Effects of hormonal replacement therapy on plasma sex hormone-binding globulin, androgen and insulin-like growth factor-1 levels in postmenopausal women

Gender-based differences in neuroprotective effects of hydrogen gas against intracerebral hemorrhage-induced depression

BACKGROUND

Post-stroke depression (PSD) severely affects recovery in patients with intracerebral hemorrhage (ICH). Although hydrogen gas (H₂) exerts excellent neuroprotective effects in patients with ICH, there are sex-based differences in H₂ efficacy in several diseases. Herein, we determined whether estrogen increases susceptibility to the neuroprotective effects of H₂ in males with ICH-induced depression.

METHODS

A rodent model of ICH in the basal ganglia was established using autologous blood injection (30 μL). Mice were treated with 2.9% H₂ for 2 h daily for 3 days post-ICH. Estrogen (1 mg/kg) was administered by subcutaneous injection daily for 3 days to male mice post-ICH. Thirty days post-ICH, PSD was evaluated by sucrose preference, forced swimming, and 3-chamber social tests. Following the completion of behavioral tests, levels of superoxide dismutase (SOD) and reactive oxygen species (ROS), astrocytic activation, phosphorylated (p)-NF-κB-positive astrocytes, p-NF-κB, p-IKKβ, IL-1β, and IL-6 expression were determined.

RESULTS

Compared with female mice, H₂ administration post-ICH exhibited fewer neuroprotective effects, including decreased sucrose consumption and time spent sniffing a novel mouse, increased immobility time, downregulated total SOD content, upregulated ROS content and p-NF-κB levels, and elevated astrocyte branches, whereas estrogen enhanced the neuroprotective effects of H₂ in male mice. A reduced number of p-NF-κB-positive astrocytes, downregulated expression of p-NF-κB, p-IKKβ, IL-1β, and IL-6 in the amygdala were demonstrated in ICH-males treated with estrogen plus H₂.

CONCLUSIONS

Estrogen was responsible for increased H₂ sensitivity in male mice with ICH. The underlying mechanism may be associated with the suppression of NF-κB signaling in astrocytes.

Impact of sex hormone-binding globulin on the human phenome

Background: Sex hormone-binding globulin (SHBG) is a circulating glycoprotein and a regulator of sex hormone levels, which has been shown to influence various traits and diseases. The molecular nature of SHBG makes it a feasible target for preventative or therapeutic interventions. A systematic study of its effects across the human phenome may uncover novel associations. Methods: We used a Mendelian randomization phenome-wide association study (MR-pheWAS) approach to systematically appraise the potential functions of SHBG while reducing potential biases such as confounding and reverse causation common to the literature. We searched for potential causal effects of SHBG in UK Biobank (N = 334 977) and followed-up our top findings using two-sample MR analyses to evaluate whether estimates may be biased due to horizontal pleiotropy. Results: Results of the MR-pheWAS across over 21 000 outcome phenotypes identified 12 phenotypes associated with genetically elevated SHBG after Bonferroni correction for multiple testing. Follow-up analysis using two-sample MR indicated the associations of increased natural log SHBG with higher impedance of the arms and whole body, lower pulse rate, lower bone density, higher odds of hip replacement, lower odds of high cholesterol or cholesterol medication use and higher odds of gallbladder removal. Conclusions: Our systematic MR-pheWAS of SHBG, which was comprehensive to the range of phenotypes available in UK Biobank, suggested that higher circulating SHBG affects the body impedance, bone density and cholesterol levels, among others. These phenotypes should be prioritized in future studies aiming to investigate the biological effects of SHBG or develop targets for therapeutic intervention.

Sex steroid hormone receptor expression in the vaginal wall in cervical cancer survivors after radiotherapy

Background: Sex steroid hormones and their receptors are important in female sexual function. The aim of this study was to investigate the expression and distribution of estrogen receptor (ER)α, ERβ, G-protein-coupled ER-1 (GPER), androgen receptor (AR), progesterone receptor (PR)A, PRB and connective tissue growth factor (CTGF) in the vaginal wall among women who had been treated for cervical cancer with radiotherapy. Material and methods: We included cervical cancer survivors treated with radiotherapy and premenopausal control women of the same age scheduled for benign gynecological surgery. We analyzed the expression and distribution of sex steroid hormone receptors and CTGF in biopsies from the vaginal wall, by real-time PCR and immunohistochemistry (IHC). Serum samples were analyzed for hormone levels and radiation dose at biopsy site were calculated and correlated to levels of the sex steroid hormone receptors. Results: In the cervical cancer survivors (n = 34), we found a lower expression of ERα at both mRNA and protein levels, compared to the control women (n = 37). In the survivors with high radiation dose at biopsy site, the immunostaining of ERα and AR was lower in the epithelium and the stroma, compared to survivors with minimal radiation dose. The later group showed expression of ERα comparable to the control women. The cancer survivors were sufficiently substituted with systemic estradiol with no difference in the serum estradiol levels compared to control women. Conclusions: We found that external radiation reduces the ERα and AR protein expression in the vaginal mucosa, indicating that the vaginal changes in irradiated cervical cancer survivors and the lack of response to hormonal treatment could be due to the decreases in sex steroid hormone receptor expression.

Hormone Replacement Therapy: Would it be Possible to Replicate a Functional Ovary?

Background: Throughout history, menopause has been regarded as a transition in a woman’s life. With the increase in life expectancy, women now spend more than a third of their lives in menopause. During these years, women may experience intolerable symptoms both physically and mentally, leading them to seek clinical advice. It is imperative for healthcare providers to improve the quality of life by reducing bothersome menopausal symptoms and preventing disorders such as osteoporosis and atherosclerosis. The current treatment in the form of hormone replacement therapy (HRT) is sometimes inadequate with several limitations and adverse effects. Objective and rationale: The current review aims to discuss the need, efficacy, and limitations of current HRT; the role of other ovarian hormones, and where we stand in comparison with ovary-in situ; and finally, explore towards the preparation of an HRT model by regeneration of ovaries tissues through stem cells which can replicate a functional ovary. Search methods: Four electronic databases (MEDLINE, Embase, Web of Science and CINAHL) were searched from database inception until 26 April 2018, using a combination of relevant controlled vocabulary terms and free-text terms related to ‘menopause’, ‘hormone replacement therapy’, ‘ovary regeneration’, ‘stem cells’ and ‘ovarian transplantation’. Outcomes: We present a synthesis of the existing data on the efficacy and limitations of HRT. HRT is far from adequate in postmenopausal women with symptoms of hormone deprivation as it fails to deliver all hormones secreted by naïve ovarian tissue. Moreover, the pharmacokinetics of synthetic hormones makes them substantially different from natural ones. Not only does the number and type of hormones given in HRT matter, but the route of delivering and their release in circulation are also imperative. The hormones are delivered either orally or topically in a non-physiological uniform manner, which brings along with it several side effects. These identify the need for a hormone delivery system which replicates, integrates and reacts as per the requirement of the female body. Wider implications: The review outlines the strengths and weaknesses of HRT and highlights the potential areas for future research. There is a tremendous potential for research in this field to understand the collective roles of the various ovarian hormones and to devise an auto-regulated hormone delivery system which replicates the normal physiology. Its clinical applications can prove to be transformative for postmenopausal women helping them to lead a healthy and productive life.

Sex-related differences in oxidative stress and neurodegeneration

Oxidative stress has been implicated in a number of neurodegenerative diseases spanning various fields of research. Reactive oxygen species can be beneficial or harmful, depending on their concentration. High levels of reactive oxygen species can lead to oxidative stress, which is an imbalance between free radicals and antioxidants. Increased oxidative stress can result in cell loss. Interestingly, sex differences have been observed in oxidative stress generation, which may underlie sex differences observed in neurodegenerative disorders. An enhanced knowledge of the role of sex hormones on oxidative stress signaling and cell loss can yield valuable information, leading to sex-based mechanistic approaches to neurodegeneration.

Association of Serum Sex Hormones with Hemostatic Factors in Women On and Off Hormone Therapy: The Multiethnic Study of Atherosclerosis

BACKGROUND

Hormone therapy (HT) is associated with increased risk of both venous and arterial thrombosis, which are multifactorial in origin.

OBJECTIVES

Our objectives were twofold: first, we sought to examine associations between endogenous serum sex hormone levels and biomarkers of thrombosis and/or coagulation in postmenopausal hormone nonusers. Second, we separately studied the associations between serum sex hormone levels and biomarkers of thrombosis and/or coagulation in postmenopausal hormone users considering the fact that pattern of circulating hormones is different in women taking exogenous hormones.

PATIENTS/METHODS

We performed a cross-sectional analysis of postmenopausal women enrolled in a large multiethnic community-based cohort study, The Multiethnic Study of Atherosclerosis. We hypothesized that higher levels of estrogen-related sex hormones would be associated with biomarkers of thrombosis, suggesting mechanisms for differences in thrombotic risk from HT. Women (n = 2878) were included if they were postmenopausal and had thrombotic biomarkers (homocysteine, fibrinogen, C-reactive protein [CRP], factor VIII, and d-dimer) and sex hormone levels (total testosterone [T], bioavailable testosterone, sex hormone binding globulin [SHBG], estradiol [E2], and dehydroepiandrosterone [DHEA]) measured. A smaller random sample of 491 women also had von Willebrand factor (vWF), plasminogen activator inhibitor (PAI-1), and tissue factor pathway inhibitor (TFPI) levels measured.

RESULTS AND CONCLUSIONS

We found that elevated levels of estradiol and SHBG in HT users were associated with elevated levels of CRP and lower levels of TFPI, both of which may be related to a prothrombotic milieu in HT users. HT nonusers had far more prothrombotic associations between elevated serum sex hormone levels and thrombotic biomarkers when compared with HT users.

Age, body mass, usage of exogenous estrogen, and lifestyle factors in relation to circulating sex hormone-binding globulin concentrations in postmenopausal women

BACKGROUND

Circulating concentrations of sex hormone-binding globulin (SHBG) have been associated with cardiovascular diseases, type 2 diabetes, metabolic syndrome, and hormone-dependent cancers; however, correlates of SHBG concentrations are not well understood.

METHODS

We comprehensively investigated correlates of SHBG concentrations among 13 547 women who participated in the Women's Health Initiative and who had SHBG measurements. We estimated study- and ethnicity-specific associations of age, reproductive history, usage of exogenous estrogen, body mass index (BMI), and lifestyle factors such as physical activity, smoking, alcohol consumption, coffee intake, and dietary factors with SHBG concentrations. These estimates were pooled using random-effects models. We also examined potential nonlinear associations using spline analyses.

RESULTS

There was no significant ethnic difference in the age-adjusted mean concentrations of SHBG. Age, exogenous estrogen use, physical activity, and regular coffee intake were positively associated with SHBG concentrations, whereas BMI was inversely associated with SHBG concentrations after adjustment for potential confounding factors. Similar patterns were observed among both ever users and never users of exogenous estrogen. The spline analysis indicated nonlinear relations of regular intake of coffee, age, and BMI with SHBG concentrations. Two or more cups/day of regular coffee consumption and age of 60 years or older were associated with higher SHBG concentrations; the inverse BMI-SHBG relation was especially strong among women whose BMI was below 30.

CONCLUSIONS

In this large sample of postmenopausal women, age, exogenous estrogen use, physical activity, regular coffee intake, and BMI were significant correlates of SHBG concentrations, presenting potential targets for interventions.

Testosterone and libido in surgically and naturally menopausal women

The assessment and then treatment of a change in libido, or a change in the desire to partake in sexual activity, during the menopausal transition and beyond has been a challenging and elusive area of clinical research. This is partly due to the multidimensional nature of female sexuality, the difficulties of measuring testosterone in women in a reliable and accurate manner, and the complexity of the neurobiology and neurobehavior of female sexual desire. In addition, there is a lack of evidence for diagnostic specificity of low free testosterone levels for the symptom of low libido in women for whom there are no confounding interpersonal or psychological factors; although, in the symptomatic population of surgically or naturally menopausal women, a low level of free testosterone often accompanies a complaint of reduced desire/libido. The randomized clinical trial research on testosterone replacement for naturally and/or surgically menopausal women with sexual dysfunction has been criticized for a high placebo response rate, supraphysiological replacement levels of testosterone, the perception of modest clinical outcome when measuring objective data such as the frequency of sexual intercourse relative to placebo, and the unknown safety of long-term testosterone replacement in the estrogen-replete surgically or naturally menopausal woman. A careful review of current evidence from randomized, controlled trials lends support to the value of the replacement of testosterone in the estrogen-replete menopausal woman for whom libido and desire has declined. The issue of long-term safety remains to be answered.

Androgenic hormones and aging--the link with female sexual function

In women, sexual function, hormones and aging are inextricably related. Sexual activity in women involves interest and motivation, the ability to become aroused and achieve orgasm, the pleasure of the experience and subsequent personal satisfaction. Androgens, as endogenous hormones or given as a therapy, potentially influence female sexual function, with research into the effects of exogenous androgens in women mostly devoted to effects on sexual desire. Some studies have been conducted to delineate the effects of testosterone on arousal, however arousal determined by laboratory measures does not always correlate with subjective reporting of a sensation of arousal. Overall large randomised controlled trials of exogenous testosterone show benefits over placebo on sexual desire, arousal, orgasm, pleasure and satisfaction. The aspects of consideration of androgen therapy for women that continue to stimulate debate in this therapeutic area include whether female sexual dysfunction is a condition that merits pharmacotherapy, how effective is such treatment and whether testosterone therapy is safe.

Metabolic and hormonal parameters in post-menopausal women 10 years after transdermal oestradiol treatment, alone or combined to micronized oral progesterone

BACKGROUND

In the post-Women's Health Initiative Study era few post-menopausal women complete long term hormonal treatment (HT).

OBJECTIVE

To analyse metabolic/hormonal parameters and frequency of the metabolic syndrome (METS) in post-menopausal women after 10 years of HT.

METHODS

Retrospective data from parallel cohorts of post-menopausal women receiving HT for 10 years was analysed. Regimens included: transdermal oestradiol (50 microg) (n=22), sequential cyclic HT with transdermal oestradiol (50 microg) plus 200 mg/day micronized oral progesterone (cycle days 12-25) (n=83), or continuous combined HT with transdermal oestradiol (50 microg) plus 100 mg/day micronized oral progesterone (n=46). A group of women who elected not to use HT served as a control group (n=35).

RESULTS

Frequency of the METS did not significantly increase after 10 years of HT. Oestradiol and sex hormone binding globulin (SHBG) levels displayed a significant increase compared to baseline after 10 years of HT (all regimens). These values were significant higher when compared to the control group. Glucose levels were significantly higher after 10 years in women receiving the sequential cyclic regimen. Although not reaching statistical significance, there was a trend for transdermal oestradiol alone to increase HDL-C and decrease triglyceride levels.

CONCLUSION

Serum oestradiol and SHBG levels were significantly higher after 10 years of transdermal oestradiol, alone or combined with micronized oral progesterone, without differences observed in serum metabolic parameters. More research through randomised clinical trials is required.

Differential regulation of dehydroepiandrosterone and estrogen on bone and uterus in ovariectomized mice

Dehydroepiandrosterone (DHEA) may be useful in the treatment of postmenopausal osteoporosis (PMO). Our present study has found the preferable stimulatory effect of DHEA on bone, in contrast to the proliferative effects of estradiol (E2) on the endometrium and the uterus, which suggests that DHEA has greater potential clinical value than estrogens in prophylaxis and therapeutics for PMO.

INTRODUCTION

A series of findings raise the possibility that DHEA may be useful in the treatment of PMO. Our present study thus aimed at the differential effects of DHEA and E2 on bone and the uterus in ovariectomized mice as well as the involvement of aromatase, ERalpha, ERbeta, and AR in the effects.

METHODS

Ovariectomized and sham BALB/c mice were given daily treatment with either DHEA or E2 for three months, respectively. Bone mineral density was determined by DEXA after the last treatment. Mice were necropsied in 3 months after the treatment to analyze the ultrastructure of their femur osteoblasts (OBs) with a transmission electron microscope (TEM); DHEA, DHEA sulfate (DHEAS) and E2 levels were assayed by EIA; production in vitro of E2 in the uterus or tibia was assayed to evaluate the profile of P450arom activity; ERalpha and ERbeta mRNA levels in the uterus and tibia were determined by real-time PCR. The primary murine OBs were treated with DHEA and E2, respectively for 72 h. Real-time polymerase chain reaction (PCR) and western blot were carried out to evaluate aromatase, ERalpha, ERbeta and AR expression in OBs.

RESULTS

Both DHEA and E2 significantly improved BMD and OB ultrastructure; E2 but not DHEA has significantly increased uterus wet weight, endometrium epithelial and gland thickness. Dehydroepiandrosterone not only increased serum, femoral DHEA, DHEAS and E2 concentration, but also increased uterine DHEA and DHEAS other than E2 concentration in site, while E2 only increased serum, uterine and femoral E2 concentration, but failed to alter the concentrations of DHEA and DHEAS. Moreover, DHEA significantly increased tibia P450arom enzyme activity, while E2 increased uterine and tibia aromatase activity. Furthermore, DHEA increased uterine ERbeta and ERalpha, and ERbeta transcription in the tibia, while E2 increased ERalpha transcription in the uterus and tibia. Dehydroepiandrosterone increased aromatase, ERalpha, ERbeta and AR expression in OBs, and increased significantly, but E2 apparently decreased the ratio of ERbeta/ERalpha.

CONCLUSIONS

Although both DHEA and E2 augment BMD, the proliferative effects of E2 on the endometrium and uterus reflect the different modes of action on bone and the uterus, indicating that the preferable stimulatory effect of DHEA on bone appears to the more potential clinical values than estrogens in prophylaxis and therapeutics for PMO. But applicability of the findings from rodents in humans needs further study.

A randomized, open-label, crossover study comparing the effects of oral versus transdermal estrogen therapy on serum androgens, thyroid hormones, and adrenal hormones in naturally menopausal women

OBJECTIVE

To compare the changes induced by oral versus transdermal estrogen therapy on the total and free serum concentrations of testosterone (T), thyroxine (T4), and cortisol (C) and the concentrations of their serum binding globulins sex hormone-binding globulin, thyroxine-binding globulin, and cortisol-binding globulin in naturally menopausal women.

DESIGN

Randomized, open-label, crossover. Interventions included a 6-week withdrawal from previous hormone therapy (baseline), followed in randomized order by 12 weeks of oral conjugated equine estrogens (CEE) (0.625 mg/d) and 12 weeks of transdermal estradiol (TD E2) (0.05 mg/d), with oral micronized progesterone (100 mg/d) given continuously during both transdermal estrogen therapy regimens.

RESULTS

Twenty-seven women were enrolled in the study, and 25 completed both treatment periods. The mean(SD) percentage changes from baseline of sex hormone-binding globulin, total T, and free T with oral CEE were +132.1% (74.5%), +16.4% (43.8%), and -32.7% (25.9%), respectively, versus +12.0% (25.1%), +1.2% (43.7%), and +1.0% (45.0%) with TD E2. The mean (SD) percentage changes of thyroxine-binding globulin, total T4, and free T4 with oral CEE were +39.9% (20.1%), +28.4% (29.2%), and -10.4% (22.3%), respectively, versus +0.4% (11.1%), -0.7% (16.5%), and +0.2% (26.6%) with TD E2. The mean (SD) percentage changes of cortisol-binding globulin, total C, and free C with oral CEE were +18.0% (19.5%), +29.2% (46.3%), and +50.4% (126.5%), respectively, versus -2.2% (11.3%), -6.7% (30.8%), and +1.8% (77.1%) with TD E2. Concentrations of all hormones and binding globulins were significantly different (P < or = 0.003) during administration of oral versus transdermal estrogen therapy, except for free T4 and free C.

CONCLUSIONS

Compared with oral CEE, TD E2 exerts minimal effects on the total and free concentrations of T, T4, and C and their binding proteins.

Hormone replacement therapy use and plasma levels of sex hormones in the Norwegian Women and Cancer postgenome cohort - a cross-sectional analysis

Background

Hormone replacement therapy use (HRT) is associated with increased breast cancer risk. Our primary objective was to explore hormone levels in plasma according to HRT use, body mass index (BMI) and menopausal status. A secondary objective was to validate self-reported questionnaire information on menstruation and HRT use in the Norwegian Women and Cancer postgenome cohort (NOWAC).

Methods

We conducted a cross-sectional study of sex hormone levels among 445 women aged 48–62 who answered an eight-page questionnaire in 2004 and agreed to donate a blood sample. The samples were drawn at the women's local general physician's offices in the spring of 2005 and sent by mail to NOWAC, Tromsø, together with a two-page questionnaire. Plasma levels of sex hormones and Sex Hormone Binding Globulin (SHBG) were measured by immunometry. 20 samples were excluded, leaving 425 hormone measurements.

Results

20% of postmenopausal women were HRT users. The plasma levels of estradiol (E₂) increased with an increased E₂ dose, and use of systemic E₂-containing HRT suppressed the level of Follicle Stimulating Hormone (FSH). SHBG levels increased mainly among users of oral E₂ preparations. Vaginal E₂ application did not influence hormone levels. There was no difference in BMI between HRT users and non-users. Increased BMI was associated with increased E₂ and decreased FSH and SHBG levels among non-users. Menopausal status defined by the two-page questionnaire showed 92% sensitivity (95% CI 89–96%) and 73% specificity (95% CI 64–82%), while the eight-page questionnaire showed 88% sensitivity (95% CI 84–92%) and 87% specificity (95% CI 80–94%). Current HRT use showed 100% specificity and 88% of the HRT-users had plasma E₂ levels above the 95% CI of non-users.

Conclusion

Users of systemic E₂-containing HRT preparations have plasma E₂ and FSH levels comparable to premenopausal women. BMI has an influence on hormone levels among non-users. NOWAC questionnaires provide valid information on current HRT use and menopausal status among Norwegian women who are between 48 and 62 years old.

Low sex hormone-binding globulin and testosterone levels in association with erectile dysfunction among human immunodeficiency virus-infected men receiving testosterone and oxandrolone

INTRODUCTION

Men with acquired immunodeficiency syndrome (AIDS) wasting and hypogonadism are frequently treated with testosterone and oxandrolone, an orally administered anabolic-androgenic steroid hormone. We observed reductions in testosterone and sex hormone-binding globulin (SHBG) levels, in association with complaints of erectile dysfunction, after prolonged exposure to this therapeutic regimen.

AIM

First description of an association between long-term receipt of oxandrolone with erectile dysfunction, low SHBG and testosterone.

METHODS

Case report of three human immunodeficiency virus-infected hypogonadal male patients receiving treatment for wasting syndrome and hypogonadism, and highly active antiretroviral therapy. All three patients received long-term oxandrolone in addition to testosterone replacement therapy.

RESULTS

Testosterone and SHBG levels for patients 1, 2, and 3, respectively: total testosterone 183, 71, and 151 ng/dL (260-1,000 ng/dL); free testosterone (not done for patient 3) 58.3 and 26.9 pg/mL (50-210 pg/mL); SHBG 6, 9, and 6 nmol/L (7-50 nmol/L). No other hormonal abnormalities were detected. Following discontinuation of oxandrolone, levels of total testosterone rose, consistent with increase in SHBG. One patient received repeat SHBG assay documenting rise in SHBG level. Patient 2 reported return of libido and early morning erections several weeks after discontinuation of oxandrolone.

CONCLUSIONS

Patients had erectile dysfunction in association with low testosterone and SHBG, in spite of exogenous testosterone replacement. Discontinuation of oxandrolone led to the normalization or improvement of testosterone levels in all three patients with symptomatic improvement in one patient. First pass metabolism of orally administered oxandrolone may decrease hepatic synthesis of SHBG, allowing exogenously supplied testosterone to be excreted. Further work is necessary to elucidate the relationship.

Endogenous sex hormone levels and mammographic density among postmenopausal women

BACKGROUND

Mammographic density is one of the strongest predictors of breast cancer risk. The mechanism by which breast density increases breast cancer risk is unclear although it has been hypothesized that breast density reflects cumulative exposure to estrogens.

METHODS

To evaluate this hypothesis, we conducted a cross-sectional study among 520 postmenopausal women in the Nurses' Health Study that examined the relation between circulating sex hormones and mammographic density. Women were postmenopausal and not taking exogenous hormones at the time of blood collection and mammogram. Percent breast density was measured from digitized mammograms using a computer-assisted method. Circulating estrone, estradiol, androstenedione, testosterone, DHEA, DHEA sulfate, sex hormone-binding globulin, progesterone, and prolactin were measured in plasma.

RESULTS

In contrast to the prior hypothesis, circulating estrogens were inversely related to percent mammographic density. The mean percent mammographic density was 25.6% among women in the lowest quartile of circulating estradiol compared with 14.4% among women in the highest quartile [Spearman correlation (r) = -0.22, P < 0.0001]. Circulating estrogens alone explained 1% to 5% of the variation of mammographic density. Body mass index was positively associated with circulating estradiol levels (r = 0.45, P < 0.0001) and inversely related to percent mammographic density (r = -0.51, P < 0.0001). After adjustment for body mass index, there was no association between estradiol and breast density (r = 0.01, P = 0.81). Likewise, there was no relation between the other sex hormones measured or prolactin and mammographic density after adjustment for body mass index.

CONCLUSION

These findings indicate that in postmenopausal women, mammographic density is independent of circulating sex hormone levels.

Sex hormone-binding globulin and serum testosterone are inversely associated with C-reactive protein levels in postmenopausal women at high risk for cardiovascular disease

PURPOSE

C-reactive protein (CRP), androgens, and menopausal loss of endogenous estrogens are associated with cardiovascular disease (CVD). We hypothesized that high androgens, low estradiol, and low sex hormone-binding globulin (SHBG) would be associated with high CRP in postmenopausal women.

METHODS

CRP, SHBG, estradiol, and total testosterone were measured using baseline bloods of 221 hormone therapy (HT)-nonusers and 162 HT-users from a cross-sectional analysis in a nested case-control sample of the Women's Health Study. Hormones and CRP were ln-transformed and relationships were assessed with Spearman correlations and linear regression.

RESULTS

ln-SHBG (beta=-0.40; p<0.01) and ln-testosterone (beta=-0.24; p=0.04) were the only independent hormonal predictors of ln-CRP among HT-nonusers after adjusting for age, hypertension, smoking, body mass index, diabetes, exercise, HDL cholesterol, alcohol intake, and CVD occurrence during follow-up. Upon stratification, the association between ln-SHBG and ln-CRP persisted among HT nonusers who subsequently developed CVD (beta=-0.55; p=0.01), but not among women who remained CVD-free (p=0.28). The inverse relationship between ln-SHBG and ln-CRP was strongest among the leanest women. None of the sex-hormones predicted ln-CRP among HT-users.

CONCLUSIONS

SHBG and total testosterone were inversely associated with CRP among HT nonusers in this study. The relationship between SHBG and CRP was more strongly inverse among leaner women.

Plasma sex hormone concentrations and subsequent risk of breast cancer among women using postmenopausal hormones

BACKGROUND

Sex hormone concentrations are associated with breast cancer risk among women not using postmenopausal hormones (PMH); however, whether a relationship exists among PMH users is unknown. Therefore, we conducted a prospective, nested case-control study within the Nurses' Health Study (NHS) cohort to examine the association between plasma sex hormone concentrations and postmenopausal breast cancer among women using PMH at blood collection.

METHODS

Blood samples were collected from 1989 to 1990. During follow-up through May 31, 2000, 446 women developed breast cancer and were matched by age, date and time of day of blood collection, and fasting status to 459 control subjects (PMH users) who did not develop cancer. We used conditional logistic regression to estimate relative risks (RRs) and 95% confidence intervals (CIs). We compared hormone concentrations of the 459 control subjects with those of 363 postmenopausal NHS participants not taking PMH. All statistical tests were two-sided.

RESULTS

PMH users had statistically significantly higher estradiol, free estradiol, sex hormone-binding globulin, and testosterone, and lower free testosterone concentrations than non-PMH users. Among PMH users, we found modest associations with breast cancer risk when comparing the highest versus lowest quartiles of free estradiol (RR = 1.7, 95% CI = 1.1 to 2.7; P(trend) = .06), free testosterone (RR = 1.6, 95% CI = 1.1 to 2.4; P(trend) = .03), and sex hormone-binding globulin (RR = 0.7, 95% CI = 0.5 to 1.1; P(trend) = .04), but not of estradiol or of testosterone. However, estradiol and free estradiol were statistically significantly positively associated with breast cancer risk among women older than 60 years (RR = 2.8, 95% CI = 1.5 to 5.0; P(trend) = .002 and 2.6, 95% CI = 1.4 to 4.7; P(trend) = .001, respectively) and among women with a body mass index of less than 25 kg/m2 (RR = 1.8, 95% CI = 1.1 to 3.1, P(trend) = .01 and 2.4, 95% CI = 1.4 to 4.0, P(trend) = .003, respectively).

CONCLUSION

Although women using PMH have a different hormonal profile than those not using PMH, plasma sex hormone concentrations appear to be associated with breast cancer risk among PMH users.

The relationship between serum dehydroepiandrosterone sulfate concentration and bone mineral density, lipids, and hormone replacement therapy in premenopausal and postmenopausal women

OBJECTIVE

To investigate the relationship between serum dehydroepiandrosterone sulfate (DHEAS) concentration and bone mineral density (BMD), lipids, and hormone replacement therapy (HRT) in postmenopausal women.

METHODS

Two hundred twenty-seven women aged >40 years were admitted to the study and divided into three groups: 61 premenopausal normally menstruating women, 108 postmenopausal women who were not receiving HRT, and 58 postmenopausal women receiving HRT. DHEAS levels and lipid patterns were measured. BMD measurements of the lumbar spine (L1-L4) were performed by dual-energy x-ray absorptiometry (DXA).

RESULTS

A positive correlation between DHEAS levels and BMD was found in all three groups. A linear regression model was used to assess the effect of age, body mass index (BMI), parity, and BMD of lumbar vertebrae (L1-L4) on changes in the serum level of DHEAS and found that aging and BMD at the spine had a significant association with serum level of DHEAS and only aging after adjustment for age, BMI, parity, and lipid patterns among the three groups. Age (RR 0.80), DHEAS (RR 0.98), and osteoporosis/osteopenia rate (RR 24.94) were also found to be independent influencing factors for HRT use.

CONCLUSIONS

A positive correlation between DHEAS levels and BMD was found in all three groups. Our study confirms earlier reports that DHEAS levels decrease with age in premenopausal and, especially, postmenopausal women regardless of estrogen treatment. DHEAS levels in postmenopausal women were not associated with atherogenic lipid patterns in the present study.

Different effects of tibolone and continuous combined estrogen plus progestogen hormone therapy on sex hormone binding globulin and free testosterone levels--an association with mammographic density

OBJECTIVE

To compare the effects of tibolone and continuous combined hormone therapy on circulating sex steroids and their binding proteins and their relationship to mammographic density.

STUDY DESIGN

A prospective, double-blind placebo-controlled study. A total of 166 postmenopausal women were equally randomized to receive tibolone 2.5 mg, estradiol 2 mg/norethisterone acetate 1 mg (E2/NETA) or placebo. Serum analyses of sex steroids, insulin-like growth factor (IGF-I) and binding proteins and assessment of mammographic breast density were performed at baseline and after 6 months of treatment.

RESULTS

Estrogens were markedly increased and androgens decreased by E2/NETA. In contrast, tibolone had only a minor influence on circulating estrogens. Sex hormone binding globulin (SHBG) levels were reduced by 50%, while levels of androgens increased. Baseline values of estrone sulfate (E1S), around 1.0-1.1 nmol/l, were increased to 44.7 nmol/l by E2/NETA and to only 1.7 nmol/l by tibolone (p < 0.001). Mammographic breast density displayed a negative correlation with age and body mass index and a positive association with SHBG. After 6 months there was also a negative correlation with levels of free testosterone. Conclusion We found that tibolone and E2/NETA caused distinct differences in estrogen/androgen status and blood levels of possible breast mitogens. The negative association between free testosterone and mammographic density could be a possible explanation for tibolone having less influence on the breast.

Effects of conjugated equine estrogen vs. raloxifene on serum insulin-like growth factor-i and insulin-like growth factor binding protein-3: a 2-year, double-blind, placebo-controlled study

OBJECTIVE

To assess and compare the effect of conjugated estrogen and of the selective estrogen receptor modulator raloxifene on serum levels of insulin-like growth factor-I (IGF-I) and insulin-like growth factor binding protein-3 (IGFBP-3) and on the IGF-I/IGFBP-3 ratio.

DESIGN

A 2-year randomized, double-blind, placebo-controlled study.

SETTING

Endocrinology outpatient department.

PATIENT(S)

Fifty-six postmenopausal, hysterectomized women.

INTERVENTION(S)

Women received raloxifene hydrochloride in doses of 60 mg/day (n = 15) or 150 mg/day (n = 13), conjugated equine estrogen (CEE) in doses of 0.625 mg/day (n = 15), or a placebo (n = 13) over the course of 2 years.

MAIN OUTCOME MEASURE(S)

At baseline and after 6, 12, and 24 months of treatment, serum levels of IGF-I, IGFBP-3, and insulin were measured, and an IGF-I/IFGBP-3 ratio was calculated.

RESULT(S)

Both raloxifene and CEE decreased serum IGF-I concentration. In contrast to CEE, which had no effect, both raloxifene doses of 60 and 150 mg/day significantly increased serum IGFBP-3 during the 2 years. Compared with placebo, the decrease in IGF-I/IGFBP-3 ratio was -32.5% (95% CI: -20.1; -44.8%) for CEE; -16.4% (95% CI: -3.6; -29.2%) for raloxifene at 150 mg/day; and -15.4% (95% CI: -1.0; -29.8%) for raloxifene at 60 mg/day. No effect of CEE or raloxifene was found on insulin concentration at any time point.

CONCLUSION(S)

Long-term use of both CEE and raloxifene decreases serum IGF-I and the IGF-I/IGFBP-3 ratio, but, unlike CEE, raloxifene produced a significant yet small increase in IGFBP-3.

Adrenocortical effects of oral estrogens and soy isoflavones in female monkeys

The goal of this study was to evaluate the long-term adrenocortical effects of premenopausal oral contraceptives (OC) and postmenopausal conjugated equine estrogens (CEE) and soy isoflavones in a female cynomolgus monkey model. Half of the animals received a triphasic OC for a period of 26 months, after which all monkeys were ovariectomized and randomized to one of three diet groups for 36 months: 1). isoflavone-depleted soy protein (control) (n = 54); 2). soy protein with isoflavones (129 mg/d equivalent) (SPI+) (n = 56); or 3). isoflavone-depleted soy protein with CEE (0.625 mg/d equivalent) (n = 59). In the premenopausal phase, OC treatment resulted in significantly higher cortisol (F) and lower dehydroepiandrosterone sulfate, androstenedione, and testosterone relative to intact controls. In the postmenopausal phase, CEE treatment resulted in significantly higher basal F and lower dehydroepiandrosterone sulfate, androstenedione, and testosterone when compared with control and SPI+ diets. Serum F and androgens in the SPI+ group did not differ significantly from the control group. The SPI+ group had significantly lower adrenal weight than either control or CEE groups, and this effect was localized primarily to the zona fasciculata region of the adrenal cortex. These findings suggest that long-term estrogen treatment may contribute to an androgen-deficient and hypercortisolemic state.

Elevated sex-hormone binding globulin in elderly women with Alzheimer’s disease

BACKGROUND

Hormone levels change significantly with increasing age. These changes may be related to, or be associated with, the emergence of age-related diseases, such as Alzheimer's disease (AD).

METHODS

Five hundred and seventy-six women over the age of 65 were studied from the Washington Heights-Inwood Columbia Aging Project (WHICAP). These women were selected from a group of healthy Medicare beneficiaries that were aged 65 and older living in the geographically defined area of northern Manhattan in New York City. Serum levels of estrone (E1), estradiol (E2), total testosterone (TT), dehydroepiandosterone (DHEA), luteinizing hormone (LH), follicle stimulating hormone (FSH), and sex-hormone binding globulin (SHBG) were measured.

RESULTS

Significant differences were found between patients with AD and controls only in the level of SHBG, which was 20% higher in patients compared to controls (68.5nmol/l versus 54.7nmol/l, P<0.001). We also estimated levels of total E2 because after menopause, E2 is largely derived from E1. AD patients had significantly lower levels of estimated E2 (AD 0.46 versus controls 0.49, P<0.01). Differences remained significant after adjusting for age, ethnic group, education, and body mass index (BMI).

CONCLUSIONS

A marked increase in SHBG levels was found in AD patients. SHBG normally responds to circulating testosterone and estrogen, therefore, elevated SHBG suggests an abnormal increase in its production and regulation. Further work is needed to clarify the cause and consequences of this observation.

Modification of serum IGF-I, IGFBPs and SHBG levels by different HRT regimens

During the menopause, levels of SHBG, IGF-I and IGFBPs are significantly modified by the use of different HRT regimens.

OBJECTIVE

The aim of this study is to evaluate the influence of three different HRT regimens on serum levels of SHBG, IGF-I, IGFBP-1 and IGFBP-3 in postmenopausal women.

METHODS

41 postmenopausal women requesting HRT were enrolled in the study. Subjects were divided in three groups according to the therapy assigned; Group A: estradiol 2 mg/day+cyproterone acetate 1 mg/day in a cyclic sequential regimen; Group B: estradiol hemihydrate 2 mg/day plus norethisterone acetate (NETA) 1 mg/day in a continuous combined regimen; Group C: estradiol hemihydrate 1 mg/day plus NETA 0.5 mg/day in a continuous combined regimen. Blood samples were drawn before the start of hormonal treatment and after 6 months of HRT. Levels of SHBG, IGF-I, IGFBP-1 and IGFBP-3 in the serum were measured by means of a specific immunoassay.

RESULTS

In group A, a significant increase of SHBG, no change of IGFBPs and a significant decrease of IGF-I were observed; in group B and in group C, no significant variations for any of the parameters were recorded.

CONCLUSIONS

The association of cyproterone acetate to oral estradiol determines a significant reduction of IGF-I levels and an increase of SHBG; nevertheless, it does not seem to influence the serum levels of the IGF-I binding proteins. The treatment with oral continuous combined estrogens plus androgenic progestins, at low doses, produces minor, not significant, changes in the circulating levels of IGF-I, SHBG and IGFBPs.

Pharmacokinetics of oral micronized beta-estradiol in postmenopausal women receiving maintenance hemodialysis

BACKGROUND

Although 11% of postmenopausal women with end-stage renal disease (ESRD) are prescribed hormone replacement therapy (HRT), the appropriate use remains poorly explored. Although there remains controversy surrounding the benefits of HRT, it may be of particular interest in this population, which has a high risk of bone loss and a fourfold increase in fracture risk compared to the general population. However, the appropriate dose of estrogen for use in postmenopausal women with ESRD is not known. The objective of this study was to evaluate the steady-state pharmacokinetics of oral micronized beta-estradiol in postmenopausal women with ESRD compared with postmenopausal women with normal renal function in order to determine equivalent dosing.

METHODS

Six postmenopausal women with ESRD receiving maintenance hemodialysis and 6 healthy postmenopausal controls received 14 days of micronized beta-estradiol (1.0 mg for control, 0.5 mg for ESRD). Blood, urine, and dialysate samples were obtained during a dosage interval on day 14. Estradiol, estrone, albumin, and sex-hormone binding globulin (SHBG) concentrations were determined. Free estradiol concentrations were calculated using a previously described method.

RESULTS

Women with ESRD had significantly lower serum albumin (610 +/- 31 micromol/L vs. 684 +/- 83 micromol/L) and SHBG (78 +/- 17 vs. 118 +/- 13 nmol/L) than control subjects. Total clearance of estradiol was not significantly different. Due to difference in binding, free estradiol concentrations were significant higher in ESRD women (53.2 +/- 17.7 pg/mL) than control women (43.5 +/- 8.7 pg/mL), despite receiving 50% of the dose. There was no significant difference in estrone concentrations. Clearance of both estradiol and estrone in the dialysate was minimal.

CONCLUSION

Women with ESRD should receive approximately 50% of the dose typically prescribed to women without ESRD.

Variability of serum estrogens among postmenopausal women treated with the same transdermal estrogen therapy and the effect on androgens and sex hormone binding globulin

OBJECTIVE

To examine the variability of serum estrogens in response to transdermal estrogen replacement therapy (ET), and to determine the effects on androgens and sex hormone binding globulin (SHBG).

DESIGN

Randomized, double-blind, placebo-controlled study.

SETTING

Women's hospital.

PATIENT(S)

Two groups of postmenopausal women: [1] 21 women not on ET enrolled and 17 completed the study; [2] 19 women on continuous transdermal ET enrolled and 13 completed the study.

INTERVENTION(S)

Women not on ET were administered a placebo patch or a newly initiated estrogen patch, then crossed over to the alternate treatment. Serum samples were obtained at baseline and the subsequent 3 days from the placebo and new-patch groups and from a separate group of women receiving continuous estrogen patch treatment.

MAIN OUTCOME MEASURE(S)

Estradiol (E(2)), estrone, estrone sulfate, T, dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEAS), androstenedione, free androgen index, and SHBG.

RESULT(S)

There was considerable intrapatient and interpatient variability in the estrogen response to identical treatment doses, with E(2) values differing between women as much as 138 pg/mL and E(2) increases above baseline differing as much as 90 pg/mL. Continuous treatment increased SHBG and decreased androstenedione levels; however, levels of T, DHEA, DHEAS, and free androgen index did not change.

CONCLUSION(S)

There is great variability of estrogen in response to transdermal ET, but minimal effect on circulating androgens.

Sexuality in the climacteric years

Menopause is a time of anatomic, physiological and psychological changes that often influence in the sexuality of aging female. Being sexual functioning an important aspect of health and well-being, doctors should have an holistic approach reassuring about the possibility of treating the various symptoms. The central nervous system is an important target for sex steroid hormone; estrogen, progestagens and androgens are able to modulate several brain functions, and receptors for gonadal steroids have been identified in several brain areas. Because there is no test that physicians can make to assess sexual function, taking a sexual history is probably the most important aspect in the diagnostic and treatment of sexual problems. Hormonal transition with decreasing levels of estrogen and testosterone produces clinical effects, so women need to make adjustments for this period of life. Testosterone is an important component of female sexuality, and alterations in its circulating levels play an important role in psychological and sexual changes that occur after menopause. This is the reason why the research in identifying women who have a decrease androgen active should be aimed. Treatment may include education about sexuality and medical management of symptoms or problems interfering with sexual activity. Also treatment implications and the diverse aspects that may influence on sexuality in the climacteric years are discussed.

Positive effects on cardiovascular and breast metabolic markers of oral estradiol and dydrogesterone in comparison with transdermal estradiol and norethisterone acetate

OBJECTIVES

To assess differences in two sequential combined hormone replacement therapy (HRT) products on selected cardiovascular and breast metabolic markers. The products were different concerning the route of administration of estradiol and its combined progestin, either oral or transdermal, and the androgenic properties of progestogens, respectively, dydrogesterone and norethisterone acetate.

METHODS

One hundred and nineteen healthy non-hysterectomized postmenopausal women were included in this open, multi-center, two parallel group trial. They were randomized to a treatment of six 28-day cycles with oral estradiol sequentially combined with dydrogesterone (oE2/D10) or a sequential combination patch of estradiol plus norethisterone acetate (tdE/NETA). At baseline and after six cycles the high-density lipoprotein cholesterol (HDL-C), the sex hormone binding globulin (SHBG) and the total insulin-like growth factor-I (IGF-I) blood levels were determined by a central laboratory. A total of 89 women were compliant to the protocol.

RESULTS

After six cycles, a statistically significant difference (P<0.001) concerning HDL-C, SHBG and IGF-I levels was found between the two treatment groups. The HDL-C levels were increased in the oE2/D10 group and decreased in the tdE/NETA group, with a final difference of about 0.3 mmol/l. The oE2/D10 treatment induced a sharp increase (about 57 mmol/l) in SHBG levels. IGF-I levels decreased with both the products, but the difference in favor of the oE2/D10 treatment was of about 30 ng/ml. Moreover, patients on tdE/NETA with an IGF-I baseline value below the median showed an increase.

CONCLUSION

Oral estradiol sequentially combined with dydrogesterone, a non-androgenic progestogen, induced positive changes of some cardiovascular (HDL-C) and breast (SHBG and IGF-I) metabolic markers. These effects were significantly different from those obtained with a transdermal estradiol associated to an androgenic progestogen.

The hypoandrogenic woman: pathophysiologic overview

OBJECTIVE

To review the pathophysiologic changes associated with androgen insufficiency in the female.

DESIGN

A review of the English-language literature from 1940 to 2001.

CONCLUSION(S)

Data suggest that diminished androgen levels, most frequently noted in the surgically menopausal patient, may be associated with a number of symptoms including reduced sexual libido and desire, loss of motivation, flat affect, and reduced energy. Lack of consensus in defining abnormally low values for free and total serum androgen levels have made the definition of hypoandrogenic states difficult.

Changes in sex hormone-binding globulin, insulin, and serum lipids in postmenopausal women on a low-fat, high-fiber diet combined with exercise

Dietary factors including fat and fiber have been reported to play a role in the development of breast cancer, possibly mediated by changes in estradiol. Diet and exercise have been shown to affect levels of sex hormone-binding globulin (SHBG), which in turn regulate the bioavailability of estradiol. Diet and exercise also affect insulin levels, which play a role in the synthesis of SHBG, and the hormone itself is a potent mitogen for many cancer cell lines. This study was designed to measure the effects of a low-fat, high-fiber diet, combined with regular aerobic exercise, on the levels of SHBG, insulin, and serum lipids in postmenopausal women with or without hormone replacement therapy (HRT). Two groups of postmenopausal women, 11 on HRT and 11 not on HRT, underwent a low-fat (1O% fat calories), high-fiber (65-70 g/day) diet-and-exercise intervention for three weeks. Serum SHBG, insulin, and lipids were measured before and after the regimen. After the intervention, SHBG levels were significantly increased for the women on HRT (44.5 +/- 3.4 vs. 62 +/- 6.4 nmol/l) and the women not on HRT (32.1 +/- 4.6 vs. 45.5 +/- 6.1 nmol/l, both changes p < 0.01). Also after the intervention, insulin levels were significantly reduced for the women on HRT (196 +/- 44.4 vs. 119.8 +/- 28.7 pmol/l) and the women not on HRT (144.2 +/- 17.9 vs. 115.5 +/- 20.8 pmol/l, both changes p < 0.01). Body mass index and total cholesterol were significantly reduced for both groups of women (all changes p < 0.01). Although the exact mechanism for the change in SHBG is not known, the increases in SHBG and reductions in insulin as a result of this lifestyle intervention should reduce the risk for breast cancer in postmenopausal women.

Effects of HRT on serum levels of IGF-I in postmenopausal women

OBJECTIVES

It is thought that insulin-like growth factor-1 (IGF-I) stimulates bone formation. We aimed to determine the effects of oral and transdermal hormone replacement therapy (HRT) on serum IGF-I levels and to investigate the effects of basal IGF-I levels on the levels obtained at the end of the therapy.

METHODS

Sixty-six postmenopausal women were administered either oral (n=44) or transdermal (n=22) HRT for 6 months. Serum levels of IGF-I were determined before and after HRT in all subjects. Groups were divided into two subgroups according to the median value of serum IGF-I levels (basal IGF-I levels above or below the median value). The increase of IGF-I levels after HRT were calculated (%) for all women. Mean increases of subgroups were compared. Furthermore, study groups were divided into three subgroups according to the changing of IGF-I (increase>25%, between 25% increase and 25% decrease and decrease>25%). Mean basal IGF-I levels of these three subgroups were compared.

RESULTS

Mean serum levels of IGF-I before and after HRT were not significantly different in both oral and transdermal groups (P>0.05). Mean increases of IGF-I after HRT for the patients with low basal IGF-I levels, were 65% in oral and 77% in transdermal groups. However, mean increase of the patients with high basal IGF-I levels were -8 and -16% respectively. Moreover, mean level of basal IGF-I was significantly low in women who have more than a 25% increase after HRT (P<0.05).

CONCLUSION

HRT seems to significantly increase serum levels of IGF-I in postmenopausal women with low basal levels of IGF-I.

Hormone replacement therapy increases ACTH/dehydroepiandrosterone sulfate in menopause

OBJECTIVE

To demonstrate that hypoestrogenism in menopause is in part responsible for the decrease in circulating dehydroepiandrosterone sulfate (DHEA-S) and ACTH levels. To test this hypothesis, 25 postmenopausal women aged 47-60 years, were given orally conjugated equine estrogen (CEE) to study the effect on circulating DHEA-S, cortisol and ACTH.

DESIGN

A prospective, non-blinded study was performed. Hormonal levels were analyzed before and after three cycles of CEE 0.625 mg/day for 21 days followed each by chlormadinone acetate for 5 days.

RESULTS

Low baseline levels of DHEA-S increased significantly after HRT (1.71+/-0.75 to 3.3+/-1.5 micromol/l, (P<0.001). ACTH levels augmented moderately from 3.26+/-1.4 to 4.7+/-1.8 pmol/l (P<0.05) and cortisol from 350.4+/-118 to 450.8+/-144 nmol/l (P<0.01). A positive correlation was obtained between 17 beta-estradiol and ACTH (r=0.48), estradiol and cortisol (r=0.52) as well as estradiol and DHEA-S (r=0.60). In addition, the correlation was highly significant (P<0.001) between ACTH and DHEA-S at the term of HRT.

CONCLUSION

HRT increased DHEA-S, ACTH and cortisol concentrations, which may suggest that this therapy may exert a stimulatory effect on the pituitary gland when baseline hypoestrogenism is present, but further studies are required to clarify the mechanism underlying this process.

Changes in profiles of circulating insulin-like growth factor components during hormone replacement therapy according to the responsiveness to therapy in postmenopausal women

OBJECTIVES

Objectives of this study were (1) to evaluate the changes in the profiles of circulating insulin-like growth factor and of insulin-like growth factor-binding proteins during hormone replacement therapy and their relation with responsiveness to hormone replacement therapy and (2) to investigate the relationship between the changes in these insulin-like growth factor components and the annual changes in bone mineral density in postmenopausal women.

STUDY DESIGN

Insulin-like growth factor and insulin-like growth factor-binding proteins were measured by immunoradiometric assay and Western ligand blotting in sera from 39 postmenopausal women treated with sequential hormone replacement therapy for 1 year. Bone mineral density at the lumbar spine and the proximal portion of the femur was determined by dual-energy x-ray absorptiometry.

RESULTS

No significant change in the serum levels of insulin-like growth factor II and insulin-like growth factor-binding protein was noted during hormone replacement therapy in either the responders to therapy or the nonresponders (women with >3% bone loss per year), but serum levels of insulin-like growth factor I and proportions of insulin-like growth factor-binding proteins 1, 2, and 4 decreased during hormone replacement therapy only in the former group. Changes in insulin-like growth factor components during hormone replacement therapy did not correlate with annual bone mineral density changes.

CONCLUSION

Profiles of circulating insulin-like growth factor I and insulin-like growth factor-binding proteins might be involved in responsiveness to hormone replacement therapy, but changes in these components during hormone replacement therapy do not predict annual changes in bone mineral density.

The pharmacokinetics and efficacy of different estrogens are not equivalent

In the next decade many women will turn to the medical community for advice on maintaining or improving health after menopause. Estrogen replacement therapy, with or without progestins, alleviates menopausal symptoms, prevents or manages osteoporosis, and reduces the increased cardiovascular disease risk that results from estrogen deficiency caused by ovarian decline. Although several estrogen replacement products are available, the pharmacokinetics and efficacy of these products may vary depending on either the estrogen formulation or the route of administration, or both. For example, oral estrogens, which elicit a marked hepatic response, induce greater beneficial effects on serum lipoproteins than transdermal estrogens, which circumvent first-pass liver metabolism. Oral conjugated estrogens and transdermal estradiol increase bone density and prevent bone loss. This article summarizes the studies comparing estrogen formulations and discusses the differential effects of various estrogen products that promote postmenopausal health.

Determinants of sex hormone-binding globulin in normal postmenopausal women

OBJECTIVE

To examine the factors influencing the levels of sex hormone-binding globulin (SHBG) in normal postmenopausal women by assessing the relationship between SHBG and measured anthropometric, metabolic and hormonal variables.

DESIGN

Cross-sectional, observational study.

SUBJECTS AND METHODS

Seventy normal postmenopausal women aged 47-71 years (mean 58 years), participated in the study. Information was collected on medical, reproductive and smoking history, alcohol use, dietary intake and physical activity. Body composition measurements using dual-energy absorptiometry, and analyses of biochemical and hormonal indices were performed.

RESULTS

Bivariate correlation coefficients indicated that SHBG was inversely related to body weight (r = - 0.44), fat mass (r = - 0.35), and abdominal obesity (r = - 0.42). It was also inversely related to the glucose and insulin levels during an oral glucose tolerance test (- 0.24 < r < - 0.40), serum oestradiol (r = - 0.26), and physical activity (r = - 0.24). Multiple regression analysis indicated that significant independent correlates of SHBG concentration were fat mass, physical activity, alcohol intake, serum oestradiol, and insulin-like growth factor-1, all having a negative impact on SHBG.

CONCLUSIONS

From these observed associations, it is concluded that maintenance of body weight, moderate alcohol consumption, and physical activity will tend to reduce SHBG concentrations in postmenopausal women, thereby increasing the levels of free oestradiol. This mechanism could mediate the beneficial effects of these factors in preventing the development of osteoporosis and cardiovascular disease.

Six-month oral dehydroepiandrosterone supplementation in early and late postmenopause

The adrenal production of the delta 5-androgens, dehydroepiandrosterone (DHEA) and its sulfate ester dehydroepiandrosterone sulfate (DHEAS), declines linearly with aging. The evidence that DHEA or DHEAS administration may alleviate some of the problems related to aging has opened new perspectives for clinical research. The present study aims to investigate the effects of a 6-month DHEA supplementation in early and late postmenopausal women, with normal or overweight body mass index (BMI), on the level of circulating steroids, sex hormone binding globulin (SHBG), beta-endorphin and gonadotropins, and on the adrenal gland response to dexamethasone suppression and adrenocorticotropic hormone (ACTH) stimulation. Early postmenopausal women (50-55 years) both normal weight (BMI 20-24, n = 9) and overweight (BMI 26-30, n = 9) and late postmenopausal women (60-65 years) both of normal weight and overweight, were treated with oral DHEA (50 mg/day). Circulating DHEA, DHEAS, 17-OH pregnenolone, progesterone, 17-OH progesterone, allopregnenolone, androstenedione, testosterone, dihydrotestosterone, estrone, estradiol, SHBG, cortisol, luteinizing hormone, follicle stimulating hormone and beta-endorphin levels were evaluated monthly and a Kupperman score was performed. The product/precursor ratios of adrenal steroid levels were used to assess the relative activities of the adrenal cortex enzymes. Before and after 3 and 6 months of therapy, each women underwent an ACTH stimulating test (10 micrograms i.v. in bolus) after dexamethasone administration (0.5 mg p.o.) to evaluate the response of cortisol, DHEA, DHEAS, androstenedione, 17-OH pregnenolone, allopregnanolone, progesterone and 17-OH progesterone. The between-group differences observed before treatment disappeared during DHEA administration. Levels of 17-OH pregnenolone remained constant during the 6 months. Levels of DHEA, DHEAS, androstenedione, testosterone and dihydrotestosterone increased progressively from the first month of treatment. Levels of estradiol and estrone significantly increased after the first/second month of treatment. Levels of SHBG significantly decreased from the second month of treatment only in overweight late postmenopausal women, while the other groups showed constant levels. Progesterone levels remained constant in all groups, while 17-OH progesterone levels showed a slight but significant increase in all groups. Allopregnanolone and plasma beta-endorphin levels increased progressively and significantly in the four groups, reaching values three times higher than baseline. Levels of cortisol and gonadotropins progressively decreased in all groups. The product/precursor ratios of adrenal steroid levels at the sixth month were used to assess the relative activities of the adrenal cortex enzymes and were compared to those found before therapy. The 17,20-desmolase, sulfatase and/or sulfotransferase, 17,20-lyase and 5 alpha-reductase activities significantly increased, while the 3 beta-hydroxysteroid-oxidoreductase activity did not vary. On the contrary, the 11-hydroxylase and/or 21-hydroxylase activities showed a significant decrease after 6 months of treatment. In basal conditions, dexamethasone significantly suppressed all the adrenal steroids and this suppression was greater after 3 and 6 months of treatment for DHEA, DHEAS and allopregnanolone, while it remained unchanged for other steroids. Before treatment, ACTH stimulus induced a significant response in all parameters; after the treatment, it prompted a greater response in delta 5- and delta 4-androgens, progesterone and 17-OH progesterone, while cortisol responded less in both younger and older normal-weight women. The endometrial thickness did not show significant modifications in any of the groups of postmenopausal women during the 6 months of treatment. Treatment with DHEA was associated with a progressive improvement of the Kupperman score in all groups, with major effects on the vasomotor symptoms in

Testosterone inhibits estrogen-induced mammary epithelial proliferation and suppresses estrogen receptor expression

This study investigated the effect of sex steroids and tamoxifen on primate mammary epithelial proliferation and steroid receptor gene expression. Ovariectomized rhesus monkeys were treated with placebo, 17beta estradiol (E2) alone or in combination with progesterone (E2/P) or testosterone (E2/T), or tamoxifen for 3 days. E2 alone increased mammary epithelial proliferation by approximately sixfold (P:<0.0001) and increased mammary epithelial estrogen receptor (ERalpha) mRNA expression by approximately 50% (P:<0.0001; ERbeta mRNA was not detected in the primate mammary gland). Progesterone did not alter E2's proliferative effects, but testosterone reduced E2-induced proliferation by approximately 40% (P:<0.002) and entirely abolished E2-induced augmentation of ERalpha expression. Tamoxifen had a significant agonist effect in the ovariectomized monkey, producing a approximately threefold increase in mammary epithelial proliferation (P:<0.01), but tamoxifen also reduced ERalpha expression below placebo level. Androgen receptor (AR) mRNA was detected in mammary epithelium by in situ hybridization. AR mRNA levels were not altered by E2 alone but were significantly reduced by E2/T and tamoxifen treatment. Because combined E2/T and tamoxifen had similar effects on mammary epithelium, we investigated the regulation of known sex steroid-responsive mRNAs in the primate mammary epithelium. E2 alone had no effect on apolipoprotein D (ApoD) or IGF binding protein 5 (IGFBP5) expression, but E2/T and tamoxifen treatment groups both demonstrated identical alterations in these mRNAs (ApoD was decreased and IGFBP5 was increased). These observations showing androgen-induced down-regulation of mammary epithelial proliferation and ER expression suggest that combined estrogen/androgen hormone replacement therapy might reduce the risk of breast cancer associated with estrogen replacement. In addition, these novel findings on tamoxifen's androgen-like effects on primate mammary epithelial sex steroid receptor expression suggest that tamoxifen's protective action on mammary gland may involve androgenic effects.

Effects of chronic oestrogen replacement on stress-induced activation of hypothalamic-pituitary-adrenal axis control pathways

Oestrogen replacement therapy reportedly suppresses hypothalamic-pituitary-adrenal (HPA) axis responses to an emotional stressor in postmenopausal women. However, most studies in the rat suggest a facilitatory role for oestrogen in the control of HPA axis function. One explanation for this difference may be the regimen of oestrogen replacement: during oestrogen replacement therapy, oestrogen levels are low and constant whereas most animal studies examined the HPA axis response when oestrogen levels are rising. In the present study, we assessed HPA axis stress responses in mature ovariectomized rats after plasma oestrogen levels had been maintained at physiological levels for a prolonged period (25 or 100 pg/ml for 7 days). In the case of both an emotional stressor (noise) and a physical stressor (immune challenge by systemic interleukin-1beta administration), oestrogen replacement suppressed stress-related Fos-like immunolabelling, in hypothalamic neuroendocrine cells and plasma adrenocorticotropin hormone responses. From the present data, and past reports, it appears unlikely that these effects of oestrogen are due to a direct action on corticotropin-releasing factor or oxytocin cells. Therefore, to obtain some indication of oestrogen's possible site(s) of action, Fos-like immunolabelling was mapped in the amygdala and in brainstem catecholamine groups, which are neuronal populations demonstrating substantial evidence of involvement in the generation of HPA axis stress responses. In the amygdala, oestrogen replacement suppressed central nucleus responses to immune challenge, but not to noise. Amongst catecholamine cells, oestrogen replacement was more effective against responses to noise than immune challenge, suppressing A1 and A2 (noradrenergic) and C2 (adrenergic) responses to noise, but only A1 responses to immune challenge. These data suggest that, as in postmenopausal women on oestrogen replacement therapy, chronic low-level oestrogen replacement can suppress HPA axis stress responses in the rat. Moreover, oestrogen appears to exert effects at multiple sites within putative HPA axis control pathways, even though most of the relevant neuronal populations do not contain genomic receptors for this gonadal steroid and the pattern of oestrogen action differs for an emotional vs a physical stressor.

The aging ovary

During reproductive life, ovarian steroid biosynthesis is gonadotropin dependent and occurs in theca and granulosa cells. In the menopausal ovary, there is atresia of ovarian follicles, with sparing of the androgen-producing theca-interstitial cell component. The aging ovary, therefore, produces significantly reduced amounts of estrogen, with continued, though decreased, androgen production. After menopause, ovarian estradiol biosynthesis is minimal, with circulating estrogen being derived principally from peripheral aromatization of ovarian and adrenal androgens. Androgen biosynthesis from the adrenal gland, in addition to that from the ovary, decreases with age. Although ovarian androgen production declines with age, there is not an abrupt decrease as is seen with ovarian estrogen levels at the time of menopause. The biological activity of these steroids, either before or after menopause, depends on the amount of steroid available in the unbound fraction. To this end, sex hormone-binding globulin (SHBG) levels are an important determinant of hormone action. Not only does the concentration of SHBG influence the biological effect of testosterone and estradiol, but these steroids also regulate SHBG concentrations.