Prevention of early postmenopausal bone loss using low doses of conjugated estrogens and the non-hormonal, bone-active drug ipriflavone

Isoflavone intervention and its impact on bone mineral density in postmenopausal women: a systematic review and meta-analysis of randomized controlled trials

Due to estrogen deficiency, postmenopausal women may suffer from an imbalance in bone metabolism that leads to bone fractures. Isoflavones, a type of phytoestrogen, have been suggested to improve bone metabolism and increase bone mass. Therefore, isoflavones are increasingly recognized as a promising natural alternative to hormone replacement therapy for postmenopausal women who face a heightened risk of osteoporosis and are susceptible to bone fractures.

PURPOSE

This study aimed to evaluate the efficacy of isoflavone interventions on bone mineral density (BMD) in postmenopausal women by means of systematic review and meta-analysis.

METHODS

The electronic database searches were performed on PubMed, Embase, Scopus, and Cochrane Library databases, covering literature up to April 20, 2023. A random-effects model was used to obtain the main effect estimates, with a mean difference (MD) and its 95% confidence interval (CI) as the effect size summary. The risk of bias assessment was conducted using the Risk of Bias 2 (RoB2) tool.

RESULTS

A total of 63 randomized controlled trials comparing isoflavone interventions (n = 4,754) and placebo (n = 4,272) were included. The results indicated that isoflavone interventions significantly improved BMD at the lumbar spine (MD = 0.0175 g/cm2; 95% CI, 0.0088 to 0.0263, P < 0.0001), femoral neck (MD = 0.0172 g/cm2; 95% CI, 0.0046 to 0.0298, P = 0.0073), and distal radius (MD = 0.0138 g/cm2; 95% CI, 0.0077 to 0.0198, P < 0.0001) in postmenopausal women. Subgroup analysis showed that the isoflavone intervention was effective for improving BMD when the duration was ≥ 12 months and when the intervention contained genistein of at least 50 mg/day.

CONCLUSION

This systematic review and meta-analysis suggests that isoflavone interventions, especially those containing genistein of at least 50 mg/day, can effectively enhance BMD in postmenopausal women.

The volume of brisk walking is the key determinant of BMD improvement in premenopausal women

SUMMARY

Osteoporosis is an increasing health problem in postmenopausal women. Our findings indicated that long-term brisk walking with a volume greater than 16 per week is effective for improving BMD in premenopausal women.

PURPOSE

To examine the effects of brisk walking on bone mineral density (BMD) in premenopausal women, and further determine the effective frequency, intensity, time and volume (frequency x duration) of brisk walking for training strategy prescription.

METHODS

222 healthy premenopausal women were recruited for BMD measurement. According to the survey of their physical activity level, 84 subjects (age: 46±1.8) whose physical activity index ≥40 were categorized into the brisk walking group, and 138 subjects (age: 47±2.2) whose physical activity index <40 were assigned to the sedentary group. The BMD of these two groups were statistically compared with an independent t test. Next, 35 subjects from the original sedentary group were recruited for BMD measurement after 2-year moderate brisk walking. According to the volume of physical activity per week, they were divided into the control group (n = 10, aged 49±0.9), volume 8 group (n = 4, aged 48±1.2), volume 12 group (n = 7, aged 49±1.4), volume 16 group (n = 8, aged 49±1.3), and volume 20 group (n = 6, aged 49±1.5). ANOVA was used to analyze BMD before and after brisk walking among the five groups.

RESULTS

The BMD in the brisk walking group (1.00±0.008 g/cm2) was significantly higher than that in the sedentary group (0.89±0.008 g/cm2) (P<0.001). Stepwise regression analysis revealed that the volume of brisk walking was significantly correlated with BMD (P<0.001). In particular, brisk walking with a volume greater than 16 (a score of duration up to 4 and a score of frequency up to 4 or 5) per week is effective for improving BMD in premenopausal women (P = 0.03, P = 0.002, respectively).

CONCLUSIONS

Long-term brisk walking is an efficient way to improve BMD. Taking brisk walks for 30 minutes per day 3 or more times per week (volume>16) is recommended to prevent bone loss in premenopausal women.

Isoformononetin, a methoxydaidzein present in medicinal plants, reverses bone loss in osteopenic rats and exerts bone anabolic action by preventing osteoblast apoptosis

PURPOSE

Daidzein (Daid) has been implicated in bone health for its estrogen-'like' effects but low bioavailability, unfavorable metabolism and uterine estrogenicity impede its clinical potential. This study was aimed at assessing isoformononetin (Isoformo), a naturally occurring methoxydaidzein, for bone anabolic effect by overcoming the pitfalls associated with Daid.

METHODS

Sprague-Dawley ovariectomized (OVx) rats with established osteopenia were administered Isoformo, 17β-oestradiol (E2) or human parathyroid hormone. Efficacy was evaluated by bone microarchitecture using microcomputed tomography and determination of new bone formation by fluorescent labeling of bone. Osteoblast apoptosis was measured by co-labeling of bone sections with Runx-2 and TUNEL. Biochemical markers of bone metabolism were measured by ELISA. Plasma and bone marrow levels of Isoformo and Daid were determined by LC-MS-MS. Rat bone marrow stromal cells were harvested to study osteoblastic differentiation by Isoformo and Daid. New born rat pups were injected with Isoformo and Daid to study the effect of the compounds on the expression of osteogenic genes in the calvaria by real time PCR.

RESULTS

In osteopenic rats, Isoformo treatment restored trabecular microarchitecture, increased new bone formation, increased the serum osteogenic marker (procollagen N-terminal propeptide), decreased resorptive marker (urinary C-terminal teleopeptide of type I collagen) and diminished osteoblast apoptosis in bone. At the most effective osteogenic dose of Isoformo, plasma and bone marrow levels were comprised of ~90% Isoformo and the rest, Daid. Isoformo at the concentration reaching the bone marrow achieved out of its most effective oral dosing induced stromal cell mineralization and osteogenic gene expression in the calvaria of neonatal rats. Isoformo exhibited uterine safety.

CONCLUSIONS

Our study demonstrates that Isoformo reverses established osteopenia in adult OVx rats likely via its pro-survival effect on osteoblasts. Given its bone anabolic and anti-catabolic effects accompanied with safety at uterine level we propose its potential in the management of postmenopausal osteoporosis.

Positive skeletal effects of cladrin, a naturally occurring dimethoxydaidzein, in osteopenic rats that were maintained after treatment discontinuation

Effects of cladrin treatment and withdrawal in osteopenic rats were studied. Cladrin improved trabecular microarchitecture, increased lumbar vertebral compressive strength, augmented coupled remodeling, and increased bone osteogenic genes. A significant skeletal gain was maintained 4 weeks after cladrin withdrawal. Findings suggest that cladrin has significant positive skeletal effects.

INTRODUCTION

We showed that a standardized extract of Butea monosperma preserved trabecular bone mass in ovariectomized (OVx) rats. Cladrin, the most abundant bioactive compound of the extract, promoted peak bone mass achievement in growing rats by stimulating osteoblast function. Here, we studied the effects of cladrin treatment and withdrawal on the osteopenic bones.

METHODS

Adult female Sprague-Dawley rats were OVx and left untreated for 12 weeks to allow for significant estrogen deficiency-induced bone loss, at which point cladrin (1 and 10 mg/kg/day) was administered orally for another 12 weeks. Half of the rats were killed at the end of the treatments and the other half at 4 weeks after treatment withdrawal. Sham-operated rats and OVx rats treated with PTH or 17β-estradiol (E2) served as various controls. Efficacy was evaluated by bone microarchitecture using microcomputed tomographic analysis and fluorescent labeling of bone. qPCR and western blotting measured mRNA and protein levels in bone and uterus. Specific ELISA was used for measuring levels of serum PINP and urinary CTx.

RESULTS

In osteopenic rats, cladrin treatment dose dependently improved trabecular microarchitecture, increased lumbar vertebral compression strength, bone formation rate (BFR), cortical thickness (Cs.Th), serum PINP levels, and expression of osteogenic genes in bones; and reduced expression of bone osteoclastogenic genes and urinary CTx levels. Cladrin had no uterine estrogenicity. Cladrin at 10 mg/kg maintained acquired skeletal gains 4 weeks after withdrawal.

CONCLUSION

Cladrin had positive skeletal effects in osteopenic rats that were maintained after treatment withdrawal.

Soy isoflavones in the management of postmenopausal osteoporosis

This is a review article designed to address the effects of soy isoflavones on bone metabolism in postmenopausal women and their place in the prevention and treatment of postmenopausal osteoporosis. Soy isoflavones are natural products that could be used as an alternative to menopausal hormone therapy because they are structurally and functionally related to 17beta-estradiol. In vitro and animal studies have shown that they act in multiple ways to exert their bone-supporting effects. They act on both osteoblasts and osteoclasts through genomic and nongenomic pathways. Epidemiological studies and clinical trials suggest that soy isoflavones have beneficial effects on bone mineral density, bone turnover markers, and bone mechanical strength in postmenopausal women. However, there are conflicting results related to differences in study design, estrogen status of the body, metabolism of isoflavones among individuals, and other dietary factors. The long-term safety of soy isoflavone supplements remains to be demonstrated.

Isoflavones prevent bone loss following ovariectomy in young adult rats

Soy protein, a rich source of phytoestrogens, exhibit estrogen-type bioactivity. The purpose of this study was to determine if ingestion of isoflavones before ovariectomy can prevent bone loss following ovariectomy. Twenty-four nulliparous Wistar rats were randomly divided into four groups. In the normal diet groups, a sham operation was performed on Group A, while ovariectomy was performed on Group B. For Groups C and D, all rats were fed with an isoflavone-rich (25 mg/day) diet for one month, then bilateral ovariectomy were performed. In the rats in Group C, a normal diet was begun following the ovariectomy. The rats in Groups D continued to receive the isoflavone-rich diet for two additional months postoperatively. All rats were sacrificed 60 days after surgery. The weight of bone ash of the long bones and whole lumbar spine were determined. A histological study of cancellous bone was done and biochemical indices of skeletal metabolism were performed and analyzed. The markers of bone metabolism exhibited no significant changes. When compared with the sham-operated rats fed a normal diet, the bone mass of ovariectomized rats decreased significantly; pre-ovariectomy ingestion of an isoflavone-rich diet did not prevent bone loss. The bone mass of rats treated with an isoflavone-rich diet for three months was higher than controls two months after ovariectomy.

Dietary isoflavones did not prevent the development of post-ovariectomy bone loss, but long-term ingestion of an isoflavone-rich diet increased the bone mineral contents after ovariectomy in young rats.

Protective Effects of Sodium Daidzein Sulfonate on Trabecular Bone in Ovariectomized Rats

The ovariectomized (OVX) rat, as an established animal model of human osteoporosis, was adopted in the present experiment to study the protective effects of sodium daidzein sulfonate (SDS) on trabecular bone. Six-month-old Sprague-Dawley rats were sham-operated or ovariectomized. Five days later, the OVX rats were randomly assigned to one of three experimental groups and treated for 90 days with vehicle, 17beta-estradiol (E(2)) or SDS. Compared with OVX rats, SDS administration (15 mg/kg) prevented OVX-induced decrease in lumbar vertebral and femoral bone mineral density (BMD), and significantly increased bone mechanical strength parameters, including ultimate stress and elastic modulus. In the OVX group, the structure of trabecular plate in the femoral head was absorbed and became progressively thinner or was removed completely, accompanied by enlargement of marrow cavities and amalgamation of two or more marrow cavities. Administration of SDS and E(2 )prevented the change of trabecular bone microarchitecture induced by OVX, increasing the trabecular bone area and trabecular thickness, while decreasing the trabecular separation. These results indicate that SDS administration prevents OVX-induced decrease in BMD and bone mechanical strength, and has a moderate protective effect on the microarchitecture of trabecular bone in aged Sprague-Dawley rats.

Alendronate in combination with calcium and vitamin D prevents bone loss after orthotopic liver transplantation: a prospective single-center study

Bone loss is a common complication in patients before and after liver transplantation (LT). The aim of this study was to investigate the efficacy of prophylactic treatment with bisphosphonates after LT in preventing progressive bone loss in LT patients. We included 136 patients with end-stage liver diseases awaiting LT. Bone mineral density (BMD) (by dual X-ray absorptiometry) and markers of bone metabolism were determined before, and 4, 12, 24, 36, and 48 months after LT. All patients received vitamin D and calcium supplementation before and after LT, those with osteopenia or osteoporosis prior to LT were additionally treated with alendronate following LT. Decreased BMD was seen in a high percentage of patients undergoing LT (osteopenia 48.5%, osteoporosis 23.5%). Reduced BMD before LT was not related to gender, underlying liver disease, or Child-Turcotte-Pugh classification. Body mass index (BMI) prior to LT, however, correlated significantly with the fracture risk. Alendronate prevented the ubiquitously observed bone loss after LT in patients with osteoporosis and osteopenia and, in addition, led to an increase in BMD in patients with osteoporosis within 24 months after LT. In conclusion, our study suggests that alendronate is efficacious in preventing the natural course of bone loss associated with LT.

Oral oestrogen and combined oestrogen/progestogen therapy versus placebo for hot flushes

BACKGROUND

Hot flushes and night sweats are common symptoms experienced by menopausal women. Hormone therapy (HT), containing oestrogens alone or oestrogens together with progestogens in a cyclic or continuous regimen, is often recommended for their alleviation.

OBJECTIVES

To examine the effect of oral HT compared to placebo on these vasomotor symptoms and the risk of early onset side-effects.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders Group and Subfertility Group trials register (searched May 2002). This register is based on regular searches of MEDLINE, EMBASE, CINAHL, the Cochrane Central Register of Controlled Trials (CENTRAL), PsycINFO, the handsearching of 20 relevant journals and conference proceedings, and searches of several key grey literature sources. We also contacted all relevant pharmaceutical companies, The Journal of the International Menopause Society and Climacteric.

SELECTION CRITERIA

Double-blind, randomised, placebo-controlled trials of oral HT for at least three months duration.

DATA COLLECTION AND ANALYSIS

Study quality and outcome data were assessed independently. Random effects models were considered appropriate due to the variety of trial methodologies. The meta-analyses were explored for sensitivity to trial quality and therapy duration. Symptom frequency and severity were assessed separately, together with withdrawals and side-effects. Frequency data were analysed using the Weighted Mean Difference (WMD) between treatment and placebo outcomes. For severity data, odds ratios were estimated from the proportional odds model. From 115 references originally identified, 24 trials meeting the selection criteria were included in the review. Study participants totaled 3,329. Trial duration ranged from three months to three years.

MAIN RESULTS

There was a significant reduction in the weekly hot flush frequency for HT compared to placebo (WMD -17.92, 95% CI -22.86 to -12.99). This was equivalent to a 75% reduction in frequency (95% CI 64.3 to 82.3) for HT relative to placebo. Symptom severity was also significantly reduced compared to placebo (OR 0.13, 95% CI 0.07 to 0.23). Withdrawal for lack of efficacy occurred significantly more often on placebo therapy (OR 10.51, 95% CI 5.00 to 22.09). Withdrawal for adverse events, commonly breast tenderness, oedema, joint pain and psychological symptoms, was not significantly increased (OR 1.25, 95% CI 0.83 to 1.90), although the occurrence of any adverse events was significantly increased for HT (OR 1.41, 95% CI 1.00 to 1.99). In women who were randomised to placebo treatment, a 57.7% (95% CI 45.1 to 67.7) reduction in hot flushes was observed between baseline and end of study.

REVIEWERS' CONCLUSIONS

Oral HT is highly effective in alleviating hot flushes and night sweats. Therapies purported to reduce such symptoms must be assessed in blinded trials against a placebo or a validated therapy because of the large placebo effect seen in well conducted randomised controlled trials, and also because during menopause symptoms may fluctuate and after menopause symptoms often decline. Withdrawals due to side-effects were only marginally increased in the HT groups despite the inability to tailor HT in these fixed dose trials. Comparisons of hormonal doses, product types or regimens require analysis of trials with these specific "within study" comparisons.

Dietary phytoestrogens and their effect on bone: evidence from in vitro and in vivo, human observational, and dietary intervention studies

Impressive data from the many studies on cultured bone cells and rat models of postmenopausal osteoporosis support a significant bone-sparing effect of the soy isoflavones genistein and daidzein. Translating this research to the clinic has been more challenging, and thus far only a few clinical studies have attempted to tease out the influence of phytoestrogens on bone from the many other components of the diet. Human studies have shown promising although variable results. Studies have been mostly of short duration and with relatively small sample sizes, making it difficult to observe significant and accurate changes in bone. Levels of intake of the soy protein and isoflavones are varied, and the optimal isoflavone intake for bone-sparing effects remains to be determined. Clinical studies thus far performed can be broadly divided into those that have assessed biochemical evidence of reduced bone turnover from measurement of surrogate markers of osteoblast and osteoclast activity, and those that have examined changes in bone mineral density. There are no studies examining effects on fracture rate. This review focuses specifically on the potential influence of phytoestrogens on bone by examining the evidence from 17 in vitro studies of cultured bone cells, 24 in vivo studies of animal models for postmenopausal osteoporosis, 15 human observational/epidemiologic studies, and 17 dietary intervention studies. On balance, the collective data suggest that diets rich in phytoestrogens have bone-sparing effects in the long term, although the magnitude of the effect and the exact mechanism(s) of action are presently elusive or speculative.

Phytoestrogen genistein acts as an estrogen agonist on human osteoblastic cells through estrogen receptors alpha and beta

Genistein, a soybean isoflavone, has estrogen-like activity in mammals, including the prevention of bone loss. However, whether its mechanism of action on bone turnover is distinct from that of estrogen or raloxifene is unknown. Although genistein has been reported to bind both estrogen receptor (ER) isoforms (alpha and beta), little is known concerning differential activation of gene expression via these ER isoforms. To examine this question, comparison of the responses of normal fetal osteoblast (hFOB) cells stably expressing either ERalpha (hFOB/ERalpha9) or ERbeta (hFOB/ERbeta6), to treatment with genistein, 17beta-estradiol (E(2)) or raloxifene were conducted. In hFOB/ERalpha9 cells, both genistein and E(2) increased the endogenous gene expression of the progesterone receptor (PR), the proteoglycan versican, and alkaline phosphatase (AP), but inhibited osteopontin (OP) gene expression and interleukin-6 (IL-6) protein levels. Raloxifene had no effect on these bone markers. Genistein, but not raloxifene, also mimicked E(2) action in the hFOB/ERbeta6 cells increasing PR gene expression and inhibiting IL-6 production. To determine whether the gene regulatory actions of genistein in human osteoblast cells occur at the level of transcription, its action on the transcriptional activity of a PR-A promoter-reporter construct was assessed. Both genistein and E(2) were found to stimulate the PR promoter in the hFOB cell line when transiently co-transfected with either ERalpha or ERbeta. Whereas hFOB cell proliferation was unaffected by E(2), raloxifene or genistein at low concentrations, higher concentrations of genistein, displayed significant inhibition. Together, these findings demonstrate that genistein behaves as a weak E(2) agonist in osteoblasts and can utilize both ERalpha and ERbeta.

Effects of genistein and hormone-replacement therapy on bone loss in early postmenopausal women: a randomized double-blind placebo-controlled study

The natural isoflavone phytoestrogen genistein has been shown to stimulate osteoblastic bone formation, inhibit osteoclastic bone resorption, and prevent bone loss in ovariectomized rats. However, no controlled clinical trial has been performed so far to evaluate the effects of the phytoestrogen on bone loss in postmenopausal women. We performed a randomized double-blind placebo-controlled study to evaluate and compare with hormone-replacement therapy (HRT) the effect of the phytoestrogen genistein on bone metabolism and bone mineral density (BMD) in postmenopausal women. Participants were 90 healthy ambulatory women who were 47-57 years of age, with a BMD at the femoral neck of <0.795 g/cm2. After a 4-week stabilization on a standard fat-reduced diet, participants of the study were randomly assigned to receive continuous HRT for 1 year (n = 30; 1 mg of 17beta-estradiol [E2] combined with 0.5 mg of norethisterone acetate), the phytoestrogen genistein (n = 30; 54 mg/day), or placebo (n = 30). Urinary excretion of pyridinoline (PYR) and deoxypyridinoline (DPYR) was not significantly modified by placebo administration either at 6 months or at 12 months. Genistein treatment significantly reduced the excretion of pyridinium cross-links at 6 months (PYR = -54 +/- 10%; DPYR = -55 +/- 13%; p < 0.001) and 12 months (PYR = -42 +/- 12%; DPYR = -44 +/- 16%; p < 0.001). A similar and not statistically different decrease in excretion of pyridinium cross-links was also observed in the postmenopausal women randomized to receive HRT. Placebo administration did not change the serum levels of the bone-specific ALP (B-ALP) and osteocalcin (bone Gla protein [BGP]). In contrast, administration of genistein markedly increased serum B-ALP and BGP either at 6 months (B-ALP = 23 +/- 4%; BGP = 29 +/- 11%; p < 0.005) or at 12 months (B-ALP = 25 +/- 7%; BGP = 37 +/- 16%; p < 0.05). Postmenopausal women treated with HRT had, in contrast, decreased serum B-ALP and BGP levels either at 6 months (B-ALP = -17 +/- 6%; BGP = -20 +/- 9%; p < 0.001) or 12 months (B-ALP = -20 +/- 5%; BGP = -22 +/- 10%; p < 0.001). Furthermore, at the end of the experimental period, genistein and HRT significantly increased BMD in the femur (femoral neck: genistein = 3.6 +/- 3%, HRT = 2.4 +/- 2%, placebo = -0.65 +/- 0.1%, and p < 0.001) and lumbar spine (genistein = 3 +/- 2%, HRT = 3.8 +/- 2.7%, placebo = -1.6 +/- 0.3%, and p < 0.001). This study confirms the genistein-positive effects on bone loss already observed in the experimental models of osteoporosis and indicates that the phytoestrogen reduces bone resorption and increases bone formation in postmenopausal women.

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.

Combination treatment of osteoporosis: a clinical review

OBJECTIVE

Because of the limited efficacy of available agents and to limit toxicity, there is considerable interest in combination pharmacotherapy for osteoporosis.

METHODS

A search was performed for randomized controlled trials in MEDLINE (1966-present) using the keywords osteoporosis treatment and combination.

RESULTS

Twenty-four randomized controlled trials evaluated osteoporosis medications in combination. Study duration ranged from 1 to 4 years. No serious adverse events were definitively attributable to study drugs. Fracture reduction outcome is not shown for any combination regimen. The literature was mixed regarding bone density augmentation. Combinations of nandrolone decanoate plus calcitonin, calcitonin plus growth hormone (GH), or pamidronate plus GH may be contradictory or detrimental to bone mineral density (BMD). For postmenopausal osteoporosis or osteopenia, four combinations appear to increase hip and lumbar BMD: 10 mg alendronate with 0.625 mg conjugated equine estrogens (CEE), cyclic etidronate with 0.625mg CEE, 10 mg alendronate with 2 mg estradiol (E(2)), and tibolone with fluoride. For steroid-related osteoporosis, intermittent etidronate with fluoride increases lumbar BMD.

CONCLUSIONS

The few trials including Food and Drug Administration (FDA)-approved medications suggest that 10 mg/day alendronate with estrogen (equivalent of 0.625 mg CEE daily) can increase BMD moreso than each medication given singly in postmenopausal osteoporotic women. Estrogen dose and type must be controlled in future trials. Long-term safety data are lacking. The utility of these combinations rests on whether bone density changes will translate into decreased fracture rates.

Oral oestrogen replacement therapy versus placebo for hot flushes

BACKGROUND

Hot flushes and night sweats are common symptoms experienced by menopausal women. Hormone replacement therapy (HRT), containing oestrogens alone or oestrogens together with progestogens in a cyclic or continuous regimen, is often recommended for their alleviation.

OBJECTIVES

To examine the effect of oral HRT compared to placebo on these vasomotor symptoms and the risk of early onset side-effects.

SEARCH STRATEGY

As developed by the Menstrual Disorders Group and Subfertility group of the Cochrane Collaboration.

SELECTION CRITERIA

Double-blind, randomised, placebo-controlled trials of oral HRT therapy for at least three months duration.

DATA COLLECTION AND ANALYSIS

Study quality and outcome data were assessed independently. Random effects models were considered appropriate due to the variety of trial methodologies. The meta-analyses were explored for sensitivity to trial quality and therapy duration. Symptom frequency and severity were assessed separately, together with withdrawals and side-effects. Frequency data were analysed using the Weighted Mean Difference (WMD) between treatment and placebo outcomes. For severity data, odds ratios were estimated from the proportional odds model. From 99 references originally identified, 21 trials meeting the selection criteria were included in the review. Study participants totalled 2,511. Trial duration ranged from three months to three years.

MAIN RESULTS

There was a significant reduction in the weekly hot flush frequency for HRT compared to placebo (WMD -17.46, 95% CI -24.72, -10.21). This was equivalent to a 77% reduction in frequency (95% CI 58.2, 87.5) for HRT relative to placebo. Symptom severity was also significantly reduced compared to placebo (OR 0.13, 95% CI 0.08, 0.22). Withdrawal for lack of efficacy occurred significantly more often on placebo therapy (OR 17.25, 95% CI 8.23, 36.15). Withdrawal for adverse events, commonly breast tenderness, oedema, joint pain and psychological symptoms, was not significantly increased for HRT therapy (OR 1.38, 95% CI 0.87, 2.21). In women who were randomised to placebo treatment, a 50.8% (95% CI 41.7, 58.5) reduction in hot flushes was observed between baseline and end of study.

REVIEWER'S CONCLUSIONS

Oral HRT is highly effective in alleviating hot flushes and night sweats. Therapies purported to reduce such symptoms must be assessed in blinded trials against a placebo or a validated therapy. Withdrawals due to side-effects were only marginally increased in the HRT groups despite the inability to tailor HRT in these fixed dose trials. Comparisons of hormonal doses, product types or regimens require analysis of trials with these specific "within study" comparisons.

Phytoestrogens as hormone replacement therapy: an evidence-based approach

Postmenopausal women have sought nonestrogen alternatives to hormone replacement in order to avoid possible risks and side effects of the therapy. Selective estrogen receptor modulators have been developed to tailor therapy to a specific risk/benefit profile that will best fit the patient. More women have looked to phytoestrogens, such as the isoflavones found in the soy plant, to tailor their menopausal therapy in a "natural" way. This review examines the evidence regarding the risks and benefits of isoflavones as hormone replacement therapy. Controlled trials have shown a reduction in postmenopausal hot flashes when subjects' diets were supplemented with soy. There is less evidence for a benefit in vaginal dryness symptoms. Furthermore, dietary supplementation also appears to lower total and low-density lipoprotein cholesterol in hypercholesterolemic subjects. A synthetic isoflavone, ipriflavone, has been shown in controlled trials to prevent postmenopausal bone loss, though there is much less evidence that soy isoflavones will accomplish this goal. Finally, although unopposed estrogen replacement may promote breast and endometrial cancer, there is no evidence that phytoestrogens will do the same. In contrast, great interest has been taken in the potential cancer-protective effects of phytoestrogens, though prospective evidence in postmenopausal women is not available. Although data regarding the use of isoflavone extracts are incomplete, dietary supplementation with soy foods appears to be a safe and possibly beneficial option for postmenopausal women.

Isoflavone-rich soy protein isolate attenuates bone loss in the lumbar spine of perimenopausal women

BACKGROUND

No published studies have directly examined the effect of soy protein with isoflavones on bone or bone turnover in perimenopausal women.

OBJECTIVE

Our objective was to determine the effects of 24 wk of consumption of soy protein isolate with isoflavones (80.4 mg/d) in attenuating bone loss during the menopausal transition.

DESIGN

Perimenopausal subjects were randomly assigned, double blind, to treatment: isoflavone-rich soy (SPI+; n = 24), isoflavone-poor soy (SPI-; n = 24), or whey (control; n = 21) protein. At baseline and posttreatment, lumbar spine bone mineral density (BMD) and bone mineral content (BMC) were measured by using dual-energy X-ray absorptiometry. At baseline, midtreatment, and posttreatment, urinary N:-telopeptides and serum bone-specific alkaline phosphatase (BAP) were measured.

RESULTS

The percentage change in lumbar spine BMD and BMC, respectively, did not differ from zero in the SPI+ or SPI- groups, but loss occurred in the control group (-1.28%, P: = 0.0041; -1.73%, P: = 0.0037). By regression analysis, SPI+ treatment had a positive effect on change in BMD (5.6%; P: = 0.023) and BMC (10.1%; P: = 0.0032). Baseline BMD and BMC (P: < or = 0.0001) negatively affected the percentage change in their respective models; baseline body weight (P: = 0.0036) and bone-free lean weight (P: = 0.016) contributed positively to percentage change in BMD and BMC, respectively. Serum BAP posttreatment was negatively related to percentage change in BMD (P: = 0.0016) and BMC (P: = 0.019). Contrast coding using analyses of covariance with BMD or BMC as the outcome showed that isoflavones, not soy protein, exerted the effect.

CONCLUSION

Soy isoflavones attenuated bone loss from the lumbar spine in perimenopausal women.

Steroid-induced osteoporosis in systemic lupus erythematosus

The patient with SLE is at considerable risk of osteoporosis, because of the inflammatory disease itself, its consequences, and its treatments. Because of their extensive use, glucocorticoids are thought to be the most frequent cause of drug-related osteoporosis and may be responsible for much of the bone loss in lupus. This article focuses on the mechanisms of steroid-induced osteoporosis in SLE and outlines strategies for prevention and treatment.

The effects of six months of treatment with a low-dose of conjugated oestrogens in menopausal women

OBJECTIVE

Hormone replacement therapy (HRT) is usually prescribed as medium- to high-dose formulations. Little is known, however, about dose-dependency of oestrogen effects on plasma hormone levels, markers of cardiovascular risk in lipid metabolism and the haemostatic system, or markers of bone turnover.

SUBJECTS AND DESIGN

In an open trial, three groups of 12 or 13 healthy, non-obese postmenopausal women received conjugated equine oestrogens (CEE) for 6 months at doses of 0.3 mg/day (group 1), 0.6 mg/day (group 2) or 1.25 mg/day (group 3). From day 1 to day 10, CEE was administered alone, and from day 11 to day 21, in combination with 5 mg of medrogestone. Each treatment cycle was followed by a pause of 7 days. Fasting blood samples were obtained before treatment as well as on days 10, 21 and 28 of the first, third and sixth months on treatment. All results obtained on day 10 were grouped together as phase A, on day 21 as phase B, and on day 28 as phase C.

MEASUREMENTS

Plasma concentrations of oestradiol (E), dehydroepiandrosterone sulphate (DHEA-S), total testosterone (T), FSH, PRL, sex hormone binding globulin (SHBG), type I procollagen propeptide (PICP) and the cross-linked carboxyterminal telopeptide of type I collagen (ICTP), total cholesterol, HDL-cholesterol, triglycerides (TG), apolipoprotein (apo) A-1, apo B, lipoprotein(a)[Lp (a)], fibrinogen, factor VIIc and plasminogen activator inhibitor 1 (PAI-1) were evaluated with commercially available kits.

RESULTS

Dose-dependently, the three regimens increased E, SHBG and factor VIIc activity and decreased FSH, DHEAS, cholesterol, LDL-cholesterol and apoB. HDL-cholesterol and apoA-1 were slightly decreased in group 1 but increased in groups 2 and 3. The high CEE dosage in group 3 resulted in a significant increase of TG and decrease of Lp(a) and PAI-1. Markers of bone turnover were not significantly changed by any CEE dosage.

CONCLUSIONS

Six months of treatment with 0.3 mg/day of conjugated equine oestrogen significantly lowers serum levels of total cholesterol and LDL-cholesterol without causing the adverse increases of triglycerides or factor VIIc, which were observed at higher doses. However, this low-dose treatment did not yield the maximal LDL-cholesterol lowering effect. Moreover, the positive effects of HRT on HDL-cholesterol, apolipoprotein A-I, lipoprotein (a) and plasminogen activator inhibitor-1 required at least the medium dose of 0.6 mg conjugated equine oestrogens per day. Therefore, further studies are needed to determine which dose of conjugated equine oestrogens has the optimal effect on cardiovascular risk and bone turnover.

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.

Therapy for osteoporosis. Miscellaneous and experimental agents

None of the currently available medications for osteoporosis have demonstrated an ability to fully prevent the occurrence of new vertebral or peripheral osteoporotic fractures once the disease is established. Several new therapies, therefore, are currently being developed to optimize the risk/benefit ratio of osteoporosis treatment. This article discusses a number of treatments currently being considered, including anabolic steroids, growth hormone or insulin-like growth factors, ipriflavone, parathyroid peptides, and strontium. Several other compounds have been suggested recently for treatment of osteoporosis and other are at very early stages of their development. In addition to pharmacologic approaches to the treatment of osteoporosis, hip protectors also may reduce hip fractures.

Effect of chronic treatment with ipriflavone in postmenopausal women with low bone mass

We present the results of two multicenter, double-blind, placebo-controlled, 2-year studies to evaluate the efficacy and tolerability of ipriflavone in postmenopausal women (PMW) with low bone mass. 453 PMW (aged 50-65 years) with a vertebral (VMD) or radial (RMD) mineral density value 1 SD lower compared with age-matched controls, were randomly selected to receive oral ipriflavone (200 mg T.I.D. at meals) or matching placebo, plus 1 g oral calcium daily. Vertebral (study A, by dual X-ray absorptiometry-DXA) and radial (study B, by dual photon absorptiometry-DPA) bone density, serum bone Gla-protein (BGP), and urinary hydroxyproline/creatinine (HOP/Cr) were measured every 6 months. In both studies, the Valid Completers (VC) analysis showed a maintenance of bone mass in ipriflavone-treated women, whereas in the placebo group, bone mineral density (BMD) was significantly decreased. The final outcome was a bone-sparing effect of 1.6% in study A, and of 3.5% in study B after 2 years. The Intention to Treat (ITT) analysis confirmed the decrease in the placebo group, with no changes in ipriflavone-treated women. A significant (P < 0.05) between-treatment difference was found in both studies. Biochemical markers of bone turnover decreased in patients treated with ipriflavone, thus suggesting a reduction of bone turnover rate. Twenty-six women treated with ipriflavone and 28 receiving the placebo dropped out because of side effects, mainly gastrointestinal. The compliance to the oral long-term treatment was good. The results of these studies show that ipriflavone is able to prevent both axial and peripheral bone loss in PMW with low bone mass, and is well tolerated.

Ipriflavone prevents radial bone loss in postmenopausal women with low bone mass over 2 years

Two hundred and fifty-five postmenopausal women with distal forearm bone mineral density (BMD) 1 SD below the mean value for normal age-matched postmenopausal subjects were randomly allocated to a 2-year treatment with oral ipriflavone (200 mg t.i.d) or a matched placebo, according to a double-masked, parallel group design. All patients also received a 1 g/day calcium supplement. Distal radius BMD and bone metabolism markers were measured at baseline, and every 6 months. Blood haematology and chemistry and physical parameters were monitored at the same time. One hundred and ninety-six patients completed 2 years of treatment. BMD changes from baseline were analysed according to valid completers (VC) and intention to treat (ITT) analyses. In both cases radial BMD was maintained in patients treated with ipriflavone while in decrease in those receiving the placebo, the between-treatment difference being significant at year 1 and year 2. Urinary hydroxyproline/creatinine levels were decreased in the ipriflavone-treated group and increased in the placebo group, with a significant between-treatment difference. Adverse reactions, mainly gastrointestinal, occurred to a similar extent in the two treatment groups.

Design for an ipriflavone multicenter European fracture study

In order to investigate the efficacy of ipriflavone (i.p.) on the prevention of vertebral fractures and the effect on bone mineral density (BMD) in women with postmenopausal osteoporosis, a large multicentric European study was designed and is presently ongoing. Included in the study were 460 Caucasian, nonobese postmenopausal women aged > 45 and < 75 years, menopaused for at least 12 months. Inclusion was on the basis of a lumbar bone mineral density (BMD) lower than 2 SD compared with healthy women aged 50 years, corresponding to values below 0.860 g/cm2 (antero-posterior measurement) by Hologic QDR 1000. Women with prevalent vertebral fractures were excluded as well as those presenting secondary osteoporosis or having been treated with medications that could affect bone metabolism. This study was designed as a 3-year, double-blind, placebo-controlled, parallel group study that randomized the women to the oral administration of either 3 x 200 mg/day of i.p. or placebo. All patients received a daily supplement of 500 mg calcium. The primary purpose of the study was to evaluate the efficacy of i.p. in preventing vertebral nontraumatic fractures. Fracture is defined here as a > or = 20% decrease in any anterior, central, or posterior T4-L4 vertebral height. Blinded vertebral X-ray readings and vertebral morphometry have been centralized in an independent Center, with standardized evaluation of two experts. Power calculations have been based on the hypothesis that 21% of placebo-treated patients would fracture within 3 years and that treatment with i.p. would lead to a 50% reduction in the incidence of fracture. Statistical tests have been designed to have a power of 80%, with a type I error equal to 5%. Secondary endpoints were changes in vertebral, radial, and femoral BMD. Centralized controls on 100% BMD scans would ensure the good quality of BMD readings. This study should verify the hypothesis that i.p. significantly decreases the risk of vertebral fracture in postmenopausal, osteoporotic women.

Miscellaneous and experimental agents

Current therapeutic approaches to postmenopausal bone loss or established osteoporosis vary widely among the different regions of the world. Because no treatment of osteoporosis has unequivocally demonstrated full prevention of the appearance or the recurrence of axial or peripheral fractures so far, many investigational compounds are being developed. Anabolic steroids act mainly as inhibitors of bone resorption with very few, if any, effects on bone formation. Because of the high occurrence of signs of virilization and the weak effects on bone structure, the risk/benefit ratio in osteoporosis should be considered at least problematic. If ongoing large-scale trials confirm the expected benefits of estrogen antagonist/agonists on the skeleton and confirm no cardiovascular risk to postmenopausal women with optimal uterine safety, these substances are likely to become the most prominent alternative to hormonal replacement therapy after the menopause. Additional studies are requested to evaluate the potential benefit of growth hormone or insulin-like growth factors in treatment of osteoporosis. Ipriflavone acts predominantly as an inhibitor of bone resorption. To confirm the efficacy of ipriflavone on the prevention of vertebral fractures and its effects on bone mineral density in women with postmenopausal established osteoporosis, a large multicentric European study is being conducted. Treatment with parathyroid peptides induces a significant gain in bone mass, mainly in the axial skeleton. Long-term studies that compare peptides, doses, and regimes are needed to better understand the exact position of parathyroid peptides as treatment of osteoporosis. Prolonged administration of strontium to postmenopausal osteoporotic women resulted in a decoupling between bone resorption and formation that yielded a significant increase in the lumbar spine bone mineral density of treated subjects. In the view of these promising results and of the excellent tolerance of strontium during preliminary trials, additional investigations of this compound in prevention and treatment of osteoporosis should be promptly initiated. Several other compounds have been punctually suggested for treatment of osteoporosis or are at very early stages of development. Finally, besides pharmacologic approaches to the treatment of osteoporosis, hip fractures may also be reduced by the use of hip protectors.