Influence of postmenopausal hormone replacement therapy on an estrogen metabolite biomarker of risk for breast cancer.

Whether postmenopausal hormone-replacement therapy (HRT) increases the risk of breast cancer remains controversial, despite numerous epidemiological studies. We approached the question from a biochemical rather than an epidemiological direction - we hypothesized that if estrogen administration increases the risk of breast cancer, it should also alter a known estrogen biomarker of risk towards what has been observed in patients who already have breast cancer. The specific biomarker we studied was the ratio of the urinary excretion of two principal estradiol metabolites, 2-hydroxyestrone and 16 alpha-hydroxyestrone, which is markedly decreased in women with breast cancer and women with familial risk for breast cancer. We studied 34 healthy postmenopausal women not on HRT and 19 women on HRT (Premarin 0.625 mg daily plus Provera, 2.5 mg daily, in women with a uterus and Premarin alone in women without a uterus); treatment duration ranged from 3 months to 15 years. We also studied four women with recently diagnosed, untreated breast cancer. The women with breast cancer showed a significantly lower 2-hydroxyestrone to 16 alpha-hydroxyestrone ratio than control women on HRT (1.35 +/- 0.13 vs. 2.71 +/- 0.84; p < 0.0001). There was no significant difference in the metabolite ratio between healthy women on HRT and women not on HRT (2.82 +/- 0.92 vs. 2.71 +/- 0.84). There was no significant difference between women receiving Premarin alone and women receiving Premarin plus Provera (2.46 +/- 0.84 vs. 3.13 +/- 0.90), and neither differed significantly from women not on HRT (2.71 +/- 0.84). The finding that the ratio of women on HRT was not decreased to or toward the ratio in women with breast cancer can be interpreted, we believe, as a suggestive item of biochemical evidence that HRT is not a risk for breast cancer.     

Effect of estrogen (Premarin) replacement therapy on serum level of total estrogen and urinary excretion of calcium and hydroxyproline in postmenopausal Chinese women

The study subjects included a total of 30 postmenopausal Chinese women, including 14 natural menopausal women, 13 castrated menopausal women and 3 post-irradiated menopausal women. Premarin 1.25 mg/day was given orally for 3 weeks and off one week, repeated for 6 cycles. Fasting morning urine and blood samples were collected before hormone treatment and at the end of 3 weeks, 11 weeks, and 23 weeks of Premarin therapy. Serum total estrogen level was measured by radioimmunoassay. Urinary calcium and creatinine were measured by atomic absorption and Jeffe's reaction, respectively. The concentration of urinary hydroxyproline was determined by Kivirikko's method. After Premarin therapy, the mean concentration of serum total estrogen increased 3 to 4 times from the pretreatment level of 71.7 pg/ml. On the other hand, the mean value of calcium/creatinine (Ca/Cr) molar ratio dropped down from 0.249 to 0.098. The mean value of hydroxyproline/creatinine (HOPr/Cr) molar ratio was reduced from 0.028 to 0.012. In view of the hormonal and biochemical changes after Premarin therapy, it is concluded that estrogen (Premarin) replacement should be effective in the treatment of enhanced bone loss or osteoporosis in postmenopausal women. The relationship of estrogen and calcitonin in the regulation of bone metabolism is also discussed.     

Effect of bacterial vaginosis, Lactobacillus and Premarin estrogen replacement therapy on vaginal gene expression changes

The aim of the study was to investigate gene expression profiles of post-menopausal women receiving Premarin estrogen replacement therapy (ERT), compared to controls, and to examine any correlations between the bacterial vaginosis (BV) status of the subjects. Based upon an expected finding of a 50-60% difference between gene expression of host antimicrobials with alpha=0.05 (2-sided), beta=0.20 the calculation of 7 subjects per group, led to a sample size of 10 subjects receiving Premarin estrogen replacement therapy and 10 healthy, age-matched controls. Vaginal samples were collected at a single timepoint and processed for RNA recovery and Affymetrix array analysis, as well as Nugent scoring and denaturing gradient gel electrophoresis to identify bacteria. Lactobacillus iners was the most commonly detected species in the normal flora and this was confirmed with L. iners-specific PCR method. Vaginal swabs from 6 Premarin and 8 control vaginal samples provided a non-invasive means to analyze human gene expression. There was no significant up-regulation of cancer-associated gene expression in subject receiving Premarin ERT, but some evidence that the potentially protective innate immunity was reduced in patients with BV. Of those with a normal flora, there was a 2-fold down-regulation of carcinoma associated forkhead box A1 gene expression. BV was associated with 7-fold down-regulation of host antimicrobial colony stimulating factor, -9.83-fold for IL-1alpha, -8.33 for IL-1beta and -3.63 for IL-6. This is the first study to use gene arrays to correlate changes in host expression response to estrogen replacement therapy and BV.     

Effect of postmenopausal hormone replacement therapy on lipoprotein and homocysteine levels in Chinese women.

Epidemiological studies have revealed that postmenopausal estrogen replacement therapy results in a marked reduction in the risk for cardiovascular diseases. In the present study, we evaluated plasma lipoprotein profile as well as homocysteine levels in 145 postmenopausal and premenopausal Chinese women living in Hong Kong. We also investigated the effect of hormone-replacement therapy (HRT) with estrogen or estrogen combined with progestin on plasma lipoprotein profile and homocysteine concentrations in those individuals. Postmenopausal women displayed significantly higher plasma levels of total cholesterol, LDL-cholesterol and apoB as well as higher plasma homocysteine levels than that of premenopausal women. HRT with either estrogen (17beta-estradiol or conjugated equine estrogen) alone or estrogen combined with progestin for 3.5-4.5 years significantly improved the lipoprotein profile in postmenopausal women by decreasing the levels of total cholesterol (12-20% reduction), LDL-cholesterol (26-29% reduction) and apoB (21-25% reduction). In women treated with 17beta-estradiol or conjugated equine estrogens their plasma levels of apoAl were significantly elevated (18% elevation) as compared to non-users. HRT also reduced plasma concentrations of homocysteine (13-15% reduction). In conclusion, we found that long-term HRT was associated with improvement in plasma lipoprotein profile and a reduction in homocysteine concentration in postmenopausal women. These results support the notion that the improvement of lipoprotein profile and a reduction in homocysteine concentration may contribute to the beneficial effect of HRT on cardiovascular risk.     

Effect of hormone replacement therapy on the production of bone-resorbing cytokines by peripheral blood cells in postmenopausal women.

We studied the effects of hormone replacement therapy (HRT) with estrogen on postmenopausal changes in the production of bone-resorbing cytokines interleukin 1 beta (IL-1beta) and tumor necrosis factor alpha (TNFalpha). Both cytokines were measured in the supernatants of lipopolysaccharide (LPS)-stimulated whole-blood cells from 72 untreated and 44 HRT-treated women by ELISA. The levels of IL-1beta were significantly higher in women in their 40s and 50s and in postmenopausal women than in women in their teens, 20s and 30s, while the levels of TNFalpha did not show any changes related to age. Both levels in HRT-treated women were significantly lower than those in untreated women at almost every postmenopausal stage. In a prospective study, HRT induced significant declines in both levels. These results show that estrogen decreases the accelerated production of IL-1beta and reduces the production of TNFalpha in postmenopausal women at each postmenopausal stage, even in late-postmenopausal women.     

Hormone replacement therapy increases renal kallikrein excretion in healthy postmenopausal women

Hypertension and its related increase in cardiovascular morbidity in postmenopausal women is a major public health problem. The hypotensive property of urinary kallikrein has been described since 1909. Despite the controversy surrounding the effects of hormone replacement therapy on blood pressure regulation, its mechanisms remain incompletely understood, and no evidence has yet been provided for its effects on renal kallikrein excretion in postmenopausal women. In a double-blind, randomized study we examined the effects of hormone replacement therapy in the form of 2 mg 17-beta estradiol (ERT) or 2 mg 17-beta estradiol combined with continuous 5 mg medroxyprogesterone acetate (HRT) on urinary kallikrein excretion in postmenopausal women. Thirty-nine postmenopausal women collected their urine for 24 hours on two separate occasions 3 months apart. During the 3 month period women were randomized to placebo, ERT, or HRT. Urine samples were assayed for kallikrein activity, normalized to urine creatinine and expressed as mU/gm creatinine. Urinary kallikrein excretion increased significantly after 3 months in the ERT (p < 0.001) and HRT (p < 0.01) groups, and decreased non-significantly in the placebo group (p > 0.06). There were no significant blood pressure changes after 3 months of therapy. The findings demonstrate that hormone replacement therapy in the form of estrogen or estrogen combined with continuous medroxyprogesterone is effective in increasing urinary kallikrein excretion. Given that a decrease in kallikrein excretion may mark risk for development of hypertension, the findings of this study are of value in demonstrating a novel mechanism underlying cardioprotective properties of postmenopausal hormone replacement therapy in women without pre-existing coronary disease.     

Hormonal modulation of interleukin-6, tumor necrosis factor and associated receptor secretion in postmenopausal women

Hormone replacement therapy (HRT) reduces the risk for osteoporosis but transiently increases cardiovascular risk for some postmenopausal women. This study investigated the hypothesis that these risks are associated with HRT-induced changes in mononuclear cell secretion of interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-alpha), and associated soluble receptors. Compared to the untreated condition (n=8), estrogen therapy (n=7) and estrogen+progestin therapy (n=7) both caused 2-fold elevations in TNF-alpha secretion. IL-6 secretion was increased (48%, P=0.04) only by estrogen+progestin therapy. Although soluble receptor secretion was not different among groups, soluble TNF receptor type I and IL-6 receptor secretion were inversely related to plasma follicle stimulating hormone (P<0.05). Both therapies reduced plasma osteocalcin (a marker for osteoporosis) by approximately 50% (P<0.002). Plasma C-reactive protein (CRP, a marker for cardiovascular risk) was 3-fold higher in women receiving only estrogen, compared to untreated women (P=0.01), and twice as high as those receiving estrogen+ progestin (P=0.045). Simple linear relationships were not observed between cytokine secretion and these markers, but a significant HRT/TNF-alpha interaction with osteocalcin (P=0.022) and an HRT/IL-6 interaction with CRP (P =0.016) indicated more complex relationships between hormone replacement, cytokine activity, and health risks associated with menopause.     

Bridging advanced glycation end product, receptor for advanced glycation end product and nitric oxide with hormonal replacement/estrogen therapy in healthy versus diabetic postmenopausal women: a perspective

Cardiovascular diseases (CVD) are the most significant cause of death in postmenopausal women. The loss of estrogen biosynthesis with advanced age is suggested as one of the major causes of higher CVD in postmenopausal women. While some studies show beneficial effects of estrogen therapy (ET)/hormonal replacement therapy (HRT) in the cardiovascular system of healthy postmenopausal women, similar studies in diabetic counterparts contradict these findings. In particular, ET/HRT in diabetic postmenopausal women results in a seemingly detrimental effect on the cardiovascular system. In this review, the comparative role of estrogens is discussed in the context of CVD in both healthy and diabetic postmenopausal women in regard to the synthesis or expression of proinflammatory molecules like advanced glycation end products (AGEs), receptor for advanced glycation end products (RAGEs), inducible nitric oxide synthases (iNOS) and the anti-inflammatory endothelial nitric oxide synthases (eNOS). The interaction of AGE-RAGE signaling with molecular nitric oxide (NO) may determine the level of reactive oxygen species (ROS) and influence the overall redox status of the vascular microenvironment that may further determine the ultimate outcome of the effects of estrogens on the CVD in healthy versus diabetic women.     

Hormonal Therapy and Risk of Breast Cancer in Mexican Women

The use of hormonal therapies, including hormonal contraceptives (HC) and postmenopausal hormone replacement therapy (HRT) have been shown to influence breast cancer (BC) risk. However, the variations of these effects among populations and ethnic groups are not completely documented, especially among Hispanic women. We evaluated the association between HC and premenopausal BC risk, and between HRT and postmenopausal BC risk in Mexican women. Data from a Mexican multi-center population-based case–control study ofwomen aged 35 to 69 years were analysed. A total of 1000 cases and 1074 matched controls were recruited between 2004 and 2007. Information on hormonal therapy was collected through a structured questionnaire. Results were analysed using conditional logistic regression models. Overall, HC were used by 422/891 (47.3%) premenopausal women and HRT was used by 220/1117 (19.7%) postmenopausal women. For HC, odds ratios (ORs) for BC were 1.11 (95% confidence interval (CI): 0.82, 1.49) for current users and 1.68 (95% CI: 0.67, 4.21) for ever-users. No clear effect of duration of use was observed. For HRT, the OR for BC was significantly increased in ever users (OR: 1.45; 95% CI: 1.01, 2.08). A non-significant increased risk was observed for combined estrogen/progestin, (OR =  1.85; 95% CI: 0.84, 4.07) whereas no effect was observed for the use of estrogen alone (OR = 1.14; 95% CI: 0.68, 1.91). Our results indicate that, HC had a non-significant effect on the risk of pre-menopausal BC, but suggested that injected contraceptives may slightly increase the risk, whereas HRT had a significant effect on post-menopausal BC in this population. This study provides new information about the effects of HC and HRT on BC risk in a Mexican population, which may be of relevance for the population of Latin America as a whole.     

Biological effects of hormone replacement therapy in relation to serum estradiol levels

OBJECTIVE: Tissues in various parts of the body have different sensitivities to estradiol. However, it is very difficult to measure the serum estradiol levels precisely in women receiving oral conjugated equine estrogen, which is a mixture of estrogens. In the present study, we precisely measured the serum levels of estradiol in postmenopausal women undergoing hormone replacement therapy (HRT), and we clarified the relationships between serum estradiol levels and the effects of HRT on the Kupperman index, bone mineral density (BMD), serum gonadotropin, lipid metabolism and unscheduled bleeding as the clinical endpoints. METHODS: Sixty-eight postmenopausal or bilaterally ovariectomized women, aged 30-64 years, who had been suffering from vasomotor symptoms such as hot flush or atrophy of the vagina were randomly assigned to two groups: one group of 34 patients who received oral administration of 0.625 mg conjugated equine estrogen (CEE, Premarin, Wyeth) and 2.5 mg medroxyprogesterone acetate (MPA, Provera, Upjohn) every other day, and another group of 34 patients who received oral administration of 0.625 mg CEE and 2.5 mg MPA every day. All subjects were re-classified into three groups according to the serum estradiol level after 12 months of treatment: (1) low estradiol group (<15 pg/ml, n = 25); (2) middle estradiol group (> or =15 and <25 pg/ml, n = 27), and (3) high estradiol group (> or =25 pg/ml, n = 16). We examined the relationships between serum estradiol level and the effects of estradiol on the Kupperman index, BMD, serum gonadotropin levels, lipid profile and unscheduled bleeding in these three groups. Results: Results obtained by using our newly developed high-performance liquid chromatography (HPLC)-radioimmunoassay (RIA) system clearly showed that the effects on each tissue in postmenopausal women receiving oral CEE and MPA is closely related to estradiol level. The effects of HRT on BMD, serum gonadotropin levels and lipid profile were shown to be clearly dependent on the serum estradiol levels, while the effect of HRT on the Kupperman index was independent of the serum estradiol level. Furthermore, it was also found that a very low concentration of estradiol (<15 pg/ml) was sufficient to suppress the serum LH and FSH levels and to relieve vasomotor symptoms, and that the minimum concentration of estradiol required to increase BMD was 15 pg/ml. On the other hand, the level of estradiol required to reduce total cholesterol, low density lipoprotein-cholesterol (LDL-C) and apolipoprotein B (Apo B) was found to be more than 25 pg/ml, while the level required to increase high density lipoprotein-cholesterol (HDL-C) and apolipoprotein A1 (Apo A1) was at least 15 pg/ml. The incidence of unscheduled bleeding was also lower in the low estradiol group than in the other estradiol level groups. CONCLUSION: These results suggest that the different clinical endpoints have different response thresholds and thus reflect tissue sensitivity to estradiol levels achieved by HRT.     

MPA and postmenopausal coronary artery atherosclerosis revisited

Whether progestins, particularly medroxyprogesterone acetate (MPA), attenuate the cardiovascular benefits of postmenopausal estrogen replacement therapy (ERT) has been controversial for over a decade. Concerns related first to findings that MPA attenuated increases of high density lipoprotein cholesterol (HDLC) concentrations of postmenopausal women compared to conjugated equine estrogen (CEE) alone. That observation was followed by early cynomolgus monkey studies that suggested MPA decreased estrogen's cardiovascular benefits (vascular reactivity and coronary artery atherosclerosis inhibition). In a more recent and larger trial with cynomolgus monkeys, no differences were seen in the coronary artery atherosclerosis protective effect of CEE when MPA was co-administered (HRT). The lack of attenuation of ERTs benefits by progestins has also been seen in at least three studies of carotid artery intima-media thickness (IMT) of postmenopausal women. Additionally, the majority of studies of vascular reactivity of postmenopausal women have not found differences when CEE is given alone or with MPA. Seven observational studies of cardiovascular outcomes of postmenopausal women permit separate consideration of ERT versus HRT use; there is no evidence of attenuation of ERTs benefits by progestin use. In conclusion, it is evident that the current experimental, clinical, and observational data do not provide evidence that progestins attenuate estrogen's cardiovascular benefits.     

Hormone replacement therapy and cardiovascular disease: lessons from a monkey model of postmenopausal women

Concerns exist about the cardiovascular effects of hormone replacement therapy (HRT) in postmenopausal women because results from the Women's Health Initiative (WHI) and the Heart and Estrogen/Progestin Replacement Study (HERS) are contradictory. In both of these studies, postmenopausal conjugated equine estrogens + medroxyprogesterone acetate did not reduce risk, and somewhat increased the risk of myocardial infarction in both primary (WHI) and secondary (HERS) prevention. These results appear to contradict numerous observational clinical trials and animal studies, which reported profound beneficial effects of HRT on cardiovascular disease risk. Results of both human and monkey studies indicate that estrogen replacement therapy (ERT)/HRT is effective in inhibiting progression of early stage (fatty streak) atherosclerosis but that ERT/HRT is much less effective in inhibiting progression of more advanced (established plaque) atherosclerosis. Results of these monkey studies are consistent with those of studies in women wherein ERT/HRT was initiated in postmenopausal women with different initial amounts of atherosclerosis. Based on these findings, it is speculated that ERT/HRT may be more cardioprotective in younger postmenopausal women with less coronary artery disease, and less effective in women with established coronary artery disease. Researchers are challenged to define the relative cardiovascular risk/benefit in different populations of postmenopausal women based on differences in age, amounts of pre-existing atherosclerosis, and risk factors.     

Effect of postmenopausal hormone replacement therapy on lipoprotein and homocysteine levels in Chinese women

Epidemiological studies have revealed that postmenopausal estrogen replacement therapy results in a marked reduction in the risk for cardiovascular diseases. In the present study, we evaluated plasma lipoprotein profile as well as homocysteine levels in 145 postmenopausal and premenopausal Chinese women living in Hong Kong. We also investigated the effect of hormonereplacement therapy (HRT) with estrogen or estrogen combined with progestin on plasma lipoprotein profile and homocysteine concentrations in those individuals. Postmenopausal women displayed significantly higher plasma levels of total cholesterol, LDLcholesterol and apoB as well as higher plasma homocysteine levels than that of premenopausal women. HRT with either estrogen (17-estradiol or conjugated equine estrogen) alone or estrogen combined with progestin for 3.5–4.5 years significantly improved the lipoprotein profile in postmenopausal women by decreasing the levels of total cholesterol (12–20% reduction), LDL-cholesterol (26–29% reduction) and apoB (21–25% reduction). In women treated with 17estradiol or conjugated equine estrogens their plasma levels of apoAI were significantly elevated (18% elevation) as compared to non-users. HRT also reduced plasma concentrations of homocysteine (13–15% reduction). In conclusion, we found that long-term HRT was associated with improvement in plasma lipoprotein profile and a reduction in homocysteine concentration in postmenopausal women. These results support the notion that the improvement of lipoprotein profile and a reduction in homocysteine concentration may contribute to the beneficial effect of HRT on cardiovascular risk.     

Plasma C-reactive protein is not elevated in physically active postmenopausal women taking hormone replacement therapy.

We tested the hypothesis that hormone replacement therapy (HRT)-related increases in C-reactive protein (CRP) would either be blunted or absent in postmenopausal women who regularly perform endurance exercise. Plasma CRP is an independent predictor of future cardiovascular events in healthy men and women. Oral HRT increases plasma CRP concentrations in postmenopausal women. Regular aerobic exercise reduces the risk of cardiovascular events and is associated with lower CRP concentrations in adults. To date, no study has evaluated the influence of habitual physical activity on the elevation of CRP associated with HRT. Plasma CRP concentrations were measured in 114 postmenopausal women: 39 physically active (endurance trained) and 75 sedentary postmenopausal subjects. Sixty-five women were users of HRT (22 physically active and 43 sedentary), and 49 were nonusers (17 physically active and 32 sedentary). CRP levels were approximately 75% higher (P < 0.01) in the sedentary users vs. nonusers of HRT (1.9 +/- 1.8 vs. 1.1 +/- 1.0 mg/l). In contrast, there was no difference in CRP levels between the physically active users and nonusers of HRT (0.6 +/- 0.4 vs. 0.4 +/- 0.2 mg/l; P = 0.61). Regardless of HRT status, CRP concentrations were approximately 65% lower in the physically active compared with sedentary women. In conclusion, physically active postmenopausal women exhibit lower plasma CRP concentrations compared with sedentary controls. Importantly, the HRT-related elevation in plasma CRP levels observed in sedentary women is absent in women who engage in regular endurance exercise. These data suggest that habitual physical activity may prevent the elevation in CRP concentrations due to HRT.     

Prevalence of estrogen receptor alpha PvuII and XbaI polymorphism in population of Polish postmenopausal women

Numerous data indicate that polymorphism of estrogen receptor alpha (ERalpha) may predict lipid levels, lipid response to hormone replacement therapy (HRT), myocardial infarction risk, bone fracture risk, bone mineral density (BMD) and changes in BMD over time. In this study we aimed to evaluate distribution of ERalpha PvuII and XbaI genotypes in population of Polish postmenopausal women qualified to different protocols of HRT. Subject of the study were 64 consecutive postmenopausal women aged from 45 to 65 years (mean 56.6) assigned to HRT. ERalpha PvuII and XbaI polymorphism was determined by PCR-restriction fragment length polymorphism (RFLP). The absence of PvuII and XbaI restriction sites were indicated by "P" and "X" and presence by "p" and "x", respectively. PvuII genotype was distributed as follows: PP 17.2% (n=11), Pp 50% (n=32), pp 32.83% (n=21). Frequency of XbaI genotype was: XX 6.25% (n=4), Xx 34.4% (n=22), xx 59.4% (n=38). Four haplotypes with following frequencies were recognized: PX 17.3%, px 47.4%, Px 24.4% and pX 10.9%. Prevalence of estrogen receptor alpha PvuII and XbaI polymorphisms in Polish women is similar to previously studied population.     

Naloxone does not influence cardiovascular responses to mild mental stress in postmenopausal women

The interaction between central opioid activity, sex hormones, and the cardiovascular reactivity to stress is unknown. Twenty-eight healthy postmenopausal women, 16 without, and 12 with hormone replacement therapy (HRT) participated in this randomized, double-blind, cross-over study. The opioid receptor antagonist naloxone or placebo was administered intravenously on 2 different days and mild mental stress was induced by the Stroop Color-Word Test. Cardiovascular responses were assessed noninvasively by impedance cardiography. Stress significantly increased stroke volume, cardiac output, blood pressure, and heart rate, which was not influenced by opioid receptor blockade. Whereas naloxone increased cortisol plasma concentrations irrespective of HRT status, luteinizing hormone concentrations, which were higher in non-HRT compared with HRT women, were increased by naloxone in women with HRT only. These data suggest that the opioidergic tone of the hypothalamus-pituitary-adrenal axis persists in postmenopausal women, irrespective of HRT use, while the opioidergic tone on the hypothalamus-pituitary-gonadal axis seems to depend on an estrogenic milieu. Naloxone does not alter cardiovascular mental stress reactions in postmenopausal women independent of their hormone substitution status.     

Longitudinal associations of the endocrine environment on fat partitioning in postmenopausal women

Among postmenopausal women, declining estrogen may facilitate fat partitioning from the periphery to the intra-abdominal space. Furthermore, it has been suggested that excess androgens contribute to a central fat distribution pattern in women. The objective of this longitudinal study was to identify independent associations of the hormone milieu with fat distribution in postmenopausal women. Fifty-three healthy postmenopausal women, either using or not using hormone replacement therapy (HRT) were evaluated at baseline and 2 years. The main outcomes were intra-abdominal adipose tissue (IAAT), subcutaneous abdominal adipose tissue, and total thigh fat analyzed by computed tomography scanning and leg fat and total body fat mass measured by dual-energy X-ray absorptiometry. Serum estradiol, estrone, estrone sulfate, total testosterone, free testosterone, androstenedione, dehydroepiandrosterone sulfate), sex hormone-binding globulin (SHBG), and cortisol were assessed. On average, in all women combined, IAAT increased by 10% (10.5 cm(2)) over 2 years (P < 0.05). Among HRT users, estradiol was inversely associated with, and estrone was positively associated with, 2-year gain in IAAT. Among HRT nonusers, free testosterone was inversely associated with, and SHBG was positively associated with, 2-year gain in IAAT. These results suggest that in postmenopausal women using HRT, greater circulating estradiol may play an integral role in limiting lipid deposition to the intra-abdominal cavity, a depot associated with metabolically detrimental attributes. However, a high proportion of weak estrogens may promote fat partitioning to the intra-abdominal cavity over time. Furthermore, among postmenopausal women not using HRT, greater circulating free testosterone may limit IAAT accrual.     

Cholesterol-fed ovariectomized monkeys are good animal models for human atherosclerosis of postmenopausal women

Although it is well known that the incidence of atherosclerosis is markedly increased in postmenopausal women, antiatherosclerotic effects of estrogen replacement therapies are not clear. One of the reasons for this is due to the lack of appropriate animal models for atherosclerosis of postmenopausal women. Therefore, we attempted to develop an animal model for atherosclerosis of postmenopausal women and examined the antiatherosclerotic effects of estrogen replacement therapy. Adult ovariectomized Japanese monkeys were fed 2% cholesterol diet alone (C-group) or in combination with conjugated estrogen (CE-group) for 30 months. The serum estradiol-17β levels of the CE-group were varied between 10 and 204.5 ng/dl during treatment. In the C-group, the serum total cholesterol levels were increased from 110 to 270 mg/dl, and atheroma was first observed after 3-months treatment with angioscopy. In the CE-group, the levels of the serum total cholesterol during treatment were 30% lower than those of the C-group, and the aortic lesions were first observed after 12-months treatment with angioscopy. The aortic intimal thickness of the CE-group was 58% of the C-group. This finding showed good agreement with the angioscopic observation. The aortic lesions were of a fibromuscular type in both groups. In conclusion, a cholesterol-fed ovariectomized monkey is an appropriate animal model for atherosclerosis of postmenopausal women. Furthermore, angiofiberscopic and histopathological observations suggested that estrogen replacement therapy was valid for atherosclerosis of postmenopausal women.     

Benefits and risks of hormone replacement therapy (HRT)

In western countries more than 30% of the female population are postmenopausal. Approximately 30% of postmenopausal women suffer from clinical symptoms of the climacteric such as vasomotor symptoms, associated with hot flushes, night sweat, insomnia and depressive mood. Sufficient hormonal replacement therapy (HRT) will abolish specific menopausal symptoms in over 90% of patients, unspecific symptoms such as headache respond to placebo and HRT equally well. The question of cancer risk related to HRT will be addressed in this review. In combination with progestins, estrogens are obviously protective regarding ovarian and endometrial cancer. The association between HRT and breast cancer risk is presently unclear. Epidemiological data available so far do not provide compelling evidence as to a cause and effect relationship between HRT and breast cancer risk. There seems to be an overall trend towards a slightly increased risk with increasing duration of HRT use. Guidelines for HRT use in women with a history of endometrial and breast cancer are provided in this article.     

Trace mineral status in post menopausal women: impact of hormonal replacement therapy.

The risks of disturbances in trace mineral nutrition and metabolism are high following menopause. The aim of the study was to investigate the trace mineral status in postmenopausal women and the influence of hormonal replacement therapy on this status. Forty-four healthy postmenopausal women, aged 50-60 years old participated in the study. Eighteen were treated by combined hormonal replacement therapy (HRT) per os for at least two years, and 26 were untreated. Plasma trace mineral levels (Zn, Se, Cr, Mn, Cu), red blood cell antioxidant enzymes (Cu-Zn SOD, Se-GPX, Cu), urinary Zn, Cr, Mg, and Ca excretion were measured. Zinc, selenium and manganese plasma levels, activities of Cu-Zn-SOD and GSH-Px in erythrocytes were not statistically different between the two groups. The percentage of zinc plasma levels below the cut off of 10.7 micromol/L was higher in HRT treated group than in untreated one, whereas zinc excretion was reduced. Plasma copper concentrations were higher in women treated by HRT, whereas erythrocyte copper levels were not modified. Plasma chromium concentrations were significantly higher in women receiving HRT and urinary Cr excretion was decreased. The HRT group also exhibited lower losses of urinary zinc and magnesium than untreated women. These data suggest that hormonal replacement therapy provides beneficial effects on trace mineral status related to menopause.