Vitamin D receptor gene polymorphisms, bone mineral density and fractures in postmenopausal women with osteoporosis

VDR gene ApaI polymorphism and risk of postmenopausal osteoporosis: a meta-analysis from 22 studies

OBJECTIVE

The ApaI polymorphism (G > T, rs7975232) of the vitamin D receptor (VDR) gene in the risk of postmenopausal osteoporosis has been widely researched, and the results have yielded conflicts. Therefore, we performed an updated pooled analysis to comprehensively assess the association between VDR ApaI polymorphism and postmenopausal osteoporosis risk.

METHODS

We searched eligible studies about ApaI polymorphism and osteoporosis through the PubMed, Embase, CNKI and Wanfang databases; case-control studies containing available genotype frequencies of A/a were chosen. We used the odds ratio with 95% confidence interval to assess the strength of this association. Sensitivity analysis and publication bias assessment were performed. Trial sequential analysis (TSA) was performed to evaluate a sufficient sample.

RESULTS

Twenty-two studies assessed the relationship between ApaI polymorphism and the risk of osteoporosis in postmenopausal women. The comprehensive analyses showed no significant association for ApaI polymorphism with postmenopausal osteoporosis in the overall population, equally valid for Asian and Caucasian subgroups with any genetic model. TSA still indicated the results were robust.

CONCLUSION

The present meta-analysis suggests that the VDR ApaI genotype may not affect the risk of postmenopausal osteoporosis in Asians and Caucasians.

Vitamin D Receptor Gene Polymorphisms Affect Osteoporosis-Related Traits and Response to Antiresorptive Therapy

The present study analyzed the effect of vitamin D receptor (VDR) gene polymorphisms (ApaI, TaqI, BsmI, FokI, and Cdx2) on bone mineral density (BMD), biochemical parameters and bone turnover markers, fracture prevalence, and response to three types of antiresorptive therapy (estrogen-progesterone, raloxifene, and ibandronate) in 356 postmenopausal women from Slovakia. Association analysis revealed a significant effect of BsmI polymorphism on lumbar spine BMD, serum osteocalcin (OC), and β-CrossLaps levels. While ApaI and Cdx2 polymorphisms were associated with OC and alkaline phosphatase, TaqI polymorphism affected all turnover markers. ApaI, TaqI, and BsmI genotypes increased the risk of spinal, radial, or total fractures with odds ratios ranging from 2.03 to 3.17. Each of therapy types evaluated had a beneficial effect on all osteoporosis-related traits; however, the VDR gene affected only ibandronate and raloxifene treatment. ApaI/aa, TaqI/TT, and BsmI/bb genotypes showed a weaker or no response to ibandronate therapy in femoral and spinal BMD. The impact of aforementioned polymorphisms on turnover markers was also genotype dependent. On the contrary, only TaqI and BsmI polymorphisms influenced raloxifene therapy, even only in lumbar spine BMD. These results point to the potential of using the VDR gene in personalized pharmacotherapy of osteoporosis.

Evaluation of Association Studies and an Updated Meta-Analysis of VDR Polymorphisms in Osteoporotic Fracture Risk

Background: Several studies have examined the association between vitamin D receptor (VDR) polymorphisms and osteoporotic fracture risk; however, the results are not uniform. Furthermore, many new articles have been published, and therefore, an updated meta-analysis was performed to further explore these issues.

Objectives: The aim of the study was to investigate the association between VDR, BsmI, ApaI, TaqI, FokI, and Cdx2 polymorphisms and osteoporotic fracture risk.

Methods: The odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the association between VDR BsmI, ApaI, TaqI, FokI, and Cdx2 polymorphisms and the risk of osteoporotic fracture. We also used the false-positive reporting probability (FPRP) test and the Venice criteria to evaluate the credibility of the statistically significant associations.

Results: Overall, this study found that the VDR ApaI and BsmI polymorphisms significantly increased the risk of osteoporotic fracture in European countries and America, respectively. However, when sensitivity analysis was performed after excluding low-quality and Hardy–Weinberg disequilibrium (HWD) studies, it was found that only individuals with the double-mutated genotype have an increased risk of osteoporotic fracture in European countries. In addition, when the credibility of the positive results was assessed, it was found that the positive results were not credible.

Conclusion: This meta-analysis indicates that there may be no significant association among the polymorphisms of VDR BsmI, ApaI, TaqI, FokI, and Cdx2 and the risk of osteoporotic fracture. The increased risk of osteoporotic fracture is most likely due to false-positive results.

Does the VDR gene polymorphism influence the efficacy of denosumab therapy in postmenopausal osteoporosis?

INTRODUCTION

One of the challenges of personalized medicine is a departure from traditional pharmacology toward individualized, genotype-based therapies. Postmenopausal osteoporosis is a prevalent condition requiring intensive treatment, whose effects are measurable only after a long time, and the goal is bone fracture prevention. This study aimed to determine the influence of VDR gene variation on anti-osteoporotic one-year treatment with denosumab in 63 Polish women with postmenopausal osteoporosis.

MATERIALS AND METHODS

The correlation between bone mineral density (BMD) of the lumbar vertebral column (L1-L4) and femoral neck, and genotype distributions for the ApaI, BsmI, FokI, and TaqI variants of the VDR gene was analyzed. Bone fractures during denosumab therapy were also investigated.

RESULTS

In the case of the Bsml polymorphism, female patients with BB and Bb genotypes had statistically significantly higher values of BMD and T-score/Z-score indicators, which persisted after a year of denosumab treatment. Our results indicated that the Bsml polymorphism contributes to better bone status, and, consequently, to more efficient biological therapy. The study did not reveal significant differences between changes (delta) in BMD and genotypes for the analyzed VDR gene loci. In the entire study group, one bone fracture was observed in one patient throughout the yearlong period of denosumab therapy.

CONCLUSIONS

BB and Bb genotypes of the Bsml polymorphism of the VDR gene determine higher DXA parameter values both before and after one-year denosumab therapy in postmenopausal women with osteoporosis.

Vitamin D, Vitamin D Receptor (VDR) Gene Polymorphisms (ApaI and FokI), and Bone Mineral Density in Patients With Inflammatory Bowel Disease

In the etiology of inflammatory bowel disease (IBD) and osteoporosis, the connecting element is the involvement of environmental and genetic factors. Vitamin D receptor (VDR) gene polymorphisms may be associated with the pathogenesis of IBD and bone mineral density (BMD). The study aimed to analyze the relationship between ApaI and FokI polymorphisms of the VDR gene, serum vitamin D concentration, and BMD in patients with IBD. The studied group consisted of 172 patients (85 with Crohn's disease [CD], 87 with ulcerative colitis [UC], and 39 healthy subjects - control group [CG]) were examined. Lumbar spine densitometry (L1-L4) and the femoral neck (FN) measurements were performed using dual-energy X-ray absorptiometry (DXA). Serum concentrations of 25-hydroxyvitamin D were determined using electrochemiluminescence binding assay (ECLIA). Polymorphisms were determined with polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). . We found no statistically significant differences in vitamin D concentration between the 3 studied groups. CD patients who were FF homozygotes had significantly lower FN BMD than FF homozygous from CG (p-value < 0.05). CD patients who were Aa heterozygotes had significantly lower lumbar spine (L2-L4) BMD than Aa heterozygotes from CG (p-value < 0.05). Among patients with the same polymorphic variants, but belonging to different studied groups, statistically significant differences in bone mineral density in the lumbar spine and the closer end of the femoral neck were observed. We consider that it is the disease entity, not the polymorphism variant, may have a decisive impact on BMD.

Vitamin D receptor Bsm I polymorphism and osteoporosis risk in postmenopausal women: a meta-analysis from 42 studies

OBJECTIVE

This study aimed to quantitatively summarize the evidence for VDR BsmI gene polymorphism and osteoporosis risk in postmenopausal women.

MATERIALS AND METHODS

The PubMed, EMBASE, Weipu, CNKI, and Wanfang databases were searched for eligible studies. Case-control studies containing available genotype frequencies of B/b were chosen, and odds ratio (OR) with 95% confidence interval (CI) was used to assess the strength of this association.

RESULTS

4485 osteoporosis and 5490 controls were identified in our meta-analysis. In the stratified analysis, a significant association was observed between VDR BsmI gene polymorphism and osteoporosis susceptibility in Caucasians (additive model: OR = 0.809, 95% CI 0.678~0.965, p = 0.019; recessive model: OR = 0.736, 95% CI 0.568~0.955, p = 0.021; and co-dominant model: bb vs. BB OR = 0.701, 95% CI 0.511~0.962 p = 0.028), and we failed to find any significant relationship in Asians.

CONCLUSION

The present meta-analysis suggests that VDR BsmI genotype is associated with increased risk of postmenopausal osteoporosis in Caucasians but not in Asians. To draw comprehensive and true conclusions, further prospective studies with larger numbers of participants worldwide are needed to examine associations between VDR BsmI polymorphism and osteoporosis in postmenopausal women.

Association of Vitamin D Gene Polymorphisms and Bone Mineral Density in Healthy young Saudi Females

BACKGROUND

Osteoporosis is a systemic skeletal disease characterized by low bone mineral density. Vitamin D metabolism may play a pivotal role in its pathophysiology.

OBJECTIVES

To determine the association between Vitamin D receptor gene polymorphisms and bone density, as well as its relation to biochemical markers of bone turnover, in a healthy Saudi female population.

METHODS

A cross-sectional study was carried out at Taibah University, Madinah Region, Kingdom of Saudi Arabia. After receiving informed consent, blood samples from 300 subjects were collected to measure calcium, phosphorus, alkaline phosphatase, parathyroid hormone osteocalcin, and 1,25-OHD and perform genetic analysis of SNPs in vitamin D receptors (VDR) rs2228570, rs731236, and rs11568820.

RESULTS

There were significant differences between the CC, CT, and TT alleles of VDR rs2228570. Carrying the TT allele was associated with increased risks of decreased bone density and the presence of osteopenia with lower vitamin D3 levels (p≤0.001). The VDR rs731236 gene showed that CC allele carriers had significant risk of osteopenia. The AA genotype of rs11568820 showed lower levels of physical activity, bone mineral density, Z scores, serum osteocalcin, phosphorus, and parathyroid hormones.

CONCLUSION

The presence of the TT allele of the SNP rs2228570 of the VDR gene and the SNP rs731236 of the CC genotype was associated with the presence of osteopenia and decreased bone mineral density alongside malfunctions of vitamin D.

The association between vitamin D receptor FokI gene polymorphism and osteoporosis in postmenopausal women: a meta-analysis

OBJECTIVE

This study aimed to quantitatively summarize the evidence for vitamin D receptor (VDR) FokI gene polymorphism and osteoporosis risk in Caucasian and Asian postmenopausal women.

MATERIALS AND METHODS

The PubMed, EMBASE, Weipu, CNKI, and Wanfang databases were searched for eligible studies. Case-control studies containing available genotype frequencies for F/f were chosen, and the odds ratio (OR) with 95% confidence interval (CI) was used to assess the strength of this association.

RESULTS

In total, 3349 osteoporosis cases and 3202 controls were identified in our meta-analysis. In the stratified analysis, a significant association was observed between VDR FokI gene polymorphism and postmenopausal osteoporosis susceptibility in Asian subjects (additive model: OR = 1.529, 95% CI 1.053-2.219, p = 0.026; dominant model: OR 2.711, 95% CI 1.693-4.342 p < 0.001; co-dominant model: ff vs. FF, OR 2.796, 95% CI 1.439-5.433 p = 0.002), and we failed to find any significant relationship in Caucasian populations.

CONCLUSION

The present meta-analysis suggests that the VDR FokI genotype is associated with increased risk of osteoporosis in Asian women but not in Caucasian women. To draw comprehensive and true conclusions, further prospective studies with larger numbers of participants worldwide are needed to examine associations between VDR FokI polymorphism and osteoporosis.

Association between polymorphisms in GGPS1 and RANKL genes and postmenopausal osteoporosis in Romanian women

Objectives: This study aimed to assess the relationship between bone mineral density, fragility fractures, fracture risk and polymorphisms of two osteoporosis-candidate genes (GGPS1 and RANKL) in Romanian women with postmenopausal osteoporosis. Methods: An analytical, prospective, transversal, observational, case-control study on 364 postmenopausal women, of which 228 were previously diagnosed with osteoporosis, was carried out between June 2016 and August 2017 in Cluj Napoca, Romania. Clinical data and blood samples were collected from all study participants. Polymorphisms in GGPS1 and RANKL genes were genotyped using TaqMan SNP Genotyping assays, run on a QuantStudio 3 real-time PCR machine. Results: The CT genotype in GGPS1 rs10925503 was associated with significant lower bone mineral density values at lumbar spine and femoral neck sites and a higher fracture risk compared to controls. No significant association was found between genotypes of RANKL rs2277439 with bone mineral density or fracture risk compared to the healthy controls. Conclusions: Our study showed a strong association between low bone mineral density and genotype CT of GGPS1 rs10925503 polymorphisms. No association was found for RANKL rs2277439 polymorphism.

The interactions of physical activity, exercise and genetics and their associations with bone mineral density: implications for injury risk in elite athletes

Low bone mineral density (BMD) is established as a primary predictor of osteoporotic risk and can also have substantial implications for athlete health and injury risk in the elite sporting environment. BMD is a highly multi-factorial phenotype influenced by diet, hormonal characteristics and physical activity. The interrelationships between such factors, and a strong genetic component, suggested to be around 50-85% at various anatomical sites, determine skeletal health throughout life. Genome-wide association studies and case-control designs have revealed many loci associated with variation in BMD. However, a number of the candidate genes identified at these loci have no known associated biological function or have yet to be replicated in subsequent investigations. Furthermore, few investigations have considered gene-environment interactions-in particular, whether specific genes may be sensitive to mechanical loading from physical activity and the outcome of such an interaction for BMD and potential injury risk. Therefore, this review considers the importance of physical activity on BMD, genetic associations with BMD and how subsequent investigation requires consideration of the interaction between these determinants. Future research using well-defined independent cohorts such as elite athletes, who experience much greater mechanical stress than most, to study such phenotypes, can provide a greater understanding of these factors as well as the biological underpinnings of such a physiologically "extreme" population. Subsequently, modification of training, exercise or rehabilitation programmes based on genetic characteristics could have substantial implications in both the sporting and public health domains once the fundamental research has been conducted successfully.

Association of vitamin D receptor ApaI gene polymorphism with osteoporosis susceptibility in postmenopausal Han Chinese women in Xinjiang

Osteoporosis is a polygenic disorder and has been demonstrated to be associated with ~30 candidate genes, the majority of which have also been implicated in the regulation of bone mineral density (BMD). Vitamin D receptor (VDR) is the candidate gene that has been most extensively studied. Certain studies have reported that the VDR single nucleotide polymorphism ApaI is associated with the risk of osteoporosis in Caucasian and African women. However, this association has not yet been studied in postmenopausal Han Chinese women in the Xinjiang area. In the present study, ApaI polymorphisms of VDR were defined by polymerase chain reaction-restriction fragment length polymorphism, in order to analyze the distribution of ApaI polymorphisms in postmenopausal Han Chinese women from Xinjiang. BMD was measured by dual energy X-ray absorptiometry at the lumbar spine (L2-4), Ward's triangle, great trochanter and femoral shaft. A total of 336 women were included in this study. The genotype distribution of ApaI was consistent with the Hardy-Weinberg equilibrium (all P>0.05). There were no significant differences in ApaI genotype frequencies between the 90 cases in the osteoporosis group and 246 cases in the non-osteoporosis group (P=0.946). Meanwhile, it was identified that BMD values of the tested locations were negatively correlated with age (P<0.05) and positively correlated with body mass index (BMI; P<0.05). On further attribution risk analysis, BMD was identified as a risk factor [odds ratio (OR): 0.464, 95% confidence interval (CI): 0.372-0.580, P=0.001] and BMI a protective factor (OR: 1.502, 95% CI: 1.008-2.240, P=0.032) in osteoporosis. When BMD was adjusted for confounding factors including age and BMI, it was observed that the ApaI polymorphism was not associated with BMD at the sites tested (P>0.05). In conclusion, the present study identified no significant association of the common VDR polymorphism ApaI with BMD at several skeletal sites in postmenopausal Han Chinese women in the Xinjiang area. Age was negatively correlated with BMD at different sites and identified as a risk factor; while BMI was positively correlated with BMD and identified as a protective factor.

Clinical characteristics associated with bone mineral density improvement after 1-year alendronate/vitamin d3 or calcitriol treatment: Exploratory results from a phase 3, randomized, controlled trial on postmenopausal osteoporotic women in China

Baseline and on-treatment characteristics, including age, obesity, calcium intake, and bone turnover markers, may predict the bone mineral density (BMD) response in women with postmenopausal osteoporosis (PMO) to 1 to 2 years of antiresorptive therapy and/or vitamin D supplementation. This study aimed to explore clinical characteristics associated with 12-month BMD improvement in Chinese women with postmenopausal osteoporosis (PMO).In this post hoc analysis of a previous phase 3 multicenter, randomized controlled trial, Chinese PMO women who were treated with once weekly alendronate 70 mg/vitamin D3 5600 IU (ALN/D5600) or once daily calcitriol 0.25 mcg, and had measurements of 1-year lumbar spine BMD (LS-BMD) and on-treatment bone turnover markers (BTMs) were included in the analysis.In Chinese PMO patients on ALN/D5600, 1-year LS-BMD change was negatively correlated with age (β = -0.00084, P < .01), dietary calcium (β = -0.0017, P = .07), and procollagen type 1 N-terminal propeptide (P1NP) change at month 6 (β = -0.000469, P = .0016), but positively with body mass index (BMI) (β = 0.00128, P = .08); baseline P1NP above the median was associated with a significantly greater BMD percentage change at the lumbar spine (P = .02) and the total hip (P = .0001). In the calcitriol group, a significant 1-year LS-BMD increase was associated with BMI (β = 0.0023, P = .02), baseline P1NP (β = 0.00035, P = .0067), history of prior vertebral fracture(s) (β = 0.034, P < .0001) and baseline serum 25(OH)D level (β = -0.00083, P = .02).The presented findings from Chinese postmenopausal osteoporotic women suggested clinically meaningful baseline and on-treatment characteristics predicting BMD improvement after 1 year of ALN/D5600 treatment, which differed from calcitriol treatment with baseline identifiable associations. The study remained exploratory and further accumulation of evidence is needed.

Effects of genetic variants on serum parathyroid hormone in hyperparathyroidism and end-stage renal disease patients: A systematic review and meta-analysis

BACKGROUND

Parathyroid hormone (PTH) is one of the principal regulators of calcium homeostasis, crucial for normal functioning of the kidneys, bones, heart, and nervous system. Different pathologic conditions can affect serum PTH level resulting in hyperparathyroidism or hypoparathyroidism. Our study assessed the association of previously reported polymorphisms with the level of PTH (expressed in pg/mL) among individuals with different pathologic conditions affecting PTH level.

METHODS

We searched Web of Science, MEDLINE, and Scopus to identify relevant articles published up to July 2017. The search yielded 6967 publications of which 44 fulfilled the inclusion criteria. We conducted meta-analyses for calcium-sensing receptor gene (CaSR) rs1801725 polymorphism in patients with primary hyperparathyroidism and vitamin D receptor gene (VDR) rs1544410 polymorphism in patients with end-stage renal disease (ESRD).

RESULTS

None of the polymorphisms were significantly associated with PTH levels in the overall population. In subgroup analysis by ethnicity for VDR rs1544410 gene polymorphism, we found significant differences under dominant model (SMD: -0.18 [-0.32, -0.05], P < .01) and AA versus GG comparison (SMD: -0.29 [-0.52, -0.06], P < .01) in Asian patients with ESRD, while nominally significant results (P < .05) were observed for AG versus GG and AA versus GG comparisons in European individuals with ESRD.

CONCLUSION

Scientific evidence of genetic association of serum PTH level among individuals with different pathologic conditions remains deficient and published results provide weak evidence. Further well-conducted studies on larger sample sets designed according to evidence-based principles are warranted to assure clinically applicable findings.

Associations between VDR Gene Polymorphisms and Osteoporosis Risk and Bone Mineral Density in Postmenopausal Women: A systematic review and Meta-Analysis

Results on the relationships between vitamin D receptor (VDR) gene polymorphisms and postmenopausal osteoporosis (PMOP) susceptibility and bone mineral density (BMD) are conflicting. The aim of the study is to identify more eligible studies that calculated pooled OR and WMD with 95% CI to assess their associations. Overall, there were significant correlations between VDR ApaI, VDR FokI and PMOP susceptibility. Subgroup analysis showed that VDR ApaI polymorphism significantly decreased the osteoporosis risk in Caucasian postmenopausal women. In Asian populations, VDR BsmI and VDR FokI were associated with an increased risk of PMOP. As to the associations between VDR polymorphisms and BMD, Caucasian PMOP women carrying the ApaI aa genotype were at risk of high BMD in femoral neck, and low femoral neck BMD was observed in Caucasian PMOP women with FokI Ff genotype. PMOP women with the Cdx2 GA genotype had a lower lumbar spine BMD in overall and Caucasian populations compared with PMOP women with GG genotype. Different VDR gene polymorphisms have different impacts on PMOP risk and BMD.

Effect of zoledronic acid therapy on postmenopausal osteoporosis between the Uighur and Han population in Xinjiang: An open-label, long-term safety and efficacy study

WHAT IS KNOWN AND OBJECTIVE

Postmenopausal osteoporosis is becoming an urgent health problem in China. A once-yearly infusion of zoledronic acid can be very effective for the treatment of postmenopausal osteoporosis in significantly reducing the risk of hip, vertebral and other fractures. This study aimed to investigate zoledronic acid treatment on postmenopausal osteoporosis in Uighur and Han patients in Xinjiang province, China.

METHODS

A self-controlled and prospective trial design was adopted. A total of 155 Uighur and 151 Han patients were enrolled. All subjects received an intravenous infusion of zoledronic acid (5 mg) at day 0 (baseline) and at 12 months. Patients were followed up for 24 months; the bone mineral density (BMD) of the left total hip and L1-L4 vertebrae was measured at day 0 and at 24 months.

RESULTS AND DISCUSSION

BMD was significantly higher after zoledronic acid treatment compared with baseline levels in all patients, as assessed at 24 months. Moreover, the BMD of left total hip increased with 2.7% in the Han group was significantly higher than that of the Uighur group with 1.4% (left total hip, 95% CI: 2.6% to 2.8% in Han group vs 1.2% to 1.4% in Uighur group). The BMD of L1-L4 vertebrae increased with 2.2% in the Han group was significantly higher than that of the Uighur group with 1.6% (L1-L4 vertebrae, 95% CI, 2.0% to 2.4% in Han group vs 1.4% to 1.7% in Uighur group); P < .001. There was no significant difference in drug-related adverse effects between the two groups (P > .05).

WHAT IS NEW AND CONCLUSION

Zoledronic acid appears to be more effective in postmenopausal osteoporosis in Han than in Uighur subjects. The reasons for this require further investigation.

The relationship between vitamin D receptor (VDR) polymorphism and the occurrence of osteoporosis in menopausal Iranian women

BACKGROUND

Osteoporosis, a multifactorial disease with reduced bone mineral density which increases the probability of bone fractures, is caused by calcium deficiency, and its incidence increases with age. It has been determined that mutations in functional regions of vitamin D receptor gene will affect the metabolism of minerals especially calcium and, therefore, bone density. The present study evaluates the relation between vitamin D receptor polymorphisms, TaqI (rs731236) and ApaI (rs7975232), and osteoporosis in menopausal Azari women in Zanjan province.

MATERIALS AND METHODS

This case-control study has been conducted on 50 menopausal women suffering from osteoporosis and 50 menopausal women who did not suffer from osteoporosis in Zanjan province. The diagnosis of osteoporosis was confirmed using DEXA instrument. Peripheral blood was collected from the subjects and controls to extract DNA and assess the ApaI and TaqI polymorphisms using PCR-RFLP method. The results were interpreted using independent T-test, chi-square, and Pearson correlation coefficient with a p-value less than 0.05.

RESULTS

There was not a significant difference between the frequency of ApaI (AA/Aa/aa) and TaqI (TT/Tt/tt) genotypes in cases (mean age 68.72) and controls (mean age 64.7) (p=0.37 and p=0.64, respectively). In addition, ApaI/TaqI allele haplotype in osteoporotic population showed non-significant relation (p value=0.563) compared with the control group.

DISCUSSION AND CONCLUSION

The relationship between the genotypes and osteoporosis, cancers, and mineral metabolism disorders has been studied for a long time. Although there has been a significant relation between the aforementioned genotypes and osteoporosis or reduced mineral density-related bone fractures in some studied, some other studies have opposing results. Therefore, it is only possible to reach an acceptable conclusion by studying the haplotype of the polymorphisms in subjects.

Targeted next generation sequencing of the entire vitamin D receptor gene reveals polymorphisms correlated with vitamin D deficiency among older Filipino women with and without fragility fracture

This study aimed to discover genetic variants in the entire 101 kB vitamin D receptor (VDR) gene for vitamin D deficiency in a group of postmenopausal Filipino women using targeted next generation sequencing (TNGS) approach in a case-control study design. A total of 50 women with and without osteoporotic fracture seen at the Philippine Orthopedic Center were included. Blood samples were collected for determination of serum vitamin D, calcium, phosphorus, glucose, blood urea nitrogen, creatinine, aspartate aminotransferase, alanine aminotransferase and as primary source for targeted VDR gene sequencing using the Ion Torrent Personal Genome Machine. The variant calling was based on the GATK best practice workflow and annotated using Annovar tool. A total of 1496 unique variants in the whole 101-kb VDR gene were identified. Novel sequence variations not registered in the dbSNP database were found among cases and controls at a rate of 23.1% and 16.6% of total discovered variants, respectively. One disease-associated enhancer showed statistically significant association to low serum 25-hydroxy vitamin D levels (Pearson chi-square P-value=0.009). The transcription factor binding site prediction program PROMO predicted the disruption of three transcription factor binding sites in this enhancer region. These findings show the power of TNGS in identifying sequence variations in a very large gene and the surprising results obtained in this study greatly expand the catalog of known VDR sequence variants that may represent an important clue in the emergence of vitamin D deficiency. Such information will also provide the additional guidance necessary toward a personalized nutritional advice to reach sufficient vitamin D status.

Lack of association between vitamin D receptor polymorphisms ApaI (rs7975232) and BsmI (rs1544410) and osteoporosis among the Han Chinese population: A meta-analysis

In this study, we aimed to assess the relationship between vitamin D receptor gene polymorphisms and osteoporosis in the Han Chinese population. Articles regarding associations between vitamin D receptor polymorphisms (ApaI rs7975232 and BsmI rs1544410) and osteoporosis were retrieved from databases in November 2014. Eligible studies were tested by the Hardy-Weinberg equilibrium. The odds ratio and 95% confidence interval (95% CI) were analyzed to evaluate the strength of the associations. Pooled effect estimates were derived using a fixed-effect model and a random-effect model according to the heterogeneity of the test results. A subgroup analysis by study type and a sensitivity analysis based on studies that conform to the Hardy-Weinberg equilibrium and studies with postmenopausal women as participants were performed. This meta-analysis involved 15 eligible studies including 1580 cases and 1389 controls. The pooled estimated odds ratios in the dominant and additive genetic models were 0.73 (95% CI: 0.46-1.14, p=0.17) and 1.01 (95% CI: 0.77-1.33, p=0.81), respectively, for rs7975232 and 1.01 (95% CI: 0.81-1.26, p=0.91) and 1.01 (95% CI: 0.77-1.33, p=0.92), respectively, for rs1544410. The subgroup analysis showed that regardless of the dominant or additive genetic model, the effect of pooled odds ratios for rs7975232 and rs1544410 was insignificant. The sensitivity analysis also showed that the pooled effect was not significantly changed. In conclusion, no evidence of association is apparent between polymorphisms of vitamin D receptor genes and osteoporosis risk in the Han Chinese population.

Osteoporosis in liver disease: pathogenesis and management

Osteoporosis affects a substantial proportion of patients with chronic liver disease. Pathologic fracture in osteoporosis significantly affects quality of life and life expectancy. By some estimates, 40% of patients with chronic liver disease may experience osteoporotic fracture. In this study we review the pathogenesis, diagnosis and treatment of specific liver disease entities and their relation to osteoporosis.

BsmI, ApaI and TaqI Polymorphisms in the Vitamin D Receptor Gene (VDR) and Association with Lumbar Spine Pathologies: An Italian Case-Control Study

Three adjacent single nucleotide polymorphisms of the vitamin D receptor gene (VDR) BsmI (rs1544410), ApaI (rs7975232), and TaqI (rs731236) are commonly studied in several pathologies. We aimed to evaluate the distribution of VDR BsmI, ApaI, and TaqI allele, genotype, and haplotype frequencies in an Italian cohort of 266 patients with lumbar spine disorders assessed by Magnetic Resonance Imaging and 252 asymptomatic controls. The exposure to putative risk factors was evaluated by a questionnaire. Polymorphisms were detected by PCR-RFLP and TaqMan^® SNP Genotyping Assay. The results were statistically adjusted for the identified conventional risk factors. The three SNPs were in linkage disequilibrium. For all cases BbAaTT was a 3-fold risk factor OR = 3.38), whereas bbAATT (OR = 0.22), and bbaaTT (OR = 0.47) genotypes were found to be protective. Specifically, for patients affected by disc herniation only (n = 88) and all lumbar pathologies excluding stenosis and/or spondylolistesis (n = 215) B allele, Bb, Aa, and BbAaTT genotypes were risky, whereas b allele, bb, aa, and bbaaTT genotypes were protective. In patients affected by osteochondrosis with or without disc hernation (n = 50), T allele, Aa, and bbAaTT genotypes were risky, whereas t allele, AA, tt genotypes were protective. In patients affected by stenosis and/or spondylolistesis (n = 51) no significant associations were found. This is the first study showing an association of the three genetic VDR variants BsmI, ApaI, and TaqI and lumbar spine pathologies. Our study contributes to delineate genetic risk factors for specific subgroups of patients with lumbar spine pathologies highlighting the importance of haplotype analysis, and of detailed clinical evaluation of the patients for identification of genetic biomarkers.

Association analysis of the COL1A1 polymorphism with bone mineral density and prevalent fractures in Polish postmenopausal women with osteoporosis

INTRODUCTION

Polymorphism in the promoter region of collagen type 1α (COL1A1) +1245G/T (Sp1, rs1800012) was in some studies shown to be relevant for bone mineral density (BMD) and low-energy fracture prediction. The aim of the study was to confirm this finding in a group of postmenopausal women diagnosed with osteoporosis.

MATERIAL AND METHODS

We investigated 311 Caucasian women (mean age: 65.2 ±9.39 years) either after low-energy fractures (regardless of the location) or meeting World Health Organization (WHO) criteria for osteoporosis. All patients underwent clinical examination in order to exclude secondary osteoporosis; hip and lumbar spine DEXA was performed (Lunar). The three genotypes of Sp1 polymorphism were determined by RFLP (restriction fragment length polymorphism).

RESULTS

Distribution of COL1A1 genotypes (SS/Ss/ss) agreed with Hardy-Weinberg equilibrium. No relation between COL1A1 genotypes and hip/L1-L4 BMD was found. Fractures were reported in 26.3% of women. Prevalence of low-energy fractures, regardless of the type, was 50.0% in ss genotype carriers, 26.4% in SS homozygotes and 23.7% in Ss heterozygotes. There was no statistically significant recessive or dominant effect of any Sp1 genotype on fracture prevalence (p = 0.613).

CONCLUSIONS

We failed to observe that COL1A1 Sp 1 genotypes contribute to BMD determination or are associated with prevalent low-energy fractures in a Polish cohort of postmenopausal osteoporotic women.

Serum amyloid a gene polymorphism and its association with lipid profile in Saudi females with osteoporosis

Background and Objective:

Osteoporosis can be defined as a systemic skeletal disease characterized by low bone mass and micro architectural decline of bone tissue. Serum amyloid A (SAA) is a family of protein that increases up to 1,000-fold in blood during inflammation. In this study, we aimed to study the relationship between SAA1 gene polymorphism (rs12218) and lipid profile and osteoporosis.

Methods:

The study was performed on the female students of Taibah University in Al Medina, KSA during June 2014 to April 2015. According to BMD; osteoporosis group (138 students) and control group (128 students). All groups were subjected to; BMI, BMD, calcium, phosphorus, creatinine, lipid profile and SAA. Polymerase chain reaction and Real Time were done to determine the distribution of allele and genotype frequency of SAA (rs12218) C/T polymorphism.

Results:

This study shows that the TT genotype of rs12218 was more frequent in osteoporosis group than control group (P<0.001). Also, TT genotype and T allel was found to be associated with plasma total cholesterol, TG, LDLc, HDLc, Tscore, Zscore and SAA1 level in osteoporosis group (P=0.000, P=0.05, and P=0.000, P=0.000, P=0.01, P=0.02, P=0.000 respectively). The logistic regression analysis with and without lipid disorders in the osteoporosis group also show that the TT genotype of rs12218 still differed significantly between these two groups (P=0.001, OR=1.814, 95% CI: 0.719-4.577).

Conclusion:

The results of this study shows a significant association between TT genotype of rs12218 and both lipid level and osteoporosis in Saudi female population.

Association between vitamin D receptor polymorphisms and osteoporosis in patients with COPD

BACKGROUND

Patients with COPD are at an increased risk of osteoporosis. Although many studies have addressed the relationship between the vitamin D receptor (VDR) polymorphisms and bone health, this relationship has not been fully investigated in patients with COPD. In this study, we investigated the association of VDR polymorphisms with bone mineral density (BMD) and other clinical parameters in patients with COPD.

PATIENTS AND METHODS

In total, 200 patients with COPD were included in this study. The VDR polymorphisms rs1544410 (A/G-BsmI), rs7975232 (A/C-ApaI), rs731236 (C/T-TaqI), and rs10735810 (C/T-FokI) were determined by Sanger sequencing using blood DNA samples. BMD of the lumbar vertebra and the femoral neck was measured by dual-energy X-ray absorptiometry. Other clinical parameters were also evaluated. Haplotype and multivariate analyses were also performed.

RESULTS

Sex, body mass index, steroid use, percentage of forced expiratory volume in 1 second (FEV1), alkaline phosphatase, and 25-hydroxyvitamin D significantly influenced the risk of osteoporosis. Patients with osteoporosis were more likely to carry the rs7975232 C allele compared to normal patients with BMD. Haplotypes GCT and GAT were related to osteoporosis. Patients without the haplotype GAT allele showed a significantly lower T-score at the femoral neck and an increased risk of osteoporosis (odds ratio [OR]= 2.78, 95% confidence interval [CI]= 1.20-6.48, P=0.018) compared with carriers in the dominant model.

CONCLUSION

Genetic variations in VDR are significantly associated with osteoporosis among patients with COPD. Further studies are required to confirm the role of the VDR polymorphisms in osteoporosis among patients with COPD.

Lack of association of vitamin D receptor BsmI gene polymorphism with bone mineral density in Spanish postmenopausal women

Osteoporosis is a polygenic disorder that is determined by the effects of several genes, each with relatively modest effects on bone mass. The aim of this study was to determine whether the vitamin D receptor single nucleotide polymorphism BsmI is associated with bone mineral density (BMD) in Spanish postmenopausal women. A total of 210 unrelated healthy postmenopausal women aged 60 ± 8 years were genotyped using TaqMan^® SNP Genotyping Assays. Lumbar and femoral BMD were determined by dual-energy X-ray absorptiometry (DEXA). Daily calcium and vitamin D intake were determined by a food questionnaire. No differences were found in the femoral neck, trochanter, Ward’s Triangle, L2, L3, L4, L2-L4, or between the femoral neck and total hip BMD after further adjustment for potential confounding factors (P > 0.05) (age, BMI, years since menopause and daily calcium intake). The BsmI polymorphism in the VDR gene was not associated with BMD in Spanish postmenopausal women.

Polymorphism of vitamin D3 receptor and its relation to mineral bone density in perimenopausal women

Postmenopausal osteoporosis is the most common metabolic bone disease with important genetic factors. We evaluated the frequency of polymorphism 283G/A of the vitamin D3 VDR gene receptor. The study included 800 women at the postmenopausal (505) and reproductive (295) age. Statistically significant changes, depending on the genotype, were shown.

INTRODUCTION

Postmenopausal osteoporosis is the most common metabolic bone disease of strong genetic origin with population variability determined by the interaction of genetic and environmental factors. Recognition of different genetic variants underlying development of osteoporosis would make it possible to administer individual symptomatic treatment as well as early prophylactics of osteoporosis.

METHODS

The aim of the study was to evaluate the frequency of polymorphism 283G/A of the vitamin D3 VDR gene receptor and assessment of its relations with the clinical parameters of osseous turnover and degree of postmenopausal osteoporosis. The study included 800 women at the postmenopausal (505) and reproductive (295) age throughout the Wielkopolska region in Poland. The postmenopausal group included women with osteoporosis and osteopenia and the healthy ones. Women at the reproductive age were healthy. Frequency of the tested gene polymorphism was evaluated in the group where bone mineral density (BMD) was marked and in the control group.

RESULTS

The obtained test results pointed to correlation of polymorphism VDR 283G/A with the BMD scores for the lumbar vertebrae in women with osteopenia and osteoporosis, therefore the ones at risk of fractures. Vitamin D receptor (VDR) polymorphism correlated with reduced BMD values.

CONCLUSIONS

Polymorphism 283G/A of the vitamin D3 receptor gene has been proved to be the genetic factor of postmenopausal osteoporosis. The polymorphism mentioned above has been proved to be a factor of mineral bone density changes of women.

Polymorphisms in VDR gene in Tunisian postmenopausal women are associated with osteopenia phenotype

OBJECTIVES

Osteopenia is characterized by intermediate values of bone mineral density (BMD) as compared to normal and osteoporotic subjects. BMD, a surrogate phenotype for osteoporosis, is influenced in part by genetic factors. Among the genes associated with BMD, the vitamin D receptor (VDR) was the first gene studied as a potential candidate associated with BMD in adult and postmenopausal bone loss. However, results are controversial.

METHODS

To determine whether VDR polymorphisms ApaI and TaqI are associated with BMD, osteopenia, osteoporosis and low-impact fracture risk in North Africans, these genotypes were analyzed in 566 postmenopausal Tunisian women.

RESULTS

In postmenopausal Tunisian women, the GT ApaI genotype seems to be protective against osteoporosis development (p = 0.02; odds ratio = 0.54). Moreover, the presence of the combined GT/TT genotype of ApaI and TaqI polymorphisms is more frequent in normal BMD women than in osteoporotic women (p = 0.00; odds ratio = 0.41). Interestingly, the GG ApaI genotype is associated with osteopenia development (p = 0.02; odds ratio = 1.86) and also the TT TaqI polymorphism (p = 0.02; odds ratio = 1.53). The GG ApaI genotype is associated with a three times risk of vertebral fracture.

CONCLUSIONS

The ApaI polymorphism showed an association with osteopenia and low-impact vertebral fracture incidence but not with osteoporosis. The TaqI polymorphism is associated specifically with the osteopenia phenotype. The presence of the two polymorphisms increases the risk to develop osteopenia in postmenopausal Tunisian women. Osteopenia seems to be genetically determined. However, osteoporosis is the result of interaction between genetic and environmental factors.

The influence of vitamin D receptor genetic variants on bone mineral density and osteoporosis in Chinese postmenopausal women

Growing evidence indicates that the vitamin D receptor (VDR) gene is an important candidate gene for influencing the development of osteoporosis. The aim of the study was to evaluate the potential association between genetic variants of VDR gene and bone mineral density (BMD) and osteoporosis in Chinese postmenopausal women. The study included 970 Chinese postmenopausal women at the postmenopausal osteoporosis (482) and healthy controls (488). The BMD of lumbar spine (L_2–4 anterior-posterior view), femoral neck hip, and total hip was evaluated using the Norland XR-46 dual energy X-ray absorptiometry (DEXA). The genotypes of VDR genetic variants were determined by the created restriction site-PCR (CRS-PCR) and confirmed by DNA sequencing methods. Our data indicated that the VDR p.Glicine (Gly)14 alanine (Ala) and p.histidine (His) 305 glutanine (Gln) genetic variants were statistically associated with adjusted femoral neck hip BMD, adjusted lumbar spine BMD, and adjusted total hip BMD (P values < 0.05). Results from this study suggest that the VDR p.Gly14Ala and p.His305Gln genetic variants are significantly associated with BMD decrease in Chinese postmenopausal women and might be used as molecular markers for assessing the risk of BMD and osteoporosis.

VDR polymorphisms are associated with bone mineral density in post-menopausal Mayan-Mestizo women

BACKGROUND

Osteoporosis is characterized by low bone mineral density (BMD), which is determined by an interaction of genetic, metabolic and environmental factors.

AIM

To analyse the association between two polymorphisms of VDR as well as their haplotypes with BMD in post-menopausal Maya-Mestizo women.

SUBJECTS AND METHODS

This study comprised 600 post-menopausal Maya-Mestizo women. A structured questionnaire for risk factors was applied and BMD was assessed at the lumbar spine (LS) and total hip (TH) by dual-energy X-ray absorptiometry. DNA was extracted from blood leukocytes. Two single-nucleotide polymorphisms of VDR (rs731236 and rs2228570) were studied using real-time PCR allelic discrimination for genotyping. Differences between the means of the BMDs according to the genotype were analysed with covariance. Haplotype analysis was conducted.

RESULTS

TT genotype of rs731236 of VDR had higher BMD at total hip and femoral neck (FN), and one haplotype formed by the two polymorphisms was associated with only TH-BMD variations. This difference was statistically significant after adjustment for confounders. The genotype of rs2228570 of VDR analysis showed no significant differences with BMD variations.

CONCLUSION

The results showed that the TT genotype of rs731236 of VDR and one haplotype formed by rs731236 and rs2228570 polymorphisms were associated with higher BMD at TH and FN.

Vitamin D receptor gene polymorphisms and risk of osteoarthritis: A meta-analysis

The vitamin D receptor (VDR) gene polymorphisms have been reported to be involved in the development of many musculoskeletal disorders, including osteoarthritis (OA). However, results were inconsistent and there is no definite conclusion regarding the association between any VDR polymorphism and the risk of OA. In this study, we conducted a meta-analysis to determine whether BsmI, TaqI, and ApaI polymorphisms in the VDR gene are associated with OA susceptibility. Literature research was performed using PubMed and EMBASE databases. Studies illustrating the association between the three VDR polymorphisms and OA were included, and their qualities were assessed using Newcastle–Ottawa scale. Eight eligible studies, recruiting 1626 cases and 2024 controls were identified. Their methodological qualities were generally good, with scores ranging from 6 to 8 points. However, throughout all summary analyses, which were performed for multiple categories and on four contrasts (allele contrast, contrast of homozygotes, recessive and dominant models), none of the VDR BsmI, TaqI, and ApaI gene polymorphisms were found to be significantly associated with the risk of OA. On the other hand, there was no significant publication bias. Results from this meta-analysis suggested that the VDR BsmI, TaqI, and ApaI gene polymorphisms might not be important predictors of OA. More studies further investigating these associations, especially taking into account of gene–gene, gene–environment interactions, and other confounding factors are warranted.

Vitamin D receptor gene and risk of fracture in postmenopausal women: a meta-analysis

OBJECTIVE

Fracture is the major clinical outcome of osteoporosis. The vitamin D receptor (VDR) gene is thought to be a candidate gene for osteoporosis. Many genetic studies have suggested an association of VDR polymorphisms and fracture risk, but evidence remains conflicting. The aim of this study was to evaluate the genetic effect of the BsmI, TaqI, ApaI and FokI polymorphisms in the VDR gene on fracture risk in postmenopausal women.

METHODS

Relevant studies were identified from the following electronic databases: PubMed, Embase, and Web of Science before September 2013. Statistical analysis was performed by using the software STATA 12.0. A total 1975 fracture cases and 4565 controls in 14 studies with a total of 16 eligible comparisons were identified for data analysis.

RESULTS

No evidence of relationship between the VDR BsmI, TaqI, ApaI or FokI polymorphisms and fracture risk was observed with any genetic model in postmenopausal women (BsmI: b vs. B: odds ratio (OR) 1.07, 95% confidence interval (CI) 0.90-1.29; TaqI: T vs. t: OR 0.89, 95% CI 0.68-1.15; ApaI: A vs. a: OR 0.91, 95% CI 0.76-1.08; FokI: F vs. f: OR 1.20, 95% CI 0.76-1.90).

CONCLUSION

This meta-analysis suggests that ApaI, BsmI, TaqI and FokI polymorphisms may be not associated with the risk of fracture in postmenopausal women. Further studies in a larger sample population are required to confirm this finding.

The relationship between osteoprotegerin gene polymorphisms and bone mineral density in Chinese postmenopausal women

Previous evidence supports that the osteoprotegerin (OPG) gene is one of the most important candidate genes for influencing the pathogenesis of osteoporosis. The objective of this study was to investigate the relationship between OPG gene polymorphisms and osteoporosis in Chinese postmenopausal women. A total of 764 subjects were included in this study. The bone mineral density (BMD) in the lumbar spine (L2-4), neck hip and total hip was determined by dual-energy X-ray absorptiometry (DEXA). The g.19190C>A and g.25602A>G SNPs were detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), created restriction site PCR (CRS-PCR) and DNA sequencing methods. As for g.19190C>A, our data suggested that the BMD value of lumbar spine (L2-4), neck hip and total hip for subjects with CC genotype was significantly higher than that of CA and AA genotypes (P<0.05). No significant difference was detected between the association of g.25602A>G genotypes with spine BMD and neck hip BMD, while total hip BMD almost reached the significant level (P=0.063). These findings provide more evidence that the SNPs in OPG gene could affect BMD and osteoporosis, and the allele-A of g.19190C>A and allele-G of g.25602A>G genetic variants are associated with increased risk for osteoporosis in Chinese postmenopausal women.

Association between osteoprotegerin genetic variants and bone mineral density in Chinese women

Osteoprotegerin gene (OPG) is one of the most important candidate genes for osteoporosis. The aim of this study was to assess the association between the single nucleotide polymorphisms (SNPs) of OPG gene and bone mineral density (BMD). A total of 706 Chinese postmenopausal women were enrolled in this study. OPG gene variants were genotyped through created restriction site-polymerase chain reaction (CRS-PCR) and verified using DNA sequencing methods. The lumbar spine (L2-4), total hip and femoral neck were evaluated for BMD. Two genetic variants (g.18910G>A and g.27406C>T) were detected in this study. Our data indicated that the significant differences of spine BMD, neck hip BMD and total hip BMD were detected among different g.27406C>T genotype, subjects with the genotype CC were significantly higher than those of genotype CT and TT. However, the g.18910G>A polymorphism was not significantly associated with spine BMD, neck hip BMD and total hip BMD in the studied subjects. Results from this study indicated that OPG gene variants were associated with BMD in Chinese postmenopausal women. These findings will be useful to analyze the role of OPG gene in osteoporosis in the further studies.

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.

Association between osteoprotegerin genetic variants and osteoporosis in Chinese postmenopausal women

The objective of this study was to evaluate the association of single nucleotide polymorphisms (SNPs) of osteoprotegerin gene (OPG) with bone mineral density (BMD) and osteoporosis. A total of 338 Chinese postmenopausal women with primary osteoporosis and 367 healthy controls were enrolled. The lumbar spine (L₂₋₄), total hip and femoral neck hip of BMD were assessed by dual-energy X-ray absorptiometry (DEXA). OPG genetic variants were genotyped through polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), created restriction site-PCR (CRS-PCR) and DNA sequencing methods. In this study, the g.18861A>G and g.25548C>T SNPs were detected and our data suggested that the significant differences of spine BMD, femoral neck hip BMD and total hip BMD were found among different g.18861A>G genotype, subjects with the AA genotype were significantly higher than those of AG and GG genotypes (p < 0.05). The g.25548C>T variant was not significantly associated with spine BMD, femoral neck hip BMD and total hip BMD (p > 0.05), while almost reached at the significant level in total hip BMD (p = 0.061). These findings suggeste that OPG gene variants are related to BMD and osteoporosis in Chinese postmenopausal women.

Association between Vitamin D Receptor Gene BsmI Polymorphism and Bone Mineral Density in A Population of 146 Iranian Women

OBJECTIVE

Osteoporosis is a bone disorder that reduces bone mineral density (BMD) and leads to bone fracture. In addition to different factors, gene polymorphisms have been revealed to be associated with osteoporosis. In this study, we investigated the association between the BsmI polymorphism of vitamin D receptor (VDR) gene (rs1544410) and BMD in a population of Iranian women.

MATERIALS AND METHODS

In this case control study, clinical risk factors for osteoporosis were obtained from the participants through a questionnaire for a case-control study. The World Health Organisation (WHO) criteria were applied for the diagnosis of the disease. Peripheral blood samples were obtained from 146 pre- and or postmenopausal Iranian women aged between 35 and 71 years (53.53 ± 9.8). The study population was classified for BMD into normal and osteoporotic groups, who matched for age, pregnancy status, menstrual condition, and body mass index (BMI). The BMD of the lumbar spine (L1-4) and femoral neck was measured. Polymerase chain reactionrestriction fragment length polymorphism (PCR-RFLP) was performed to detect and analyze the genotype.

RESULTS

The frequencies of AA and GG were significantly different between the two groups (p value<0.05), with the first genotype being higher in the patients and the second being higher in the normal group. The GG genotype was significantly associated with increased BMD in the lumbar spine (p value<0.05) but non-significant in the femoral neck (p value>0.05).

CONCLUSION

BsmI polymorphism of VDR gene has a significant association with BMD in the lumbar spine and may have a minor effect on the proximal femur BMD in Iranian women.