Lack of association between vitamin D receptor genes BsmI as well as ApaI polymorphisms and osteoporosis risk: A pooled analysis on Chinese individuals

Association Between Vitamin D Receptor BsmI Polymorphism and Low Bone Mineral Density in Postmenopausal Women in the MENA Region

BACKGROUND/OBJECTIVES

Low bone mineral density increases the risk of bone fractures, and this condition is especially common in postmenopausal women. Genetic factors significantly influence bone mineral density. This meta-analysis examined the relationship between vitamin D receptor (VDR) gene polymorphisms (BsmI, ApaI, and TaqI) and bone mineral density in postmenopausal women in the Middle East and North Africa (MENA) region.

METHODS

The PubMed, Embase, Scopus, and Web of Science databases were searched from inception to March 2024 for case-control studies on VDR BsmI, ApaI, and TaqI polymorphisms and their relationship with low bone density. Associations with low bone mineral density were tested with respect to different genetic models (dominant, recessive, allelic) using RevMan v5.3.

RESULTS

The meta-analysis included seven studies for BsmI, six for ApaI, and seven for TaqI, representing 704/689 cases/controls for BsmI, 914/711 for ApaI, and 974/895 for TaqI. No significant association was found between VDR polymorphisms and low bone mineral density in postmenopausal women, except in the dominant model (CC + CG vs. GG) for the BsmI variant (OR = 1.27, 95% CI: 1.01-1.59, p = 0.04).

CONCLUSIONS

We found a modest association between the BsmI polymorphism and increased risk of low bone mineral density (BMD) in postmenopausal women from the MENA region, suggesting its potential as a biomarker. No associations were observed for ApaI or TaqI. These findings highlight the complex genetic-environmental interactions influencing BMD.

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.

Narrative role of vitamin D receptor with osteoporosis and obesity in a sample of Egyptian females: a pilot study

BACKGROUND

Vitamin D receptor (VDR) is known as one of the cellular regulators for several metabolic pathways indicating its pivotal role in the pathological pathway of numerous diseases. Considering the high frequency of osteoporosis and obesity among women, the current study aimed to explore the prospective assembly of the most frequent two VDR loci, single nucleotide polymorphism SNPs rs731236 (TaqI) and rs7975232 (ApaI) with a genetic predisposition to osteoporosis (skeletal) and obesity (chronic non-skeletal disorders), in Egyptian women. This was a cross-sectional study, including 97 Egyptian females (25-65 years), randomly chosen, from all employees and workers of the National Research Centre, Egypt. Anthropometric measurements (weight, height, BMI), dual-energy X-ray absorptiometry (DEXA), and molecular genetic analysis were done.

RESULTS

The variation of ApaI genotype between the normal and osteoporotic groups denotes a remarkable association of the homozygote ApaI genotype with osteoporosis risk. Among the normal weight group, bone mineral density (BMD) was significantly associated with TaqI VDR gene polymorphism as the presence of the heterozygote genotype was accompanied with higher BMD while the homozygote one was detected with lower BMD. Also, TaqI VDR gene polymorphism was significantly associated with BMI when participants were divided according to the presence of osteoporosis; increased BMI was expressed in the non-osteoporotic women group carrying the homozygote genotype of Taq I VDR gene while the presence of the heterozygote genotype (TaqI) in the osteoporotic group was associated with increased BMI.

CONCLUSIONS

The heterozygote TaqI genotype is protective against the osteoporosis phenotype and accompanied with increased BMI among osteoporotic women, while the homozygote ApaI genotype has a significant association with osteoporosis risk.

Association between vitamin D receptor BsmI, FokI, and Cdx2 polymorphisms and osteoporosis risk: an updated meta-analysis

Background: Many studies have reported the association between vitamin D receptor (VDR) polymorphism and osteoporosis risk. However, their results were conflicting. Six previous meta-analyses have been published to analyze VDR BsmI, FokI, and Cdx2 polymorphisms on osteoporosis risk. However, they did not evaluate the reliability of statistically significant associations. Furthermore, a lot of new articles have been published on these themes, and therefore an updated meta-analysis was performed to further explore these issues.

Objectives: To explore the association between VDR BsmI, FokI, and Cdx2 polymorphisms polymorphisms and osteoporosis risk.

Methods: The odds ratios (ORs) and 95% confidence intervals (95% CIs) were pooled to evaluate the association between VDR BsmI, FokI, and Cdx2 polymorphisms and osteoporosis risk. To evaluate the credibility of statistically significant associations, we applied the false-positive report probabilities (FPRPs) test and the Venice criteria.

Results: Overall, statistically significantly increased osteoporosis risk was found in Indians and women for VDR FokI polymorphism. Statistically significantly decreased osteoporosis risk was found in West Asians for VDR BsmI polymorphism. However, when we performed a sensitivity analysis after excluding low quality and Hardy–Weinberg Disequilibrium (HWD) studies, significantly decreased osteoporosis risk was only found in overall population for VDR BsmI polymorphism. Further, less-credible positive results were identified when we evaluated the credibility of positive results.

Conclusion: These positive findings should be interpreted with caution and indicate that significant association may most likely result from less-credible, rather than from true associations or biological factors on the VDR BsmI and FokI polymorphisms with osteoporosis risk.

Vitamin D receptor gene polymorphism in patients with osteomalacic myopathy in Egypt

INTRODUCTION

Vitamin D works by binding to vitamin D receptor (VDR). The muscle involvement in hypovitaminosis D was broadly named osteomalacic myopathy.

METHODS

A case control study involved 20 female patients diagnosed with osteomalacic myopathy compared with 15 age-matched healthy female controls. We assessed both for VDR genotype single-nucleotide polymorphisms (SNP) at 3 sites (ApaI, BsmI, and FokI).

RESULTS

ApaI and BsmI genotypes distribution in both groups showed non-significant difference unlike FokI genotypes in which we found significantly higher percentages of single allele mutation in patients vs. controls.

CONCLUSION

The relation of VDR gene SNPs to muscle function was studied before but in healthy subjects. We tried to correlate if presence/absence of a certain mutation is responsible for the appearance of osteomalacic myopathy.

Vitamin D receptor (VDR) gene FokI, BsmI, ApaI, and TaqI polymorphisms and osteoporosis risk: a meta-analysis

Background

Osteoporosis is a disease of the bones in which the density of the bones decreases. The prevalence of this disease greatly varies in different populations of the world. Numerous studies have been investigated VDR gene polymorphisms as osteoporosis risk in different ethnic groups. In present meta-analysis, the aim is to find out the role of VDR gene polymorphisms (FokI, BsmI, ApaI, and TaqI) in osteoporosis risk.

Methods

Suitable case-control studies for present meta-analysis were retrieved from four electronic databases. Open Meta-Analyst program was used for statistical analyses.

Results

Studies investigated BsmI (65 studies; 6880 cases/8049 controls), ApaI (31 studies; 3763 cases/3934 controls), FokI (18 studies; 1895 cases/1722 controls), and TaqI (26 studies; 2458 cases/2895 controls) polymorphisms that were included in the present meta-analysis. A significant association was found between the dominant model of FokI (ORff + Ffvs.FF = 1.19, 95% CI = 1.04–1.36, p = 0.01, I2 = 39.36%) in the overall analysis and recessive model of the Caucasian population of TaqI polymorphism (ORTT + Ttvs.tt = 1.35, 95% CI = 1.11–1.63, p = 0.002, I2 = 50.07%) with osteoporosis. On the other hand, no such effect is found in any other genetic models and in any other gene polymorphisms of the overall analyses or sub-group analyses.

Conclusion

In conclusion, the authors found that the dominant model of FokI in the overall analysis and recessive model of TaqI in the Caucasian population are significantly associated with the development of osteoporosis.