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

Gene detection of VDR BsmI locus and its approteins, genes and growthplication in rational drug use in patients with osteoporosis

Aim: This paper determines the polymorphism distribution of the VDR BsmI gene in 350 patients and provides medication recommendations for osteoporosis based on detection results. Materials & methods: Chi-square tests compared genotype and allele frequencies with other populations. Results: Genotype frequencies were 91.66 bb, 8.72 Bb and 0.21% BB, with allelic frequencies of 95.43 b and 4.57% B, adhering to Hardy-Weinberg equilibrium. These findings suggest that VDR gene polymorphisms, particularly at the BsmIlocus, play an essential role in bone health and osteoporosis treatment. Genotype-based drug selection reduced adverse reactions from 14 to two cases. Conclusion: These findings improve clinical treatment efficacy and guide rational drug use for osteoporosis patients.

Associations between the VDR Gene rs731236 (TaqI) Polymorphism and Bone Mineral Density in Postmenopausal Women from the RAC-OST-POL

BACKGROUND

Postmenopausal osteoporosis is not only related to hormonal factors but is also associated with environmental and genetic factors. One of the latter is the polymorphism of vitamin D receptor (VDR). The aim of the reported study was to comprehensively analyze the VDR gene polymorphic variants rs731236 (TaqI), rs1544410 (BsmI) and rs7975232 (ApaI) in the Polish population of postmenopausal women.

METHODS

The study group consisted of 611 women after menopause (their median age was 65.82 ± 6.29 years). Each of them underwent bone densitometry (DXA) of the non-dominant femoral neck and total hip with a biochemical analysis of vitamin D3 serum concentration and genotyping of the above-mentioned single nucleotide polymorphisms (SNPs); the obtained results were analyzed in the aspect of waist circumference (WC), body mass index (BMI) and past medical history.

RESULTS

The genotype prevalence rates of all SNPs were compatible with Hardy-Weinberg equilibrium (p > 0.050). Out of the studied polymorphisms, only rs731236 genotype variants affected DXA, with AG heterozygotes showing the worst bone parameters. Neither patient age nor vitamin D3 concentration, BMI, WC or comorbidities was associated with rs731236 genotype.

CONCLUSIONS

Out of the polymorphisms studied, only rs731236 genotypes differed among the DXA results, while the AG heterozygotes were characterized by the lowest median bone mineral density.

La osteocalcina se asocia con la densidad mineral ósea y los polimorfismos del gen VDR en la diabetes tipo 1 y 2

Objetivos

El metabolismo óseo se encuentra alterado en la diabetes mellitus (DM). El objetivo de este estudio es evaluar la relación entre los marcadores de remodelado óseo (MRO), los polimorfismos en el gen receptor de la vitamina D (VDR) y la densidad mineral ósea (DMO) en la DM tipo 1 (T1D) y tipo 2 (T2D).

Métodos

Se incluyó a 165 pacientes (53 T1D y 112 T2D). La DMO se midió mediante absorciometría de rayos X de energía dual (DEXA). Se realizó un análisis de la osteocalcina (OC) en plasma, beta-CrossLaps (β-CTX), propéptido aminoterminal del procolágeno tipo 1 (P1NP) y los polimorfismos en el gen VDR.

Resultados

Se incluyó a 53 pacientes con T1D (41 años (31–48)) y 112 con T2D (60 años [51–66]). No se observaron diferencias estadísticamente significativas en relación a la DMO. Los pacientes con T1D presentaron niveles superiores de OC (p<0,001) y P1NP (p<0,001). Las áreas bajo la curva para la predicción de patología ósea para la OC fueron 0,732 (p=0,038) en T1D y 0,697 (p=0,007) en T2D. Se observó una relación estadísticamente significativa entre el alelo A de BsmI (p=0,03), el alelo A de ApaI (p=0,04) y el alelo C de Taql (p=0,046) y una menor DMO. Así mismo, se encontró una correlación significativa entre los niveles elevados de OC y el alelo G de BsmI (p=0,044), el alelo C de ApaI (p=0,011), el alelo T de Taql (p=0,006) y el alelo C de FokI (p=0,004).

Conclusiones

El elevado valor predictivo negativo del punto de corte de la OC indica que la OC podría ser útil a la hora de descartar el riesgo de pérdida ósea, lo que permitiría diseñar un tratamiento personalizado para prevenir dicha patología.

Osteocalcin associates with bone mineral density and VDR gene polymorphisms in type 1 and type 2 diabetes

Objectives

Bone metabolism is impaired in diabetes mellitus (DM). Our objective is to evaluate the association of bone turnover markers (BTM) and vitamin D receptor (VDR) gene polymorphisms with bone mineral density (BMD) in DM type 1 (T1D) and DM type 2 (T2D).

Methods

A total of 165 patients (53 T1D and 112 T2D) were enrolled. BMD was measured by dual-energy X-ray absorptiometry (DEXA). Plasma osteocalcin (OC), beta-CrossLaps (β-CTX) and N-amino terminal propeptide of type I collagen (P1NP) and VDR gene polymorphisms were evaluated.

Results

Participants were 53 T1D (41 years [31-48]) and 112 T2D (60 years [51-66]). BMD were not statistically different between the groups. OC (p<0.001) and P1NP levels (p<0.001) were higher in patients with T1D. The areas under the curve for the prediction of bone pathology were 0.732 (p=0.038) for OC in T1D and 0.697 (p=0.007) in T2D. A significant association was found between lower lumbar BMD and the A allele of BsmI (p=0.03), the A allele of ApaI (p=0.04) and the allele C of the Taql (p=0.046). Also, a significant correlation was found with higher OC levels and the G allele of BsmI (p=0.044), C allele of ApaI (p=0.011), T allele of Taql (p=0.006) and with C allele of FokI (p=0.004).

Conclusions

The high negative predictive value of the cut-off point for OC suggests that could be useful in excluding the risk suffering bone loss, allowing offering a personalized clinical approach to prevent this pathology.

Demystifying the Risk Factors and Preventive Measures for Osteoporosis

Background

Osteoporosis is a major health problem, globally. It is characterized by structural bone weakness leading to an increased risk of fragility fractures. These fractures commonly affect the spine, hip and wrist bones. Consequently, Osteoporosis related proximal femur and vertebral fractures represent a substantial, growing social and economic burden on healthcare systems worldwide. Indentification of the risk factors, clinical risk assessment, utilization of risk assessment tools and appropriate management that play a crucial role in reducing the burden of Osteoporosis by tackling modifiable risk factors.

Methods

This chapter explores various risk factors that are associated with Osteoporosis and provides an overview of various clinical and diagnostic risk assessment tools with a particular emphasis on evidence-based strategies for their prevention.

Conclusion

The role of emerging technologies such as Artificial Intelligence (AI) and perspectives such as newer diagnostic modalities, monitoring and surveillance approaches in prevention of risk factors in the pathogenesis of Osteoporosis is highlighted.

Relevance of Serum Levels and Functional Genetic Variants in Vitamin D Receptor Gene among Saudi Women with Gestational Diabetes Mellitus

Background: This study explored the association between ApaI-TaqI Single Nucleotide Polymorphisms (SNPs) in a Vitamin D receptor (VDR) and the risk of Gestational Diabetes Mellitus (GDM) in Saudi women, along with the serum levels of vitamin D. Methods: Ninety women with GDM and 90 non-GDM women were enrolled, based on the inclusion and exclusion criteria for pregnant women enrolled in a single-center study. Blood samples were retrieved from 180 pregnant women using ethylenediaminetetraacetic acid (EDTA) tubes. Serum samples were used to measure the vitamin D, 25-hydroxyvitamin D (25(OH)D or calcidiol), and lipid profiles. Blood was used to measure the hemoglobin A1c levels and to isolate the DNA. The polymerase chain reaction (PCR) was performed for the ApaI (rs79785232), BsmI (rs1544410), FokI (rs2228570), and TaqI (rs731236) SNPs in the VDR gene using restriction fragment length polymorphism analysis. Validation was performed using Sanger sequencing. Statistical analyses were performed between the patients with and without GDM using various statistical software packages. Results: The Hardy-Weinberg equilibrium analysis was statistically significant (p > 0.05). The ApaI, BsmI, and TaqI SNPs were associated with alleles, genotypes, and different genetic models (p < 0.05). Vitamin D levels were associated with deficient levels (p = 0.0002), as well as with a normal and overweight body mass index (p = 0.0004). When vitamin D levels were measured with GDM covariates, the fasting plasma glucose (FPG) (p = 0.0001), postprandial blood glucose (PPBG) (p < 0.0001), oral glucose tolerance test (OGTT)-1 h (p = 0.005), high-density lipoprotein (p = 0.022), and low-density lipoprotein cholesterol (LDLc) (p = 0.001) levels were significantly different. When similar vitamin D levels were measured for each genotype, we confirmed that the ApaI SNP was associated with sufficient levels (p < 0.0001), whereas the BsmI, FokI, and TaqI (p < 0.05) were associated with insufficient levels. The logistic regression model confirmed that the first hour of the OGTT (p = 0.005) was strongly associated with GDM, whereas the analysis of variance confirmed that FPG and PPBG (p < 0.05) were strongly associated with all the SNPs evaluated in the VDR gene. Additionally, the second hour of the OGTT (p = 0.048) and LDLc (p = 0.049) were associated with the ApaI and FokI SNP. Moreover, the first hour OGTT (p = 0.045) and lipid profile parameters (p < 0.05) were associated. Haplotype analysis revealed positive associations among the examined SNPs, which seemed compatible with the hypothesis that variants and combinations of multiple SNP genotypes enhance the risk of GDM in women. Haplotype analysis revealed that different combinations of alleles, such as AGCC, CATT, CGTC, AGTC, and CATT (p < 0.05), were strongly associated. The linkage disequilibrium (LD) analysis showed a strong association with all combinations (p < 0.05). Among the gene-gene interactions, all possible combinations showed a positive association (p < 0.05). Conclusions: Low vitamin D levels were observed in women with GDM. The ApaI, BsmI, and TaqI SNPs were associated with genotype and allele frequencies (p < 0.05). Vitamin D and the SNPs in the VDR gene were associated, according to the ANOVA, logistic regression, haplotype analysis, LD analysis, and the generalized multifactor dimensionality reduction model (p < 0.05).

Osteoprotegerin genetic polymorphisms and their influence on therapeutic response to ibandronate in postmenopausal osteoporotic females

OBJECTIVES

The present study investigated osteoprotegerin (OPG) genetic polymorphisms and their influence on the therapeutic response to ibandronate in postmenopausal osteoporotic females.

METHODS

This case-control study included 135 postmenopausal females (89 osteoporotic females and 46 non-osteoporotic females). Each osteoporotic patient received a monthly 150 mg ibandronate tablet for six months, and blood samples were taken before and after treatment. Bone mineral density (BMD) was measured using DEXA Scan. Three SNPs (A163G, T245G, and G1181C) of the OPG gene were selected for analysis.

RESULTS

Serum OPG levels were significantly lower in osteoporotic subjects than in the control group. The percentage changes in OPG levels in the osteoporotic group before and after treatment with ibandronate were significant (p < .001). After six months of therapy with ibandronate, the percentage changes in OPG levels with AA, TT, TC, GC, and GG genotypes were significant. Following six months of ibandronate treatment, the AA genotype of rs3134069, TT, TC genotypes of rs3102735, GG, and GC genotypes of rs2073618 SNP showed a significant increase in OPG levels. Age, BMI, and GC polymorphism (rs2073618 (G/C) G1181C) were inversely associated with low BMD. Adjusted odds ratios (OR) showed that BMI, GC, GG polymorphism (rs2073618 (G/C) G1181C) and TC polymorphism (rs3102735 (T/C) A163G) were inversely associated with low BMD.

CONCLUSION

The inverse association of rs2073618 and rs3102735 with low BMD indicates the protective role of these SNPs in our population. More research is needed to replicate these results in another cohort and to determine the molecular processes by which such SNPs may influence BMD.