Vitamin D Receptor Polymorphisms Research Articles

Vitamin D and it’s Association with FokI VDR Polymorphism in Patients with Asthma-COPD Overlap

Background: Asthma-COPD overlap is a new phenotype in respiratory ailments. It has been shown that this group of patients might possess vitamin D3 deficiency. The association of vitamin D receptor (VDR) gene polymorphism with serum vitamin D status in ACO patients has not been investigated yet. Objective: To assess the association of VDR gene polymorphism (FokI) with serum vitamin D status in patients with Asthma-COPD overlap. Methods: This cross-sectional study was carried out in the Department of Physiology of Bangabandhu Sheikh Mujib Medical University, Dhaka, from January 2018 to July 2018 on 23 (twenty-three) patients (aged ≥40 years) with ACO. For comparison, 24 (twenty-four) apparently healthy age, smoking duration and BMI matched subjects were selected. For all participants single nucleotide polymorphism of VDR gene FokI (rs10735810) was done by DNA extraction, polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). Vitamin D3 was measured by using automated analyzer: ARCHITECT Plus ci4100. The results were expressed as mean with standard error (mean±SEM) and frequency distribution. The data were statistically analyzed by Graphpad prism (Version 7) using independent sample ‘t’ test, two sample proportion test, Fisher exact test and ANOVA test. In the interpretation of results, ≤0.05 level of probability (p) was accepted as significant. Results: The mean±SEM of serum 25(OH)D were 16.37±0.78 and 18.46±1.01 ng/ml in control and study groups, respectively. The frequency distribution of FokI genotype was 86.95% (FF), 8.69% (Ff), 4.35% (ff) and 91.66% (FF), 4.17% (Ff), 4.17% (ff) in ACO patients and healthy subjects, respectively. When FoKI VDR SNP was analyzed with serum vitamin D status in patients with ACO, statistically no association was seen. Conclusions: FokI VDR SNP is not associated with serum vitamin D status in patients with ACO. J Rang Med Col. March 2024; Vol. 9, No. 1: 22-27

Comparing vitamin D receptor gene polymorphisms in rs11568820, rs7970314, rs4334089 between COVID-19 patients with mild and severe symptoms: a case control study

The associations of vitamin D receptor (VDR)- single nucleotide polymorphisms (SNPs) with the symptoms of COVID-19 may vary between patients with different severities of COVID-19. Therefore, in the present study, we aim to compare VDR polymorphisms in severe and mild COVID-19 patients. In this study, a total number of 85 hospitalized patients and 91 mild/moderate patients with COVID-19 were recruited. SNPs in VDR genes were determined using ARMS and then confirmed by sanger sequencing. The mean (SD) age of participants in hospitalized and non-hospitalized group was 59.0 (12.4) and 47.8 (14.8) years, respectively. Almost 46% of participants in hospitalized and 48% of participant in non-hospitalized group were male. The frequency of TT genotype of SNP rs11568820 was significantly lower in hospitalized than non-hospitalized group (3.5% vs. 17.6%; P = 0.018). However, there was no significant differences between genotypes of SNPs rs7970314 and rs4334089 and also alleles frequencies in all SNPs of two groups. The genotype of rs11568820 SNP had an inverse association with hospitalization of patients with COVID-19 after adjustment for comorbidities [OR 0.18, 95% CI 0.04, 0.88; P = 0.034]. While, there was no relationship between genotypes of SNPs rs7970314 and rs4334089 and hospitalization. The TT genotype of rs11568820 plays protective role in sever COVID-19 and hospitalization. Further studies with a large sample size which consider various confounding factors are warranted to confirm our results.

Vitamin D receptor gene polymorphisms role in COVID-19 severity: Results of a Mexican patients' cohort.

Vitamin D status has been involved with coronavirus disease 19 (COVID-19) severity. This may be mediated by vitamin D metabolism regulatory genes. Of interest is the vitamin D receptor (VDR) gene, which has been previously associated with other inflammatory and respiratory diseases. In order to investigate the role of VDR gene polymorphisms in COVID-19 severity and outcome, a total of 292 COVID-19 patients were classified according to severity in moderate (n=56), severe (n=89) and critical (n=147) and, according to outcome in survivor (n=163) and deceased (n=129), and analysed for FokI and TaqI VDR gene polymorphisms by polymerase chain reaction-based restriction enzyme digestion. The FokI and TaqI single nucleotide polymorphisms (SNPs) were not associated with COVID-19 severity or mortality individually but when analysed by haplotype, TC was associated with an increased risk of presenting critical COVID-19. Additionally, FokI CT genotype was more frequent in COVID-19 patients with hypertension, and T allele carriers presented higher aspartate aminotransferase levels. Our results suggest a relationship between VDR FokI and TaqI SNPs and COVID-19 severity in Mexican population. Although there are some previous reports of VDR polymorphisms in COVID-19, this represents the first report in Latin American population. Further studies on other populations are encouraged.

Delving the vitamin D receptor variation and expression profiles in the context of type 2 diabetes among families.

Vitamin D is essential for insulin secretion and sensitivity. Consequently, its inadequacy is linked to higher insulin resistance and Type 2 Diabetes (T2D). The Vitamin D receptor (VDR) gene is one potential candidate for T2D, and multiple polymorphisms in VDR have been examined in various populations, but no conclusive answers have been provided. This study was designed to evaluate the susceptibility of VDR gene polymorphism and its expression in diabetic families in Pakistan. In this family-based study, twenty diabetic families with a positive family history of T2D and at least three T2D patients were recruited from outpatient clinics and public hospitals. The current study comprised 143 individuals with 55 affected and 88 unaffected individuals.Blood samples of the selected families were collected. DNA was extracted from the collected samples and the PCR-RFLP method was followed to identify the genotyping and RT-qPCR for expression. Phenotypic and genotypic pedigrees of the families were developed by the progeny online tool. The association values of SNPs were determined by TDT and DFAM analysis implemented on Plink software. The results explained a significant familial aggregation among phenotypic characters including Age, Gender, BMI (body mass index), age of disease diagnosis, disease duration, and blood pressure in the probands, affected FDRs (First Degree Relatives) and affected SDRs (Second Degree Relatives). A significant association of rs731236 C/T (OR = 1.522), rs2228570 C/T (OR = 1.327) with p < 0.05. Whereas, for rs1544410 G/A (OR = 0.9706) and rs7975232 T/G (OR = 0.7368) no considerable association evidence was seen (p > 0.05) in families. The mRNA expression of VDR increased threefold (p = 0.0204) in patients compared to controls. Variation-based expression analysis exhibited that the rs2228570 genotype influences the expression. A linkage was found among the FDRs with probands. Variation in the gene VDR at loci rs731236 and rs2228570 was associated with familial T2D. However further research is required to explore more genetic factors that could influence T2D risks in families.

Relationship between vitamin D receptor genotypes (FOK1rs2228570) and IL18 gene expression in sample of multiple sclerosis Iraqi patients

BACKGROUND: Multiple Sclerosis known as MS, this chronic inflammatory demyelinating condition affects the nervous system. It is a heterogenic and multifactorial disease. The goal of the current study was to investigate the relationship between MS patients’ IL18 gene expression and the vitamin D receptor gene polymorphism (FOK1rs2228570). OBJECTIVE: The aim of the study to investigate the association of vitamin D receptor (FOK1rs2228570) gene polymorphism and pro inflammatory cytokine (IL18) gene expression among multiple sclerosis Iraqi patients. Detection VDR polymorphism and determine whether this SNP is involved in susceptibility to multiple sclerosis and estimation IL18 gene expression and explore its relation with multiple sclerosis susceptibility. METHODS: Blood samples were taken from 75 MS patients in Iraq (30 men and 45 women), as well as from 75 volunteers who seemed to be in a favorable state of health and fell within the age range of 20 to 50 years. Tetra-ARMS Polymerase Chain Reaction (Tetra-ARMS PCR) was used to find polymorphisms in the vitamin D receptor (VDR) gene, and Real-time Polymerase Chain Reaction (RT-PCR) was used to measure IL18 gene expression. RESULTS: The findings from the analysis of VDR gene polymorphism in patients with MS indicated that the wild-type genotype T/T was present in 8 individuals, accounting for 10.6%, the heterogeneous genotype TC was 36 (48%), and the homogeneous genotype CC was 31 (41.3%), whilst T allele frequency was 52(34.6%) and C allele was 98(65.3%) with (P⩽ 0.01) significant difference and even as in control T/T genotype was 49(65.3%), TC genotype was 21(28%), CC genotype was 5(6.66%), T allele frequency was 119(79.3%) and C allele was 31(20.6%) with significant difference (P⩽ 0.001). While estimation of IL18 expression showed high elevation in patients’ group (2.59 ± 0.51 fold) by significance difference (P⩽ 0.5) when compared to control group (1.35 ± 0.14 fold). The relationship between IL18 gene expression with VDR variant in MS patients demonstrated a significant rise (2.9 ± 0.51 fold) at CC genotype patients in IL18 folding gene expression, followed by (4.6 ± 0.17 fold) in TC genotype patients and finally (1.4 ± 0.08 fold) in TT genotype patients with highly significant (P⩽ 0.01). CONCLUSION: The VDR(FOK1rs2228570) genotype was significantly correlated with IL18 expression in MS patients from Iraq.

Vitamin D status, vitamin D receptor polymorphisms, and risk of type 2 diabetes: A prospective cohort study.

Vitamin D status has been associated with risk of type 2 diabetes (T2D), but evidence is scarce regarding whether such relation differs by glycemic status. To prospectively investigate the association between serum 25-hydroxyvitamin D [25(OH)D] and risk of incident T2D across the glycemic spectrum and the modification effect of genetic variants in vitamin D receptor (VDR). This prospective study included 379,699 participants without T2D at baseline from the UK Biobank. Analyses were performed according to glycemic status and HbA1c levels. Cox proportional hazard models were used to calculate hazard ratios (HRs) and 95% CIs. During a median of 14.1 years of follow-up, 6,315 participants with normoglycemia and 9,085 prediabetes patients developed T2D. Compared to individuals with 25(OH)D <25 nmol/L, the multivariable-adjusted hazard ratios (95% CIs) of incident T2D for those with 25(OH)D ≥75 nmol/L was 0.62 (0.56, 0.70) among the normoglycemia and 0.64 (0.58, 0.70) among the prediabetes. A significant interaction was observed between 25(OH)D and VDR polymorphisms among participants with prediabetes (Pinteraction=0.017), whereby the reduced HR of T2D associated with higher 25(OH)D was more prominent in those carrying T allele of rs1544410. Triglycerides levels mediated 26% and 34% of the association between serum 25(OH)D and incident T2D among participants with normoglycemia and prediabetes. Higher serum 25(OH)D concentrations were associated with lower T2D risk across the glycemic spectrum below the threshold for diabetes, and the relations in prediabetes were modified by VDR polymorphisms. Improving lipid profile, mainly triglycerides, accounted for part of the favorable associations.

Association between Vitamin D Receptor Fokl and Bsml Gene Polymorphism and Diabetes Mellitus in Nepalese Population

Vitamin D being involved in the secretion of insulin is a known fact. Moreover, studies have shown that steroids might be a factor in influencing insulin sensitivity. Vitamin D receptor (VDR), a factor required for genetic regulation involving vitamin D, thus can be regarded as a good candidate for Diabetes Mellitus (DM). Several studies have been conducted on the association between VDR polymorphism and the risk of DM but did not provide clear-cut answers. This study was conducted to search for the involvement of FokI and BsmI polymorphisms of the VDR gene with DM in a Nepalese population. A total of 200 blood samples were collected; 100 from clinically diagnosed DM patients and 100 from healthy controls. DNA was extracted from blood by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis, where FokI and BsmI primers as well as restriction enzymes were used. After restriction digestion, SNPs of FokI (T/C) [rs2228570] and BsmI (A/G) [rs1544410] were assayed using agarose gel electrophoresis. As patients and controls were likened for genotype distribution and allelic frequencies, it was found that the frequency of VDR gene BsmI rs1544410 differed significantly (p &lt; 0.05, each) between cases and control whereas A allele was dominant (91%) in healthy controls with Odd ratio (OR) of 0.55, unlike VDR Fokl were not significantly associated between subjects and control. The data obtained from this research suggests that the VDR gene (especially BsmI) is associated with the risk of DM.

Association of Vitamin D Deficiency and Vitamin D Receptor Gene Polymorphisms with Type 1 Diabetes Risk: A South Indian Familial Study

Vitamin D is a potent immune modulator and is associated with autoimmune diseases, including type 1 diabetes (T1D). The vitamin D levels and its receptor gene polymorphisms together in T1D are not yet investigated in the South Indian population. The present study focused on exploring the significance of vitamin D levels and vitamin D receptor (VDR) gene polymorphisms with the risk of developing T1D in the South Indian population. Patients with T1D and unaffected first-degree relatives (FDRs) were included in this study. Genotyping of VDR polymorphisms at four different loci (FokI- F/f, BsmI- B/b, TaqI- T/t, and ApaI- A/a) was assessed through the amplification refractive mutation system-polymerase chain reaction method. Serum vitamin D levels were measured in 98 T1D patients and 75 age- and sex-matched siblings. A total of 120 patients with T1D and 214 FDRs were included. Vitamin D deficiency (VDD) was observed in a higher proportion of T1D patients than in controls (52% vs. 32%; p<0.03). The frequency of the FokI-FF genotype was significantly higher [odds ratio (OR)=1.66; p<0.03] in T1D patients conferring a susceptible association with the disease. Nevertheless, the increased frequency of heterozygous Ff genotype (OR=0.57; p<0.02) among controls may confer a protective association with T1D. Furthermore, the transmission disequilibrium test revealed over-transmission of ApaI-A (T: U=15/5; p<0.006) and BsmI-B alleles (T: U=17/5; p<0.01) and under-transmission of BsmI-b/ApaI-a/TaqI-T haplotype (T: U=5.4/14.4; p=0.04) from parents to T1D patients. The present study concludes that VDD is the major contributing risk factor to T1D development in the South Indian population. Furthermore, the FokI-FF genotype, BsmI-B, and ApaI-A alleles were positively associated with T1D. In contrast, the FokI-Ff genotype and BsmI-b/ApaI-a/TaqI-T haplotype were negatively associated with T1D.

Effects of VDR and CYP24A1 gene polymorphisms on the outcome of supraglottic larynx cancer.

Vitamin D has been demonstrated to play a protective role in carcinogenesis. Polymorphisms of the vitamin D receptor (VDR) genes and 24-α-hydroxylase (encoded by CYP24A1) may affect the outcome of some cancers. This study examines the effects of the VDR gene and CYP24A1 single nucleotide polymorphisms on the outcome of supraglottic larynx cancer. Patients diagnosed with supraglottic larynx cancer between 2017 and 2022 were enrolled. Single nucleotide polymorphisms of the VDR gene (rs2228570, rs731236, rs7975232, rs11574113, rs11168267 and rs11168266) and CYP24A1 gene (rs4809960, rs6022999, rs6068816, rs2259735 and rs2296241) were investigated. All patients were followed up for any evidence of local recurrence, regional recurrence, distant metastasis, and second primary tumor development. Cox regression analysis was performed to evaluate the prognostic value of single-nucleotide polymorphisms (SNPs). Kaplan-Meier method was used for survival analysis. 87 patients were included. The mean follow-up time was 45.02±24.47 months. Cox regression analysis for locoregional recurrence revealed that the hazard ratio of rs731236 GG was 2.098 (95% CI, range: 1.047-4.202, p=0.037). Locoregional recurrence for rs731236 AA, AG, and GG were 38.6%, 23.1%, and 53.3%, respectively. In the presence of rs731236 GG polymorphism, disease-specific survival was significantly shorter (47.63±7.48 months, p=0.015), and disease-free survival (45.71±6.3 months) was significantly shorter (p=0.040). Rates of metastases and second primary tumors were not significantly different between SNPs. This study has demonstrated the possible effects of VDR rs731236 SNP on the locoregional recurrence and prognosis of supraglottic larynx cancer.

Association between Vitamin D Receptor Polymorphism and Susceptibility to Oral Lichen Planus and Oral Squamous Cell Carcinoma.

Oral squamous cell carcinomas (OSCC) comprise 90-95% of oral cancers. Early diagnosis improved the survival rate of OSCC patients to 80-90%. Oral lichen planus (OLP) is a chorionic inflammatory disease with malignancy potential. The vitamin D receptor (VDR) plays a critical role in the pathogenesis of oral cancer. This study aimed to determine the association between VDR rs7975232 (Apa I) polymorphism and potential susceptibility to OLP and OSCC risks. In this prospective case-control study, a total of 120 blood samples were obtained from OSCC patients (n=29), OLP (n=50), and controls (n=40). VDR rs7975232 polymorphism was studied using the Polymerase Chain Reaction Restriction Fragment Length Polymorphism (PCR-RFLP) method. Statistical analysis was performed with SPSS Version 23 software. Data were expressed as means ± standard deviation (SD). Age, sex, allelic frequency, and genotyping were compared using the chi-square test. A p-value of less than 0.05 was regarded as statistically significant. The disease risk was estimated by Odds ratio (OR) with a 95% confidence interval. A significant age difference was observed between the controls and the OSCC group (p=0.001). A significant difference was observed in Aa and aa genotypes compared with AA between OSCCs and controls. Moreover, dominant (p<0.001), additive (p<0.001), and allelic (p=0.001) models were different between groups. There was a positive association between rs7975232 VDR polymorphism and susceptibility to OSCC. More experimental evidence must reveal the possible association between rs7975232 and the risk of OLP in a larger cohort.

Clinical and genetic determinants of vitamin D receptor expression in cutaneous melanoma patients.

Decrease of vitamin D receptor (VDR) expression is observed in melanocytic naevi and melanoma compared to normal skin. Little is known about factors influencing VDR expression in cutaneous melanoma (CM). We investigated the correlation of VDR expression in CM with 25-hydroxy vitamin D (25OHD) levels, demographic/clinical parameters, genetic variants of VDR and pathology of the primary tumor. Demographic/clinical parameters were recorded in 407 prospectively recruited CM patients of a multi-center controlled study (ViDMe trial). We determined VDR expression both in the nucleus and in the cytoplasm by semi-quantitative assessment in CM tissue using histochemistry in 279 patients, expressed in percentages and histoscore (H-score). Genomic DNA from 332 patients was extracted to genotype thirteen VDR single nucleotide polymorphisms (SNPs) using TaqMan. VDR expression in CM tissue from 279 patients was correlated with clinical/demographic parameters and 25OHD levels (univariable and multivariable analysis), VDR SNPs (univariable analysis) and pathology parameters of primary CM tissue (univariable analysis). Cytoplasmic VDR expression was increased in patients who stated to have a high sun exposure during their life compared to patients with low sun exposure (p H-score,univariable : 0.001, p H-score,multivariable : 0.004). The A allele of the genetic VDR polymorphism Fok1 was associated with a higher expression of the VDR in the cytoplasm (p cytoplasmic, univariable : 0.001 and p H-score, univariable : 0.02). In the primary tumor, presence of mitosis (p nucleus,%, univariable : 0.002) and perineural invasion (p nucleus,%,univariable : 0.03) were significantly associated with low nuclear VDR expression. ClinicalTrials.gov Identifier: NCT01748448.

BMP6 and VDR gene polymorphisms are associated with osteonecrosis in a sickle cell anaemia cohort.

The occurrence and severity of osteonecrosis in sickle cell anaemia (SCA) vary due to risk factors, including genetic modifiers. Bone morphogenetic proteins (BMPs), particularly BMP6, and the vitamin D receptor (VDR) play key roles in cartilage and bone metabolism, making them potential contributors to orthopaedic outcomes in SCA. Here, we evaluated the association of polymorphisms in BMP6 (rs3812163, rs270393 and rs449853) and VDR (FokI rs2228570 and Cdx2 rs11568820) genes with osteonecrosis risk in a Brazilian SCA cohort. A total of 177 unrelated SCA patients were selected. The AA genotype of BMP6 rs3812163 was independently associated with a lower osteonecrosis risk (p = 0.015; odds ratio (OR): 0.38; 95% confidence interval (CI): 0.18-0.83) and with the long-term cumulative incidence of osteonecrosis (p = 0.029; hazard ratio: 0.56, 95% CI: 0.34-0.94). The VDR rs2228570 TT genotype was independently associated with a lower osteonecrosis risk (p = 0.039; OR: 0.14; 95% CI: 0.02-0.90). In summary, our results provide evidence that BMP6 rs3812163 and the VDR rs2228570 might be implicated in osteonecrosis pathophysiology in SCA and might help identify individuals at high risk.

ApaI and Fok1 Variants of Vitamin D Receptor Gene Associated with Metabolic Syndrome Among Jordanian Women.

The association between vitamin D receptor (VDR) polymorphisms and metabolic syndrome (MS) remains debatable. The current study aimed to determine the correlation of VDR gene polymorphisms with MS among Jordanian women. This case-control study enrolled 100 women with MS and 100 age-matched women as control at Al-Hikma Modern Hospital in Jordan between January 2019 and January 2020. The levels of glycated hemoglobin, fasting glucose, triglyceride, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and 25-hydroxy vitamin D (25(OH)D) were determined from serum samples of all participants. DNA was extracted from whole blood samples, and VDR gene polymorphisms Apa1, Taq1, Bsm1, and Fok1 were analyzed by polymerase chain reaction and restriction fragment length polymorphism. There was a significant difference between MS patients and control in terms of body mass index (34.3±3.1 vs. 28.1±2.5), glycated hemoglobin (5.9±1.1 vs. 4.6±1.2), fasting blood glucose (6.4±1.6 vs. 5.2±1.4), and total cholesterol (6.5±1.2 vs. 5.3±1.8). The results also demonstrated a statistical difference in the number of MS patients and control with 25(OH)D deficiency (69.0 vs. 33.0), 25(OH)D insufficiency (25.0 vs. 42.0), and 25(OH)D sufficiency (6.0 vs. 25.0) (p < 0.001). MS was significantly associated with VDR polymorphisms among Apa1 and Fok1 genes. The genotype distribution for CC (47.0% vs. 53.0%; p = 0.002) and CA (37.0% vs. 45.0%; p = 0.001) genotypes among Apa1 VDR polymorphism, as well as among TT genotype (38.0% vs. 20.0%; p = 0.025) among Fok1 VDR gene polymorphism significantly differed between MS patients and healthy individuals. However, no associations were detected among Taq1 and Bsm1 VDR genotypes. VDR gene polymorphism of Apa1 and Fok1 variants may increase the risk of metabolic syndrome among Jordanian women.

Assessment of vitamin D status and vitamin D receptor polymorphism in Egyptian children with Type 1 diabetes

BackgroundThe endocrine system of vitamin D regulates about 3 % of the human genome. Vitamin D exerts its actions via a nuclear vitamin D receptor (VDR) which in turn regulates insulin secretion from the pancreas. VDR gene polymorphisms could have an impact on how autoimmune illnesses like Type 1 diabetes mellitus (T1DM) develop. We aimed to explore the relation between T1DM and VDR gene polymorphisms in Egyptian diabetic children and their siblings. MethodsEnzyme-linked immunosorbent assay was used to quantify 25(OH) vitamin D in the study, which had 179 participants (group 1 = 85 diabetic children, group 2 = 57 siblings of the patients, group 3 = 37 healthy controls). Real-time polymerase chain reaction (RT-PCR) was used to analyze the genotyping of the VDR gene polymorphisms Apa-I (rs7975232), Fok-I (rs2228570), Taq-I (rs731236) and Bsm-I (rs1544410). ResultsThe mean serum 25(OH) vitamin D levels was significantly lower in T1DM patients (14.99 ± 9.24 ng/mL) and siblings (16.31 ± 7.96 ng/mL) compared to the controls (19.48 ± 7.42 ng/mL) (p = 0.031). The genotypes distribution of VDR Fok-I (rs2228570) and Bsm-I (rs1544410) polymorphisms showed a significant difference between patients, siblings and controls as P = 0.001 and 0.026 respectively, while the VDR ApaI and TaqI polymorphisms did not. FokI-A allele frequency was significantly lower in T1DM patients and siblings than in controls (p < 0.001). FokI-AA genotype had a statistical significant higher vitamin D levels than other genotypes with p value of 0.024. ConclusionOur study found that T1DM children had lower vitamin D levels, and VDR FokI and BsmI gene polymorphisms were linked to T1DM in Egyptian children. Determining the relationship between vitamin D levels and VDR polymorphisms, particularly the FokI and other genetic analyses may aid in the early diagnosis of T1DM in children.

Serum 25-Hydroxyvitamin D, Vitamin D Receptor, and Vitamin-D-Binding Protein Gene Polymorphisms and Risk of Dementia Among Older Adults With Prediabetes.

The association between vitamin D and dementia risk in those with prediabetes remains uncertain. We aimed to evaluate the association of serum 25-hydroxyvitamin D (25OHD) with incident dementia among older adults with prediabetes, and examine whether apolipoprotein E (APOE) genotypes, vitamin D receptor (VDR), and vitamin-D-binding protein (VDBP) gene polymorphisms may modify this association. A total of 34237 participants aged ≥60 with prediabetes (HbA1c <6.5% and ≥5.7%) and without dementia at baseline were included from the UK Biobank. Serum 25-hydroxyvitamin D (25OHD) was measured using chemiluminescent immunoassay method. The primary outcome was incident all-cause dementia. Secondary outcomes included incident Alzheimer's disease (AD) and vascular dementia, respectively. The VDR and VDBP gene polymorphisms included single nucleotide polymorphisms of rs7975232, rs1544410, rs2228570, rs731236, and rs7041, rs4588, respectively. During a median follow-up of 11.8 years, 941 (2.7%) participants developed incident all-cause dementia. Overall, serum 25OHD was inversely associated with all-cause dementia (per standard deviation increment, adjusted hazard ratio: 0.82; 95% confidence interval: 0.75, 0.89). Similar trends were found for incident AD and vascular dementia. Furthermore, there was a stronger inverse relationship between serum 25OHD and all-cause dementia among VDR rs7975232 C allele noncarriers (p-interaction < 0.05). However, APOE Ɛ4, other VDR, and VDBP gene polymorphisms did not significantly modify the relation of serum 25OHD with incident all-cause dementia (all p-interactions >.05). There was an inverse association between serum 25OHD and incident dementia among older adults with prediabetes, especially in VDR rs7975232 AA allele carriers.

Vitamin D receptor (VDR) variants are risk factors for ovarian cancer: a meta-analysis and trial sequential analysis

The importance of Vitamin D in ovarian cancer (OC) has been well documented, and lower levels have been associated with susceptibility to OC. Vitamin D exerts its effect through the vitamin D receptor (VDR). Common genetic variants in the VDR gene (Fok I, TaqI, BamI and ApaI) have been linked with the susceptibility to the development of OC; however, the reports remain contradictory. To draw a valid conclusion, we performed a meta-analysis of the earlier published reports in the present study. The literature search was performed in PubMed, Google Scholar, and Scopus databases. All relevant articles were screened, and eligible reports were identified based on prefixed inclusion and exclusion criteria. Data such as author’s details, year of publication, ethnicity, genotype and allele prevalence in cases and controls were extracted from the eligible reports. The meta-analysis was performed using Comprehensive Meta-analysis Software (CMA) V3. Eight articles, including data from fourteen independent cohorts, comprised 4276 cases and 6739 healthy controls considered for the analysis. VDR FokI and BamI variants revealed a significant association with an increased risk of OC. Other VDR polymorphisms (TaqI and ApaI) failed to demonstrate such an association with OC. Interestingly, the sensitivity analysis revealed minimal deviation from the parent meta-analysis, supporting the robustness of the present analysis. The trial sequential analysis revealed the inclusion of a sufficient number of studies for FokI polymorphism. It highlighted the requirement for additional case-control studies in VDR (ApaI, BamI and TaqI) to draw a definitive conclusion. FokI and BamI polymorphisms are associated with susceptibility to OC.

Vitamin D and Vitamin D Receptor FokI, ApaI, and BsmI Gene Polymorphisms and their Relation with the Risk of Breast Carcinoma: A Case-control Study

Introduction: Breast cancer stands as the leading cause of mortality among women in developing nations. The potential role of Vitamin D in mitigating the incidence of breast cancer is thought to stem from its ability to impede cell proliferation by interacting with the Vitamin D Receptor (VDR). The VDR gene is responsible for encoding the VDR, which plays a pivotal role in mediating the effects of vitamin D. Aim: To analyse vitamin D levels and the association of VDR FokI, ApaI, and BsmI genotypic distribution frequency with the risk of breast cancer. Materials and Methods: The case-control study included 220 samples, including 110 breast cancer patients and 110 agematched control women aged 30-70 years. The Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) genotyping was performed using Deoxyribonucleic acid (DNA) extracted from blood, and the circulating levels of 25-hydroxyvitamin D by case/control were estimated by chemiluminescence immunoassay. Results: The 3’ VDR polymorphism BsmI sequence showed minimal association with breast cancer risk. The bb genotype had a significantly lower odds ratio of 0.056 (p-value&lt;0.05). Conversely, the BB and Bb genotypes exhibited no statistically significant associations with odds ratios of 1.76 (95% CI: 0.36-8.54; p-value&gt;0.05) and 1.30 (95% CI: 0.27- 6.25; p-value&gt;0.05), respectively. Isolated analysis of the FokI variant revealed a significant association with increased breast cancer risk, with odds ratios of 5.49 (FF) and 6.00 (Ff), both demonstrating statistical significance (p-value&lt;0.05), and a Chi-square value of 0.006. Additionally, the p-value for serum Vitamin D levels was found to be highly significant at p-value&lt;0.001, indicating that the levels were significantly lower in individuals newly diagnosed with breast cancer compared to those in the healthy control group. Conclusion: The study found a significant link between breast cancer susceptibility and VDR (FokI) polymorphism FF and Ff genotypes, with minimal impact observed for (BsmI) polymorphism bb genotype. This implies that certain genetic variations, especially in the FokI polymorphism of the VDR gene, are associated with an elevated risk of breast cancer.

Frequency of Healthy Control Genotype of VDR Gene Polymorphisms in the Saudi Population of the Ha'il Region: A Comparative Study with Worldwide Population.

Genetic polymorphisms in the vitamin D receptor (VDR) may influence the biological effects of vitamin D and increase a person's susceptibility to cancer. Previous studies have shown that different ethnic groups exhibit varying frequencies of the VDR gene variants TaqI, ApaI, FokI, and BsmI. However, the allelic distribution of these VDR polymorphisms in the Saudi population of Ha'il region is not sufficiently explored. In this study, efforts were made to ascertain the frequency of VDR polymorphisms in the Saudi population of Ha'il region, and then comparison was made for VDR polymorphism rates with other populations of the world. Allele and genotype frequencies of VDR TaqI, ApaI, BsmI and FokI gene was determined. The frequency distribution for the variant allele of VDR TaqI, ApaI, BsmI and FokI was found to be 70, 33, 50 and 25%, respectively. A significant frequency distribution was found for VDR-TaqI, ApaI and FokI variants in comparison with other populations of the world. Whereas, almost all of the studies dealing with VDR-FokI failed to show substantial difference while comparing with the data reported from the population of Ha'il region of Saudi Arabia. A significant pattern in the frequency of VDR gene variations have been found in the Saudi population of Ha'il region, which may be attributed to ethnic variance. The understanding of the worldwide distribution of VDR markers could help with high-risk screening of those who are exposed to environmental hazards and people of Ha'il region, who are predispose to cancer.

Vitamin D receptor rs3782905 and vitamin D binding protein rs7041 polymorphisms are associated with hepatocellular carcinoma susceptibility in cirrhotic HCV patients

BackgroundThe severity of chronic hepatitis C and susceptibility to hepatocellular carcinoma (HCC) are associated with genetic variations within vitamin D receptor (VDR) in several populations. This study aims to determine the significance of the VDRs (rs2228570, rs3782905, rs11568820) and DBP (rs7041) for the susceptibility to HCC in Egyptian patients with chronic HCV infection and their effect on the progression of liver cirrhosis to carcinogenesis.MethodsSingle nucleotide polymorphisms (SNPs) VDR (rs2228570, rs3782905), and DBP rs7041 were genotyped using restriction fragment length-PCR (RFLP-PCR) technique and VDR rs11568820 was genotyped using single strand polymorphism PCR (SSP PCR). These SNPs genotypes, haplotypes and linkage disequilibrium analyses were examined in 299 Egyptian individuals (100 HCV-cirrhotic patients, 99 HCC- HCV patients, and 100 healthy controls).ResultThe VDR rs2228570 CC genotype, VDR rs3782905 GC and CC genotypes, and DBP rs7041 GG genotype are significantly higher in HCC. It is noteworthy that, VDR rs3782905 CC and DBP rs7041 TG genotypes are higher in HCV induced liver cirrhosis than with HCC progression in HCV infected patients. Furthermore, among patients, the relationship between these SNPs and smoking status, gender, and HCC susceptibility was reported.ConclusionAmong the four investigated SNPs, there are associations between VDR rs3782905 and DBP rs7041 and the HCC progression in Egyptian patients chronically infected with HCV. These SNPs are considered as risk factors in HCV induced liver cirrhosis and HCC. The combinations of these SNPs with smoking status and gender are statistically linked to a high risk of HCC. Future research with a larger sample size of subjects with HCV infection is advised, because chronic liver disease induced by HCV infection is the primary cause of HCC in Egypt. We recommend screening of these SNPs for prediction of LC and HCC development in HCV infected patients, which may improve the used therapeutic protocol. These results suggest that VDR polymorphisms may be potential determinants for HCC susceptibility in Egyptian HCV patients.

Modulation of the vitamin D/vitamin D receptor system in osteoporosis pathogenesis: insights and therapeutic approaches.

Osteoporosis is a prevalent bone disorder characterized by low bone mineral density (BMD) and deteriorated bone microarchitecture, leading to an increased risk of fractures. Vitamin D (VD), an essential nutrient for skeletal health, plays a vital role in maintaining bone homeostasis. The biological effects of VD are primarily mediated through the vitamin D receptor (VDR), a nuclear receptor that regulates the transcription of target genes involved in calcium and phosphate metabolism, bone mineralization, and bone remodeling. In this review article, we conduct a thorough literature search of the PubMed and EMBASE databases, spanning from January 2000 to September 2023. Utilizing the keywords "vitamin D," "vitamin D receptor," "osteoporosis," and "therapy," we aim to provide an exhaustive overview of the role of the VD/VDR system in osteoporosis pathogenesis, highlighting the most recent findings in this field. We explore the molecular mechanisms underlying VDR's effects on bone cells, including osteoblasts and osteoclasts, and discuss the impact of VDR polymorphisms on BMD and fracture risk. Additionally, we examine the interplay between VDR and other factors, such as hormonal regulation, genetic variants, and epigenetic modifications, that contribute to osteoporosis susceptibility. The therapeutic implications of targeting the VDR pathway for osteoporosis management are also discussed. By bringing together these diverse aspects, this review enhances our understanding of the VD/VDR system's critical role in the pathogenesis of osteoporosis and highlights its significance as a potential therapeutic target.