A meta-analysis of association of vitamin D receptor BsmI gene polymorphism with the risk of type 1 diabetes mellitus

The Effect of Vitamin D Supplementation with or without Calcium on Vitamin D Epimer and Metabolites

BACKGROUND

A possible role of vitamin D epimers and metabolites in the measurement and response to treatment of vitamin D has been reported recently. Furthermore, the influence of underlying vitamin D receptor (VDR) genetic polymorphisms which have been linked to diseases such as obesity remains unclear. We therefore aimed to examine the influence of vitamin D3 and calcium supplements on vitamin D epimer and metabolite concentrations in subjects with and those without vitamin D receptor (VDR) gene polymorphisms.

METHODS

A total of 277 participants who were part of a randomized intervention trial of vitamin D3 and calcium or a placebo for 6 months had clinical and anthropometric assessments. Blood samples were taken for measurements of vitamin D, epimers and metabolites of vitamin D, four vitamin D receptor gene polymorphism SNPs, namely, BsmI, FokI, TaqI, and ApaI, metabolic and inflammatory markers, and related biochemical variables. Repeated-measures analysis of variance was used to assess the between-group difference in cumulative changes in vitamin D epimers and metabolites at 6 months after adjusting for the presence of the 4 VDR genotypes and allele gene polymorphisms.

RESULTS

Overall, 277 participants, with a mean (±SD) age of 41 ± 12 and 204 (74%) of whom were female, were included in the study. We found no statistically significant differences in vitamin D metabolites or (epimers) between male and females or younger subjects compared to those over 40 years of age except in 7C4 BL (p < 0.05). There was a statistically significant difference in 1,25(OH)2D3 concentrations between subjects with and those without genotypes AG and the allele G SNP2_Taql VDR gene polymorphism. Vitamin D3 concentrations were also significantly lower in subjects with the CC SNP3_Apal gene polymorphism compared to those without the CC SNP3 gene. No statistically significant effects were seen on vitamin D epimers and metabolites concentration in response to supplements before or after adjusting for the presence of the 4 VDR genotypes and allele gene polymorphisms.

CONCLUSIONS

The CC SNP3 gene had statistically significant influence on vitamin D3 levels. Vitamin D and/or calcium supplements, however, had no effects on vitamin D epimer and metabolite concentration before or after adjusting for the presence of the 4 VDR genotypes and alleles.

Association between partial remission phase in type 1 diabetes and vitamin D receptor Fok1 rs2228570 polymorphism

OBJECTIVES

The aim of the current study was to assess the natural course of partial remission (PR) phase of type 1 diabetes (T1D) and to highlight the putative association between vitamin D receptor (VDR) (Fok1) gene polymorphism and PR phase.

METHODS

Ninety participants with newly diagnosed T1D were followed up for a total of 12 months. The VDR (Fok1) rs2228570 gene polymorphism was genotyped using allelic discrimination (AD) assay.

RESULTS

Fifty-four patients (60 %) reached PR with an average duration of 5.63 ± 2.9 months. Among remitters, the frequency of CC "FF" genotype and allelic frequency of C "F" were significantly higher (p<0.001). Furthermore, participants expressing "CC" genotype had earlier onset of PR and spent a significantly longer duration in remission (p<0.001). Younger age (p<0.001; OR 41.6; CI 12.12-142.99), absence of DKA (p<0.001; OR 16, CI 4.36-50.74), higher C-peptide levels (p<0.001; OR 19.55; CI 6.52-58.63), and presence of CC "FF" genotype of VDR (p<0.001; OR 6.74; CI 2.41-18.86) best predicted the overall occurrence of PR.

CONCLUSIONS

Younger age, less extent of metabolic derangements, and expression of a CC "FF" genotype were found to influence the occurrence of PR. Data from the current study showed that the "C" allele could have a protective role on preserving residual β-cell mass and could predict both onset and duration of PR among newly diagnosed T1D. These findings support the growing concept of future tailored precision medicine.

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.

Frequency of Vitamin D Receptor Gene Polymorphisms in a Population with a very High Prevalence of Vitamin D Deficiency, Obesity, Diabetes and Hypertension

BACKGROUND

Although vitamin D levels and underlying vitamin D receptor (VDR) genetic polymorphisms have been linked to many common diseases including obesity, the association remains unclear. There is also co-existence of pathologically high proportions of obesity and vitamin D deficiency conditions in our UAE society. We therefore aimed to determine the genotypes and allele percentage frequency distribution of four polymorphisms-FokI, BsmI, ApaI and TaqI-in the VDR gene in healthy Emirati individuals and their association with vitamin D levels and chronic conditions including diabetes mellitus, hypertension and obesity.

METHODS

277 participants who were part of a randomized controlled trial had their assessment that included clinical and anthropometric data. Whole blood samples were taken for measurements of vitamin D [25(OH) D], four vitamin D receptor gene polymorphism SNPs, including BsmI, FokI, TaqI and ApaI, metabolic and inflammatory markers and related biochemical variables. Multiple logistic regression analysis was used to assess the influence of vitamin D receptor gene SNPs on vitamin D status after adjusting for clinical parameters known to influence vitamin D status in the study population.

RESULTS

Overall, 277 participants with a mean (±SD) age of 41 ± 12, 204 (74%) of them being female, were included in the study. There were statistically significant differences in vitamin D concentrations between different genotypes of the four VDR gene polymorphisms (p < 0.05). There were, however, no statistically significant differences in vitamin D concentrations between subjects with and those without the four VDR gene polymorphisms genotype and alleles except for AA and AG and allele G in Apal SNP (p < 0.05). Multivariate analysis revealed no significant independent associations between vitamin D status and the four VDR gene polymorphisms after adjusting for dietary intake, physical activity, sun exposure, smoking and body mass index. In addition, no significant differences were found in the frequency of the genotypes and alleles of the four VDR genes among patients with obesity, diabetes and hypertension compared to those without these medical conditions.

CONCLUSIONS

Although we found statistically significant differences in vitamin concentrations between different genotypes of the four VDR gene polymorphisms, multivariate analysis revealed no association after adjusting for clinical parameters known to influence vitamin D status. Furthermore, no association was found between obesity and related pathologies and the four VDR gene polymorphisms.

Gene Polymorphisms Associated with Central Precocious Puberty and Hormone Levels in Chinese Girls

Central precocious puberty (CPP) is associated with adverse health outcomes in females; however, CPP pathogenesis remains unclear. In this study, we investigated the association of 20 single nucleotide polymorphisms (SNPs) in eight genes with CPP risk and hormone levels. A case-control study on 247 and 243 girls with and without CPP, respectively, was conducted at Kunming Children's Hospital, China, from September 2019 to August 2020. The genotype of the SNPs and their haplotypes were identified. Additionally, the effects of the polymorphisms on hormone levels were investigated. Three variants (rs10159082, rs7538038, and rs5780218) in KISS1 and two variants (rs7895833 and rs3758391) in SIRT1 were related to an increased CPP risk (odds ratio (OR) = 1.524, 1.507, 1.409, 1.348, and 1.737; 95% confidence interval (CI) = 1.176-1.974, 1.152-1.970, 1.089-1.824, 1.023-1.777, and 1.242-2.430, respectively). Rs3740051in SIRT1 and rs1544410 in VDR reduced CPP risk (OR = 0.689, 0.464; 95% CI, 0.511-0.928, 0.232-0.925, respectively). Rs1544410, rs7975232, and rs731236 in VDR were negatively correlated with peak follicle-stimulating hormone (FSH; β = -2.181; P=0.045), basal FSH (β = -0.391; P=0.010), and insulin-like growth factor (β = -50.360; P=0.041) levels, respectively. KISS1, SIRT1, and VDR variants were associated with CPP susceptibility, and VDR SNPs influenced hormonal levels in Chinese females with CPP. In particular, VDR polymorphism rs1544410 was associated with both CPP risk and GnRH-stimulated peak FSH levels. Further functional research and large-scale genetic studies of these loci and genes are required to confirm our findings.

Association of vitamin D receptor gene polymorphism with type 1 diabetes mellitus risk in children: A protocol for systematic review and meta-analysis

BACKGROUND

Recent genetic association studies showed that there are contradictory results on the relationship between vitamin D receptor (VDR) gene polymorphisms and type 1 diabetes mellitus (T1DM) risk in children. The purpose of this systematic review is to collect the currently available evidence to evaluate the relationship between VDR gene polymorphisms and the risk of T1DM in children.

METHODS

Such medical databases as Wanfang Data, Chinese Biomedical Literature Database, Chinese National Knowledge Infrastructure, Chongqing VIP Chinese Science and Technology Periodical Database, PubMed, Embase, and Web of Science were extensively searched for relevant literatures published before June 2021 with the focus on the relationship between VDR gene polymorphisms and the risk of T1DM in children. The risk of bias was evaluated as per the Newcastle-Ottawa Scale by 2 independent researchers. Meta-analysis was performed to quantify the relationship between VDR gene polymorphisms and T1DM risk in children.

RESULTS

The results of this meta-analysis would be submitted to a peer-reviewed journal for publication.

CONCLUSION

The relationship between VDR gene polymorphisms and T1DM risk in children is explored via this meta-analysis.

ETHICS AND DISSEMINATION

Ethical approval was not required for this study. The systematic review will be published in a peer-reviewed journal, presented at conferences, and shared on social media platforms.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/Q8XA5.

Autoimmune thyroid disease and type 1 diabetes mellitus: same pathogenesis; new perspective?

Autoimmune thyroid disease (AITD) and type 1 diabetes mellitus (T1DM) are two common autoimmune diseases that can occur concomitantly. In general, patients with diabetes have a high risk of AITD. It has been proposed that a complex genetic basis together with multiple nongenetic factors make a variable contribution to the pathogenesis of T1DM and AITD. In this paper, we summarize current knowledge in the field regarding potential pathogenic factors of T1DM and AITD, including human leukocyte antigen, autoimmune regulator, lymphoid protein tyrosine phosphatase, forkhead box protein P3, cytotoxic T lymphocyte-associated antigen, infection, vitamin D deficiency, and chemokine (C-X-C motif) ligand. These findings offer an insight into future immunotherapy for autoimmune diseases.

Vitamin D receptor gene polymorphisms and the risk of the type 1 diabetes: a meta-regression and updated meta-analysis

BACKGROUND

The association between the polymorphisms in the vitamin D receptor (VDR) gene and the risk of type 1 diabetes mellitus (T1DM) has been evaluated in several studies. However, the findings were inconclusive. Thus, we conducted a meta-analysis to comprehensively evaluate the effect of VDR gene polymorphisms on the risk of T1DM.

METHODS

All relevant studies reporting the association between VDR gene polymorphisms and susceptibility to T1DM published up to May 2020 were identified by comprehensive systematic database search in ISI Web of Science, Scopus, and PubMed/MEDLINE. Strength of association were assessed by calculating of pooled odds ratios (ORs) and 95% confidence intervals (CIs). The methodological quality of each study was assessed according to the Newcastle-Ottawa Scale. To find the potential sources of heterogeneity, meta-regression and subgroup analysis were also performed.

RESULTS

A total of 39 case-control studies were included in this meta-analysis. The results of overall population rejected any significant association between VDR gene polymorphisms and T1DM risk. However, the pooled results of subgroup analysis revealed significant negative and positive associations between FokI and BsmI polymorphisms and T1DM in Africans and Americans, respectively.

CONCLUSIONS

This meta-analysis suggested a significant association between VDR gene polymorphism and T1DM susceptibility in ethnic-specific analysis.

Vitamin D receptor genetic polymorphisms and the risk of multiple sclerosis: A systematic review and meta-analysis

There are conflicting results regarding the exact effect of the vitamin D receptor (VDR) gene polymorphisms on the susceptibility to multiple sclerosis (MS). Therefore, we aimed to investigate the impact of four major studied VDR gene polymorphisms consisting of ApaI, BsmI, FokI, and TaqI on the risk of MS in the Iranian population. A literature search was performed in various databases to find case-control studies evaluating the association between VDR gene polymorphisms and MS risk in Iran. Data were extracted and odds ratios (OR) with 95% confidence intervals (CI) were calculated. Subgroup analyze was performed to detect potential sources of heterogeneity. A total of 1206 cases and 1402 controls in nine case-control studies were included. ApaI was the only variant which showed statistically significant relation in allelic (OR = 0.54 (95% CI: 0.37-0.79); P = 0.00), homozygote (OR = 3.48 (95% CI: 1.7-6.9); P = 0.00), dominant (OR = 0.56 (95% CI: 0.3-0.79); P = 0.01), and recessive (OR = 0.35 (95% CI: 0.18-0.66); P = 0.00) models. The TaqI polymorphism showed a significant negative association with MS only in the homozygote model (OR = 0.28 (95% CI: 0.08-0.9); P = 0.04). The BsmI polymorphism also showed significant relation in allelic (OR = 0.69 (95% CI: 0.51-0.94); P = 0.01), homozygote (OR = 0.46 (95% CI: 0.25-0.86); P = 0.01), and recessive OR = 0.56 (95% CI: 0.39-0.8); P = 0.00) models after performing sensitivity analysis. FokI polymorphism showed no significant association with MS risk. ApaI and TaqI TT genotype were found contributing to MS susceptibility and BsmI and FokI showed no relation with MS susceptibility in the Iranian population.

Understanding of type 1 diabetes mellitus: what we know and where we go

The incidence of type 1 diabetes mellitus (T1DM) in children and adolescents is increasing worldwide. Combined effects of genetic and environmental factors cause T1DM, which make it difficult to predict whether an individual will inherit the disease. Due to the level of self-care necessary in T1DM maintenance, it is crucial for pediatric settings to support achieving optimal glucose control, especially when adolescents are beginning to take more responsibility for their own health. Innovative insulin delivery systems, such as continuous subcutaneous insulin infusion (CSII), and noninvasive glucose monitoring systems, such as continuous glucose monitoring (CGM), allow patients with T1DM to achieve a normal and flexible lifestyle. However, there are still challenges in achieving optimal glucose control despite advanced technology in T1DM administration. In this article, disease prediction and current management of T1DM are reviewed with special emphasis on biomarkers of pancreatic β-cell stress, CSII, glucose monitoring, and several other adjunctive therapies.

Inherited Variation in Vitamin D Genes and Type 1 Diabetes Predisposition

The etiology and pathophysiology of type 1 diabetes remain largely elusive with no established concepts for a causal therapy. Efforts to clarify genetic susceptibility and screening for environmental factors have identified the vitamin D system as a contributory pathway that is potentially correctable. This review aims at compiling all genetic studies addressing the vitamin D system in type 1 diabetes. Herein, association studies with case control cohorts are presented as well as family investigations with transmission tests, meta-analyses and intervention trials. Additionally, rare examples of inborn errors of vitamin D metabolism manifesting with type 1 diabetes and their immune status are discussed. We find a majority of association studies confirming a predisposing role for vitamin D receptor (VDR) polymorphisms and those of the vitamin D metabolism, particularly the CYP27B1 gene encoding the main enzyme for vitamin D activation. Associations, however, are tenuous in relation to the ethnic background of the studied populations. Intervention trials identify the specific requirements of adequate vitamin D doses to achieve vitamin D sufficiency. Preliminary evidence suggests that doses may need to be individualized in order to achieve target effects due to pharmacogenomic variation.

Association of vitamin D receptor polymorphisms and type 1 diabetes susceptibility in children: a meta-analysis

BACKGROUND

There have been studies focused on FokI, BsmI, ApaI and TaqI polymorphisms of the vitamin D receptor (VDR) gene and susceptibility to type 1 diabetes mellitus with controversial results.

METHODS

This present study is a meta-analysis investigating the association between FokI, ApaI, TaqI and BsmI polymorphisms of VDR gene and type 1 DM in children. A literature search was performed using Medline, EMBASE, Cochrane and PubMed. Any study was considered eligible for inclusion if at least one of FokI, ApaI, TaqI and BsmI polymorphisms was determined, and outcome was type 1 DM at pediatric age.

RESULTS

A total of 9 studies comprising 1053 patients and 1017 controls met the study inclusion criteria. The pooled odds ratios (ORs) of the FokI, ApaI, TaqI and BsmI polymorphisms were combined and calculated. Forest plots and funnel plots of the OR value distributions were drawn. Our meta-analysis has demonstrated statistically significant associations between DM1 and VDR genotypes, BsmIBB (P < 0.05), BsmIBb, (P < 0.05), BsmIbb (P < 0.05), TaqITT (P < 0.05) and TaqItt (P < 0.05) in children.

CONCLUSION

The results indicated that BsmIBB, BsmIBb and TaqItt polymorphisms were associated with an increased risk of type 1 DM, whereas BsmIbb and TaqITT had protective effect for type 1 DM in children.

VDR gene polymorphisms impact on anemia at 2 weeks of anti-HCV therapy: a possible mechanism for early RBV-induced anemia

OBJECTIVES

Vitamin D receptors (VDR) bind calcitriol and modulate several physiological systems through genomic and nongenomic pathways. Calcitriol stimulates store-operated channels Ca²⁺ influx by translocation of the caveolar VDR to the plasma membrane. Intracellular Ca²⁺ levels in erythrocytes control biophysical properties and an increase in its concentration can deregulate membrane composition, cell volume, glycolytic enzymes regulation, redox state, and cell clearance.We evaluated the role of single nucleotide polymorphisms in ITPA, CYP27B1, CYP24A1, and VDR genes in the prediction of ribavirin-induced anemia in HCV-1/2/3/4 patients at 2 and 4 weeks of treatment.

PATIENTS AND METHODS

Two hundred and twenty-five patients treated with ribavirin and pegylated interferon-α were genotyped by real-time PCR.

RESULTS

BMI at baseline more than 30 kg/m² [P=0.013, odds ratio (OR): 10.95, 95% confidence interval (CI): 1.66-74.21], alanine aminotransferase at baseline more than 37 IU/l (P=0.020, OR: 0.26, 95% CI: 0.09-0.81), and the VDR BsmI AA profile (P=0.003, OR: 5.09, 95% CI: 1.72-15.05) were anemia-predictive factors at 2 weeks of therapy. At week 4, the ITPA rs6051702 AC/CC profile (P=0.001, OR: 0.19, 95% CI: 0.07-0.51) was the only factor that could predict this side effect.

CONCLUSION

The BsmI AA genotype is a predictive factor of 2-week anemia and it could be related to a VDR-enhanced activity, and thus an increased calcium influx, resulting in the deregulation of the Ca²⁺-dependent signaling, which can lead to erythrocytes hemolysis. This rapid mechanism could be responsible for the development of early anemia.These results indicate for the first time the strong, significant, and independent role of VDR in the early development of ribavirin-induced anemia and confirm the ITPA function in the prediction of anemia at week 4.

Associations among four polymorphisms (BsmI, FokI, TaqI and ApaI) of vitamin D receptor gene and end-stage renal disease: a meta-analysis

BACKGROUND AND AIMS

To evaluate the association between vitamin D receptor (VDR) BsmI, FokI, TaqI and ApaI gene polymorphisms and the risk of end-stage renal disease (ESRD).

METHODS

All eligible studies were included in our meta-analysis of a search of the PubMed, Cochrane and China National Knowledge Infrastructure (CNKI) databases according to predefined criteria. The fixed-effects or random-effects models were used to calculate the pooled odds ratio (OR) and corresponding 95% confidence interval (CI).

RESULTS

Thirteen studies including 1510 patients and 1812 controls were recruited for the analysis of the association between the VDR BsmI, FokI, TaqI and ApaI gene polymorphisms and the risk of ESRD.VDR BsmI B allele, BB genotype and bb genotype, FokI F allele, FF genotype and ff genotype, TaqI T allele, TT genotype and tt genotype, ApaI A allele, AA genotype and aa genotype were not associated with ESRD susceptibility for overall populations, Asians and Caucasians.

CONCLUSIONS

Results from the current study suggest that VDR BsmI, FokI, TaqI and ApaI gene polymorphisms are not associated with the risk of ESRD in the overall populations, Asians and Caucasians. However, more studies should be performed in the future.