβ deposition in the brains of ERα knockout mice. In our present study, Aβ was accumulated more in the ERα knockout mice brain and greatly worsened memory impairment and glial activation as well as neurogenic inflammation. These results suggest that estrogen may protect memory impairment by stimulating the degradation of Aβ and down-regulate neurogenic inflammation as well as amyloidogenesis.

Parent-of-origin effects on glucose homeostasis in polycystic ovary syndrome

CONTEXT

Polycystic ovary syndrome (PCOS) is a highly heritable complex trait. Parents of affected women have reproductive and metabolic phenotypes.

OBJECTIVE

We tested the hypothesis that there are parental effects on the heritability of fasting dysglycemia in women with PCOS.

DESIGN AND SETTING

This was a cross-sectional study at an academic medical center.

PARTICIPANTS

PARTICIPANTS included 367 women with PCOS and their parents (1101 total subjects).

MAIN OUTCOME MEASURES

We compared maternal and paternal contributions to heritability of fasting dysglycemia and to transmission of the PCOS susceptibility allele of D19S884 within the fibrillin-3 gene (D19S884-A8) on fasting dysglycemia.

RESULTS

Fathers had higher fasting glucose levels, prevalence of fasting dysglycemia and proinsulin to insulin molar ratios (P < .0001), a marker of defective insulin processing, compared with mothers. Heritability of fasting dysglycemia was significant in PCOS families (h(2) = 37%, SE = 10%, P = .001). Maternal heritability (h(2) = 51%, SE = 15%, P = .0009) was higher than paternal heritability (h(2) = 23 %, SE = 23%, P = .186) of fasting dysglycemia after adjustment for age and body mass index. Within dysglycemic probands, there was increased maternal compared with paternal transmission of D19S884-A8 (maternal 84% vs paternal 45%, χ(2) = 6.51, P = .011).

CONCLUSIONS

There was a sex difference in the parental metabolic phenotype with fathers having an increased risk of fasting dysglycemia and evidence for pancreatic β-cell dysfunction compared with mothers. However, only maternal heritability had significant effects on the prevalence of fasting dysglycemia in women with PCOS. Furthermore, there were maternal parent-of-origin effects on transmission of D19S884-A8 probands with fasting dysglycemia. These findings suggest that maternal factors, genetic and perhaps epigenetic, contribute to the metabolic phenotype in affected women.

Estrogen or raloxifene during postmenopausal weight loss: adiposity and cardiometabolic outcomes

OBJECTIVE

Estrogen-based hormone therapy (HT) attenuates abdominal fat gain after menopause, but whether HT improves abdominal fat loss during weight loss is unknown. It was hypothesized that HT or a selective estrogen receptor modulator (raloxifene) would augment reductions in abdominal visceral fat during weight loss when compared to placebo, potentially increasing improvements in glucose tolerance and lipid profile.

METHODS

Healthy postmenopausal women (n = 119; age 50-70 yr) underwent a 6-month weight-loss (primarily exercise) intervention with randomization to raloxifene (60 mg/d), HT (conjugated estrogens, 0.625 mg/d), or placebo. Outcomes were change in total and abdominal (visceral and subcutaneous) fat mass, lipid profile, and fasting and post-challenge glucose and insulin.

RESULTS

Neither HT nor raloxifene augmented loss of total or abdominal fat mass during exercise-induced weight loss when compared with placebo. Weight loss-induced improvements in risk factors were similar among the three groups, except for a greater reduction in fasted glucose in the HT group (difference in change [95%CI] from placebo; -0.40 [-0.76, -0.05]) and greater reductions in LDL (-0.36 [-0.63, -0.09]) and increases in HDL (0.15 [0.07, 0.24]) in both treatment groups.

CONCLUSIONS

Postmenopausal HT and raloxifene did not increase abdominal fat loss during weight loss, but did improve some cardiometabolic outcomes.

Endogenous sex hormones, metabolic syndrome, and diabetes in men and women

Endogenous sex hormones predict impairments of glucose regulation. Cross-sectional studies suggest that lower levels of testosterone in men and higher levels in women increase risk of metabolic syndrome and diabetes, whereas lower levels of sex hormone binding globulin in both men and women increase risk of metabolic syndrome and diabetes. In a systematic review, we summarize existing longitudinal studies, which suggest similar patterns. However, these studies are often limited to a single sex steroid measure. Whether these associations are primarily a marker of adiposity, and whether these associations differ between younger eugonadal vs older hypogonadal adults is also uncertain. The impact of exogenous sex steroid therapy may not reflect relationships between sex hormones and impaired glucose regulation that occur without supplementation. Therefore, examination of endogenous sex steroid trajectories and obesity trajectories within individuals might aid our understanding of how sex steroids contribute to glucose regulation.

Reproductive factors, exogenous hormones, and pancreatic cancer risk in the CTS

Female steroid hormones are hypothesized to play a protective role in pancreatic cancer risk. However, results from epidemiologic studies that examined hormone-related exposures have been inconsistent. The California Teachers Study is a cohort study of female public school professionals that was established in 1995-1996. Of the 118,164 eligible study participants, 323 women were diagnosed with incident invasive pancreatic cancer through December 31, 2009. Multivariable Cox proportional hazards regression methods were used to estimate hazard ratios and 95% confidence intervals for the association of pancreatic cancer risk with reproductive factors and exogenous hormone use. Current users of estrogen-only therapy at baseline (1995-1996) had a lower risk of pancreatic cancer than did participants who had never used hormone therapy (hazard ratio = 0.59, 95% confidence interval: 0.42, 0.84). Use of estrogen-plus-progestin therapy was not associated with the risk of pancreatic cancer. A longer duration of oral contraceptive use (≥10 years of use compared with never use) was associated with an increased risk of cancer (hazard ratio = 1.72, 95% confidence interval: 1.19, 2.49). Reproductive factors, including age at menarche, parity, breastfeeding, and age at menopause, were not associated with pancreatic cancer risk. Our results suggest that increased estrogen exposure through estrogen-only therapy may reduce pancreatic cancer risk in women.

Circulating estrone levels are associated prospectively with diabetes risk in men of the Framingham Heart Study

OBJECTIVE

In postmenopausal women and preclinical murine models, estrogen administration reduces diabetes risk; however, the relationship of estradiol and estrone to diabetes in men is poorly understood. We determined the relationship between circulating estradiol and estrone levels and diabetes risk in community-dwelling men of the Framingham Heart Study (FHS).

RESEARCH DESIGN AND METHODS

Cross-sectional relationships of estradiol and estrone levels with diabetes were assessed at examination 7 (1998-2001) in FHS generation 2 men (n = 1,458); prospective associations between hormone levels at examination 7 and incident diabetes were assessed 6.8 years later at examination 8. Type 2 diabetes mellitus was defined as fasting glucose >125 mg/dL, medication use, or both. Estradiol, estrone, and testosterone levels were measured with liquid chromatography-tandem mass spectrometry, and free estradiol and estrone were calculated.

RESULTS

In cross-sectional models, men with elevated estrone and estradiol had 40% and 62% increased likelihoods of existing diabetes per cross-sectional doubling of estrone and estradiol levels, respectively. Free estrone (cross-sectional odds ratio 1.28 [95% CI 1.02-1.62], P = 0.04) was associated with impaired fasting glucose at examination 7. There was an increase in risk of existing diabetes with increasing quartiles of total and free estrone and estradiol and an increase in risk of incident diabetes with increasing quartiles of estrone levels. In multivariate longitudinal analyses, a twofold increase in total or free estrone levels at examination 7 was associated with 77 and 93% increases, respectively, in odds of incident diabetes at examination 8.

CONCLUSIONS

Although both estradiol and estrone exhibit cross-sectional associations with diabetes in men, in longitudinal analyses estrone is a more sensitive marker of diabetes risk than is estradiol.

Risk factors for diabetes mellitus in women with primary ovarian insufficiency

Primary ovarian insufficiency (POI) is not only a gynecological problem but also has serious effects on women's health such as changes in hormone levels that can trigger fluctuations in blood sugar level and inflammation status. The present study was designed to determine vitamin D, copper, zinc, metabolic parameters [insulin, homeostasis model of assessment-insulin resistance (HOMA-IR)], inflammation parameters such as procalcitonin and high sensitivity C reactive protein (hs-CRP), and lipid profile in POI patients and control subjects with normal menstrual cycles. A total of 43 patients with nondiabetic POI were studied in order to evaluate and compare the findings with those of the control group, which comprised 33 women with normal menstrual cycles. The women with POI had higher levels of serum copper, serum insulin, glucose, LDL-cholesterol, total cholesterol, HOMA-IR, hs-CRP, and procalcitonin, whereas serum vitamin D and zinc levels were lower compared with the healthy control group. Follicle-stimulating hormone (FSH) levels were positively correlated with insulin, glucose, HOMA-IR, hs-CRP, procalcitonin, and copper and negatively correlated with vitamin D and zinc levels. In multivariate statistic analyses with body mass index and FSH as dependent variables, FSH was positively associated with copper and HOMA-IR negatively with vitamin D levels. The present study demonstrated that women with POI have traditional risk factors for diabetes mellitus, including lower levels of vitamin D, whereas higher levels of copper and HOMA-IR.

Reductions in glucose among postmenopausal women who use and do not use estrogen therapy

OBJECTIVE

Among postmenopausal women who do not use estrogen therapy (ET), we have previously reported that intensive lifestyle modification (ILS) leads to increases in sex hormone-binding globulin (SHBG) and that such increases are associated with reductions in fasting plasma glucose (FPG) and 2-hour postchallenge glucose (2HG). Oral ET decreases FPG and increases 2HG while increasing both SHBG and estradiol (E2). It is unknown if ILS reduces glucose among ET users, if changes in SHBG and E2 might mediate any glucose decreases in ET users, and if these patterns differ from those in non-ET users.

METHODS

We conducted a secondary analysis of postmenopausal women in the Diabetes Prevention Program who used ET at baseline and 1-year follow-up (n = 324) and who did not use ET at either time point (n = 382). Participants were randomized to ILS, metformin, or placebo administered at 850 mg BID.

RESULTS

ET users were younger, more often white, and more likely to have had bilateral oophorectomy than non-ET users. Among ET users, ILS reduced FPG (P < 0.01) and 2HG (P < 0.01), and metformin reduced FPG (P < 0.01) but not 2HG (P = 0.56), compared with placebo. Associations between SHBG and total E2 with FPG and 2HG were not significant among women randomized to ILS or metformin. These patterns differed from those observed among women who did not use ET.

CONCLUSIONS

We conclude that among glucose-intolerant ET users, interventions to reduce glucose are effective but possibly mediated through different pathways than among women who do not use ET.

Effects of micronized progesterone added to non-oral estradiol on lipids and cardiovascular risk factors in early postmenopause: a clinical trial

Background

Much attention has been drawn to the deleterious effects of adding progestins to estrogen as hormone therapy (HT) in postmenopausal women. Some widely prescribed progestins have been shown to partially oppose the beneficial effects of estrogens on surrogate markers of cardiovascular disease (CVD) risk. Progestins with higher androgenic activity may interfere with lipid profile and glucose tolerance, and could affect mechanisms of estrogen-induced C-reactive protein (CRP) stimulation. Recent data have shown that norpregnane derivatives, but not micronized progesterone, increase the risk of venous thromboembolism among transdermal estrogens users. The aim of the present study was to assess the effects of combining micronized progesterone with non-oral estrogen therapy on lipid profile and cardiovascular risk factors in a sample of early postmenopausal women.

Methods

Clinical trial including 40 women receiving intranasal 17β estradiol 3 mg/day for two months and 46 women receiving percutaneous 17β estradiol gel 1.5 mg/day for three months (E2). Both groups received an additional 200 mg/day of micronized progesterone by vaginal route 14 days/month (E2+P). Outcome measures included body weight, waist circumference, body mass index (BMI), lipid profile and ultra-sensitive C-reactive protein (usCRP) at baseline and during the E2 or E2+P portions of treatment.

Results

Mean age was 51±3 years. Mean time since menopause was 22.2±10 months. Most participants were overweight; HT did not change BMI. E2 and E2+P did not affect waist circumference and weight. Menopausal symptoms improved after HT. The effects of intranasal and percutaneous estradiol were similar, regardless of the addition of progesterone. Similarly, for the overall group of 86 women, micronized progesterone did not alter the response to E2. Blood pressure, glucose, insulin, HDL-c, triglycerides, and usCRP remained constant with or without micronized progesterone. Total cholesterol decreased after E2, and progesterone maintained this reduction. LDL-c levels were similar at baseline and with E2, and lower during E2+P in relation to baseline.

Conclusions

Cyclic, short term exposure to vaginal micronized progesterone did not alter the metabolic and cardiovascular effects of non-oral E2 in early, apparently healthy, postmenopausal women.

Trial registration

ClinicalTrials.gov NCT01432028

The 2012 hormone therapy position statement of: The North American Menopause Society

OBJECTIVE

This position statement aimed to update the evidence-based position statement published by The North American Menopause Society (NAMS) in 2010 regarding recommendations for hormone therapy (HT) for postmenopausal women. This updated position statement further distinguishes the emerging differences in the therapeutic benefit-risk ratio between estrogen therapy (ET) and combined estrogen-progestogen therapy (EPT) at various ages and time intervals since menopause onset.

METHODS

An Advisory Panel of expert clinicians and researchers in the field of women's health was enlisted to review the 2010 NAMS position statement, evaluate new evidence, and reach consensus on recommendations. The Panel's recommendations were reviewed and approved by the NAMS Board of Trustees as an official NAMS position statement.

RESULTS

Current evidence supports the use of HT for perimenopausal and postmenopausal women when the balance of potential benefits and risks is favorable for the individual woman. This position statement reviews the effects of ET and EPT on many aspects of women's health and recognizes the greater safety profile associated with ET.

CONCLUSIONS

Recent data support the initiation of HT around the time of menopause to treat menopause-related symptoms and to prevent osteoporosis in women at high risk of fracture. The more favorable benefit-risk ratio for ET allows more flexibility in extending the duration of use compared with EPT, where the earlier appearance of increased breast cancer risk precludes a recommendation for use beyond 3 to 5 years.

Does Menopause Increase Diabetes Risk? Strategies for Diabetes Prevention in Midlife Women

Menopause is a significant milestone for midlife women. The characteristic changes in sex hormones and associated symptoms mark a time of increased risk for chronic disease, most notably cardiovascular disease. The diabetes epidemic, combined with recent epidemiologic studies linking sex hormone profiles with incident diabetes risk, have recently raised the possibility that the menopause may increase diabetes risk as well. This report reviews studies of menopause and diabetes risk, as well as the potential mechanisms through which menopause might affect traditional and more novel diabetes risk factors. Diabetes risk appears to be more strongly linked with factors associated with chronological aging and sex hormones rather than changes in menopausal status per se. Strategies to reduce diabetes risk, namely lifestyle changes, hormone therapy and other pharmacologic interventions are also discussed vis à vis midlife women and menopause.

Importance of oestrogen receptors to preserve functional β-cell mass in diabetes

Protecting the functional mass of insulin-producing β cells of the pancreas is a major therapeutic challenge in patients with type 1 (T1DM) or type 2 diabetes mellitus (T2DM). The gonadal hormone 17β-oestradiol (E2) is involved in reproductive, bone, cardiovascular and neuronal physiology. In rodent models of T1DM and T2DM, treatment with E2 protects pancreatic β cells against oxidative stress, amyloid polypeptide toxicity, lipotoxicity and apoptosis. Three oestrogen receptors (ERs)--ERα, ERβ and the G protein-coupled ER (GPER)--have been identified in rodent and human β cells. Whereas activation of ERα enhances glucose-stimulated insulin biosynthesis, reduces islet toxic lipid accumulation and promotes β-cell survival from proapoptotic stimuli, activation of ERβ increases glucose-stimulated insulin secretion. However, activation of GPER protects β cells from apoptosis, raises glucose-stimulated insulin secretion and lipid homeostasis without affecting insulin biosynthesis. Oestrogens are also improving islet engraftment in rodent models of pancreatic islet transplantation. This Review describes developments in the role of ERs in islet insulin biosynthesis and secretion, lipid homeostasis and survival. Moreover, we discuss why and how enhancing ER action in β cells without the undesirable effect of general oestrogen therapy is a therapeutic avenue to preserve functional β-cell mass in patients with diabetes mellitus.

Menopause and risk of diabetes in the Diabetes Prevention Program

OBJECTIVE

The study objectives were to examine the association between menopause status and diabetes risk among women with glucose intolerance and to determine if menopause status modifies response to diabetes prevention interventions.

METHODS

The study population included women in premenopause (n = 708), women in natural postmenopause (n = 328), and women with bilateral oophorectomy (n = 201) in the Diabetes Prevention Program, a randomized placebo-controlled trial of lifestyle intervention and metformin among glucose-intolerant adults. Associations between menopause and diabetes risk were evaluated using Cox proportional hazard models that adjusted for demographic variables (age, race/ethnicity, family history of diabetes, history of gestational diabetes mellitus), waist circumference, insulin resistance, and corrected insulin response. Similar models were constructed after stratification by menopause type and hormone therapy use.

RESULTS

After adjustment for age, there was no association between natural menopause or bilateral oophorectomy and diabetes risk. Differences by study arm were observed in women who reported bilateral oophorectomy. In the lifestyle arm, women with bilateral oophorectomy had a lower adjusted hazard for diabetes (hazard ratio [HR], 0.19; 95% CI, 0.04-0.94), although observations were too few to determine if this was independent of hormone therapy use. No significant differences were seen in the metformin (HR, 1.29; 95% CI, 0.63-2.64) or placebo arms (HR, 1.37; 95% CI, 0.74-2.55).

CONCLUSIONS

Among women at high risk for diabetes, natural menopause was not associated with diabetes risk and did not affect response to diabetes prevention interventions. In the lifestyle intervention, bilateral oophorectomy was associated with a decreased diabetes risk.

An old friend in a new light: the role of osteocalcin in energy metabolism

Accumulating evidence suggests interactions between bone and energy metabolism, which may affect the risk of cardiovascular disease. Recent animal studies indicate that osteocalcin (OC) plays a key role in the coordinated regulation of glucose and insulin metabolism while insulin receptors on osteoblasts may regulate bone turnover and circulating OC levels. Association studies, weight loss interventions, and observational data lend some support to the existence and relevance of these mechanisms in humans. However, corroborating evidence from pharmacologic interventions in either bone or glucose metabolism is limited by the number, design, and complex pharmacological effects of the drugs used. Furthermore, such clinical trials are complicated by the alteration of metabolic feedback mechanisms in the insulin resistant state. Purpose-designed studies are needed to further establish the existence and significance of the role of OC and its subfractions in human insulin metabolism. In this review we summarize existing animal evidence regarding the role of OC and its subfractions in bone and energy metabolism and assess current clinical trial evidence relating to the significance and consequences of this relationship in humans.

Associations of polychlorinated biphenyl exposure and endogenous hormones with diabetes in post-menopausal women previously employed at a capacitor manufacturing plant

There is an increasing body of literature showing associations of organochlorine exposure with risk of diabetes and insulin resistance. Some studies suggest that associations differ by gender and that diabetes risk, in turn, may be affected by endogenous steroid hormones. This report examines the relationships of serum PCBs and endogenous hormones with history of diabetes in a cohort of persons previously employed at a capacitor manufacturing plant. A total of 118 women were post-menopausal with complete data, of whom 93 were not using steroid hormones in 1996, at the time of examination, which included a survey of exposure and medical history, height, weight and collection of blood and urine for measurements of lipids, liver function, hematologic markers and endogenous hormones. This analysis examines relationships of serum polychlorinated biphenyls (PCBs), work exposure and endogenous hormones with self-reported history of diabetes after control for potential confounders. All PCB exposure groups were significantly related to history of diabetes, but not to insulin resistance as measured by the homeostatic model assessment of insulin resistance (HOMA-IR) in non-diabetics. Diabetes was also independently and inversely associated with follicle stimulating hormone (FSH), dehydroepiandrosterone sulfate (DHEAS) and triiodothyronine (T3) uptake. HOMA-IR was positively associated with body mass index (BMI) and C-reactive protein (CRP) and inversely associated with sex hormone binding globulin (SHBG) and T3 uptake after control for PCB exposure. Possible biologic mechanisms are discussed. This study confirms previous reports relating PCB exposure to diabetes and suggests possible hormonal pathways deserving further exploration.

Gender differences in the prevalence of diabetes mellitus in chronic hospitalized patients with schizophrenia on long-term antipsychotics

Gender-specific relationships between diabetes mellitus (DM) and schizophrenia have previously received little systematic study. The results showed that the overall DM prevalence was 20% with rates of 17% (58/343) in males and 27% (46/172) in females (p<0.01). Furthermore, increased body mass index (BMI), abdominal obesity and antipsychotic types were predictors of diabetes in these chronic schizophrenic patients.

Effects of soy isoflavones and genistein on glucose metabolism in perimenopausal and postmenopausal non-Asian women: a meta-analysis of randomized controlled trials

OBJECTIVE

Several randomized controlled trials (RCTs) have examined the role of soy isoflavones on cardiovascular risk factors in perimenopausal and postmenopausal women and have yielded inconsistent results. This meta-analysis aimed to assess the overall effect of soy isoflavones on glucose metabolism: fasting blood glucose, insulin, and insulin resistance.

METHODS

We searched for all articles published in English and indexed in Medline from January 1990 to December 2009. We included RCTs for soy isoflavone supplementation in perimenopausal and postmenopausal women not taking hormone therapy, selecting non-Asian women only. The main outcomes were fasting blood glucose changes from baseline.

RESULTS

We identified 10 eligible RCTs containing blood glucose data of 794 women. The main result was that soy isoflavones did not affect fasting blood glucose significantly. Under a random-effects model, the average difference in fasting blood glucose values between women assigned to isoflavones and women assigned to placebo was -2.16 mg/dL (95% CI, -5.21 to 0.89 mg/dL; P = 0.17). In genistein studies, the mean difference was -7.15 mg/dL (95% CI, -11.47 to -2.82). However, the effects on insulin and homeostasis model assessment insulin resistance were significant: -1.37 microIU/mL (95% CI, -1.92 to -0.81 microIU/mL) and -0.39 (95% CI, -0.65 to -0.14), respectively. Subgroup analyses did not show a significant effect of isoflavone dose, whereas isoflavone mixtures and genistein had a different effect on fasting blood glucose.

CONCLUSIONS

This meta-analysis of RCTs showed that isoflavone use was not associated with a significant glycemia reduction in perimenopausal and postmenopausal non-Asian women. However, the few studies that reported insulin and homeostasis model assessment insulin resistance changes suggested that soy isoflavones and genistein alone had a beneficial effect on glucose metabolism.

Bone and glucose metabolism: a two-way street

Evidence from rodent models indicates that undercarboxylated osteocalcin (ucOC), a product of osteoblasts, is a hormone affecting insulin production by the pancreas and insulin sensitivity in peripheral tissues, at least in part through enhanced secretion of adiponectin from adipocytes. Clinical research to test whether this relationship is found in humans is just beginning to emerge. Cross-sectional studies confirm associations between total osteocalcin (OC), ucOC and glucose metabolism but cannot distinguish causality. To date, longitudinal studies have not provided a consistent picture of the effects of ucOC or OC on fasting glucose and insulin sensitivity. Further exploration into the physiological and mechanistic effects of ucOC and OC, in rodent models and clinical studies, is necessary to determine to what extent the skeleton regulates energy metabolism in humans.

Effects of dehydroepiandrosterone (DHEA) on cardiovascular risk factors in older women with frailty characteristics

OBJECTIVE

this analysis was to investigate the effects of dehydroepiandrosterone (DHEA) on cardiovascular risk factors in older women with frailty characteristics.

DESIGN, SETTING AND PARTICIPANTS

the study was a double-blind, randomised, placebo-controlled trial of 99 women (mean 76.6 +/- 6.0 year) with the low DHEA-S level and frailty.

INTERVENTION

participants received 50 mg/day DHEA or placebo for 6 months; all received calcium (1,000-1,200 mg/day diet) and supplement (combined) and cholecalciferol (1,000 IU/day). Women participated in 90-min twice weekly exercise regimens, either chair aerobics or yoga.

MAIN OUTCOME MEASURES

assessment of outcome variables included hormone levels (DHEA-S, oestradiol, oestrone, testosterone and sex hormone-binding globulin (SHBG)), lipid profiles (total cholesterol, high density lipoprotein (HDL) cholesterol, low density lipoprotein (LDL) cholesterol and triglycerides), body composition measured by dual energy absorptiometry, glucose levels and blood pressure (BP).

RESULTS

eighty-seven women (88%) completed 6 months of study; 88% were pre-frail demonstrating 1-2 frailty characteristics and 12% were frail with > or =3 characteristics. There were significant changes in all hormone levels including DHEA-S, oestradiol, oestrone and testosterone and a decline in SHBG levels in those taking DHEA supplements. In spite of changes in hormone levels, there were no significant changes in cardiovascular risk factors including lipid profiles, body or abdominal fat, fasting glucose or BP.

CONCLUSION

research to date has not shown consistent effects of DHEA on cardiovascular risk, and this study adds to the literature that short-term therapy with DHEA is safe for older women in relation to cardiovascular risk factors. This study is novel in that we recruited women with evidence of physical frailty.

Gender discrimination in the influence of hyperglycemia and hyperosmolarity on rat aortic tissue responses to insulin

Hyperglycaemia initiates endothelial dysfunction causing diabetic macro- and micro-vasculopathy, the main causes of morbidity and mortality in diabetes mellitus. The vasculopathy exhibits gender peculiarities. We therefore explored gender differences in comparing the effects of hyperglycaemia (50 mM) per se with its hyperosmolar (50 mM) effects on vascular tissue responses to insulin. Endothelium-intact or denuded thoracic aortic rings from age-matched male and female Sprague-Dawley rats were incubated for 10 min or 6 h (acute versus chronic exposure) in normal, hyperglycaemic or hyperosmolar Krebs solution. Relaxant responses to insulin (6.9x10(-7)-6.9x10(-5) M) of the phenylephrine-contracted tissues were recorded. Endothelium denudation in both genders inhibited relaxation to insulin in all conditions, more significantly in female than in male tissues, suggesting the female response to insulin is more endothelium-dependent than the male. Acutely and chronically exposed normoglycemic endothelium-intact or -denuded tissues responded similarly to insulin. Chronic hyperglycemic or hyperosmolar exposure did not alter the endothelium-denuded tissue responses to insulin, whereas the responses of the endothelium-intact male and female hyperosmolar, and male hyperglycemic tissues were enhanced. The results show that insulin exerts an endothelium-dependent and independent relaxation with the female tissue responses more endothelium-dependent than the male. The data also suggest that hyperosmolarity per se enhances aortic tissue relaxant responses to insulin whereas hyperglycemia per se inhibits the same and more so in female than male tissues. These effects are endothelium-dependent.

Antidiabetic effects of fermented soybean products on type 2 diabetes

Historically, the incidence of type 2 diabetes has been lower in Asian populations compared with those in Western countries. One possible reason for the lower incidence among Asians is that they consume fermented soybean products, which are unique to the traditional Asian diet. Some have hypothesized that dietary phytoestrogens and soy peptides in fermented soybean foods consumed in traditional Asian diets may help prevent and slow the progression of type 2 diabetes. This review evaluates the existing evidence from animal studies and clinical and epidemiologic investigations on fermented soybeans in the prevention and treatment of type 2 diabetes. Nutritional studies performed in animals and intervention studies with humans suggest that the ingestion of soy protein with isoflavones improves glucose control and reduces insulin resistance. Korean fermented soybean products such as doenjang, kochujang, and chungkookjang contain alterations in the structures and content of isoflavonoids and small bioactive peptides, which are produced during fermentation. Several studies revealed improvements in insulin resistance and insulin secretion with the consumption of these fermented products. Therefore, fermented soybean products may help prevent or attenuate the progression of type 2 diabetes. Although the lack of human intervention trials does not permit definitive conclusions, the evidence does suggest that fermented soy products may be better for preventing or delaying the progression of type 2 diabetes compared with nonfermented soybeans.

Effects of high-dose isoflavones on metabolic and inflammatory markers in healthy postmenopausal women

OBJECTIVE

After menopause, women experience changes in body composition, especially an increase in fat mass. In addition, advancing age, decreased physical activity, and increased inflammation may predispose them to develop type 2 diabetes. Isoflavones have been shown to improve metabolic parameters in postmenopausal women. However, the effect of isoflavones on adipokines/cytokines remains unclear. The purpose of this study was to evaluate the effect of high-dose isoflavones on inflammatory and metabolic markers in postmenopausal women.

METHODS

We measured glucose, insulin, and adipokines/cytokines in 75 healthy postmenopausal women who were randomized to receive 20 g of soy protein with 160 mg of total isoflavones (64 mg genistein, 63 mg daidzein, and 34 mg glycitein) or 20 g of soy protein placebo for 12 weeks. Women taking estrogen discontinued therapy at least 3 months before the study. The supplements were given in a powder form and consumed once daily with milk or other beverages.

RESULTS

Mean ages in the placebo and active groups were similar (P = 0.4). Average time since menopause was 9 years, and two thirds of the women underwent natural menopause. There was no significant difference in body mass index at baseline between the groups (placebo, 25.1 kg/m; active, 26 kg/m) and it did not change significantly during the study. At baseline, the placebo group had significantly higher levels of tumor necrosis factor alpha (P < 0.0001); otherwise, there was no difference in any other parameter. After 12 weeks of treatment, there were significant positive changes in tumor necrosis factor alpha levels within the placebo group (P < 0.0001) and adiponectin levels within the isoflavone group (P = 0.03). Comparison of pre-post change between the groups showed a small but significant increase in serum adiponectin levels in the isoflavone group (P = 0.03) compared with the placebo group. No significant changes were seen in any other parameter between the two groups.

CONCLUSIONS

Healthy, normal-weight postmenopausal women may not experience improvement in metabolic parameters when given high-dose isoflavones despite an increase in serum adiponectin levels. The role of isoflavones in obese and insulin-resistant postmenopausal women needs exploration.

Influence of menopause on diabetes and diabetes risk

Many postmenopausal women live with diabetes mellitus; however, little information is available about how the changes that occur around the time of menopause might uniquely affect management of diabetes mellitus in this population. Although the weight gain that commonly occurs during the menopausal transition is largely attributable to aging rather than the transition itself, changes in body composition have been independently associated with menopausal status. These changes in body composition have, in turn, been associated with alterations in insulin sensitivity and glucose metabolism in postmenopausal women. Hormone therapy seems to have neutral or beneficial effects on the adverse changes in body composition associated with menopause. Whether menopausal status independently influences diabetes risk remains controversial. Nevertheless, consistent findings from large clinical trials suggest that postmenopausal hormone therapy decreases the risk of developing diabetes mellitus. Similarly, many studies suggest that postmenopausal hormone therapy has neutral or beneficial effects on glycemic control among women already diagnosed as having diabetes mellitus. Future studies are needed to elucidate the mechanisms that underlie these relationships and to determine how these observations should influence recommendations for the care of postmenopausal women with diabetes mellitus.

The effects of estrogen therapy and estrogen combined with different androgenic progestins on carbohydrate and lipid metabolism in overweight-obese younger postmenopausal women

OBJECTIVE

The aim of the present study was to compare the effect of three different progestins with differing androgenicity on carbohydrate and lipid metabolism in overweight-obese younger postmenopausal women. Additionally, the relationship between testosterone and insulin resistance was assessed.

METHODS

The study included 125 postmenopausal women. Estradiol (E(2)) 2 mg/day was given to 20 hysterectomized women and the remaining 105 women were randomized into three treatment groups: E(2) 2 mg/day plus dienogest 2 mg/day (n=35); E(2) 2 mg/day plus norethisterone acetate (NETA) 1 mg/day (n=35); E(2) 2 mg/day plus medroxyprogesterone acetate (MPA) 2.5 mg/day (n=35). A 75-g oral glucose tolerance test was performed at the initial and 3-month visit. Serum glucose, insulin, total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and triglycerides were measured before and after treatment.

RESULTS

A significant treatment-related increase was observed only in the E(2)/MPA group for insulin resistance (p=0.031). When the change in the insulin/glucose ratio was compared, the E(2) group was significantly different from the E(2)/MPA and E(2)/NETA groups (p=0.008 and 0.02, respectively). Only the E(2)/dienogest group showed a treatment-related increase in fasting glucose level (p=0.037). A decrease in total cholesterol and LDL-C levels was observed in all groups (p=0.004 and 0.012, respectively). The only significant decrease in HDL-C level was observed in the E(2)/NETA group (p=0.005).

CONCLUSION

Estrogen therapy had a positive effect on carbohydrate and lipid metabolism in overweight-obese postmenopausal women. The addition of progestin to estrogen therapy attenuated estrogen's positive effects slightly; however, the biological actions of the three different androgenic progestins used did not result in any variation.

Soy isoflavone supplementation and fasting serum glucose and lipid profile among postmenopausal Chinese women: a double-blind, randomized, placebo-controlled trial

OBJECTIVE

Long-term effects of soy-derived isoflavones on lipids remain uncertain, and few data are available on their effects on glycemic control. We examined the effects of isolated soy germ isoflavones on the changes in fasting glucose (FG) and lipids.

DESIGN

A double-blind, randomized, placebo-controlled trial was conducted in 203 postmenopausal Chinese women aged 48 to 62 years. They were randomly assigned to receive daily doses of 500 mg calcium, and 0 mg isoflavones (placebo, n=67), 40 mg isoflavones (n=68), and 80 mg isoflavones (n=68). Serum FG, triglycerides, high-density lipoprotein, low-density lipoprotein, total cholesterol, and lipoprotein cholesterol were measured at baseline and 1 year after treatment. The primary data analysis was performed on the 203 randomized women according to the intent-to-treat principle. The last value carried forward was used for any missing data at follow-up.

RESULTS

We observed moderate but significant favorable effects of soy isoflavones on the changes (P=0.012) and percentage of changes (P=0.031) in FG (analysis of variance). The 1-year mean (SD) differences of FG changes were -5.2 (-9.4 to -1.0) mg/dL (P=0.010) and -3.3 (-7.5 to 0.9) mg/dL (P=0.18) in the 40- and 80-mg isoflavone groups compared with the placebo group. We also noted a significant interaction between the treatment and baseline FG on the changes in FG (P=0.004). The isoflavone effects were much more significant in women with baseline FG 100 mg/dL or more than in those with FG less than 90 mg/dL. We observed little effect of soy isoflavones on changes in serum lipids among the treatment groups.

CONCLUSIONS

One-year of soy isoflavone supplementation might have a favorable effect on FG in women, but has no significant effect on serum lipids.

Differential effects of various progestogens on metabolic risk factors for breast cancer

Biological and epidemiological findings suggest that metabolic factors - insulin, insulin-like growth factor-I (IGF-I) and sex hormone-binding globulin (SHBG) - are involved in the development and promotion of breast cancer. Estrogens, particularly if administered orally, counteract metabolic factors that increase breast cancer risk, i.e. they reduce insulin and IGF-I and increase SHBG. This could contribute toward explaining epidemiological data showing that unopposed oral estrogens do not increase breast cancer risk, or do so only modestly. In contrast to natural progesterone and progesterone-derived progestins, progestins endowed with androgenic (or glucocorticoid) activity negatively influence these metabolic factors, counteracting the favorable effects of estrogens. While most biological and epidemiological findings suggest that natural progesterone does not augment breast cancer risk, available data show an increased risk with synthetic progestins - with the possible exception of progesterone-derived dydrogesterone. Different mechanisms for different progestins could possibly be involved. Differences from progesterone with regard to pharmacokinetics and pharmacodynamics, potency, interaction with the two isoforms of the progesterone receptor, and binding to other steroid receptors could all be relevant. These remain theoretical speculations for the time being, but the possibility that some progestins increase breast cancer risk through their negative influence on metabolic factors cannot be rejected.

Plasma sex steroid hormones and risk of developing type 2 diabetes in women: a prospective study

AIMS/HYPOTHESIS

Prospective data directly investigating the role of endogenous sex hormones in diabetes risk have been scant, particularly in women. We aimed to examine comprehensively plasma sex hormones in connection with risk of developing type 2 diabetes in postmenopausal women.

METHODS

We conducted a prospective, nested case-control study of plasma oestradiol, testosterone and dehydroepiandrosterone sulfate and risk of type 2 diabetes in a cohort of women health professionals with a mean age of 60.3 and 12.2 years since menopause. Among women not using hormone therapy and free of baseline cardiovascular disease, cancer and diabetes, 359 incident cases of type 2 diabetes were matched with 359 controls during an average follow-up of 10 years.

RESULTS

Oestradiol and testosterone were each strongly and positively associated with risk of type 2 diabetes. After adjustment for BMI, family history, lifestyle and reproductive variables, the multivariable relative risks (95% CI) comparing the highest vs lowest quintile were 12.6 (2.83-56.3) for total oestradiol (p = 0.002 for trend), 13.1 (4.18-40.8) for free oestradiol (p < 0.001 for trend), 4.15 (1.21-14.2) for total testosterone (p = 0.019 for trend) and 14.8 (4.44-49.2) for free testosterone (p < 0.001 for trend). These associations remained robust after adjusting and accounting for other metabolic syndrome components and baseline HbA(1c) levels.

CONCLUSIONS/INTERPRETATION

In postmenopausal women, higher plasma levels of oestradiol and testosterone were strongly and prospectively related to increased risk of developing type 2 diabetes. These prospective data indicate that endogenous levels of sex hormones may play important roles in the pathogenesis of type 2 diabetes. ClinicalTrials.gov ID no.: NCT00000479.

Vascular and metabolic effects of sex steroids: new insights into clinical trials

The early discontinuation of the Women's Health Initiative trials of daily conjugated estrogens and medroxyprogesterone and of conjugated estrogens only was hailed as the "death to the use of hormone replacement regimens" in menopause. The analyses showed risks outweighing benefits of hormone therapy when given broadly to postmenopausal women. The expanding basic science and clinical research on the specific actions of sex steroids at the genomic and nongenomic level, however, shed new insight into these results. This review focuses on the vascular and metabolic effects of sex steroids to illustrate new advances. Understanding the mechanisms of sex steroid receptor action in a tissue-specific manner, ligand-specific dose responses, and the effects of steroid hormones in normal compared to diseased tissues may explain some of the outcomes in the clinical trials. Further research will clarify the potential benefits and risks of hormone therapy after menopause, both in individual patients and in selected populations.

The effects of black cohosh therapies on lipids, fibrinogen, glucose and insulin

OBJECTIVE

Black cohosh (Actaea racemosa) is an herb commonly used to treat menopausal symptoms. Little is known about its effect on other physiologic parameters that could result in untoward events. This study examines the effect of black cohosh on lipids, fibrinogen, glucose and insulin.

METHODS

Three hundred and fifty-one, 45-55 years old, peri or post-menopausal women experiencing vasomotor symptoms participated in a 3-month, double blind trial with randomization to: (1) black cohosh (160 mg daily); (2) multibotanical including black cohosh (200 mg daily); (3) multibotanical plus soy diet counseling; (4) conjugated equine estrogen .625 mg, with or without medroxyprogesterone acetate 2.5mg daily, for women with or without a uterus, respectively; (5) placebo. Baseline and month 3 total cholesterol, high density lipoprotein (HDL) cholesterol, low density lipoprotein (LDL) cholesterol (calculated), triglyceride, insulin, glucose, and fibrinogen serum concentrations were measured in 310 women. Baseline information was also collected on medical history, demographic characteristics, and diet.

RESULTS

There were no statistically significant differences in the adjusted mean change from baseline to 3 months between the herbal groups and placebo in total cholesterol, LDL, HDL, triglycerides, glucose, and insulin. Adjusted fibrinogen levels appear to increase in the multibotanical treatment group in comparison with the other herbal groups and placebo overall (P = .02), but there was no statistically significant difference in the pairwise test against placebo (P = .11).

CONCLUSIONS

Black cohosh containing therapies had no demonstrable effects on lipids, glucose, insulin or fibrinogen.

Endogenous sex hormones and glucose tolerance status in postmenopausal women

CONTEXT

In postmenopausal women, endogenous estradiol (E2) and free testosterone (T) have been positively associated with glucose intolerance and type 2 diabetes. Most studies have not examined these associations in a large group of postmenopausal women.

OBJECTIVE

The objective was to examine the association between endogenous sex hormones and glucose tolerance in postmenopausal women.

DESIGN, SETTING, AND PARTICIPANTS

This was a cross-sectional study of 1973 postmenopausal women ages 45-84 yr, not taking hormone replacement therapy, in the Multi-Ethnic Study of Atherosclerosis baseline examination.

MAIN OUTCOME MEASURES

Impaired fasting glucose (IFG) and diabetes were defined based on fasting blood sugar and/or treatment for diabetes. In women with normal glucose tolerance, insulin resistance was estimated using homeostasis model assessment of insulin resistance (HOMA-IR).

RESULTS

Increasing quartiles of bioavailable T and E2 and decreasing quartiles of SHBG were associated with significantly increased odds of IFG and diabetes (all P for trend<0.001). Except for the association of bioavailable T with diabetes, the other associations persisted after multivariable adjustment. Although higher dehydroepiandrostenedione (DHEA) was associated with greater odds of IFG (P for trend=0.02), it was not associated with diabetes. Of 1100 women with normal glucose tolerance, E2 and DHEA were positively associated, and SHBG was inversely associated with HOMA-IR (all P<0.001) after multivariable adjustment. Bioavailable T was associated with HOMA-IR (P<0.001), but not fasting glucose.

CONCLUSION

Of postmenopausal women, endogenous bioavailable T, E2, and DHEA were positively associated and SHBG was negatively associated with insulin resistance.

Effects of low-dose continuous combined hormone replacement therapy on glucose homeostasis and markers of cardiovascular risk in women with type 2 diabetes

BACKGROUND

Low-dose hormone replacement therapy (HRT) has attracted interest for the treatment of postmenopausal symptoms in diabetes because of concerns about increased risk of coronary heart disease (CHD) and stroke with conventional HRT containing conjugated equine oestrogens (CEEs) and medroxyprogesterone acetate (MPA).

OBJECTIVES

We assessed the effects on glucose homeostasis and cardiovascular risk factors of continuous oral 17beta oestradiol (1 mg) and norethisterone (0.5 mg) in postmenopausal women with type 2 diabetes.

DESIGN

Double-blind, randomized placebo-controlled trial.

ASSESSMENTS

Hyperinsulinaemic isoglycaemic clamp and cardiovascular risk factors were assessed before and after 3 months of treatment.

RESULTS

Twenty-eight women completed the study. HRT decreased fasting glucose compared with placebo [-9.4% with HRT vs.+2.3% for placebo, 95% confidence interval (CI) -23.2 to -0.3] and total cholesterol (-13.7 vs.+1.0%, 95% CI -22.4 to -3.1%) No significant effect was seen on metabolic clearance rate of glucose, glycated haemoglobin (HbA1c), triglycerides, high density lipoprotein (HDL)-cholesterol or C-reactive protein (CRP).

CONCLUSIONS

In women with type 2 diabetes, low-dose HRT decreased fasting glucose and total cholesterol without detectable adverse effects on glucose clearance, triglycerides and CRP as reported with conventional HRT.

Effects of sex and hormone replacement therapy use on the prevalence of isolated impaired fasting glucose and isolated impaired glucose tolerance in subjects with a family history of type 2 diabetes

Impaired fasting glucose (IFG) is more prevalent in men and impaired glucose tolerance (IGT) more prevalent in women. To explore whether this sex difference is related to female sex hormones, we performed a cross-sectional analysis of data from 2,164 (1,329 women and 835 men) first-degree relatives of individuals with type 2 diabetes. Subjects were categorized based on a 75-g oral glucose tolerance test. Sex and hormone replacement therapy (HRT) effects on the distribution of glucose tolerance were assessed using multinomial logistic regression corrected for familial clustering. Compared with men, women were more likely to have isolated IGT (relative risk 1.8 [95% CI 1.3-2.5]) and less likely to have isolated IFG (0.5 [0.3-0.7]) adjusted for ethnicity, age, waist, fasting insulin, and early insulin release (DeltaI(0-30)/DeltaG(0-30)). To evaluate HRT effects, postmenopausal women using (n = 238) or not using (n = 378) HRT were compared. HRT users were more likely to have isolated IGT (2.2 [1.2-4.0]) after adjustment, but the prevalence of isolated IFG did not differ by HRT status. Based on the influence of sex and HRT on the prevalence of isolated IFG and isolated IGT, we conclude that female sex hormones may play an important role in the pathogenesis of IFG and IGT.

Meta-analysis: effect of hormone-replacement therapy on components of the metabolic syndrome in postmenopausal women

AIM

To quantify the effects of hormone-replacement therapy (HRT) on components of the metabolic syndrome in postmenopausal women.

METHODS

Comprehensive searches of electronic databases were performed from April 1966 to October 2004. We included randomized controlled trials that were of at least 8 weeks duration and evaluated the effect of HRT on metabolic, inflammatory or thrombotic components. Insulin resistance was calculated by homeostasis model assessment (HOMA-IR). Subgroup analysis evaluated the effects for transdermal and oral treatment and for diabetic and non-diabetic women.

RESULTS

Pooled results of 107 trials showed that HRT reduced abdominal fat [-6.8% (CI, -11.8 to -1.9%)], HOMA-IR [-12.9% (CI, -17.1 to -8.6%)] and new-onset diabetes [relative risk 0.7 (CI, 0.6-0.9)] in women without diabetes. In women with diabetes, HRT reduced fasting glucose [-11.5% (CI, -18.0 to -5.1%)] and HOMA-IR [-35.8% (CI, -51.7 to -19.8%)]. HRT also reduced low-density lipoprotein/high-density lipoprotein cholesterol ratio [-15.7% (CI, -18.0 to -13.5%)], lipoprotein(a) [Lp(a)] [-25.0% [CI, -32.9 to -17.1%)], mean blood pressure [-1.7% (CI, -2.9 to -0.5%)], E-selectin [-17.3% (CI, -22.4 to -12.1%)], fibrinogen [-5.5% (CI, -7.8 to -3.2%)] and plasminogen activator inhibitor-1 [-25.1% (CI, -33.6 to -15.5%)]. Oral agents produced larger beneficial effects than transdermal agents, but increased C-reactive protein (CRP) [37.6% (CI, 17.4-61.3%)] and decreased protein S [-8.6% CI, -13.1 to -4.1%)], while transdermal agents had no effect.

CONCLUSIONS

HRT reduces abdominal obesity, insulin resistance, new-onset diabetes, lipids, blood pressure, adhesion molecules and procoagulant factors in women without diabetes and reduced insulin resistance and fasting glucose in women with diabetes. Oral agents adversely affected CRP and protein S, while transdermal agents had no effects.

Changes in intra-abdominal fat in early postmenopausal women: effects of hormone use

OBJECTIVE

Intra-abdominal fat (IAF) accumulates with age, is greater among postmenopausal vs. premenopausal women, and is linked to risk for both type 2 diabetes and cardiovascular disease. Whether hormone replacement therapy (HRT) prevents or attenuates changes in IAF and related risk factors is not clear. The objectives of this observational study were to 1) determine whether HRT attenuated the expected age-related increase in IAF and 2) identify the independent effects of HRT and fat distribution on changes in disease risk factors.

RESEARCH METHODS AND PROCEDURES

Subjects were early postmenopausal white women 45 to 55 years of age. Women either used HRT at the time of enrollment (n = 33) or did not (n = 17). Subjects were evaluated at baseline and 2 years for body composition (DXA), body fat distribution (computed tomography), insulin sensitivity (Si; minimal model), and serum lipids.

RESULTS

IAF increased significantly over 2 years, and this increase was not attenuated by HRT. HRT users had less IAF throughout the study. HRT users showed an increase in Si, whereas non-users showed a decrease. Superficial subcutaneous adipose tissue was significantly and independently related to total cholesterol, whereas IAF was related to high-density lipoprotein cholesterol, triglycerides, and Si.

DISCUSSION

HRT users had less IAF at baseline and throughout the study. Whether HRT altered the relationship between total body fat and IAF or whether differences between groups existed before the study should be addressed through a randomized, interventional study design. HRT had a significant effect on Si; IAF and superficial subcutaneous adipose tissue were significant determinants of disease risk factors.

The effect of medroxyprogesterone acetate on estrogen-dependent risks and benefits--an attempt to interpret the Women's Health Initiative results

The results of the two arms of the Women's Health Initiative (WHI) study allow a comparative assessment of the contribution of the progestogen component to the changes in risk of cardiovascular disease and cancer during treatment of postmenopausal women with conjugated equine estrogens and medroxyprogesterone acetate (CEE/MPA). However, the high proportion of older and overweight or obese women compromises any conclusions, since we estimate that 50% of the women would have the metabolic syndrome. In overweight postmenopausal women with hyperinsulinemia, the risk of breast cancer is elevated and cannot be increased further by hormone replacement therapy (HRT). Therefore, the non-significant, but consistent reduction in breast cancer risk during treatment with CEE alone might be based on an improvement of hyperinsulinemia. The 24% increase in breast cancer risk in the CEE/MPA group can be regarded as an artifact due to very low numbers of breast cancer diagnoses in the placebo group of women who had received HRT prior to the WHI study. The elevated risk of venous thromboembolism and the transient increase in the risk of coronary heart disease (CHD) during treatment with CEE/MPA but not CEE alone suggests a direct effect of MPA on the vessel wall. MPA has been demonstrated to upregulate the thrombin receptor, the thrombin-induced production of tissue factor and procoagulatory activity in the vessel wall owing to its glucocorticoid activity. In contrast, CEE alone reduced non-significantly the risk of CHD in women aged 50-59 years, suggesting that primary prevention is possible if estrogen replacement therapy is initiated early. As clinical studies on the effect of different progestogens combined with estrogens are scarce, a possible superiority of progestogens other than MPA remains to be proven.