A systematic review of the skeletal effects of estrogen therapy in postmenopausal women. II. An assessment of treatment effects

Psoralidin, a coumestan analogue, as a novel potent estrogen receptor signaling molecule isolated from Psoralea corylifolia

A novel biological activity of psoralidin as an agonist for both estrogen receptor (ER)α and ERβ agonist has been demonstrated in our study. Psoralidin has been characterized as a full ER agonist, which activates the classical ER-signaling pathway in both ER-positive human breast and endometrial cell lines as well as non-human cultured cells transiently expressing either ERα or ERβ. The estrogenic activity was determined using the relative expression levels of either reporter or the endogenous genes dependent on the agonist-bound ER to the estrogen response element (ERE). Psoralidin at 10 μM was able to induce the maximum reporter gene expression corresponding to that of E2-treated cells and such activation of the ERE-reporter gene by psoralidin was completely abolished by the cotreatment of a pure ER antagonist, implying that the biological activities of psoralidin are mediated by ER. Psoralidin was also able to induce the endogenous estrogen-responsive gene, pS2, in human breast cancer cells MCF-7. It was observed that activation of the classical ER-signaling pathway by psoralidin is mediated via induction of ER conformation by psoralidin and direct binding of the psoralidin-ER complex to the EREs present in the promoter region of estrogen-responsive genes, as shown by chromatin immunoprecipitation assay results. Finally, molecular docking of psoralidin to the ligand binding pocket of the ERα showed that psoralidin is able to mimic the binding interactions of E2, and thus, it could act as an ER agonist in the cellular environment.

Hormone therapy in postmenopausal women and risk of endometrial hyperplasia

BACKGROUND

Reduced circulating estrogen levels around the time of the menopause can induce unacceptable symptoms that affect the health and well-being of women. Hormone therapy (both unopposed estrogen and estrogen/progestogen combinations) is an effective treatment for these symptoms, but is associated with risk of harms. Guidelines recommend that hormone therapy be given at the lowest effective dose and treatment should be reviewed regularly. The aim of this review is to identify the minimum dose(s) of progestogen required to be added to estrogen so that the rate of endometrial hyperplasia is not increased compared to placebo.

OBJECTIVES

The objective of this review is to assess which hormone therapy regimens provide effective protection against the development of endometrial hyperplasia or carcinoma.

SEARCH METHODS

We searched the Cochrane Menstrual Disorders and Subfertility Group trials register (searched January 2012), The Cochrane Library (Issue 1, 2012), MEDLINE (1966 to January 2012), EMBASE (1980 to January 2012), Current Contents (1993 to May 2008), Biological Abstracts (1969 to 2008), Social Sciences Index (1980 to May 2008), PsycINFO (1972 to January 2012) and CINAHL (1982 to May 2008). Attempts were made to identify trials from citation lists of reviews and studies retrieved, and drug companies were contacted for unpublished data.

SELECTION CRITERIA

Randomised comparisons of unopposed estrogen therapy, combined continuous estrogen-progestogen therapy, sequential estrogen-progestogen therapy with each other or placebo, administered over a minimum period of 12 months. Incidence of endometrial hyperplasia/carcinoma assessed by a biopsy at the end of treatment was a required outcome. Data on adherence to therapy, rates of additional interventions, and withdrawals owing to adverse events were also extracted.

DATA COLLECTION AND ANALYSIS

In this update, 46 studies were included. Odds ratios (ORs) were calculated for dichotomous outcomes. The small numbers of studies in each comparison and the clinical heterogeneity precluded meta-analysis for many outcomes.

MAIN RESULTS

Unopposed estrogen is associated with increased risk of endometrial hyperplasia at all doses, and durations of therapy between one and three years. For women with a uterus the risk of endometrial hyperplasia with hormone therapy comprising low-dose estrogen continuously combined with a minimum of 1 mg norethisterone acetate (NETA) or 1.5 mg medroxyprogesterone acetate (MPA) is not significantly different from placebo at two years (1 mg NETA: OR 0.04; 95% confidence interval (CI) 0 to 2.8; 1.5 mg MPA: no hyperplasia events).

AUTHORS' CONCLUSIONS

Hormone therapy for postmenopausal women with an intact uterus should comprise both estrogen and progestogen to reduce the risk of endometrial hyperplasia.

Eucommia Leaf Extract (ELE) Prevents OVX-Induced Osteoporosis and Obesity in Rats

The cortex of Eucommia ulmoides Oliver is widely used to treat kidney deficiency in traditional Chinese medicine. Its leaves have recently been reported to have anti-obesity properties in metabolic syndrome-like rat models. Due to a sharp decline in estrogen production, obesity, together with osteoporosis, are common problems in postmenopausal women. In this study, we examined the potential effect of Eucommia leaf extract (ELE) in preventing osteoporosis and obesity induced by ovariectomy (OVX). Forty-six female Wistar rats were divided into six groups: Sham-Cont, OVX-Cont, and four OVX groups administered estradiol and different concentrations of ELE 1.25%, ELE 2.5%, and ELE 5%. Treatments were administered after ovariectomy at six weeks of age and continued for 12 weeks. OVX induced a significant decrease in the bone mineral density (BMD) of the lumbar, femora, and tibiae, together with a marked increase in body mass index (BMI). The administration of 5% ELE led to a significant increase in tibial and femoral BMD, as well as significantly increased bone-strength parameters when compared with OVX-Cont rats. According to the suppressed Dpd and increased osteocalcin concentrations in ELE 5% rats, we suggest that varying proportions of bone formation and bone absorption contributed to the enhanced BMD in the femora and tibiae. In addition, significant decreases in body weight, BMI and fat tissue in 5% ELE rats were also observed. These results suggest that ELE may have curative properties for BMD and BMI in OVX rats, and could provide an alternative therapy for the prevention of both postmenopausal osteoporosis and obesity.

Systematic review of methods used in meta-analyses where a primary outcome is an adverse or unintended event

BACKGROUND

Adverse consequences of medical interventions are a source of concern, but clinical trials may lack power to detect elevated rates of such events, while observational studies have inherent limitations. Meta-analysis allows the combination of individual studies, which can increase power and provide stronger evidence relating to adverse events. However, meta-analysis of adverse events has associated methodological challenges. The aim of this study was to systematically identify and review the methodology used in meta-analyses where a primary outcome is an adverse or unintended event, following a therapeutic intervention.

METHODS

Using a collection of reviews identified previously, 166 references including a meta-analysis were selected for review. At least one of the primary outcomes in each review was an adverse or unintended event. The nature of the intervention, source of funding, number of individual meta-analyses performed, number of primary studies included in the review, and use of meta-analytic methods were all recorded. Specific areas of interest relating to the methods used included the choice of outcome metric, methods of dealing with sparse events, heterogeneity, publication bias and use of individual patient data.

RESULTS

The 166 included reviews were published between 1994 and 2006. Interventions included drugs and surgery among other interventions. Many of the references being reviewed included multiple meta-analyses with 44.6% (74/166) including more than ten. Randomised trials only were included in 42.2% of meta-analyses (70/166), observational studies only in 33.7% (56/166) and a mix of observational studies and trials in 15.7% (26/166). Sparse data, in the form of zero events in one or both arms where the outcome was a count of events, was found in 64 reviews of two-arm studies, of which 41 (64.1%) had zero events in both arms.

CONCLUSIONS

Meta-analyses of adverse events data are common and useful in terms of increasing the power to detect an association with an intervention, especially when the events are infrequent. However, with regard to existing meta-analyses, a wide variety of different methods have been employed, often with no evident rationale for using a particular approach. More specifically, the approach to dealing with zero events varies, and guidelines on this issue would be desirable.

Dietary phytoestrogens maintain contractile responses to carbachol with age in the female rat isolated bladder

AIMS

Development of urinary incontinence, for many women, occurs following menopause. Dietary phytoestrogens consumed over the long term may affect the contractile function and maintenance of the urinary bladder in post menopausal women. This study examined the muscarinic receptor mediated contractile responses in the rat isolated bladder in response to ovariectomy and long term dietary phytoestrogen consumption.

MAIN METHODS

Ovariectomised or sham-operated female Wistar rats (8 weeks) were fed either normal rat chow (soy, phytoestrogens) or a non-soy (phytoestrogen free) diet. Bladders were dissected from rats at 12, 24 and 52 weeks of age and placed in 25 ml organ baths filled with McEwans solution.

KEY FINDINGS

The contractile response to carbachol, in 12 week old female rats did not change as a result of dietary phytoestrogens or ovariectomy (P>0.05). At 24 weeks of age, detrusor muscle strip responses to carbachol from non-soy fed ovariectomised rats were attenuated (P<0.05). At 52 weeks, bladder detrusor strip responses to carbachol were reduced in all treatment groups with the exception of the soy-fed sham operated rats.

SIGNIFICANCE

These results suggest an age-related reduction in the contractile response of the detrusor to the muscarinic receptor agonist carbachol, which may be prevented by long term dietary phytoestrogen intake.

Hormone therapy in postmenopausal women and risk of endometrial hyperplasia

BACKGROUND

Declining circulating estrogen levels around the time of the menopause can induce unacceptable symptoms that affect the health and well being of women. Hormone therapy (both unopposed estrogen and estrogen/progestogen combinations) is an effective treatment for these symptoms, but is associated with risk of harms. Guidelines recommend that hormone therapy be given at the lowest effective dose and treatment should be reviewed regularly. The aim of this review is to identify the minimum dose(s) of progestogen required to be added to estrogen so that the rate of endometrial hyperplasia is not increased compared to placebo.

OBJECTIVES

The objective of this review is to assess which hormone therapy regimens provide effective protection against the development of endometrial hyperplasia and/or carcinoma.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders and Subfertility Group trials register (searched January 2008), The Cochrane Library (Issue 1, 2008), MEDLINE (1966 to May 2008), EMBASE (1980 to May 2008), Current Contents (1993 to May 2008), Biological Abstracts (1969 to 2008), Social Sciences Index (1980 to May 2008), PsycINFO (1972 to May 2008) and CINAHL (1982 to May 2008). Attempts were made to identify trials from citation lists of reviews and studies retrieved, and drug companies were contacted for unpublished data.

SELECTION CRITERIA

Randomised comparisons of unopposed estrogen therapy, combined continuous estrogen-progestogen therapy and/or sequential estrogen-progestogen therapy with each other or placebo, administered over a minimum period of twelve months. Incidence of endometrial hyperplasia/carcinoma assessed by a biopsy at the end of treatment was a required outcome. Data on adherence to therapy, rates of additional interventions, and withdrawals due to adverse events were also extracted.

DATA COLLECTION AND ANALYSIS

In this substantive update, forty five studies were included. Odds ratios were calculated for dichotomous outcomes. The small numbers of studies in each comparison and the clinical heterogeneity precluded meta analysis for many outcomes.

MAIN RESULTS

Unopposed estrogen is associated with increased risk of endometrial hyperplasia at all doses, and durations of therapy between one and three years. For women with a uterus the risk of endometrial hyperplasia with hormone therapy comprising low dose estrogen continuously combined with a minimum of 1 mg norethisterone acetate or 1.5 mg medroxyprogesterone acetate is not significantly different from placebo (1mg NETA: OR=0.04 (0 to 2.8); 1.5mg MPA: no hyperplasia events).

AUTHORS' CONCLUSIONS

Hormone therapy for postmenopausal women with an intact uterus should comprise both estrogen and progestogen to reduce the risk of endometrial hyperplasia.

Parathyroid hormone(1-84) treatment of postmenopausal women with low bone mass receiving hormone replacement therapy

Treatment of postmenopausal osteoporosis (PMO) is based primarily on antiresorptive agents, including hormone replacement therapy (HT). To evaluate whether anabolic therapy together with HT provides additional benefits in the treatment of PMO, we evaluated the effects of parathyroid hormone (PTH) 1-84 in postmenopausal women with low bone mineral density (BMD) who were receiving chronic (> or =6 months) HT. Subjects were randomized to receive 100 microg PTH(1-84) or placebo injections daily for 24 months (n = 90/group). The primary efficacy outcome was change from baseline in lumbar spine BMD. Secondary end points included changes in hip and distal radius BMD, bone turnover markers, and fracture incidence. The study was terminated early following recommendations regarding HT for PMO. At 18 months, the mean increase in lumbar spine BMD was 7.9% for PTH(1-84) subjects vs. 1.5% for those receiving HT alone; between-group differences were significant at 6 months and persisted throughout the study. Lumbar spine BMD increased in 94% of women receiving PTH(1-84) compared to 59% for HT alone. Femoral neck BMD and bone turnover markers were significantly higher in PTH(1-84)-treated subjects, but the changes in total hip and distal radius BMD were not significant. PTH(1-84) treatment was generally well-tolerated, with hypercalciuria, hypercalcemia, nausea, vomiting, and dizziness reported more frequently in the HT + PTH(1-84) group. In conclusion, addition of PTH(1-84) to stable HT produced marked increases in lumbar spine BMD and may represent an additional approach to the treatment of PMO women receiving HT.

Postmenopausal hormone therapy: who now takes it and do they differ from non-users?

BACKGROUND

Considerable changes in hormone therapy use have taken place in the last few years.

AIMS

To determine current usage of postmenopausal hormone therapy and assess the trend and rate of change in hormone therapy usage over the last 13 years. Additionally, to assess differences between current users and non-users for health-related and risk factor variables.

METHODS

Questions regarding hormone therapy use have been included in an annual face to face population health survey of South Australians eight times since 1991. In 2004, additional questions on health status and quality of life were included.

RESULTS

In 2004, current use of hormone therapy was 15.4, 19.8 and 31.2% in all women over 40, 50 and 50-59 years, respectively. Ever use of hormone therapy among all women over 50 years was 46.5% with a mean duration of use of 7.46 years. Hormone therapy users did not differ from non-users in chronic disease indicators, body mass index, complementary medicine or therapist use, other health service use, socioeconomic status or quality of life. Increased hormone therapy use was associated with higher income, better educated, employed and married women in their sixth decade. Current use has varied over the years, with an increase to 2000, but a drop in 2003 and 2004.

CONCLUSION

Apart from menopausal symptoms, there is no evidence to support differences between users and non-users in terms of quality of life or health characteristics, requiring more appropriate selection of women for hormone therapy.

Effects of black cohosh (Cimicifuga racemosa) on bone turnover, vaginal mucosa, and various blood parameters in postmenopausal women

OBJECTIVES

In this study, the effects of the Cimicifuga racemosa (CR) preparation CR BNO 1055 on markers of bone metabolism, hormones, sex hormone-binding globulin (SHBG), lipometabolism, vaginal maturity, and routine laboratory parameters were compared with those of conjugated estrogens (CE) and placebo.

DESIGN

Sixty-two postmenopausal women were included in this double-blind study. Treatment duration with CR (daily dose corresponds to 40 mg of herbal drug), CE (0.6 mg/day), or placebo was 12 weeks. Markers of bone turnover (bone-specific alkaline phosphatase, CrossLaps), estradiol, follicle-stimulating hormone, leuteinizing hormone, SHBG, triglycerides, total cholesterol, high-density cholesterol, low-density cholesterol, and routine clinical chemistry parameters were determined from blood samples. Vaginal "maturity index" was determined from vaginal smears.

RESULTS

The analyses of bone turnover markers indicated beneficial effects for CR and CE on bone metabolism. CR stimulated osteoblast activity, whereas CE inhibited osteoclast activity. Whereas CE showed strong estrogenic effects on vaginal mucosa, CR showed weak estrogen-like activity. No significant effects were seen on coagulation markers and liver enzymes in the blood. CR was well tolerated.

CONCLUSION

These results suggest that CR has beneficial bone remodeling and weak estrogen-like effects in the vaginal mucosa.

[The more efficacious acupoints of Zusanli and Sanyinjiao than that of non-acupoints on bone mass in osteopenic ovariectomized rats]

OBJECTIVE

To clarify whether the acupoints of Zusanli (ST36) and Sanyinjiao (SP6) have specific actions other than non-acupoints to bone.

METHODS

Forty Sprague-Dawley female rats were divided into five groups: Sham operated (sham) group; Ovariectomized (OVX, model) group; non-acupuncture group; OVX, needling on Zusanli and Sanyinjiao (Acp-A) group; OVX, needling on the reverse sides of Zusanli and Sanyinjiao (Acp-B) group; OVX, periostineal stimulation on the same height as points of Zusanli and Sanyinjiao (Acp-C) group. The experiment was continued for 23 weeks and then all animals were sacrificed.

RESULTS

OVX had a significantly higher body weight and lower bone mineral density (BMD) on the lumbar vertebrae, total femora and tibiae than sham rats, however, Acp-A showed a higher BMD compared with the other OVX groups. On the other hand, bone weights, bone strength and bone morphometry such as trabecular volume, trabecular separation, labeled width and bone formation rate also showed the same improvements in Acp-A as compared to the other OVX rats.

CONCLUSION

The stimulation on Zusanli and Sanyinjiao specifically prevented the development of osteopenic rats compared with non-acupoints.

Indications for hormone therapy: the post-Women's Health Initiative era

Information from the Women's Health Initiative (WHI) trial has given physicians valuable tools for counseling women aged 50 to 79 years about the short-term risks of hormone therapy (HT). Unanswered questions remain, particularly on the risks and benefits of discontinuing HT among long-term users. The decision to discontinue HT should be carefully considered, because stopping and re-starting after several months may "reset the clock" for risks associated with changes in hepatic protein synthesis. The current authors recommend low-dose transdermal hormonal formulations,but no large-scale randomized trials exist to confirm the veracity of this recommendation. It has been suggested that starting HT in the menopausal transition would alleviate the HT risks observed withWHI. Until additional data are available to counsel women in the menopausal transition, however, the conservative counseling approach is to apply those figures available from the WHI, particularly because women aged 50 to 59 years using estrogen-progestin therapy have an unfavorable risk-benefit ratio, similar to that seen in older women.

Practical measurement of total and bioavailable estradiol in female macaques

BACKGROUND

Commercially available, direct assay kits provide a simple and rapid means for measuring estradiol. Similarly, ammonium sulfate precipitation of SHBG-bound steroids is a reliable alternative to equilibrium dialysis or ultrafiltration for assessing bioavailability. However, while these techniques are useful for humans, they have yet to be evaluated systematically for macaques-species which are frequently used to model estrogen effects on women's health.

METHODS

A reference assay (which included chromatography) and two modified versions of a human kit (one in which monkey serum was assayed directly, and another in which an extraction step was added) were used to measure estradiol in matching samples. Ammonium sulfate precipitation and an established ultrafiltration technique were used to assess bioavailability.

RESULTS

Values from both kit modifications correlated significantly with those from the reference assay. Although both modifications underestimated values, the addition of the extraction step resulted in far more useful estimates due to the consistency of underestimation across the standard curve. Measures of bioavailability from ammonium sulfate precipitation and ultrafiltration were strongly correlated and consistent across all concentrations.

CONCLUSIONS

Simplified techniques developed for humans can be used in macaques, although the addition of an extraction step markedly improves the performance of direct assay kits.

Hormone replacement therapy in postmenopausal women: endometrial hyperplasia and irregular bleeding

BACKGROUND

The decline in circulating oestrogen around the time of the menopause often induces unacceptable symptoms that affect the health and well being of women. Hormone replacement therapy (both unopposed oestrogen and oestrogen and progestogen combinations) is an effective treatment for these symptoms. In women with an intact uterus, unopposed oestrogen may induce endometrial stimulation and increase the risk of endometrial hyperplasia and carcinoma. The addition of progestogen reduces this risk but may cause unacceptable symptoms, bleeding and spotting which can affect adherence to therapy.

OBJECTIVES

The objective of this review is to assess which hormone replacement therapy regimens provide effective protection against the development of endometrial hyperplasia and/or carcinoma with a low rate of abnormal vaginal bleeding.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders and Subfertility Group trials register (searched January 2003), The Cochrane Library (Issue 2, 2003), MEDLINE (1966 to January 2003), EMBASE (1980 to January 2003), Current Contents (1993 to January 2003), Biological Abstracts (1969 to 2002), Social Sciences Index (1980 to January 2003), PsycINFO (1972 to February 2003) and CINAHL (1982 to January 2003). The search strategy was developed by the Cochrane Menstrual Disorder and Subfertility Group. Attempts were also made to identify trials from citation lists of review articles and drug companies were contacted for unpublished data. In most cases, the corresponding author of each included trial was contacted for additional information.

SELECTION CRITERIA

The inclusion criteria were randomised comparisons of unopposed oestrogen therapy, combined continuous oestrogen-progestogen therapy and sequential oestrogen-progestogen therapy with each other and placebo administered over a minimum treatment period of six months. Trials had to assess which regimen was the most protective against the development of endometrial hyperplasia/carcinoma and/or caused the lowest rate of irregular bleeding.

DATA COLLECTION AND ANALYSIS

Sixty RCTs were identified. Of these 23 were excluded and seven remain awaiting assessment. The reviewers assessed the thirty included studies for quality, extracted the data independently and odds ratios for dichotomous outcomes were estimated. Outcomes analysed included frequency of endometrial hyperplasia or carcinoma, frequency of irregular bleeding and unscheduled biopsies or dilation and curettage, and adherence to therapy.

MAIN RESULTS

Unopposed moderate or high dose oestrogen therapy when compared to placebo was associated with a significant increase in rates of endometrial hyperplasia with increasing rates at longer duration of treatment and follow up. Odds ratios ranged from (1 RCT; OR 5.4, 95% CI 1.4 to 20.9) for 6 months of treatment to (4 RCTs; OR 9.6, 95% CI 5.9 to 15.5) for 24 months treatment and (1 RCT; OR 15.0, 95% CI 9.3 to 27.5) for 36 months of treatment with moderate dose oestrogen (in the PEPI trial, 62% of those who took moderate dose oestrogen had some form of hyperplasia at 36 months compared to 2% of those who took placebo). Irregular bleeding and non adherence to treatment were also significantly more likely under these unopposed oestrogen regimens that increased bleeding with higher dose therapy. Although not statistically significant, there was a 3% incidence (2 RCTs) of hyperplasia in women who took low dose oestrogen compared to no incidence of hyperplasia in the placebo group. The addition of progestogens, either in continuous combined or sequential regimens, helped to reduce the risk of endometrial hyperplasia and improved adherence to therapy. At longer duration of treatment, continuous therapy was more effective than sequential therapy in reducing the risk of endometrial hyperplasia. There was evidence of a higher incidence of hyperplasia under long cycle sequential therapy (progestogen given every three months) compared to monthly sequential therapy (progestogen given every month). No increase in endometrial cancer was seen in any of t in any of the treatment groups during the duration (maximum of six years) of these trials. During the first year of therapy irregular bleeding and spotting was more likely in continuous combined therapy than sequential therapy. However, during the second year of therapy bleeding and spotting was more likely under sequential regimens.

REVIEWERS' CONCLUSIONS

There is strong and consistent evidence in this review that unopposed oestrogen therapy, at moderate and high doses, is associated with increased rates of endometrial hyperplasia, irregular bleeding and consequent non adherence to therapy. The addition of oral progestogens administered either sequentially or continuously is associated with reduced rates of hyperplasia and improved adherence to therapy. Irregular bleeding is less likely under sequential than continuous therapy during the first year of therapy but there is a suggestion that continuous therapy over long duration is more protective than sequential therapy in the prevention of endometrial hyperplasia. Hyperplasia is more likely when progestogen is given every three months in a sequential regimen compared to a monthly progestogen sequential regimen.

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.

Dietary soy protein maintains some indices of bone mineral density and bone formation in aged ovariectomized rats

Hormone replacement therapy (HRT) has been used to prevent osteoporosis in postmenopausal women. However, HRT may increase the incidence of some cancers and has other side effects. There is considerable interest in dietary alternatives that include the consumption of soy and isoflavones derived from soy. The purpose of this study was to determine the effects of dietary soy protein on bone density, formation and resorption in cortical and cancellous bone in aged, ovariectomized rats. Specific emphasis was placed on indices of bone formation. Rats were assigned to the following groups: baseline; sham surgery + casein diet; sham + soy protein diet; ovariectomy (Ovx) + casein diet; Ovx + soy protein diet. The diets were fed for 3 mo. The Ovx Soy group had a greater bone mineral density (BMD) than the Ovx Casein group. There was a trend (P < 0.10) for greater periosteal bone formation rates in the Sham Soy compared with the Sham Casein group. In the Ovx Soy group, indices of endocortical bone formation were greater than those of the Ovx Casein group. There were no significant differences in resorption indices or endochondral growth (bone elongation) rates with soy in either the Sham or Ovx groups. In cancellous bone, the double-labeled surface and bone formation rates were greater in the Ovx Soy group than in the Ovx Casein group. These results show that dietary soy had a beneficial effect on the preservation of BMD associated with estrogen deficiency bone loss in aged rats. These data also show that at the tissue level, soy functions in a manner different from estrogen by increasing or sustaining elevated bone formation rates after ovariectomy.

The epidemiology of osteoporosis and fractures in geriatric medicine

Several conclusions can be drawn from this article, the most important of which are as follows: 1. Low bone mass is widely prevalent among older men and women and is associated with important fracture consequences. 2. The prevalence of osteoporosis and fracture is projected to increase over the next several decades. 3. Although Caucasian women are at greatest risk, substantial numbers of men and women of non-Caucasian heritage are also affected. 4. The population burden of disease consequences, including mortality, morbidity, and social and personal cost, is anticipated to increase as well. 5. In the group at greatest risk (Caucasian women), osteoporosis and fracture have well-established risk factors, many of which are modifiable. 6. Relevance of these risk factors for groups other than Caucasian women appears likely but requires further investigation. 7. Personal and societal costs associated with osteoporosis are enormous; as such, identification of persons at risk and prevention and treatment of this disease should be public health priorities.

Phytoestrogens: endocrine disrupters or replacement for hormone replacement therapy?

OBJECTIVES

This review presents findings with clear statements from the literature as well as own results of effects of soy, red clover and their isoflavones as well as of the Cimicifuga racemosa extract BNO 1055. Experimental and clinical effects on climacteric complaints, osteoprotective effects, activity in the urogenital tract, and risks concerning cardiovascular diseases and mammary and endometrial tissue will be compared, also in comparison to classical hormone preparations. The question whether soy and red clover products and/or Cimicifuga racemosa (CR) preparations are endocrine disrupters or may fulfill the criteria of the so-called phyto-SERMs will be discussed.

METHODS

Review of selected publications since 1980 and summary of unpublished own results of the authors.

RESULTS

Experimental and clinical evidences suggest that soy/red clover and their isoflavones do not fulfill the criteria of an ideal SERM. They appear to have mild osteoprotective effects but do not improve climacteric complaints. Furthermore, they seem to stimulate uterine growth and mammary epithelial proliferation. In ovariectomized rats, the CR extract BNO 1055 showed many of the beneficial effects of 17beta-estradiol, including effects in the brain/hypothalamus to reduce serum LH levels, effects in the bone to prevent osteoporosis and estrogenic effects in the urinary bladder. The CR extract BNO 1055 had no uterotrophic effect.

CONCLUSION

If clinical studies confirm these results, the Cimicifuga racemosa preparation BNO 1055 would appear as an ideal SERM and may therefore be an alternative to hormone replacement therapy.

Hormone replacement therapy: optimising the dose and route of administration

Several new products and regimens for estrogen replacement in the postmenopausal woman have recently been introduced, giving physicians and patients greater choice not only in dose but also in route of administration. Estrogen treatment in the postmenopausal woman has several proven benefits for those who have vasomotor symptoms or problems related to urogenital atrophy. However, the most controversial area is in the long-term preventive benefits of estrogen against the development of osteoporosis and cardiovascular disease, particularly in women older than 60 years. It is in these areas that decisions on the dose and optimal route of administration of estrogen replacement therapy (ERT) must be made. Although adding a progestogen to an ERT regimen is mandatory, particularly in a woman with an intact uterus, discussion now focuses on which progestogen least attenuates the beneficial effects of estrogen. Emerging trends suggest that lower doses of estrogen (i.e. ethinylestradiol 5 microg/day, estradiol 0.25 mg/day or conjugated estrogens [CEE] 0.3 mg/day) continuously combined with lower doses of medroxyprogesterone (MPA) are equally effective at relieving vasomotor symptoms as the most commonly prescribed regimen in the US (CEE 0.625mg/MPA 2.5mg daily), with fewer adverse events, leading to greater patient acceptance and likelihood for continuation of therapy. This is especially important when therapy is initiated at an older age.

Phytoestrogens for hormone replacement therapy?

Due to some severe side effects "classical" hormone replacement therapy (HRT) is currently being challenged by a therapy with phytoestrogens. Particularly soy and red clover derived isoflavones are advertised as selective estrogen receptor modulators (SERMs) with only desired and no undesired estrogenic effects. Evidence that this is the case however is scarce. Most studies investigating climacteric complaints did not find beneficial effects. A proposed beneficial effect on mammary cancer is unproven. The majority of studies however indicate an antiosteoporotic effect of isoflavones, while putative beneficial effects in the cardiovascular system are questionable due to the fact that estradiol which--like isoflavones--increase HDL and decrease LDL concentrations appear not to prevent arteriosclerosis in the human. In the urogenital tract, including the vagina, soy and red clover derived isoflavones are without effects. Cimicifuga racemosa extracts are traditionally used for the treatment of climacteric complaints. Evidence is now available that the yet unknown compounds in Cimicifuga racemosa extracts prevent climacteric complaints and may also have antiosteoporotic effects.

Meta-analyses of therapies for postmenopausal osteoporosis. V. Meta-analysis of the efficacy of hormone replacement therapy in treating and preventing osteoporosis in postmenopausal women

OBJECTIVE

To review the effect of hormone replacement therapy (HRT) on bone density and fractures in postmenopausal women.

DATA SOURCE

We searched MEDLINE and EMBASE from 1966 to 1999, the Cochrane Controlled Register, citations of relevant articles, and proceedings of international meetings for eligible randomized controlled trials. We contacted osteoporosis investigators to identify additional studies, and primary authors for unpublished data.

STUDY SELECTION

We included 57 studies that randomized postmenopausal women to HRT or a control (placebo or calcium/vitamin D) and were of at least 1 yr in duration. Seven of these studies reported fractures.

DATA ABSTRACTION

For each study, three independent reviewers assessed the methodological quality and abstracted the data.

DATA SYNTHESIS

HRT showed a trend toward reduced incidence of vertebral fractures [relative risk (RR) 0.66, 95% confidence interval (CI) 0.41-1.07; 5 trials] and nonvertebral fractures (RR 0.87, 95% CI 0.71-1.08; 6 trials). HRT had a consistent effect on bone mineral density (BMD) at all sites. The difference between HRT and control in the percent change in bone density at 2 yr was 6.76 (5.83, 7.89; 21 trials) at the lumbar spine and 4.53 (3.68, 5.36; 14 trials) and 4.12 (3.45, 4.80; 9 trials) at the forearm and femoral neck, respectively.

CONCLUSIONS

HRT has a consistent, favorable and large effect on bone density at all sites. The data show a nonsignificant trend toward a reduced incidence in vertebral and nonvertebral fractures.

Preventing fractures in postmenopausal women with osteoporosis. A review of recent controlled trials of antiresorptive agents

The evidence from randomised, controlled trials of the ability of antiresorptive treatments to reduce the risk of fractures in postmenopausal women with osteoporosis is reviewed and summarised. The aminobisphosphonates, alendronic acid and risedronic acid, and the selective estrogen receptor modulator raloxifene have all been shown to reduce the incidence of radiographic vertebral fractures. Only alendronic acid and risedronic acid have been shown to reduce the incidence of non-spine fractures in women with postmenopausal osteoporosis. There is evidence of antifracture efficacy for calcium plus vitamin D, primarily in a nursing home setting or in people with low intakes of these nutrients. Furthermore, since both the placebo and active treatment groups received calcium and vitamin D in most controlled trials of antiresorptive agents, it appears that the other agents provide benefits beyond those of calcium and vitamin D alone. There is insufficient published evidence from randomised controlled trials to convincingly support the antifracture efficacy of other agents, including calcitonin, estrogen and etidronic acid, at this time. Data from observational studies suggest, however, that estrogen and etidronic acid may have antifracture efficacy in this population.

Assessment by quantitative ultrasonometry of the effects of hormone replacement therapy on bone mass

OBJECTIVE

This study was undertaken to evaluate the impact of hormone replacement therapy on results of quantitative ultrasonometry of the heel.

STUDY DESIGN

A total of 2006 healthy perimenopausal women (mean age, 52.2 (10.3 years) were recruited in 5 German centers: 611 women (30%) had received hormone replacement therapy and 1395 (70%) had not. About 90% of the hormone replacement therapy users were current users, and the rest had stopped <6 months before the study. Speed of sound, broadband ultrasonographic attenuation, and the stiffness index were compared among the following groups: all users and nonusers of hormone replacement therapy, hormone replacement therapy users and nonuser control subjects matched for age and body mass index, and hormone replacement therapy users grouped in relation to the duration of hormone replacement therapy use and age and control subjects matched for body mass index.

RESULTS

Women who were using hormone replacement therapy had significantly higher values (P <.001) than did nonusers for all ultrasonographic variables, even after we controlled for age and body mass index. Women who had used hormone replacement therapy for >3 years had significantly higher values (P <.001) than did matched control subjects for all variables. Differences increased with the duration of hormone replacement therapy use.

CONCLUSION

Quantitative ultrasonometric measurement at the heel differentiates hormone replacement therapy users from nonusers, reflects duration of hormone replacement therapy use, and could be useful in both clinical trials and patient management.

A systematic review of the skeletal effects of estrogen therapy in postmenopausal women. I. An assessment of the quality of randomized trials published between 1977 and 1995

PURPOSE

To examine the quality of published randomized controlled trials of the effects of estrogen treatment on fracture risk and measures of bone mass.

DATA SOURCES

Articles on estrogen treatment for osteoporosis published between 1977 and 1995 were identified by searching Medline and Excerpta Medica databases and bibliographies of original papers and published reviews.

STUDY SELECTION

Studies selected were randomized controlled trials of the efficacy of estrogens in preventing loss of bone mass or fractures in postmenopausal women.

DATA EXTRACTION

Data extraction and quality assessment were performed in duplicate, with assistance of a manual. Raters were blinded as to authors and their affiliations and the publication details.

RESULTS

Of 99 eligible randomized controlled trials published between 1977 and 1995, eight included no extractable data, and 23 contained results that were published in duplicate. Total quality scores increased over time, but this was accounted for by improvements only in the measurement technologies used to estimate bone mineral content or density. There was no improvement in the quality of randomization methods, the extent to which withdrawals were accounted for, or in the baseline comparability of treated and control patients. Neither sample sizes nor durations of follow-up increased over time.

CONCLUSIONS

This body of literature fails to address whether estrogen therapy reduces fracture rates, and does not allow for comparison of the effects of different active therapies on change in bone density. Although there were improvements in the techniques for estimating bone mass and delivering estrogen treatment, the studies published in the 1990s were no more informative for making clinical or policy decisions than those published in the 1970s.