Association of estrogen receptor alpha gene polymorphisms with bone mineral density in postmenopausal Indian women

Association between the ESR1 and ESR2 polymorphisms and osteoporosis risk: An updated meta-analysis

BACKGROUND

Gene polymorphisms of estrogen receptor (ESR) 1 PvuII (rs2234693), XbaI (rs9340799), G2014A (rs2228480), ESR2 AluI (rs4986938), and RsaI (rs1256049) had been reported to be associated with the risk of osteoporosis. However, these conclusions were inconsistent, therefore, an updated meta-analysis was conducted to further explore these issues.

OBJECTIVE

To evaluate the association between gene polymorphisms of ESR1 PvuII (rs2234693), XbaI (rs9340799), G2014A (rs2228480), ESR2 AluI (rs4986938), RsaI (rs1256049), and osteoporosis risk.

MATERIALS AND METHODS

PubMed, Medline, Ovid, Embase, CNKI, and China Wanfang databases were searched. Association was assessed using odds ratio with 95% confidence interval. Moreover, the false-positive reporting probability, Bayesian false-finding probability, and Venetian criteria were used to assess the credibility of statistically significant associations.

RESULTS

Overall, ESR1 PvuII (rs2234693) and XbaI (rs9340799) were associated with the risk of osteoporosis in Indians. Moreover, ESR1 G2014A (rs2228480) was associated with the decreased risk of osteoporosis in East Asians. Moreover, ESR2 Alul (rs4986938) was associated with the increased risk of osteoporosis in East Asians and Caucasians. There was a significant association between ESR2 Rsal (rs1256049) and osteoporosis risk in overall population. When only high-quality and Hardy-Weinberg equilibrium studies were included in the sensitivity analysis, all results did not change in the present study. When the credibility was evaluated applying false-positive reporting probability, Bayesian false-finding probability, and Venetian criteria, all significant associations were considered as false positive results.

CONCLUSIONS

In summary, this study shows that all substantial associations between gene polymorphisms of ESR1 (PvuII, XbaI, and G2014A) and ESR 2 (AluI and RsaI) and osteoporosis risk are possibly false positive results instead of real associations or biological variables.

Whole-Body Vibration Therapy as a Modality for Treatment of Senile and Postmenopausal Osteoporosis: A Review Article

Whole-body vibration therapy is an intentional biomechanical stimulation of the body using various frequencies of vibrations with the motive of health improvement. Ever since its discovery, this therapy has been extensively used in physiotherapeutic measures and the sports industry. For its property of increasing bone mass and density, space agencies use this therapy on astronauts who return to Earth after long-term space missions to regain lost bone and muscle mass. The potential of this therapy to restore bone mass encouraged researchers to look for its scope in the treatment of age-related bone degenerative diseases such as osteoporosis and sarcopenia, as well as in the correction of posture control and gait in geriatrics and post-menopausal women. Osteoporosis and osteopenia account for roughly half of all fractures worldwide. These degenerative diseases also cause gait and posture changes. Bisphosphonates, monoclonal antibodies, parathyroid hormone fragments, hormone replacement therapies, and calcium and vitamin D supplementation are among the medical treatments available. Lifestyle changes and physical exercise are advised. However, vibration therapy's scope as a treatment option is yet to be explored. The safe range of frequency, amplitude, duration, and intensity of the therapy is still to be determined. This article is a review of the results of various clinical trials done in the last 10 years that target the effect of vibration therapy in both osteoporotic women and the elderly for the treatment of such ailments and deformities. We collected data from PubMed using advanced search and applied the exclusion criteria. In total, we analyzed nine clinical trials.

Association of ESR1 and ESR2 Polymorphisms with Osteoporosis: A Meta-Analysis from 36 Studies

BACKGROUND

Recently, the roles of ESR1 and ESR2 polymorphisms in osteoporosis have been extensively reported, with conflicting findings. Therefore, we performed this present study to evaluate the potential associations between ESR1 and ESR2 polymorphisms and osteoporosis risk.

METHODOLOGY

All included literatures published up to April 2021 were identified by searching Pubmed, Embase, Web of Science, Cochrane Library, Chinese National Knowledge Infrastructure (CNKI) and Wanfang databases. Pooled odds ratio (OR) and 95% confidence interval (CI) were calculated the associations using a fixed or random effects model.

RESULTS

36 observational studies involving five gene polymorphisms (ESR1 PvuII, ESR1 XbaI, ESR1 G2014A, ESR2 AluI and ESR2 RsaI) covering 12507 cases and 18487 controls were included. The results of our meta-analysis demonstrated the variant A allele of ESR2 RsaI polymorphism might play a remarkable protective role in developing osteoporosis under all genetic models. However, no associations were observed between ESR1 PvuII, ESR1 XbaI, ESR1 G2014A and ESR2 AluI polymorphisms with the risk of osteoporosis under all genetic models.

CONCLUSIONS

Our meta-analysis suggests that genetic polymorphism in ESR2 RsaI may lead to decreased risk for osteoporosis. Further larger studies are needed to confirm this conclusion.

Osteoporosis and its Association with Vitamin D Receptor, Oestrogen α Receptor, Parathyroid Receptor and Collagen Type I alpha Receptor Gene Polymorphisms with Bone Mineral Density: A Pilot Study from South Indian Postmenopausal Women of Tamil Nadu

The involvement of many putative genetic factors makes osteoporosis a complex disease. With increasing longevity of the Indian population, it's now being realized that, as within the West, osteoporotic fractures are also a significant explanation for morbidity and mortality in postmenopausal women. Studies have suggested that the genetic component liable for bone mass could be linked to single nucleotide polymorphisms. Therefore, this study is aimed to research the role of seven gene polymorphisms previously associated with bone phenotype in a cohort of postmenopausal South Indian women from Tamil Nadu. The subjects for the study (n = 300) included 100 osteoporotic women (age 59.3 ± 9.26), 100 osteopenic women (age 55.6 ± 8.17) and 100 non-osteoporotic women as controls (age 55.4 ± 8.85).Genetic polymorphisms were determined by polymerase chain reaction (PCR)-restriction fragment length polymorphism. Case-control genetic association analysis of BsmI of the VDR and BstBI of the PTH gene showed a significant allelic association with low bone mineral density amongst the osteoporotic postmenopausal women. The association of BMD with the VDR gene polymorphisms revealed that the average BMD in the BsmI polymorphism with the recessive genotype GG in osteoporotic women was significantly reduced compared with the average BMD in osteoporotic women with AA and AG genotypes. In the BstBI polymorphism, the BMD in the osteoporotic subjects were significantly lower in the AA group than in the GA and GG groups. These results provide evidence for an independent association between BMD and rs1544410 in VDR and rs6254 in PTH and may contribute in being a possible genetic marker for predicting the disease susceptibility in the population tested.

Estrogen receptor α and β gene polymorphism in relation to bone mineral density and lipid profile in Northeast Indian women

Estrogen regulates bone homeostasis and has a cardio-protective effect. Its physiological functions are mediated through receptors (ER) whose expression can be regulated by presence or absence of polymorphisms. However, the association between ER polymorphisms and BMD as well as lipids are inconsistent. The aim of the study was to investigate whether polymorphisms in ESR are associated with bone mineral density (BMD) and lipids in a cohort of Indian women. We studied PvuII, XbaI polymorphisms in ESR1 and AluI, RsaI polymorphisms in ESR2 genes and their association with bone mineral density (BMD) and lipids in premenopausal (n = 293, mean age: 33.01 ± 5.23 years) and postmenopausal (n = 145, mean age: 56.91 ± 7.1 years) women from Northeast India. AluI and RsaI polymorphisms in ESR2 gene were associated with BMD in postmenopausal women. Logistic regression analysis adjusted for age, BMI, tobacco and alcohol consumption revealed that xx genotype in XbaI polymorphism is associated with osteopenia at spine (OR = 3.3, 95% CI = 1.067-10.204) in postmenopausal women suggesting that allele X is protective (OR = 0.419, 95% CI = 0.177-0.991). Genotype aa in AluI polymorphism, seemed to be protective (OR = 0.092 for osteopenia; OR = 0.152 for osteoporosis) at spine whereas A allele was associated with osteopenia at femur (OR = 2.123, 95% CI = 1.079-4.166) in postmenopausal women. Allele r of RsaI polymorphism, was associated with osteoporosis at spine (OR = 3.222, 95% CI = 1.302-7.96). Thus, AIuI polymorphism of ESR2 gene was associated with spinal and femoral BMD whereas RsaI only with spinal BMD in postmenopausal women and ESR genotypes were not associated with lipids.

Comparison of Indian Council for Medical Research and Lunar Databases for Categorization of Male Bone Mineral Density

The mainstay of diagnosis of osteoporosis is dual-energy X-ray absorptiometry (DXA) scan measuring areal bone mineral density (BMD) (g/cm²). The aim of the present study was to compare the Indian Council of Medical Research database (ICMRD) and the Lunar ethnic reference database of DXA scans in the diagnosis of osteoporosis in male patients. In this retrospective study, all male patients who underwent a DXA scan were included. The areal BMD (g/cm²) was measured at either the lumbar spine (L1-L4) or the total hip using the Lunar DXA machine (software version 8.50) manufactured by GE Medical Systems (Shanghai, China). The Indian Council of Medical Research published a reference data for BMD in the Indian population derived from the population-based study conducted in healthy Indian individuals, which was used to analyze the BMD result by Lunar DXA scan. The 2 results were compared for various values using statistical software SPSS for Windows (version 16; SPSS Inc., Chicago, IL). A total 238 male patients with a mean age of 57.2 yr (standard deviation ±15.9) were included. Overall, 26.4% (66/250) and 2.8% (7/250) of the subjects were classified in the osteoporosis group according to the Lunar database and the ICMRD, respectively. Out of the 250 sites of the DXA scan, 28.8% (19/66) and 60.0% (40/66) of the cases classified as osteoporosis by the Lunar database were reclassified as normal and osteopenia by ICMRD, respectively. In conclusion, the Indian Council of Medical Research data underestimated the degree of osteoporosis in male subjects that might result in deferring of treatment. In view of the discrepancy, the decision on the treatment of osteoporosis should be based on the multiple fracture risk factors and less reliably on the BMD T-score.

Sequence variations in estrogen receptor 1 and 2 genes and their association with egg production traits in Chinese Dagu chickens

Estrogen receptors α (ESR1) and β (ESR2) play central roles in folliculogenesis and therefore in reproductive biology. In the present study, two single nucleotide polymorphisms (SNPs) were identified in the ESR1 and ESR2 genes using PCR-single strand conformation polymorphism (PCR-SSCP) and DNA sequencing. One of the identified SNPs, a T1101C transition located within exon 4 of the ESR1 gene, was significantly associated with hen-housed egg production (HHEP) at 30, 43, 57 and 66 weeks of age (P<0.05), and egg weight (EW) at 30 weeks (P<0.05). Another SNP, a G1755A transition leading to a non-synonymous substitution (valine 459-to-isoleucine) located within exon 8 of the ESR2 gene, was also markedly correlated with the HHEP at 30, 43, 57 and 66 weeks of age (P<0.05), and EW at 30 weeks (P<0.05). A greater proportion of the additive variance was explained by the SNPs for most of the associated egg production traits (>1%). Furthermore, the results of the combined genotype-based association analysis supported the finding that the two SNPs were associated with the traits under a study. Taken together, our findings suggest that the two sequence variations in the ESR1 and ESR2 genes may provide promising genetic markers for the early selection and prediction of advantageous phenotypes in chicken breeding.

Influence of bone mineral density measurement on fracture risk assessment tool® scores in postmenopausal Indian women

AIM

Fracture risk assessment tool® calculations can be performed with or without addition of bone mineral density; however, the impact of this addition on fracture risk assessment tool® scores has not been studied in Indian women. Given the limited availability and high cost of bone mineral density testing in India, it is important to know the influence of bone mineral density on fracture risk assessment tool® scores in Indian women. Therefore, our aim was to assess the contribution of bone mineral density in fracture risk assessment tool® outcome in Indian women.

METHODS

Apparently healthy postmenopausal Indian women (n = 506), aged 40-72 years, without clinical risk factors for bone disease, were retrospectively selected, and their fracture risk assessment tool® scores calculated with and without bone mineral density were compared.

RESULTS

Based on WHO criteria, 30% women were osteoporotic, 42.9% were osteopenic and 27.1% had normal bone mineral density. Fracture risk assessment tool® scores for risk of both major osteoporotic fracture and hip fracture significantly increased on including bone mineral density (P < 0.0001). When criteria of National Osteoporosis Foundation, US was applied number of participants eligible for medical therapy increased upon inclusion of bone mineral density, (for major osteoporotic fracture risk number of women eligible without bone mineral density was 0 and with bone mineral density was 1, P > 0.05, whereas, for hip fracture risk number of women eligible without bone mineral density was 2 and with bone mineral density was 17, P < 0.0001).

CONCLUSION

Until the establishment of country-specific medication intervention thresholds, bone mineral density should be included while calculating fracture risk assessment tool® scores in Indian women.

Epidemiology and treatment of osteoporosis in women: an Indian perspective

The number of women with osteoporosis, ie, with reduced bone mass and the disruption of bone architecture, is increasing in India. While data on prevalence of osteoporosis among women in India come from studies conducted in small groups spread across the country, estimates suggest that of the 230 million Indians expected to be over the age of 50 years in 2015, 20%, ie, ~46 million, are women with osteoporosis. Thus, osteoporosis is a major public health problem in Indian women. Low calcium intakes with extensive prevalence of vitamin D deficiency, increasing longevity, sex inequality, early menopause, genetic predisposition, lack of diagnostic facilities, and poor knowledge of bone health have contributed toward the high prevalence of osteoporosis. Bone health may be optimized by creating an environment to achieve peak bone mass during adolescence, maintenance of healthy bone throughout the life cycle, and prevention of bone loss postmenopausal. In Indian women, calcium, vitamin D, and bisphosphonates are the commonest first-line therapies used. The use of other drugs such as hormone replacement therapy, estrogen agonists, calcitonin, parathyroid hormone, and denosumab is decided as per the affordability and availability of treatment options. Major gaps still remain in the diagnosis and management of osteoporosis, thus highlighting the need for more structured research in this area. This review focuses on the epidemiology of osteoporosis in Indian women and available treatments.

Association between osteoporosis and polymorphisms of the bone Gla protein, estrogen receptor 1, collagen 1-A1 and calcitonin receptor genes in Turkish postmenopausal women

In this study, we have investigated the association between osteoporosis and osteocalcin (BGLAP) -298 C>T, estrogen receptor 1 (ER1) 397 T>C, collagen type1 alpha 1 (Col1A1) 2046 G>T and calcitonin receptor (CALCR) 1340 T>C polymorphisms. Genomic DNA was obtained from 266 persons (158 osteoporotic and 108 healthy controls). Genomic DNA was extracted from EDTA-preserved peripheral venous blood of patients and controls by a salting-out method and analyzed by PCR-RFLP. As a result, there was no statistically significant difference in the genotype and allele frequencies of patients and controls for BGLAP -298 C>T, Col1A1 2046 G>T, ER1 397 T>C and CALCR 1340 T>C polymorphisms. However, ER1 CC genotype compared with TT+TC genotypes was found to increase the two fold the risk of osteoporosis [p=0.039, OR=2.156, 95% CI (1.083-4.293)] and CALCR CC genotype compared with TT+TC genotypes was found to have protective effect against osteoporosis [p=0.045, OR=0.471, 95% CI (0.237-0.9372)]. In the combined genotype analysis, ER1/CALCR TCCC combined genotype was estimated to have protective effect against osteoporosis [p=0.0125, OR=0.323, 95% CI (0.1383-0.755)] whereas BGLAP/Col1A1 CCTT and ER1/CALCR CCTT combined genotypes were estimated as risk factors for osteoporosis in Turkish population (p=0.027, p=0.009 respectively).

Relationship between bone turnover biomarkers, mandibular bone mineral density, and systemic skeletal bone mineral density in premenopausal and postmenopausal Indian women

OBJECTIVE

Postmenopausal osteoporosis is one of the most common metabolic bone disorders. Osteoporosis is reported to cause bone loss in the alveolar processes of maxilla and mandible, which provide bony framework for tooth anchorage. However, the association between systemic osteoporosis and oral health remains controversial. Available evidence suggests that Indian women have lower peak bone mass than their Western/other Asian counterparts. The present study evaluated the relationship between mandibular bone mineral density (mBMD), systemic skeletal BMD, and bone metabolism in premenopausal and postmenopausal Indian women.

METHODS

One hundred twenty-four premenopausal and 247 postmenopausal healthy women were included in the study. The BMD of the body of mandible, radius ultradistal, total hip, femur neck, and lateral spine were measured using dual-energy x-ray absorptiometry. Serum and urine biomarkers were determined using commercial kits.

RESULTS

Univariate regression analysis followed by stepwise multivariate regression analysis to obtain the best fit model demonstrated the BMD of radius ultradistal, serum inorganic phosphorus, estradiol, and sex hormone-binding globulin as significant predictors of mBMD in premenopausal women. The BMD of femur neck, serum ionized calcium, bone-specific alkaline phosphatase, osteocalcin, and urine total pyridinoline were significantly associated with mBMD in postmenopausal women. The significant association between mBMD and number of teeth present was observed in the whole group of premenopausal and postmenopausal women.

CONCLUSIONS

Varied predictors of mBMD were observed in premenopausal and postmenopausal women. The results suggest that the screening for these biomarkers and serum ionized calcium should be useful (1) to assess the status of mBMD particularly in women requiring surgical dental intervention that include bone manipulation and (2) for early detection and management of women with the risk of developing osteoporosis.

Prevalence and related risk factors of osteoporosis in peri- and postmenopausal Indian women

AIM

We undertook this study involving 200 peri- and postmenopausal women to determine the prevalence of osteoporosis, and in turn increase the awareness, education, prevention, and treatment of osteoporosis.

SETTING AND DESIGN

Postgraduate Institute of Medical Education and Research, UT Chandigarh, India, and a clinical study.

MATERIALS AND METHODS

A detailed medical, obstetrical, menstrual, and drug history was recorded in a proforma designated for the study. Height and weight was measured, weight-bearing exercise was assessed, and sunlight exposure per day for each woman was recorded. Food intake was estimated by using the 24-hour dietary recall method, and calcium and vitamin D consumption pattern was assessed. Bone mineral density (BMD) at postero-anterior lumbar spine and dual femurs was assessed by densitometer. Women were classified according to the WHO criteria.

STATISTICAL ANALYSIS USED

Student's t-test, multiple logistic regression analysis.

RESULTS

The prevalence of low BMD was found in more than half of this population (53%). The mean age in group I (normal BMD) was found to be 50.56 ± 5.74 years as compared to 52.50 ± 5.94 in group II with low BMD (P=0.02). The two groups were similar with respect to parity, education, socioeconomic status, family history of osteoporosis, hormone replacement therapy, and thyroid disorders. 46.8% of the women in group I and 33% of the women in group II had low physical activity and there was no statistically significant difference in sunlight exposure between the groups. Parity or the number of children and type of menopause was not seen to have much association with low BMD in our study. Lack of exercise and low calcium diet were significantly associated with low BMD. Multiple logistic regression analysis showed that age, exercise, menopause, and low calcium diet acted as significant predictors of low bone density.

CONCLUSION

The findings from the study suggest the need for large community-based studies so that high-risk population can be picked up and early interventions and other life style changes can be instituted if there is delay in implementing national or international health strategies to tackle this increasing global health problem. Strategies to identify and manage low BMD in the primary care setting need to be established and implemented.

Association of estrogen receptor alpha and collagen type I alpha 1 gene polymorphisms with bone mineral density in postmenopausal women

In this study, ERα gene PvuII and XbaI polymorphisms and COL1A1 gene Sp1 polymorphisms in postmenopausal women were compared with lumbar vertebra and femoral neck BMD values. In conclusion, it was designated that PvuII polymorphism was effective on average lumbar vertebra BMD value in postmenopausal women of our study group.

INTRODUCTION

Bone mineral density (BMD), the major determinant of osteoporotic fracture risk, has a strong genetic component. Several candidate gene polymorphisms have been implicated in the regulation of this process. In this study, the relationship among BMD values of lumbar vertebra and femoral neck and ERα gene PvuII and XbaI polymorphisms and COL1A1 gene Sp1 polymorphism in 126 postmenopausal women (30 normal, 46 osteopenic, and 50 osteoporotic in terms of bone mineral density) was researched.

METHODS

The ERα gene PvuII and XbaI genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) whereas the COL1A1 gene Sp1 genotype was determined by real-time PCR. BMDs at the lumbar spine (vertebrae L1-L4) and hip (femur neck) were measured by dual-energy X-ray absorptiometry.

RESULTS

According to our study results, the significant difference was found in women with normal, osteopenic, and osteoporotic bone mass in terms of ERα gene PvuII polymorphism "pp" genotype frequency. The "pp" genotype frequency was significantly lower in women with normal bone mass. Average lumbar vertebra BMD value of women with "PP" genotype was significantly higher than that with "pp" genotype. On the other hand, in the evaluations on ERα gene XbaI polymorphism and COL1A1 gene Sp1 polymorphism, it was noted that there was no difference in terms of average BMD values, genotype, and allele frequencies among groups.

CONCLUSION

In conclusion, it was designated that ERα gene PvuII polymorphism was effective on average lumbar vertebra BMD value in postmenopausal women of our study group.

Oestrogen receptor-alpha polymorphism and risk of fracture: a meta-analysis of 13 studies including 1279 cases and 6069 controls

A meta-analysis was performed to evaluate the effect of oestrogen receptor-alpha (ESR1) gene PvuII polymorphism on fracture risk. It included published data from relevant studies (up to May 2010) identified from Medline, Embase and Current Contents. The 13 included studies contained 1279 fracture cases and 6069 controls. The combined results based on these studies showed no relationship between ESR1 gene PvuII polymorphism and fracture risk. No significant difference in genotype distribution was found when stratifying by race. When stratifying by fracture type, it was found that vertebral fracture cases had a significantly higher frequency of the PvuII pp genotype than controls in five studies (552 cases and 2350 controls). This meta-analysis suggests a modest but statistically significant association between the ESR1 PvuII pp genotype and vertebral fracture.

Low bone mass in urban Indian women above 40 years of age: prevalence and risk factors

OBJECTIVE

To assess the prevalence and the relative importance of risk factors for low bone mass in Indian pre- and post-menopausal women.

METHODS

Data were collected on anthropometry and lifestyle factors in apparently healthy 80 pre- and 92 post-menopausal (40-75 years) women. Bone mineral density (BMD) was measured by dual energy X-ray absorptiometry. Fasting blood samples were analysed for Parathyroid hormone, vitamin D, calcium and zinc.

RESULTS

BMD at all three sites was significantly lower in post-menopausal than the pre-menopausal women (p < 0.001). Prevalence of osteoporosis was highest at the lumbar spine (25.8%) in post-menopausal women, while prevalence of osteopenia was high in pre-menopausal women (44.3%). Vitamin D deficiency was seen in 54.5% pre and 41.8% post-menopausal women and significant correlation of serum 25(OH)D levels (r = 0.16) was obtained only for total hip Z-score (p < 0.05). Correlation between sun index and lumbar spine BMD was marginally significant (r = 0.14, p = 0.07). Generalised linear models revealed that after adjusting for age, weight and height, percent decrease of 2.1-4.5% in BMD may be attributed to menopause.

CONCLUSION

Age, weight, height, menopause, low intakes of calcium and low 25(OH)D along with poor sunlight exposure are the major factors contributing to bone loss in Indian women above 40 years of age.

Role of the oestrogen receptor (ESR1 PvuII and ESR1 325 C->G) and progesterone receptor (PROGINS) polymorphisms in genetic susceptibility to migraine in a North Indian population

We aimed to explore the single-locus, haplotype and epistasis patterns and the contribution of oestrogen receptor [ESR1 PvuII (rs2234693), ESR1 325 C→G (rs1801132)] and progesterone receptor [PROGINS (rs1042838)] polymorphisms in genetic susceptibility to migraine by analysing 613 subjects consisting of 217 migraine patients, 217 healthy controls (HC) and 179 patients with tension-type headache (TTH). Entire data were analysed by taking the Bonferroni corrected P-value into account. We found significant association of TT genotype [odds ratio (OR) 3.458, confidence interval (CI) 1.757, 6.806; P = 0.0003] and T allele (OR 1.729, CI 1.309, 2.284; P = 0.0001) of ESR1 PvuII single nucleotide polymorphism with migraine when compared with HC. Significant association was seen only in female migraine patients at both genotype (P = 0.002; OR 3.834, CI 1.625, 9.043) and allele level (P = 0.002; OR 1.721, CI 1.228, 2.413). Moreover, higher risk was limited to migraine with aura (MA) (in case of TT genotype, P = 0.002; OR 4.377, CI 1.703, 1.246; in case of T allele, P = 0.001; OR 1.888, CI 1.305, 2.735) rather than migraine without aura (MoA) (P-value of TT genotype = 0.003; OR 3.082, CI 1.465, 6.483; P-value T allele = 0.002; OR 1.630, CI 1.188, 2.236). In case of a recessive model, risk was seen with migraine patients (P = 0.0003; OR 2.514, CI 1.635, 3.867), MA (P = 0.0001; OR 3.583, CI 1.858, 6.909) and MoA patients (P = 0.002; OR 2.125, CI 1.304, 3.464) when compared with HC. No risk was observed when TTH patients were compared with HC. No significance of ESR 325 G→C polymorphism was seen in any of the models under study. Significant differences in genotypic (P = 0.0001) and allelic frequency (P = 0.0002) were seen in case of PROGINS polymorphism when migraine patients were compared with HC, showing a protective effect (for A1A2 genotype, OR 0.292, CI 0.155, 0.549; for A2 allele, OR 0.320, CI 0.174, 0.589). Moreover, significance was seen only in case of female migraine patients at genotype (P = 0.002; OR 0.344, CI 0.176, 0.684) as well as allele levels (P = 0.004; OR 0.379, CI 0.198, 0.727) in case of PROGINS polymorphism. ESR1 PvuII TT*ESR1 325 C→G CG genotype, PROGINS A1A2*ESR1 325 C→G CG genotype and ESR1 PvuII CT*PROGINS A1A2 interacted significantly, but significance was lost after Bonferroni correction. In conclusion, ESR1 PvuII polymorphism is a significant risk factor for migraine particularly in women and MA patients, but ESR 325 C→G polymorphism is not associated with migraine susceptibility. PROGINS polymorphism seems to play a protective role in genetic susceptibility to migraine in the North Indian population.

Association of estrogen receptor alpha gene polymorphisms with BMD and their affect on estradiol levels in pre- and postmenopausal women in south Indian population from Andhra Pradesh

BACKGROUND

Osteoporosis is a multifactorial disorder with a strong genetic component and ESR1 is suggested as a candidate gene for osteoporosis. Therefore the present study is aimed to investigate the role of ESR1 gene polymorphisms and its influence on estradiol levels and BMD in osteoporotic women of Indian ethnicity.

METHODS

Four-hundred twenty-seven osteoporotic women and 460 age matched controls were included in the study. ESR1 gene polymorphism was assessed by PCR-RFLP method. Serum estradiol was measured by ELISA.

RESULTS

The frequency of pp and xx genotypes as well as p and x alleles was significantly high in pre- and postmenopausal osteoporotics when compared to controls (p<0.001). They had low BMD and estradiol levels in comparison with PP and XX genotype individuals (p<0.05).

CONCLUSION

The ESR1 gene is associated with low bone mass and low estradiol levels in all our study subjects. It is likely that the allele exerts its influence on the bone in early adulthood leading to an increased risk of osteoporosis later in life.

Interaction of interleukin-6 and estrogen receptor gene polymorphisms on bone mass accrual in Chinese adolescent girls

We assessed the main and interaction effects of interleukin-6 and estrogen receptor gene polymorphisms on bone mass accrual in Chinese adolescent girls. A total of 228 premenarche Chinese girls (9-11.5 years old) were recruited for a 2-year follow-up study. Bone mineral density (BMD) at the total body, lumbar spine (L1-L4), and total left hip were measured by dual-energy X-ray absorptiometry at baseline and follow-up. The -174G/C and -634C/G polymorphism of IL-6 gene, and PvuII and XbaI polymorphisms of the estrogen receptor (ER)-alpha gene, were determined. The -634C/G polymorphism of the IL-6 gene and PvuII polymorphism of ER-alpha gene were significantly associated with bone mass accrual after adjusting the potential confounding factors. Girls with pp genotype of ER-alpha gene had greater percentage accrual in BMD of total body (P = 0.010) and femoral intertrochanter (P = 0.038) than their PP and Pp counterparts. Girls with CC genotype of IL-6 -634G/C gene had higher percentage accrual in BMD of total body (P = 0.032) and femoral trochanter (P = 0.048) than their CG + GG counterparts. Significant interaction effects of IL-6 -634C/G polymorphism and ER-alpha PvuII polymorphism were observed on percentage change in BMD of total left hip (P = 0.009) and femoral intertrochanter (P = 0.007). The genotype CC (IL-6 -634C/G) x pp (ER-alpha PvuII) was associated with greater BMD accrual than other genotype combination in Chinese adolescent girls. We found that the IL-6 -634C/G and ER-alpha PvuII polymorphism were significantly associated with BMD accrual and that they have an interactional effect on BMD accrual in Chinese adolescent girls.

Relationship of volumetric bone mineral density and structural parameters with ERalpha gene polymorphisms

Bone mineral density (BMD) contributes to bone strength, and methods for clinical assessment of bone quality characteristics beyond what can be gathered by BMD are awaited. Peripheral quantitative computed tomography (pQCT) allows for separate assessments of cortical and trabecular bone, providing information on bone geometry. Previous studies examining the relationship between estrogen receptor alpha (ERalpha) gene polymorphisms and BMD have been performed in large populations. However, only limited information is available on the possible segregation of ERalpha gene polymorphisms with bone structural properties. The aim of our study was to evaluate the association of XbaI and PvuII ERalpha gene polymorphisms with QCT parameters. We studied 900 subjects (541 women, 449 men) participating to the InCHIANTI study. By tibial pQCT we evaluated trabecular volumetric BMD, cortical volumetric BMD, cortical bone area, and cortical thickness (CtTh). Subjects were genotyped for ERalpha gene PvuII and XbaI polymorphisms. Analysis of variance was used for statistical analysis. Male subjects with PP and XX genotypes had higher geometric parameters, and female subjects with XX and PP genotypes showed higher densitometric parameters than other genotypes; however, the differences did not reach statistical significance. After adjustment for potential confounders, we found a significant (P = 0.002) CtTh difference across PvuII polymorphism in male subjects, with higher CtTh values in PP genotypes with respect to Pp and pp genotypes. These results show a relationship between the presence of the P allele and higher values of CtTh in male subjects, indicating for ERalpha a role in the control of tibial bone geometry.

Association of estrogen receptor alpha gene polymorphisms and lifestyle factors with calcaneal quantitative ultrasound and osteoporosis in postmenopausal Vietnamese women

Genetic and lifestyle factors are important in the pathogenesis of osteoporosis. We investigated the relationships of PvuII and XbaI polymorphisms of the estrogen receptor alpha (ER-alpha) gene, lifestyle factors with speed of sound at the calcaneus (calcaneal SOS) and osteoporosis in a population-based study of 140 healthy postmenopausal women. By an analysis of covariates, women with higher copies of P or X alleles had higher calcaneal SOS compared with others (P=0.012, PP vs. pp; P=0.045, Xx vs. xx). Women with lower copies of px or higher copies of PX haplotypes had higher calcaneal SOS compared with others (P=0.021, 0 px vs. 2 px; P=0.011, 1 PX vs. 0 PX). The px and PX haplotypes, age and years since menopause were found to be independent predictors of calcaneal SOS in multiple linear regression models. Using logistic regression, we found an increased osteoporosis risk with evidence for a px haplotype dose effect (OR=2.82, 95% CI=1.50-5.31, P=0.001) and for a PX haplotype dose effect (OR=0.42, 95% CI=0.19-0.93, P=0.033). An increased educational level was associated with a reduced risk of osteoporosis (P=0.035 in the model with px, P=0.044 in the model with PX). In conclusion, the present study suggests that PvuII and XbaI polymorphims of the ER-alpha gene, age, years since menopause and educational level are associated with bone density, as assessed by calcaneal SOS, and osteoporosis in postmenopausal Vietnamese women.

Vitamin D receptor gene polymorphisms and bone mineral density in postmenopausal Indian women

OBJECTIVES

Osteoporosis is a common condition in postmenopausal women. Bone mineral density (BMD), the major determinant of osteoporotic fracture risk, has a particular genetic background. However, consensus on the association of BMD with specific gene locus has not been reached. The race and ethnicity specific divergence in association studies must be assessed to predict the susceptibility and therapeutic response of associated genes. We investigated the potential association of Vitamin D receptor (VDR) gene polymorphisms ApaI, BsmI, FokI and TaqI with BMD in 246 postmenopausal Indian women (average age 54.2+/-3.4 years).

METHODS

The subjects were genotyped by PCR-RFLP and underwent BMD measurements at spine and hip by dual energy X-ray absorptiometery.

RESULTS

The average BMD at spine and hip of women with genotypes aa, bb (presence of restriction sites for ApaI and BsmI), FF and TT (absence of restriction sites for FokI and TaqI) was more than 10% higher than those with genotypes AA, BB, ff and tt, respectively. The interaction between BsmI, ApaI and TaqI genotypes showed significant effect of BsmI-ApaI genotypes (p=0.052) in this combination on BMD. However, presence of T allele in combination showed positive influence on BMD. Within the group, genotypes BB, ff and tt were significantly prevalent in women with osteoporotic bone mass, tt and BB had significantly higher adjusted odd ratio (OR) for age more than 55years.

CONCLUSION

Study reveals that VDR gene polymorphisms are associated with BMD in Indian women and perhaps, influence some determinant of bone metabolism. Ethnicity may attribute to frequency variation, however, allele impact remains same.