Estrogen receptor alpha gene polymorphisms are associated with changes in bone remodeling markers and treatment response to estrogen

Association of Polymorphisms in FSHR, ESR1, and BMP15 with Primary Ovarian Insufficiency and Meta-Analysis

Primary ovarian insufficiency (POI) can lead to menstrual disturbance, resulting in ovarian dysfunction before age 40. Prevalence of POI is usually less than 1%; however, ethnicity or population characteristics may affect prevalence. POI is a heterogeneous disease that results from abnormalities in immunological and hormonal factors. Genetic factors can also contribute to POI. Here, we examine FSHR, ESR1, and BMP15 polymorphisms in patients with POI, and controls. We examined a hormonal gene that is important for pregnancy, follicle-stimulating hormone receptor (FSHR), as well as estrogen receptor 1 (ESR1), and associated it with FSHR expression, ovulation rate, and bone morphogenetic protein 15 (BMP15). We examined 139 Korean patients under age 40 with POI, and 350 Korean control participants without POI. Genotyping was performed by a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and TaqMan assays. Each identified genotype was subjected to statistical analysis to determine the odds ratios (ORs) and 95% confidence intervals (CIs). In combination genotype analyses, FSHR rs6165 A > G combined with ESR1 rs9340799 A > G, AG/GG (OR: 5.693; 95% CI: 1.088-29.792), as well as FSHR rs6166 A > G combined with ESR1 rs9340799 C > T, AG/GG (OR: 5.940; 95% CI: 1.134-31.131), were significantly associated with POI prevalence. Furthermore, an FSHR rs6165 A > G and BMP rs17003221 C > T, AG/CC combination was associated with POI prevalence (OR: 1.874; 95% CI: (1.059-3.316; p-value: 0.031)). In meta-analysis, FSHR rs6165 AA vs. AG + GG is associated with POI (p = 0.0013), and ESR1 rs2234693 AA vs. AG + GG is also associated with POI (p = 0.0101). Here, we compared the genotypes of FSHR, ESR1, and BMP15 in patients with POI, and controls. We found significant differences in genotype combinations between polymorphisms in FSHR and other genes. Through meta-analysis, we found that ESR1 rs9340799 and rs2234693 are associated with POI prevalence, and that BMP15 rs17003221 increases POI risk. These findings help to improve POI diagnosis in Korean women.

Menopausal hormone therapy for the management of osteoporosis

Postmenopausal osteoporosis is a frequent clinical condition which affects nearly 1 in 3 women. Estrogen deficiency leads to rapid bone loss which is maximal within the first 2-3 years after the menopause transition and can be prevented by menopause hormone therapy (MHT). Not only, MHT prevents bone loss and the degradation of the bone microarchitecture but it significantly reduces the risk of fracture at all bone sites by 20-40%. It is the only anti-osteoporotic therapy that has a proven efficacy regardless of basal level of risk, even in low-risk women for fracture. Following the publication of the WHI results, use of MHT has considerably declined due to safety concerns which raise the question as to whether it might still be used in the prevention of osteoporosis. Over the last years, subsequent re-analyses of the WHI and further trials have challenged the initial conclusions of the WHI. It is now clearer that the individual benefit-risk balance of MHT is dependent on the individual risk profile in each woman as well as whether estrogen is opposed or unopposed, the type of estrogens and progestogens or doses and routes of administration. It must be also reminded that to date osteoporosis is a chronic disease that cannot be cured. The choice of the 1st treatment option should thus always be made in the context of a more comprehensive long-term strategy. This is particular true in early postmenopausal women found to be at low/moderate risk of fragility fracture over the first 10 years after menopause but who may have a much greater lifetime risk. In the absence of contraindication, use of MHT should be considered as a 1st option for the maintenance of bone health in those women where specific bone active medications are not warranted. Subsequent reassessment of the individual benefit-risk balance of MHT is thereafter recommended, with the possibility of switching to another osteoporosis treatment if the balance is not considered as favourable as at the beginning of the menopause for women still at high risk of fracture.

[Menopause, menopause hormone therapy and osteoporosis. Postmenopausal women management: CNGOF and GEMVi clinical practice guidelines]

Postmenopausal osteoporosis is a frequent clinical condition, which affects nearly 1 in 3 women. Estrogen deficiency leads to rapid bone loss, which is maximal within the first years after the menopause transition and can be prevented by menopause hormone therapy (MHT). Assessment of the individual risk of osteoporosis is primarily based on the measurement of bone mineral density (BMD) at the spine and femur by DXA. Clinical risk factors (CRFs) for fractures taken either alone or in combination in the FRAX score were shown not to reliably predict fractures and/or osteoporosis (as defined by a T-score<-2.5) in early postmenopausal women. If DXA measurement is indicated in all women with CRFs for fractures, it can be proposed on a case-by-case basis, when knowledge of BMD is likely to condition the management of women at the beginning of menopause, particularly the benefit-risk balance of MHT. MHT prevents both bone loss and degradation of the bone microarchitecture in early menopause. It significantly reduces the risk of fracture at all bone sites by 20 to 40% regardless of basal level of risk with an estrogen-dependent dose-effect. Given the inter-individual variability in bone response, individual monitoring of the bone effect of MHT is warranted when prescribed for the prevention of osteoporosis. This monitoring is based on repeated measurement of lumbar and femoral BMD (on the same DXA measurement system) after 2years of MHT, the response criterion being no significant bone loss. Discontinuation of treatment is associated with a resumption of transient bone loss although there is a large variability in the rate of bone loss among women. Basically, there is a return to the level of fracture risk comparable to that of in untreated woman of the same age within 2 to 5years. Therefore, when MHT is prescribed for the prevention of osteoporosis in women with an increased risk at the beginning of menopause, measurement of BMD is recommended when MHT is stopped in order to consider further management of the risk of fracture whenever necessary (with possibly another anti-osteoporotic treatment).

The estrogen receptor 1 gene affects bone mineral density and osteoporosis treatment efficiency in Slovak postmenopausal women

BACKGROUND

The study investigated the associations of rs9340799:A > G (XbaI) and rs2234693:T > C (PvuII) polymorphisms in the estrogen receptor 1 gene (ESR1) with femoral neck (BMD-FN) and lumbar spine bone mineral density (BMD-LS), biochemical markers of bone turnover, calcium and phosphate levels, fracture prevalence, and a response to two types of anti-osteoporotic therapy in postmenopausal women from southern Slovakia.

METHODS

We analysed 343 postmenopausal Slovak women (62.40 ± 0.46 years). The influence of rs9340799 (AA vs. AG + GG) and rs2234693 (TT vs. TC + CC) genotypes on BMD and biochemical markers was evaluated by covariance analysis adjusted for age and BMI. Binary logistic regression was used to evaluate the genotype effect on fracture prevalence. Pharmacogenetic part of the study included women who received a regular therapy of HT (17ß estradiol with progesterone; 1 mg/day for both; N = 76) or SERMs/raloxifene (60 mg/day; N = 64) during 48 months. The genotype-based BMD change was assessed by variance analysis for repeated measurements.

RESULTS

Women with AA genotype of rs9340799 had higher BMD-FN (+ 0.12 ± 0.57 of T-score) and BMD-LS (+ 0.17 ± 0.08 of T-score) in comparison with AG + GG. The rs2234693 polymorphism did not affect any of the monitored parameters. No effect of any ESR1 polymorphisms was found on fracture prevalence. Both types of anti-osteoporotic therapy had a positive effect on BMD improvement in FN and LS sites. Considering the effect of the ESR1 gene within the HT, the subjects with rs9340799/AA genotype showed worse response than those with GG genotype (- 0.26 ± 0.10 of BMD-FN T-score; - 0.35 ± 0.10 of BMD-LS T-score) and also with AG genotype (- 0.22 ± 0.08 of BMD-LS T-score). The rs2234693/TT genotype responded poorer in BMD-LS in comparison with TC (- 0.22 ± 0.08 of T-score) and CC (- 0.35 ± 0.09 of T-score). The effect of the ESR1 gene on raloxifene therapy was reported only in BMD-LS. Subjects with rs9340799/AA genotype had a - 0.30 ± 0.11 of T-score worse response compared to AG genotype. The rs2234693/TT genotype showed - 0.39 ± 0.11 and - 0.46 ± 0.15 lower T-scores in comparison with TC and CC genotypes, respectively.

CONCLUSIONS

The rs9340799 polymorphism may contribute to decreased BMD in postmenopausal women from southern Slovakia; however, this is not related to higher fracture prevalence. Concurrently, both polymorphisms affected a response to analysed anti-osteoporotic therapies.

Association between dietary phytoestrogen intake and bone mineral density varied with estrogen receptor alpha gene polymorphisms in southern Chinese postmenopausal women

INTRODUCTION

several studies have investigated the relationship between the estrogen receptor (ER) gene polymorphisms and the efficacy of estrogen replacement therapy in postmenopausal osteoporosis. However, the association of ER polymorphisms with the effects of dietary phytoestrogens on bone metabolism has not yet been reported. This study explores the possibility that ER alpha subtype (ERα) gene polymorphisms are involved in the effects of dietary phytoestrogens on bone mineral density (BMD) in postmenopausal women.

METHODS

a total of 301 postmenopausal southern Chinese women were enrolled. Dietary phytoestrogen intake was evaluated using a food frequency questionnaire. ERα polymorphisms were examined with restriction fragment length polymorphism at the polymorphic PvuII and XbaI sites within intron 1. Dual-energy X-ray absorptiometry scans were performed to determine the BMD of the lumbar spine and hip.

RESULTS

the positive association of the lumbar spine BMD with dietary phytoestrogen intake was maintained only in groups with pp or xx genotypes (p < 0.05) and disappeared in groups with other genotypes. A positive association of the hip BMD with dietary phytoestrogen intake was observed only in the xx genotype group (p < 0.05).

CONCLUSIONS

the association of the dietary phytoestrogen intake and BMD in southern Chinese postmenopausal women varied with ERα gene polymorphisms.

ESR1 and ESR2 polymorphisms in the BIG 1-98 trial comparing adjuvant letrozole versus tamoxifen or their sequence for early breast cancer

Estrogen receptor 1 (ESR1) and ESR2 gene polymorphisms have been associated with endocrine-mediated physiological mechanisms, and inconsistently with breast cancer risk and outcomes, bone mineral density changes, and hot flushes/night sweats. DNA was isolated and genotyped for six ESR1 and two ESR2 single-nucleotide polymorphisms (SNPs) from tumor specimens from 3691 postmenopausal women with hormone receptor-positive breast cancer enrolled in the BIG 1-98 trial to receive tamoxifen and/or letrozole for 5 years. Associations with recurrence and adverse events (AEs) were assessed using Cox proportional hazards models. 3401 samples were successfully genotyped for five SNPs. ESR1 rs9340799(XbaI) (T>C) variants CC or TC were associated with reduced breast cancer risk (HR = 0.82,95% CI = 0.67-1.0), and ESR1 rs2077647 (T>C) variants CC or TC was associated with reduced distant recurrence risk (HR = 0.69, 95% CI = 0.53-0.90), both regardless of the treatments. No differential treatment effects (letrozole vs. tamoxifen) were observed for the association of outcome with any of the SNPs. Letrozole-treated patients with rs2077647 (T>C) variants CC and TC had a reduced risk of bone AE (HR = 0.75, 95% CI = 0.58-0.98, P interaction = 0.08), whereas patients with rs4986938 (G>A) genotype variants AA and AG had an increased risk of bone AE (HR = 1.37, 95% CI = 1.01-1.84, P interaction = 0.07). We observed that (1) rare ESR1 homozygous polymorphisms were associated with lower recurrence, and (2) ESR1 and ESR2 SNPs were associated with bone AEs in letrozole-treated patients. Genes that are involved in estrogen signaling and synthesis have the potential to affect both breast cancer recurrence and side effects, suggesting that individual treatment strategies can incorporate not only oncogenic drivers but also SNPs related to estrogen activity.

Hormone therapy for preventing cardiovascular disease in post-menopausal women

BACKGROUND

Evidence from systematic reviews of observational studies suggests that hormone therapy may have beneficial effects in reducing the incidence of cardiovascular disease events in post-menopausal women, however the results of randomised controlled trials (RCTs) have had mixed results. This is an updated version of a Cochrane review published in 2013.

OBJECTIVES

To assess the effects of hormone therapy for the prevention of cardiovascular disease in post-menopausal women, and whether there are differential effects between use in primary or secondary prevention. Secondary aims were to undertake exploratory analyses to (i) assess the impact of time since menopause that treatment was commenced (≥ 10 years versus < 10 years), and where these data were not available, use age of trial participants at baseline as a proxy (≥ 60 years of age versus < 60 years of age); and (ii) assess the effects of length of time on treatment.

SEARCH METHODS

We searched the following databases on 25 February 2014: Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE and LILACS. We also searched research and trials registers, and conducted reference checking of relevant studies and related systematic reviews to identify additional studies.

SELECTION CRITERIA

RCTs of women comparing orally administered hormone therapy with placebo or a no treatment control, with a minimum of six months follow-up.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study quality and extracted data. We calculated risk ratios (RRs) with 95% confidence intervals (CIs) for each outcome. We combined results using random effects meta-analyses, and undertook further analyses to assess the effects of treatment as primary or secondary prevention, and whether treatment was commenced more than or less than 10 years after menopause.

MAIN RESULTS

We identified six new trials through this update. Therefore the review includes 19 trials with a total of 40,410 post-menopausal women. On the whole, study quality was good and generally at low risk of bias; the findings are dominated by the three largest trials. We found high quality evidence that hormone therapy in both primary and secondary prevention conferred no protective effects for all-cause mortality, cardiovascular death, non-fatal myocardial infarction, angina, or revascularisation. However, there was an increased risk of stroke in those in the hormone therapy arm for combined primary and secondary prevention (RR 1.24, 95% CI 1.10 to 1.41). Venous thromboembolic events were increased (RR 1.92, 95% CI 1.36 to 2.69), as were pulmonary emboli (RR 1.81, 95% CI 1.32 to 2.48) on hormone therapy relative to placebo.The absolute risk increase for stroke was 6 per 1000 women (number needed to treat for an additional harmful outcome (NNTH) = 165; mean length of follow-up: 4.21 years (range: 2.0 to 7.1)); for venous thromboembolism 8 per 1000 women (NNTH = 118; mean length of follow-up: 5.95 years (range: 1.0 to 7.1)); and for pulmonary embolism 4 per 1000 (NNTH = 242; mean length of follow-up: 3.13 years (range: 1.0 to 7.1)).We performed subgroup analyses according to when treatment was started in relation to the menopause. Those who started hormone therapy less than 10 years after the menopause had lower mortality (RR 0.70, 95% CI 0.52 to 0.95, moderate quality evidence) and coronary heart disease (composite of death from cardiovascular causes and non-fatal myocardial infarction) (RR 0.52, 95% CI 0.29 to 0.96; moderate quality evidence), though they were still at increased risk of venous thromboembolism (RR 1.74, 95% CI 1.11 to 2.73, high quality evidence) compared to placebo or no treatment. There was no strong evidence of effect on risk of stroke in this group. In those who started treatment more than 10 years after the menopause there was high quality evidence that it had little effect on death or coronary heart disease between groups but there was an increased risk of stroke (RR 1.21, 95% CI 1.06 to 1.38, high quality evidence) and venous thromboembolism (RR 1.96, 95% CI 1.37 to 2.80, high quality evidence).

AUTHORS' CONCLUSIONS

Our review findings provide strong evidence that treatment with hormone therapy in post-menopausal women overall, for either primary or secondary prevention of cardiovascular disease events has little if any benefit and causes an increase in the risk of stroke and venous thromboembolic events.

Pharmacogenetics of osteoporosis

The challenge of personalized medicine is to move away from the traditional 'one-size-fits-all' pharmacology to genotype-based individualized therapies. As an individual's response to drugs is under the control of genes, personal genetic profiles could help clinicians to predict individual drug response and prescribe the right drug and dose, thereby optimising efficacy and avoiding risk of adverse effects. Currently, the concrete application of pharmacogenetics into clinical practice is limited to a few drugs, and the genetic prediction of drug response is far from clear for many of thve principal complex disorders. This is even more evident in the field of osteoporosis and metabolic bone disorders, for which few pharmacogenetic studies have been conducted, and no conclusive results are available. In this chapter, we review recent research on pharmacogenetics of osteoporosis, evaluate criticisms, and offer possible suggestions for improvements in this field and for possible future applications into clinical practice.

The future of pharmacogenetics for osteoporosis

The possibility to predict the outcome of medical treatments, both in terms of efficacy and development of adverse effects, is the main goal of modern personalized medicine. The principal aim of pharmacogenetics is to design specific predictive genetic tests, to be performed prior to any drug treatment, and to tailor the therapy for each patient based on the results of these tests. Few pharmacogenetic tests are today validated and commonly applied in clinical practice, and none in the area of osteoporosis and bone disorders. Surely, the complex regulation of bone metabolism and the involvement of numerous different molecular pathways makes it difficult to individuate responsible genes and polymorphisms involved in the modulation of anti-osteoporotic drug response and, subsequently, in designing specific predictive analyses.

Pharmacogenetics of osteoporosis: what is the evidence?

The early genetic prediction of personal drug therapy outcome, both in terms of identification of poor responders or nonresponders, as well as of subjects at risk of developing adverse reactions, and its translation into the clinical practice are the main challenges of personalized medicine. The application of pharmacogenetic predictive tests will be very useful mostly in cases of chronic disorders, as in metabolic bone diseases, that require long-term treatments and for whom exist effective differently acting drugs to be alternatively chosen. Pharmacogenetic tests, prior to drug administration, would hypothetically grant the optimization of drug therapy, based on patient's genotype, to ensure maximum efficacy with minimal adverse effects. This review aims to offer an overview on the principal findings in the field of pharmacogenetics of osteoporosis, and it will discuss future perspectives and possible clinical applications of pharmacogenetic tests for antiresorptive drugs.

An aromatase polymorphism (g.132810C>T) predicts risk of bisphosphonate-related osteonecrosis of the jaw

Background: Bisphosphonate (BP)-related osteonecrosis of the jaw (ONJ) is an unpredictable, debilitating adverse effect. Recently, genetic polymorphisms have arisen as promising tools to identify patients with a higher risk of drug-related adverse events. Aim: We aimed to examine the association between the aromatase polymorphism g.132810C>T, and the estrogen receptor polymorphisms g.156705T>C and g.156751A>G, and the risk of BP-related ONJ. Methods: Eighty-three subjects were included in the study. A clinical and radiological examination was conducted on oncologic subjects treated with zoledronic acid. Subjects with histologically confirmed ONJ were included in the test group (n = 30) whereas subjects with good oral health were included in control group (n = 53). Aromatase and estrogen receptor polymorphisms from blood samples were analyzed. Results: The aromatase g.132810C>T polymorphism displayed an over-representation of the TT genotype in the test group (36.67 vs 16.98%; p < 0.05). There was no significant difference in either estrogen receptor polymorphism genotype frequency between the test and control groups. Conclusion: Our data suggest a role for the g.132810C>T polymorphism in predicting ONJ risk. These results can pave the way to the personalization of BP therapy, based on individual genotype.

Effect of hormone therapy and calcitriol on serum lipid profile in postmenopausal older women: association with estrogen receptor-α genotypes

OBJECTIVE

The aim of this study was to examine the effect of conjugated equine estrogens alone (ET), conjugated equine estrogens + medroxyprogesterone (EPT), calcitriol alone, calcitriol + EPT/ET, or placebo on serum lipid profile and analyze the interaction with estrogen receptor-α gene single nucleotide polymorphisms (ESR-α SNPs) on the response to therapy.

METHODS

A total of 489 postmenopausal women older than 65 years were enrolled into a 3-year double-blind, placebo-controlled clinical trial.

RESULTS

In both intent-to-treat and complier (>80% adherent) analysis, there was a significant increase in serum high-density lipoproteins and a significant decrease in serum low-density lipoproteins (LDLs) and the LDL/high-density lipoprotein ratio in all hormone treatment groups compared with placebo (P < 0.05). However, serum triglycerides and very low-density lipoproteins increased in the EPT and ET + calcitriol groups versus placebo (P < 0.05). ESR-α SNPs PvuII and XbaI seemed to have a significant effect on the response to treatment. Genotypes containing the p allele showed a significantly greater decrease in serum cholesterol and very low-density lipoprotein than those having the P allele in the ET + calcitriol group (P < 0.05), and those with the x allele had a significantly greater decrease in serum cholesterol in the hormone therapy + calcitriol group at the end of 3 years versus the X allele, and a greater decrease in serum LDL in alleles x versus the X in the ET + calcitriol group (P < 0.05).

CONCLUSIONS

ET with or without progesterone had a favorable effect on lipid profile in postmenopausal older women, and this was dependent on estrogen receptor SNPs--PvuII and XbaI. However, this interaction with ESR-α SNPs needs to be confirmed in larger studies.

Pharmacogenetics of osteoporosis

Osteoporosis is the most common and serious skeletal disorder of the elderly; it is characterized by reduced bone mass and deterioration of bone microarchitecture, with an increased risk of low-trauma fractures. Genetic factors are important predisposing elements influencing individual bone strength variability and susceptibility to osteoporosis and related complications. The genetics of osteoporosis encompasses two main areas: disease susceptibility and pharmacogenetics of drug response. The former has been widely studied while the latter is still largely untouched. Pharmacogenetics is the study of relationships between genetic variations and inter-individual differences in drug response in terms of efficacy and adverse effects, representing an opportunity to identify new biomarkers for drug development and drug response. However, pharmacogenetic approaches to osteoporosis are still in their infancy, needing to be developed further and combined with functional studies. This article provides an overview on the current basic research applications in the pharmacogenetics of osteoporosis and their implications for clinical practice.

Genetics of osteoporosis: perspectives for personalized medicine

Osteoporosis is the most common metabolic bone disorder worldwide. At least 15 genes (e.g., ESR1, LRP5, SOST, OPG, RANK and RANKL) have been confirmed as osteoporosis susceptibility genes, and another 30 have been highlighted as promising susceptibility genes. Notably, these genes are clustered in three biological pathways: the estrogen endocrine pathway, the Wnt/β-catenin signaling pathway and the RANK/RANKL/osteoprotegerin (OPG) pathway. In this article, using data pertaining to these three biological pathways as examples, we illustrate possible principles of personalized therapy for osteoporosis. In particular, we propose to use inhibitors (e.g., denosumab) of the RANK/RANKL/OPG signaling pathway to circumvent resistance to estrogen-replacement therapy: a novel idea resulting from the consideration of a mechanistic link between the estrogen endocrine pathway and the RANK/RANKL/OPG signaling pathway. In addition, we call for more attention to be focused on rare variants of major effects in future studies.

Pharmacogenetics of osteoporosis

Osteoporosis is a complex bone disorder with a strong genetic basis. The genetics of osteoporosis encompasses two main areas: genetics of disease susceptibility and pharmacogenetics of drug response. The former has been widely studied in the past few decades, while the latter is still largely untouched. This review will provide an overview of the pharmacogenetics of osteoporosis, focusing on the major recent advances in the past two years.

Pharmacogenetics of osteoporosis: future perspectives

Drug response is known to be highly variable among treated patients and affected by many factors, such as age, sex, ethnicity, concomitant diseases, and pharmacological therapy. However, sequence variants in the human genome are now considered an important cause of differences in drug responses. Pharmacogenetics, which is the utilization of individual genetic data to predict the outcome of drug treatment with respect to both beneficial and adverse effects, represents an emerging field of genetics with the potential to become useful for the identification of the most effective drug and the most beneficial dose for a given individual. On the basis of these considerations and thanks to recent advances in genetics and molecular biology, pharmacogenetics is becoming a flowering field in both basic and clinical research. Nevertheless, to date the opportunity to apply pharmacogenetic approaches to drug response and the possibility to use genetic screenings to tailor decisions about pharmacological treatments have limited applications. And this is even truer in the field of osteoporosis, in which pharmacogenetic studies are in their infancy. In this paper we review the most recent data on pharmacogenetics of osteoporosis, highlighting the presentations at the Second International Meeting on Pharmacogenetics of Osteoarticular Disorders held in Florence in April 2008.

Age-specific effects of estrogen receptors' polymorphisms on the bone traits in healthy fertile women: the BONTURNO study

BACKGROUND

Skeletal characteristics such as height (Ht), bone mineral density (BMD) or bone turnover markers are strongly inherited. Common variants in the genes encoding for estrogen receptor alpha (ESR1) and beta (ESR2) are proposed as candidates for influencing bone phenotypes at the population level.

METHODS

We studied 641 healthy premenopausal women aged 20-50 years (yrs) participating into the BONTURNO study. Exclusion criteria were irregular cyclic menses, low trauma fracture, metabolic bone or chronic diseases. Serum C-telopeptide of type I collagen (CTX), osteocalcin (OC), and N-terminal propeptide of type I procollagen (P1NP) were measured in all enrolled subjects, who underwent to lumbar spine (LS), total hip (TH) and femoral neck (FN) BMD evaluation by DXA. Five hundred seventy Caucasian women were genotyped for ESR1 rs2234693 and rs9340799 and ESR2 rs4986938 polymorphisms.

RESULTS

Although no genotype differences were found in body parameters, subjects with combined ESR1 CCGG plus ESR2 AA-AG genotype were taller than those with opposite genotype (P = 0.044). Moreover, ESR1 rs2234693 genotypes correlated with family history of osteoporosis (FHO) and hip fracture (FHF) (P < 0.01), while ESR2 AA-AC genotypes were strongly associated with FHF (OR 2.387, 95% CI 1.432-3.977; P < 0.001).When clustered by age, 20-30 yrs old subjects, having at least one ESR1 rs2234693 C allele presented lower LS- (P = 0.008) and TH-BMD (P = 0.047) than TT genotypes. In 41-50 yrs age, lower FN-BMD was associated with ESR2 AA (P = 0.0180) subjects than in those with the opposite genotype. ESR1 rs2234693 and rs9340799 and ESR2 rs4986938 polymorphisms did not correlate with age-adjusted values of OC, CTX and P1NP.

CONCLUSION

These findings support the presence of age-specific effects of ESR1 and ESR2 polymorphisms on various skeletal traits in healthy fertile women.

Inadequate responders to osteoporosis treatment: proposal for an operational definition

The concept of inadequate response to osteoporosis treatment is not clear. In the literature several criteria have been used. We propose an operational definition of an inadequate responder based on the changes observed in bone mineral density and incident fractures while on therapy.

INTRODUCTION

Fractures may occur in compliant patients even while on active treatment. These cases have been defined as inadequate responders (IR).

METHODS

We reviewed the basis for this concept and propose an operational definition for IR.

RESULTS

Good compliance and adequate calcium and vitamin D supplementation are the first requirement. The second requirement is a treatment period of at least 1 year, since before that time treatment may not have been fully effective. Fractures are the gold standard for measuring efficacy and changes in bone density and turnover markers may be surrogates. We propose classifying patient response as: Inadequate--incident fracture and a decrease in BMD greater than a significant change (Trend Assessment Margin or TAM); Possibly inadequate--incident fracture or a decrease in BMD greater than a significant change (TAM); and Appropriate--no fracture and no decrease in BMD greater than a significant change (TAM). Additional criteria (biochemical markers, bone quality parameters) may be taken into account.

CONCLUSION

A wide consensus on the IR concept is required given its clinical, regulatory, and reimbursement implications.

Pharmacogenetics of bone treatments: the VDR and ERalpha gene story

Osteoporosis is a common skeletal disease with a strong genetic component characterized by reduced bone mass and increased risk of fragility fractures. Although osteoporosis is a worldwide problem, there are many differences in human ethnics regarding both disease morbidity and drug treatment efficacy. Polymorphisms of vitamin D receptor (VDR) and estrogen receptor-alpha (ERalpha) loci are proposed as genetic determinants of bone quality, skeletal geometry and bone turnover markers. Furthermore, varying responsiveness to vitamin D and estrogen-based treatments may reflect allele variation in their signaling pathway genes (e.g., VDR or ERalpha). Because of their specific ethnic distribution, VDR and ERalpha polymorphisms may be involved in reported human differences of osteoporosis treatment responses.

Genotypes and clinical aspects associated with bone mineral density in Argentine postmenopausal women

The aim of this study was to determine genotypes and clinical aspects associated with bone mineral density (BMD) in postmenopausal women from Córdoba, Argentina. Polymorphisms were assessed by RFLP-PCR technique using BsmI and FokI for vitamin D receptor gene (VDR) and XbaI and PvuII for estrogen receptor-alpha gene (ERalpha) as restrictases. Sixty-eight healthy, 54 osteopenic, and 64 osteoporotic postmenopausal women were recruited. Femoral neck and lumbar spine BMD were inversely correlated with age in the entire analyzed population. Height was lower in osteopenic and osteoporotic women as compared to healthy women (P < 0.05). Weight and body mass index (BMI) were the lowest in osteoporotic women (P < 0.01 versus healthy group). Serum procollagen type I Nterminal propeptide (PINP) was higher in osteoporotic women as compared to the other groups. Distribution of VDR and ERalpha genotypes was similar in the three groups. Genotype bb (VDR) was associated with low values of lumbar BMD in the healthy group (P < 0.05 versus genotype Bb), and with low values of femoral BMD (P < 0.05 versus genotype BB) in osteoporotic women. BB*Pp interaction was associated with the highest femoral neck BMD (P < 0.05), whereas the bb*xx interaction was associated with the lowest femoral neck BMD in the total population analyzed (P < 0.05). In conclusion, parameters such as age, height, weight, BMI, serum PINP, VDR genotypes, and interactions between VDR and ERalpha genotypes could be useful to predict a decrease in BMD in Argentine postmenopausal women.