The prevention of osteoporosis using sequential low-dose hormone replacement therapy with estradiol-17 beta and dydrogesterone

Effect of hormone replacement therapy on intervertebral disc height

OBJECTIVE

Intervertebral discs act as shock absorbers, thereby helping to reduce the risk of vertebral body fractures. Previous studies have shown that estrogen loss following menopause is associated with disc height reduction whereas treatment with hormone replacement therapy (HRT) helps to maintain disc height. This study reports the effect of HRT on disc height from a post hoc analysis of a prospective randomized clinical trial of the effect of HRT on bone density.

METHODS

A total of 355 healthy postmenopausal women aged (mean ± standard deviation) 55.4 ± 4.8 years were randomized to HRT with oral 1 mg or 2 mg estradiol plus dydrogesterone or placebo. Dual-energy X-ray absorptiometry measurements (Lunar DPX) were obtained at baseline and following 2 years of treatment. Intervertebral disc height was measured in discs between T12 and L3 using the bone densitometer ruler.

RESULTS

Compared with baseline, treatment with HRT resulted in a significant increase in total disc height with 1 mg estradiol (0.16 ± 0.65 cm, p = 0.015) and with 2 mg estradiol (0.21 ± 0.86 cm, p = 0.006) whilst there was no significant increase with placebo (0.13 ± 0.65 cm, p = 0.096). Between-group differences were not statistically significant.

CONCLUSIONS

These results are consistent with previous findings of a beneficial effect of estrogen on discs. This may be in part responsible for the anti-fracture efficacy of HRT on vertebral fractures.

Effects of ultra-low dose hormone therapy on biochemical bone turnover markers in postmenopausal women: A randomized, placebo-controlled, double-blind trial

Objective

Evaluate the effects of ultra-low-dose hormone therapy (Ultra-LD HT) with 17β-estradiol 0.5 mg and norethisterone acetate 0.1 mg (E2 0.5/NETA 0.1) versus placebo on bone turnover markers (BTM) in postmenopausal women.

Study Design

A multicenter, double-blind, randomized, placebo-controlled study was performed with 107 participants who received one tablet daily of E2 0.5/NETA 0.1 or placebo for 24-weeks. Bone formation markers-N-terminal propeptide of type I procollagen (PINP) and Bone-specific alkaline phosphatase (BSAP), and bone resorption markers-C-telopeptide of type I collagen (CTX-I) and N-telopeptide crosslinked of type I collagen (NTX) were assessed before and at 12 and 24-weeks of treatment.

Results

Women treated with E2 0.5/NETA 0.1 had a significant reduction in the PINP marker from baseline (58.49 ± 21.12 μg/L) to week 12 (48.31 ± 20.99 μg/L) and week 24 (39.16 ± 16.50 μg/L). Placebo group, the PINP marker did not differ significantly. The analysis of the BSAP indicated a significant increase in the placebo group (13.8 ± 5.09 μg/L and 16.29 ± 4.3 μg/L, at baseline and week 24, respectively), whereas in the treatment group the values did not change. The analysis of the NTX marker showed a significant reduction only in the treatment group (43.21 ± 15.26 nM/mM and 33.89 ± 14.9 nM/mM, at baseline and week 24, respectively). CTX-I had a significant decrease in the treatment group from baseline (0.3 ± 0.16 ng/L) to week 12 (0.21 ± 0.14 ng/L) and week 24 (0.21 ± 0.12 ng/L).

Conclusion

Women receiving E2 0.5/NETA 0.1 experienced reductions in bone resorption and formation markers, an expected effect during the anti-resorptive therapy, suggesting a protective bone effect with the Ultra-LD HT.

Genistein contributes to cell cycle progression and regulates oxidative stress in primary culture of osteoblasts along with osteoclasts attenuation

Background

The present study was designed to examine the role of isoflavone genistein (GS) on bone formation, regulating oxidative stress and cell cycle in primary osteoblasts, as well as attenuation of osteoclast formation.

Methods

Primary calvaria osteoblasts were isolated from 2 to 3 days old neonatal rat pups (n = 6–8) of Sprague Dawley rats. Osteoblasts were incubated with varying concentrations of GS and different assays viz. cell proliferation, differentiation, calcium deposition, cell cycle progression, antioxidant ability, and osteogenic gene expression were performed. Tartrate-resistant acid phosphatase (TRAP) staining and immunolocalization of cathepsin K protein were assessed in bone marrow-derived osteoclasts.

Results

Results revealed that GS markedly induced cell growth and osteoblast differentiation depending upon dose. The fluorescent dye DCFH-DA staining data proved the antioxidant ability of GS, which reduced the H₂O₂- induced intracellular oxidative stress in osteoblasts. Quantitative real-time PCR analysis revealed that GS treatment upregulated the expression of osteoblastic genes of Runt-related transcription factor 2 (Runx2), bone morphogenetic proteins 2 (BMP2), and osteocalcin. Immunolocalization of BMP2 also indicated the osteogenic efficacy of GS. Furthermore, TRAP staining and cathepsin K expression depicted that GS inhibited multinucleated osteoclasts formation.

Conclusions

In conclusion, GS isoflavone might impart protective effects against oxidative stress-induced bone loss and thus, could maintain skeletal growth.

Puerarin enhances proliferation and osteoblastic differentiation of human bone marrow stromal cells via a nitric oxide/cyclic guanosine monophosphate signaling pathway

Puerarin, a major active isoflavone extracted from the Traditional Chinese Medicine Radix Puerariae, has been studied for its comprehensive biological effects. However, to date, its effect on bone formation and the underlying mechanism of action have not been well investigated. The present study investigated the effect of puerarin on cell proliferation and osteoblastic maturation in cultured human bone marrow stromal cells (hBMSC) in vitro. Puerarin (2.5-100 µM) increased hBMSC growth in a dose-dependent manner, as indicated by an MTT assay, and stimulated osteoblastic maturation as indicated by assessment of alkaline phosphatase (ALP) activity, as well as calcium deposition into the extracellular matrix detected by alizarin red S staining. Furthermore, polymerase chain reaction analysis showed that the expression of osteoblastic markers, including Runt-related transcription factor 2/core-binding factor alpha 1, osterix and osteocalcin, were increased in hBMSCs following incubation with puerarin. Further experiments indicated that puerarin increased the nitric oxide (NO) production and cyclic guanosine monophosphate (cGMP) content in hBMSCs. The effects of puerarin were mimicked by 17β-estrodiol (10(-8) M) and were abolished in the presence of estrogen receptor antagonist ICI182780 (10(-7) M). A NO synthase inhibitor, Nx-nitro-L-arginine methylester (6 x 10(-3) M), significantly attenuated puerarin-induced increases in NO production and cGMP content, in parallel with a reduction of cell proliferation and osteoblastic differentiation as well as the expression of osteoblastic markers. These results suggested that puerarin may prevent osteoporosis by exerting stimulatory effects on bone formation and the NO/cGMP pathway, which has an important role in puerarin-induced hBMSC proliferation and osteoblastic differentiation.

Oral estradiol and dydrogesterone combination therapy in postmenopausal women: review of efficacy and safety

HRT is known to be effective for the relief of menopausal symptoms and prevention of osteoporosis. HRT should be tailored to the woman, enhancing the beneficial effects of the treatment while minimizing the risks. It is difficult to evaluate data on particular preparations of HRT and the different dosages in isolation. The purpose of this review is to highlight the efficacy and safety specific to oral estradiol and dydrogesterone combinations of four different dose strengths. A systematic literature search using Medline was carried out to identify studies containing efficacy or safety data. The findings of the retrieved publications confirm that estradiol and dydrogesterone combinations give very effective menopausal symptom relief and prevention of osteoporosis whilst maintaining a good safety profile. Data also show that these combinations of HRT give additional benefit to certain metabolic parameters including lipids, insulin, glucose and body fat distribution. By selecting the treatment and dose most suitable for each individual woman at her particular stage of menopause, the benefits can be optimized whilst mitigating the risks. HRT plays an important role in improving and maintaining women's health when used appropriately.

HRT misuse and the osteoporosis epidemic

A new study by Karim and colleagues has highlighted the intriguing issue of the consequences of cessation of long-term postmenopausal hormone use. While potential reductions in breast cancer risk and in the incidence of newly diagnosed breast cancer in the era after the Women's Health Initiative study have been heavily debated, the implications of withdrawal from hormone therapy for bone health and fracture risk have remained outside the main scope. This new study has now demonstrated that there is a very clear downside in skeletal outcome that should be considered while evaluating the pros and cons of discontinuing hormone therapy. During 532 686 person-years of observation and a follow-up period of 6.5 years, a 55% increased risk for hip fracture was observed in women who stopped hormone therapy. In view of the dramatic decline in the number of hormone users all around the world, this mini-review discusses the 'neglected' skeletal outcomes of such global trends.

What is the best balance of benefits and risks among anti-resorptive therapies for postmenopausal osteoporosis?

Pharmacologic osteoporosis therapy, particularly anti-resorptives, is recommended in postmenopausal women with clinical risk factors for fracture. Treatment decisions should be made based on the relative benefit-risk profile in different patient populations. Emerging options [e.g., selective estrogen receptor modulators (SERMs) and denosumab] may hold promise for providing protection from bone loss and for fracture risk reduction.Osteoporosis, the most common clinical disorder of bone metabolism, is characterized by low bone mineral density, deterioration of microarchitecture, and a consequent increase in bone fragility and risk of fracture. Pharmacologic therapy is recommended in postmenopausal women with clinical risk factors for fracture and includes anti-resorptive agents such as bisphosphonates, hormone therapy, SERMs, and calcitonin. The anabolic agent teriparatide (parathyroid hormone) is usually reserved for high-risk patients or those with glucocorticoid-induced osteoporosis. Strontium ranelate, available outside the USA, has both anti-resorptive and anabolic properties. Supplementation with calcium and vitamin D is recommended for all women aged 50 years and older. Bisphosphonates are often considered first-line therapy for osteoporosis and have the largest base of clinical trial data showing efficacy for global fracture risk reduction. Low-dose hormone therapy is appropriate for younger women who are experiencing other menopausal symptoms. In women for whom bisphosphonates are not appropriate or not tolerated or in younger postmenopausal women who have a low risk for hip fracture, SERMs are a suitable treatment option. Calcitonin is designated for patients who are unable or unwilling to tolerate other osteoporosis agents. Emerging options, including newer SERMs (e.g., bazedoxifene and lasofoxifene) and the monoclonal antibody denosumab, may hold promise for providing protection from bone loss and for fracture risk reduction. Because no single agent is appropriate for all patients, treatment decisions should be made on an individual basis, taking into account the relative benefits and risks in different patient populations.

Safety and efficacy of drospirenone used in a continuous combination with 17β-estradiol for prevention of postmenopausal osteoporosis

OBJECTIVE

To evaluate the combination of 17beta-estradiol and continuous drospirenone for the prevention of postmenopausal osteoporosis.

METHODS

A total of 180 (75%) healthy postmenopausal women aged 45-65 years completed a 2-year prospective study. Bone mineral density (BMD) at lumbar spine, hip and total body as well as endometrial thickness, markers of bone turnover and serum lipids were measured regularly. Treatment groups were given placebo or 1 mg 17beta-estradiol combined with 1, 2 or 3 mg drospirenone daily.

RESULTS

BMD at the lumbar spine, hip and total body increased by 7, 4 and 3%, respectively, in all hormone groups versus placebo (all p < 0.001). Bone markers all decreased accordingly (serum osteocalcin 52%, serum bone specific alkaline phosphatase 36%, serum CrossLaps 67% and urinary CrossLaps 75% from baseline; all p < 0.001). Total cholesterol and low-density lipoprotein cholesterol decreased by 8% and 13%, respectively (both p < 0.001). High-density lipoprotein cholesterol and triglycerides remained unchanged. No significant dose-related effects were found. Endometrial thickness increased by 1.2 mm only in the 1-mg drospirenone group (p < 0.01 versus placebo).

CONCLUSION

The combination of 17beta-estradiol and drospirenone has a positive effect on BMD and a potentially beneficial effect on lipids. Although endometrial thickness increased slightly, the safety of the endometrium was assured, as no cases of hyperplasia or cancer occurred.

The HRT misuse and osteoporosis epidemic: a possible future scenario

Recent controversies with hormone replacement therapy (HRT) have caused much concern in women and their health-care providers. As a result, the number of HRT users in the USA has fallen dramatically. Consequently, the potential HRT-induced reduction in fracture risk is lost so that, in the next few years, we can expect an excess of 43,008 fractures per year in women aged 65 - 69 years. In addition, the recent evidence on the merits of early initiation of HRT on cardiovascular disease risk and neurocognitive function and the effect of type and combination of hormones on breast cancer risk now require an urgent review by the regulatory authorities of their recommendations about HRT.

1 and 2 mg 17β-estradiol combined with sequential dydrogesterone have similar effects on the serum lipid profile of postmenopausal women

OBJECTIVES

The aim of this study was to assess the effects of 1 and 2 mg 17beta-estradiol on serum lipid profile. Beneficial effects have been clearly established in previous studies with a 2 mg dose; further evidence was required to confirm the beneficial effects of a 1 mg dose.

METHODS

This double-blind, placebo-controlled study involved 579 postmenopausal women randomized to oral treatment with placebo, 1 mg/day 17beta-estradiol sequentially combined with 5 or 10 mg/day dydrogesterone for the last 14 days of each 28-day cycle, or 2 mg/day 17beta-estradiol sequentially combined with 10 or 20 mg/day dydrogesterone for the last 14 days of each 28-day cycle. Treatment was continued for 26 cycles.

RESULTS

High density lipoprotein (HDL) cholesterol levels were significantly (p<0.05) increased after 26 cycles in all active treatment groups compared with placebo. In addition, low density lipoprotein (LDL) cholesterol and lipoprotein(a) levels were significantly reduced, and apolipoprotein A1 and triglyceride levels were significantly increased, in all active treatment groups after 13 and 26 cycles.

CONCLUSIONS

The results of this study clearly indicate that sequential combinations of either 1 or 2 mg 17beta-estradiol with dydrogesterone are associated with long-term, favorable changes in the serum lipid profile. There was no evidence that dydrogesterone compromised the 17beta-estradiol-induced improvements in lipid profile.

Effects of low-dose hormone therapy on menopausal symptoms, bone mineral density, endometrium, and the cardiovascular system: a review of randomized clinical trials

OBJECTIVES

First, to determine the extent of the effects of low-dose hormone therapy (HT) on menopausal symptoms, bone mineral density, endometrium, and the cardiovascular system, and, second, to determine the adverse effects of low-dose HT.

METHODS

A literature review of electronic databases was conducted to identify all prospective, randomized trials comparing the effects of low-dose HT with placebo or standard-dose therapy, using key words such as: hormone replacement therapy (HRT), low-dose HRT/conjugated equine estrogens (CEE)/estradiol, lower-dose HRT/CEE/estradiol, ultra-low-dose HRT/CEE/estradiol, menopause, cardiovascular risk, bone metabolism.

RESULTS

Low-dose HT has been shown to improve menopausal and vulvovaginal atrophic symptoms, compared to placebo, and is less likely to give rise to unacceptable side-effects, including irregular bleeding and/or breast tenderness. When compared to standard-dose HT, the low-dose HT has comparable effects on a range of menopausal symptoms and on bone density and has similar beneficial effects on surrogate end-points of coronary heart disease.

CONCLUSIONS

A change to low-dose HT has been advocated following adverse findings in recent trials of standard-dose HT. Although a literature review has shown low-dose HT to alleviate menopausal symptoms and maintain or improve bone density with fewer side-effects than standard-dose therapy, further research is required to determine what effect the lower-dose therapy will have on fracture, cardiovascular and breast disease.

A 10-year follow-up of the effect of continuous-combined hormone replacement therapy and its discontinuation on bone in postmenopausal women

Objective

To establish the effect on bone mineral density (BMD) of long-term (nine years) continuous-combined hormone replacement therapy (ccHRT) with estradiol valerate/medroxyprogesterone acetate (E2V/MPA) and follow-up one year after discontinuation of ccHRT.

Study design

A total of 279 women were treated with daily dosages of E2V + MPA: 1 mg + 2.5 mg (n = 69), 1 mg + 5 mg (n = 70) or 2 mg + 5 mg (n = 140) (Indivina®, Orion Pharma, Espoo, Finland) for 8.5 years; all subjects received the lowest dosage for the next six months. BMD was measured at baseline, between 6 and 12 months, annually until the end of study and at one-year postdiscontinuation of ccHRT.

Main outcome measure

Change in BMD during nine years of treatment with ccHRT and at one-year post-discontinuation of ccHRT.

Results

Progressive increase of vertebral BMD was observed with all dosage regimens throughout nine years, with corresponding reduction in the proportion of women fulfilling criteria for osteoporosis or osteopaenia. Femoral neck BMD reached a peak at about five to six years, whereas in the lumbar spine the BMD increase was sustained until the end of the study treatment. Mean BMD declined after cessation of ccHRT use but remained substantially above baseline levels. In a subset of women (n = 58) there was a rapid (≤4%) loss of vertebral BMD in the year after termination of ccHRT use. These women had lower than average BMD at baseline but no other factor was identified that distinguished them from the overall study population.

Conclusions

Low-dose ccHRT in postmenopausal women is associated with increases in lumbar spine BMD for at least nine years. These gains are not sustained after cessation of therapy but the rate of BMD loss varies between individuals.

Ultra low-dose hormone replacement therapy and bone protection in postmenopausal women

OBJECTIVES

The aim of the present study was to evaluate the effects of low doses of hormone replacement therapy (HRT) in normal young postmenopausal women.

METHODS

In an open trial healthy, non-obese postmenopausal women received for 2 years a low-dose continuous combined HRT (LD-HRT) containing 1mg estradiol+0.5 mg norethisterone acetate each pill for 28 days, or 0.5 mg of 17beta-estradiol and 0.25 mg of norethisterone acetate (Ultra low dose, Ultra-LD-HRT) along with 1000 mg of calcium per day. Control group consisted of women receiving only 1000 mg of calcium per day, for 2 years. Menopausal symptoms were evaluated by the Green climacteric scale for the first 12 weeks of the study while bleeding profiles, bone mineral density (BMD) and bone turnover were assessed for 24 months.

RESULTS

LD-HRT and Ultra-LD-HRT were effective in reducing menopausal clinical symptoms. In the control group, BMD significantly (P<0.05) decreased at the spine (-2.8+/-0.2%), and femoral neck (-2.8+/-0.7%). In LD-HRT treated group BMD showed a significant (P<0.05) increase at the spine (5.2+/-0.7%), and femoral neck (2.8+/-0.4%) after 24 months. In the Ultra-LD-HRT treated women spine and femoral neck BMD showed a significant (P<0.05) increase (2.0+/-0.3 and 1.8+/-0.3%, respectively) after 24 months. In these women treated with LD-HRT and Ultra-LD-HRT the BMD values were significantly (P<0.05) different from those measured in calcium-treated women.

CONCLUSIONS

LD-HRT and Ultra-LD-HRT can alleviate subjective symptoms providing an effective protection against the postmenopausal decrease of BMD.

Issues concerning the use of hormone replacement therapy and risk of fracture: a population-based, nested case-control study

AIMS

To investigate the effect of duration, how recently it has been used, and age at start of hormone replacement therapy (HRT) and the risk of bone fracture.

METHODS

A population-based, nested case-control study was conducted in Lombardia, Northern Italy. The 78,294 women aged 45-75 years who received at least one HRT prescription during 1998-2000 were followed until 2005. Cases were women who experienced bone fracture during follow-up. Up to six controls were randomly selected for each case from the cohort after matching for age and date of cohort entry. The odds ratio of fracture associated with the use of HRT was estimated by conditional logistic regression.

RESULTS

One thousand one hundred and seventy-four cases and 6760 controls were included. Compared with women who took HRT for less than 2 months, those who were treated for more than 20 months had an odds ratio (OR) of 0.80 (95% confidence interval 0.65, 0.99). This risk reduction was still significant among current HRT users (OR 0.71, 95% CI 0.55, 0.90) and in women who began therapy at the age of 55-65 years (OR 0.63, 95% CI 0.42, 0.94) or 65-75 years (OR 0.56, 95% CI 0.32, 0.99). There was no statistical evidence of a protective effect for women who had stopped treatment more than 6 months previously or those who began HRT at the age of 45-55 years.

CONCLUSIONS

HRT should be continued for long periods to achieve an optimal protection from fracture. The fracture reducing potential of HRT seems to disappear after a few months without treatment and might mainly act in women who begin therapy at older age.

HRT, osteoporosis and regulatory authorities Quis custodiet ipsos custodes?

HRT has been widely used for the relief of menopausal symptoms and the prevention and treatment of post-menopausal osteoporosis. However, following the publication of the Women's Health Initiative (WHI) and the Million Women Study (MWS), regulatory authorities issued an urgent safety restriction on HRT use in preventing post-menopausal osteoporosis, recommending that it now be considered a second-line treatment. Are such recommendations justified? Treatments for osteoporosis, in women with increased future risk for fractures but who have not yet developed the disease, should prevent all types of osteoporotic fractures. Of the available therapies, none other than HRT has been clearly demonstrated to prevent hip fractures in such women. Thus, HRT should be recommended as first-line treatment for osteoporosis prevention. Potential risks of HRT, such as increased development of breast cancer and increased thromboembolism, have long been known. The WHI showed risks in less than 0.3% of women studied, and the MWS appears to have overestimated the risk of breast cancer. Thus, no new safety issues have been identified, and the regulatory authorities may have misinterpreted the data from these recent studies. When given for the correct indications, HRT is of major benefit to many women.

Propensity of gynaecologists towards osteoporosis management and treatment

BACKGROUND

Regulation authorities have recently advised against the use of hormone replacement therapy (HRT) as a first choice treatment for postmenopausal osteoporosis, modifying the past consensus.

AIM

Analyse the sensibility to and prescription attitude for osteoporosis.

SETTING

Survey.

POPULATION

Belgian gynaecologists.

METHODS

Case construction: two cases to assess whether gynaecologists are prone to detect osteoporosis, and six others to evaluate their prescription attitude for osteoporosis.

RESULTS

About 80% of the physicians would prescribe a bone mineral density measurement (BMD) to a 66-year-old, non HRT user. About 60% prescribed calcium and Vitamin D when the BMD was normal, 90% would prescribe it when the BMD showed osteopenia or osteoporosis (p < 0.001). Few prescribed HRT (< 25%). Few advised SERMS for normal BMD, 19%-47% prescribed it in osteopenia or osteoporosis (p < 0.001). Few considered a biphosphonate in normal BMD, or osteopenia in the absence of risk factors, 25% considered it in osteopenia in the presence of risk factors, and 80% in osteoporosis (p < 0.001).

CONCLUSION

Most gynaecologists are aware of the osteoporosis problem. They often screen non HRT users and in the event of osteoporosis, they initiate a specific treatment, not HRT, but generally a combination of calcium, Vitamin D and biphosphonates.

The response to sex steroid hormones and vitamin D of cultured osteoblasts derived from ovariectomized mice with and without 17beta-estradiol pretreatment

This study investigated whether 17beta-estradiol (E2) may have different effects on osteoblasts derived from estrogen-deficient ovariectomized (OVX) mice compared to sham-operated normal animals. We studied the specific effects of 17beta-estradiol on the differentiation and function of cultured osteoblasts derived from these groups of animals, with or without estrogen replacement treatment. One-month-old mice were ovariectomized or sham-operated, and treated (every second day) for 4 weeks with 0.5 mg/kg 17beta-estradiol or with vehicle alone. At the end of the experiment, bones were removed for primary osteoblast cultures or for morphological and chemical evaluation. In cells from untreated OVX animals, alkaline phosphatase (ALP) specific activity was reduced, while collagen production and mineralization were unchanged when compared to cells from controls. In vivo estrogen pretreatment of the OVX mice elevated ALP activity and mineralization of the cells, while collagen production was reduced. The addition of 17beta-estradiol to the culture medium increased ALP activity, collagen production, and mineralization by all cultured osteoblasts, except in those derived from sham-operated, estrogen-pretreated mice, where these features remained unchanged. Osteocalcin production was unchanged. Addition of testosterone or 1,25(OH)2D3 to the culture medium induced changes that differed among the groups depending on the source of the cultured cells. It seems that ovariectomy in mice prior to culture affected the phenotype of the cultured osteoblasts and their response to estradiol, testosterone, and 1,25(OH)2D3, depending on whether animals were pretreated with estradiol or not. These results imply that the animal's estrogen status prior to culture can influence the response to estrogens; this finding may have important implications for hormone replacement therapy (HRT) in postmenopausal women.

How to manage osteoporosis after the menopause

Many women seek advice about bone health at the time of the menopause. Although fracture probability is low in the majority, treatment may be cost-effective if targeted at those at highest risk. Optimal selection of individuals for intervention is based on a case-finding approach, fracture probability being estimated using a combination of bone mineral density and clinical risk factors. A variety of therapeutic interventions is available for the prevention of osteoporotic fractures in postmenopausal women. Hormone replacement therapy (HRT) is a second-line option in most, although it has a place in the management of perimenopausal women with menopausal symptoms who are at risk from fracture and in other postmenopausal women who express a preference for HRT over other options, after being fully informed about known risks and benefits.

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.

Justification for the use of HRT in the long-term prevention of osteoporosis

Osteoporosis is a common condition in postmenopausal women and is associated with significant healthcare costs, morbidity and mortality. It is clear that long-term hormone replacement therapy (HRT) has a role to play in preventing osteoporosis by increasing bone mineral density and reducing fracture rate. It is important that these benefits, as well as those on climacteric symptoms, quality of life, colorectal carcinoma and cognition, are not underestimated in the face of the postulated risks with regard to breast cancer and cardiovascular disease. In conclusion, HRT should currently be used only for women with climacteric symptoms or an increased risk of osteoporosis, and it is important that there is an individualised approach to treatment based on each woman's risk profile.

Bone mineral density in postmenopausal women treated with a vaginal ring delivering systemic doses of estradiol acetate

OBJECTIVE

To evaluate the effect on bone mineral density of vaginal rings delivering estradiol acetate at two systemic doses versus a locally active vaginal ring in healthy postmenopausal women.

DESIGN

A total of 174 postmenopausal women (younger than age 65 years) were randomly assigned to a 0.05 mg/day vaginal ring, 0.1 mg/day vaginal ring, or 0.0075 mg/day vaginal ring (active comparator), and treated for 96 weeks. Of these, 170 took a study drug; 85 taking the study drug had data at 96 weeks, and 132 women were included in the intent-to-treat analysis. Non-hysterectomized women received 1 mg of norethisterone taken on the last 12 days of each 28-day monthly cycle. The primary endpoint was change in lumbar spine bone mineral density (L2-L4); change in total hip bone mineral density was a secondary endpoint.

RESULTS

At 96 weeks, mean lumbar spine bone mineral density increased 2.7% and 3.3% from baseline, respectively, in the 0.05-mg and 0.1-mg groups (P < 0.001 for both) compared with an 0.3% increase in the 0.0075-mg group (P = 0.56). Mean total hip bone mineral density increased 1.7% and 1.8% from baseline, respectively, in both the 0.05-mg and 0.1-mg groups (P < 0.001) and decreased 1.2% in the 0.0075-mg group (P = 0.001). All vaginal ring doses were well tolerated.

CONCLUSIONS

Vaginal rings delivering systemic doses of estradiol increase bone mineral density of the lumbar spine and total hip in healthy postmenopausal women. Safety and acceptability were similar to existing estradiol therapies.

The effect of continuous oestradiol with intermittent norgestimate on bone mineral density and bone turnover in post-menopausal women

OBJECTIVE

To assess in post-menopausal women the efficacy and tolerability of a continuous oestradiol/intermittent norgestimate HRT regimen to prevent and to reverse post-menopausal loss of bone mineral density (BMD) and to determine the effects on serum bone turnover markers markers.

METHODS

A 1-year, multicentre, international, placebo-controlled, randomised, double-blind clinical trial was conducted in 146 post-menopausal women with an intact uterus in order to assess the effect on bone loss of continuous oral 17beta-oestradiol (1 mg per day) combined with norgestimate (90 microg per day), for 3 consecutive days out of every 6-day treatment period (E2/iNGM). During a second year extension, all women agreeing to continue were on the E2/iNGM regimen. BMD was assessed prior to treatment and after 1 and 2 years or at the end of treatment in women stopping participation prematurely after at least 6 months of treatment. Serum bone turnover markers were determined prior to and at 1 year of treatment Adverse events were collected at three-monthly intervals during clinic visits over the treatment period.

RESULTS

BMD in the lumbar spine, the primary endpoint, was evaluable in 117 subjects completing >6 months of treatment. BMD increased on average by 2.4% in women on the intermittent progestin regimen. It decreased by 1.4% in placebo treated women. The change from baseline and the difference between active and placebo treatment (Delta placebo) were highly significant (P < 0.0001). On E2/iNGM, also the BMD in the total hip increased (+1.49%, Delta placebo 3.73%, P < 0.0001). The serum markers for bone formation osteocalcin and type I collagen N-propeptide were significantly reduced compared to baseline by 31 and 44%, respectively and the bone resorption marker C-terminal crosslinked telopeptide of type I collagen by 59%. Minor increases (<10%) of markers in the placebo group were not significant. During a second year extension of the trial, all subjects were on active treatment. Subjects on placebo who lost (median+/-CI 95%) 0.66% (-2.3 to +0.5) of spine BMD during the first year now gained 4.41% (2.7-7.6). They also gained 1.6% (0.1-0.3.6) in the total hip. Subjects continuously on oestradiol/intermittent norgestimate (E2/iNGM) gained an additional 5.7% (2.3-13.5) in the lumbar spine and +0.1% (-0.6 to +2.2) at the total hip. Side effects reported by women on the intermittent progestin regimen significantly in excess over reports from the placebo group were uterine bleeding, abdominal and breast pain, but not headache. Back pain and weight gain was reported by significantly fewer women on active treatment compared to placebo.

CONCLUSION

The continuous oestradiol/intermittent norgestimate HRT regimen is well tolerated, reduces bone turnover and prevents post-menopausal bone loss in healthy post-menopausal women.

Trimegestone in a low-dose, continuous-combined hormone therapy regimen prevents bone loss in osteopenic postmenopausal women

OBJECTIVE

To determine the efficacy of estrogen + progestogen therapy with 1 mg 17beta-estradiol and 0.125 mg trimegestone in the prevention of postmenopausal osteoporosis.

DESIGN

For this study, 360 healthy, postmenopausal women with osteopenia [lumbar spine bone mineral density (BMD) between -1.0 and -2.5 SD of the premenopausal mean value] were enrolled in a 2-year prospective, randomized study, and 70% completed. Treatments were 1 mg 17beta-estradiol + 0.125 mg trimegestone (n = 179) or placebo (n = 181), given as daily oral therapy. All received a daily supplement of 500 mg calcium and 400 IU vitamin D. BMD measurements at the lumbar spine, total hip, and femoral neck as well as blood and urinary biochemical markers of bone turnover (serum osteocalcin), serum bone-specific alkaline phosphatase, serum CrossLaps, and urinary CrossLaps took place regularly.

RESULTS

BMD increases relative to placebo were 6.3%, 3.9%, and 3.8% at the lumbar spine, total hip, and femoral neck, respectively (all P < 0.001). The biochemical markers of bone turnover were suppressed accordingly. Serum CrossLaps and urinary CrossLaps decreased rapidly, by 52% and 54%, respectively, whereas serum osteocalcin and serum bone-specific alkaline phosphatase revealed a more retarded decrease of 40% and 33%, respectively. Of the women receiving hormone therapy, 75% had amenorrhea from the first cycle, and 5% withdrew prematurely due to metrorrhagia or mastalgia.

CONCLUSION

This new estrogen + progestogen therapy is efficient in increasing BMD in an osteopenic postmenopausal population. Furthermore, it is well tolerated, with few adverse events and an early bleeding control, which is likely to improve compliance to the treatment over the long term.

Effects of low and high dose oestradiol and dydrogesterone therapy on insulin and lipoprotein metabolism in healthy postmenopausal women

OBJECTIVE

Menopause diminishes insulin secretion and elimination, increases risk of diabetes and adversely affects lipoprotein metabolism. This study was undertaken to establish whether oral oestradiol plus dydrogesterone postmenopausal hormone therapy can modify these changes.

DESIGN

Randomized prospective trial of postmenopausal women taking low dose therapy (1 mg/day oestradiol-17 beta with 5 or 10 mg/day dydrogesterone for days 17-28 of each cycle, n = 15) or high dose therapy (2 mg/day oestradiol-17 beta with 10 or 20 mg/day orally administered dydrogesterone, n = 9).

MEASUREMENTS

Patients underwent measurement of glucose, insulin and C-peptide in the fasting state and during an intravenous glucose tolerance test (IVGTT) at baseline and after 12 and 24 cycles of treatment. Modelling analysis was used to derive measures of insulin secretion, elimination and sensitivity. Fasting serum lipids, lipoproteins and apolipoproteins were also measured.

RESULTS

In both groups there were significant reductions in fasting glucose, insulin and C-peptide. Pancreatic insulin secretion during the IVGTT was increased by treatment (ranging from 45% to 92%, P < 0.01). Insulin elimination was increased at both the peripheral (16% to 43%, P < 0.05) and hepatic (18% to 31%, P < 0.05) levels. Insulin sensitivity was unaffected. Low density lipoprotein (LDL) cholesterol was reduced and high density lipoprotein (HDL) cholesterol increased with treatment.

CONCLUSIONS

Postmenopausal hormone therapy with oestradiol plus dydrogesterone can favourably affect lipoprotein concentrations and can reverse menopause-associated changes in insulin secretion and elimination.

Oestrogen replacement therapy promotes bone healing around dental implants in osteoporotic rats

The aim of this study was to investigate the effect of oestrogen replacement therapy on bone healing around titanium implants in osteoporotic rats. Sixty 32-week-old female SD rats were used in this study. Ovariectomies were performed in 40 rats, and other 20 rats had sham operation. Eighty-four days after surgery, osteoporotic changes in proximal tibiae were seen in four ovariectomized rats when compared with two sham-operated rats. Then pure titanium implants were placed in the bilateral proximal metaphyses of the tibiae of the remaining animals. Oestrogen replacement therapy was administrated in 18 ovariectomized rats after implantation. Nine rats from each group (ovariectomized, oestrogen-treated and sham-operated) were killed at 28 and 84 days after implantation surgery respectively, and the tibiae specimens were harvested and examined. Both at 28 and 84 days after implantation surgery, most bone histomorphometric indices in the oestrogen-treated group were significantly increased compared with those in the ovariectomized group (P < 0.05 or P < 0.01). Although the oestrogen-treated group showed lower trabecular bone volume at 28 days after implant surgery and lower mineralization rate at both the two time points than the sham-operated group, there were no significant differences in other bone histomorphometric indices between the oestrogen-treated group and the sham-operated group both at 24 and 84 days after implantation. The results of this study suggest that oestrogen replacement therapy may promote bone healing around titanium implants under osteoporotic state, and therefore it seemed to be beneficial to long-term success of dental implants in clinical postmenopausal patients.

Hormone replacement therapy: review, update, and remaining questions after the Women's Health Initiative Study

Hormone replacement therapy (HRT) is a collective term to include a variety of sex steroids, estrogens, and progestogens, given to postmenopausal women at various doses and administered through various routes. HRT is used for the relief of menopausal symptoms, with many women experiencing considerable improvement in their quality of life. It is also used for the prevention and treatment of osteoporosis, which is as effective as other available therapies. Other potential benefits of HRT are the prevention of cardiovascular disease and dementia. The main risks of HRT are an increased incidence of breast cancer and a transient increase in venous thromboembolism. The Women's Health Initiative is the largest randomized clinical trial of HRT to date, and has demonstrated benefits and risks of one specific HRT regimen. Skeletal benefits have been confirmed in terms of fracture reduction, as has a small risk of breast cancer development. Further studies of other HRT regimens are urgently required to clarify the cardiovascular effects.

Overview on the effects of progestins on bone

In view of the fact that fractures are the clinically relevant events, risk factors for fractures are discussed first. Bone mineral density (BMD) appears to be a much less important risk factor for the most severe hip fractures than the risk of falling. No results of experimental studies on hormones and fractures at advanced age are available. An overview of the effects of progestins on bone is given. Effects of progestins on bone have been studied by in vitro experiments using cell lines and by more relevant clinical observations. Prospective studies have been conducted following the use of progestins contained in oral contraceptives, alone or in combination with oestrogens; long-term contraception by injection of depot preparations; so-called "add-back" hormonal therapy attempting to reverse the adverse effects of gonadotropin releasing hormone agonists on bone and after different regimens of hormone replacement therapy (HRT) in postmenopausal women. From the data there are no indications that the various progestins, used in clinical practice, have either a bone-protective or an oestrogen antagonistic activity. Progestins do not add or subtract much of the protective action of oestrogens on the bones.

New anabolic therapies in osteoporosis

Anabolic agents represent an important new advance in the therapy of osteoporosis. Their potential might be substantially greater than the anti-resorptives. Because the anti-resorptives and anabolic agents work by completely distinct mechanisms of action, it is possible that the combination of agents could be significantly more potent than either agent alone. Recent evidence suggests that a plateau in BMD might occur after prolonged exposure to PTH. Anti-resorptive therapy during or after anabolic therapy might prevent this skeletal adaptation. Protocols to consider anabolic agents as intermittent recycling therapy would be of interest. Of all the anabolics, PTH is the most promising. However, there are unanswered questions about PTH. More studies are needed to document an anabolic effect on cortical bone. More large-scale studies are needed to further determine the reduction in nonvertebral fractures with PTH, especially at the hip. In the future, PTH is likely to be modified for easier and more targeted delivery. Oral or transdermal delivery systems may become available. Recently, Gowen et al have described an oral calcilytic molecule that antagonizes the parathyroid cell calcium receptor, thus stimulating the endogenous release of PTH. This approach could represent a novel endogenous delivery system for intermittent PTH administration. Rising expectations that anabolic therapies for osteoporosis will soon play a major role in treating this disease are likely to fuel further studies and the development of even more novel approaches to therapy.

Oral 17beta-estradiol (1 mg) continuously combined with dydrogesterone improves the serum lipid profile of postmenopausal women

OBJECTIVE

To investigate the effects of 1 mg 17beta-estradiol continuously combined with 2.5, 5, 10, or 20 mg dydrogesterone on the serum lipid profile of postmenopausal women.

DESIGN

Serum lipid profile was measured in two 1-year studies performed in healthy, nonhysterectomized, postmenopausal women. One study (n = 182) had an open design and investigated oral 17beta-estradiol 1 mg daily continuously combined with dydrogesterone 2.5 mg daily; the other study (n = 326) had a double-blind, randomized design and investigated oral 17beta-estradiol 1 mg daily continuously combined with dydrogesterone at doses of 5, 10, or 20 mg daily.

RESULTS

With all four dosages of dydrogesterone, serum total and low-density lipoprotein cholesterol were significantly reduced (-4.6% to -7.6% and -6.3% to -11.6%, respectively), whereas high-density lipoprotein cholesterol was significantly increased (+4.3% to +7.4%). Serum apolipoprotein A1 and B also improved significantly, reflecting the favorable changes in high-density lipoprotein and low-density lipoprotein cholesterol, as did lipoprotein(a).

CONCLUSION

Oral 17beta-estradiol 1 mg daily continuously combined with dydrogesterone 2.5 to 20 mg daily has beneficial effects on serum lipid profile in postmenopausal women.

Acid phosphatases

Acid phosphatases (APs) are a family of enzymes that are widespread in nature, and can be found in many animal and plant species. Mystery surrounds the precise functional role of these molecular facilitators, despite much research. Yet, paradoxically, human APs have had considerable impact as tools of clinical investigation and intervention. One particular example is tartrate resistant acid phosphatase, which is detected in the serum in raised amounts accompanying pathological bone resorption. This article seeks to explore the identity and diversity of APs, and to demonstrate the relation between APs, human disease, and clinical diagnosis.