Vitamin D receptor polymorphism rs2228570 is significantly associated with risk of dyslipidemia and serum LDL levels in Chinese Han population

Vitamin D and Dyslipidemia: Is There Really a Link? A Narrative Review

Nowadays, the interest in the extraskeletal effects of vitamin D is growing. In the literature, its several possible actions have been confirmed. Vitamin D seems to have a regulatory role in many different fields-inflammation, immunity, and the endocrine system-and many studies would demonstrate a possible correlation between vitamin D and cardiovascular disease. In this paper, we deepened the relationship between vitamin D and dyslipidemia by reviewing the available literature. The results are not entirely clear-cut: on the one hand, numerous observational studies suggest a link between higher serum vitamin D levels and a beneficial lipid profile, while on the other hand, interventional studies do not demonstrate a significant effect. Understanding the possible relationship between vitamin D and dyslipidemia may represent a turning point: another link between vitamin D and the cardiovascular system.

Relationship between vitamin D receptors gene polymorphism and arteriogenic erectile dysfunction

BACKGROUND

Over the past few decades, a number of studies have linked vitamin-D deficiency with ED (Erectile dysfunction) risk factors. There is a clear correlation between VD (vitamin-D) levels and ED, according to observational and interventional researches that have been reported in the literature. This crucial information encouraged scientists to investigate the impact of VD on erectile function in greater detail. The fact that vitamin D is a component of a healthy penis that begins in early life has just come to light, however there haven't been many research looking at the connection between vitamin D receptor gene polymorphism and erectile dysfunction.

OBJECTIVE

To evaluate the relationship between arteriogenic erectile dysfunction and the vitamin D receptor gene polymorphism.

SUBJECTS AND METHODS

Between October 2022 and October 2023, at Al-Azhar University Hospitals, 40 patients with arteriogenic ED and 40 healthy controls underwent informed consent, a detailed history, a physical examination, a penile duplex ultrasound and the extraction of peripheral blood to determine the type of polymorphism for each of the vitamin D receptors: FokI, BsmI, ApaI and TaqI by polymerase chain reaction (PCR).

RESULTS

There is no statistically significant association between arteriogenic erectile dysfunction and the vitamin D receptors (VDR) gene polymorphisms FokI, BsmI, ApaI and TaqI.

CONCLUSION

Since there is no statistically significant association between the polymorphism of the vitamin D receptor (VDR) gene and arteriogenic erectile dysfunction, it is advised to investigate other VDR gene polymorphisms as well as alternative clinical subtypes of erectile dysfunction.

Cardiovascular and microvascular outcomes according to vitamin D level and genetic variants among individuals with prediabetes: a prospective study

BACKGROUND

Whether serum vitamin D mediate vascular diseases in prediabetic populations remains unclear. This study aimed to determine the associations between circulating 25-hydroxyvitamin D [25(OH)D] levels and vitamin D receptor (VDR) polymorphisms with the risk of macrovascular complications, including myocardial infarction and stroke, and microvascular complications such as diabetic nephropathy and retinopathy, among adults with prediabetes.

METHODS

Participants with prediabetes in UK Biobank were included (N = 56,387). Multivariable dose-response and Cox proportion models were used to explore the relationship of serum 25(OH)D status and the risks of vascular complications. The interaction of VDR polymorphisms with serum 25(OH)D level on risks of vascular events was also assessed.

RESULTS

During a median follow-up of 12 years, higher levels of 25(OH)D were significantly and nonlinearly associated with a lower risk of macrovascular diseases among prediabetic individuals. The adjusted hazard ratios (95% confidential interval) of serum 25(OH)D levels of ≥ 75.0 nmol/L versus < 25 nmol/L were 0.75 (0.63-0.88) for myocardial infarction, 0.74 (0.55-1.00) for stroke, 1.02 (0.60-1.74) for diabetic nephropathy, and 1.30 (0.92-1.84) for diabetic retinopathy, respectively. The rs2228570 (FokI) polymorphisms significantly interacted with 25(OH)D on incident myocardial infarction (P-interaction = 0.042) and stroke (P-interaction = 0.033). The individuals with serum 25(OH)D level of 50.0-74.9 nmol/L and rs2228570 (FokI) homozygotes had the lowest risks of vascular complications.

CONCLUSIONS

Lower serum 25(OH)D levels are significantly and nonlinearly associated with an increased risk of cardiocerebrovascular diseases in prediabetic individuals, with VDR polymorphisms of rs2228570 (FokI) modify such associations. Monitoring a safe 25(OH)D concentration is suggested to prevent the vascular complications for prediabetes.

Vitamin D level regulates serum lipids discrepantly in adults with and without dyslipidemia

Vitamin D deficiency is associated with hyperlipidemia, but it remains unclear whether vitamin D supplementation reduces serum lipid levels. The aims of this study were to investigate the associations between increased serum 25-hydroxyvitamin D (25(OH)D) concentrations and lipid levels and identify the characteristics of people with or without lipid reduction associated with increased 25(OH)D levels. The medical records of 118 individuals (53 men; mean age, 54.4 ± 10.6 years) whose serum 25(OH)D levels increased between 2 consecutive measurements were retrospectively reviewed. People with increased 25(OH)D levels (from 22.7 (17.6-29.2) to 32.1 (25.6-36.8) mg/dL; P < 0.01) had a significant reduction in serum levels of triglycerides (TGs) (from 111.0 (80-164) to 104.5 (73-142) mg/dL; P < 0.01) and total cholesterol (TC) (from 187.5 (155-213) to 181.0 (150-210) mg/dL; P < 0.05). The individuals who responded to vitamin D (≥10% reduction in TG or TC levels) exhibited significantly higher baseline TG and TC levels than those who did not. Only patients with hyperlipidemia (not those without hyperlipidemia) at baseline exhibited significantly reduced TG and TC levels at follow-up. However, increasing serum 25(OH)D concentrations were significantly correlated with decreasing lipid levels in individuals with baseline 25(OH)D levels less than 30 ng/mL and in individuals aged 50-65 years (not in patients younger than 50 years or older than 65 years). In conclusion, increasing serum 25(OH)D concentrations may be potentially helpful for the treatment of hyperlipidemia in people with vitamin D deficiency.

Association of vitamin D and polymorphisms of its receptor with antiviral therapy in pregnant women with hepatitis B

BACKGROUND

The interruption of mother-to-child transmission (MTCT) is considered important to decrease the individual and population morbidity of hepatitis B virus (HBV) infection as well as the global burden of hepatitis B. Serum vitamin D (VD) is associated with hepatitis B.

AIM

To assess whether baseline VD levels and single nucleotide polymorphisms of the VD receptor gene (VDR SNPs) are associated with the efficacy of tenofovir disoproxil fumarate (TDF) in the prevention of MTCT in pregnant women with high HBV viral loads.

METHODS

Thirty-eight pregnant women who were at high risk for MTCT of HBV (those with an HBV DNA level ≥ 2 × 10⁵ IU/mL during 12-24 wk of gestation) receiving antiviral therapy of TDF between June 1, 2019 and June 30, 2021 in Mianyang were included in this retrospective study. The women received 300 mg TDF once daily from gestational weeks 24-28 until 3 mo after delivery. To further characterize the clinical relevance of maternal serum HBV DNA levels, we stratified patients according to HBV DNA level as follows: Those with levels < 2 × 10⁵ (full responder group) vs those levels ≥ 2 × 10⁵ IU/mL (partial responder group) at delivery. Serum levels of 25-hydroxyvitamin D [25(OH)D], liver function markers, virological parameters, VDR SNPs and other clinical parameters were collected to analyze their association with the efficacy of TDF. The Mann-Whitney U test or t test was used to analyze the serum levels of 25(OH)D in different groups. Multiple linear regressions were utilized to analyze the determinants of the maternal HBV DNA level at delivery. Univariate and multivariate logistic regression analyses were employed to explore the association of targeted antiviral effects with various characteristics at baseline and delivery.

RESULTS

A total of 38 pregnant women in Mianyang City at high risk for MTCT of HBV were enrolled in the study. The MTCT rate was 0%. No mother achieved hepatitis B e antigen or hepatitis B surface antigen (HBsAg) clearance at delivery. Twenty-three (60.5%) participants were full responders, and 15 (39.5%) participants were partial responders according to antiviral efficacy. The present study showed that a high percentage (76.3%) of pregnant women with high HBV viral loads had deficient (< 20 ng/mL) or insufficient (≥ 20 but < 31 ng/mL) VD levels. Serum 25(OH)D levels in partial responders appeared to be significantly lower than those in full responders both at baseline (25.44 ± 9.42 vs 17.66 ± 5.34 ng/mL, P = 0.006) and delivery (26.76 ± 8.59 vs 21.24 ± 6.88 ng/mL, P = 0.044). Serum 25(OH)D levels were negatively correlated with maternal HBV DNA levels [log(10) IU/mL] at delivery after TDF therapy (r = -0.345, P = 0.034). In a multiple linear regression analysis, maternal HBV DNA levels were associated with baseline maternal serum 25(OH)D levels (P < 0.0001, β = -0.446), BMI (P = 0.03, β = -0.245), baseline maternal log10 HBsAg levels (P = 0.05, β = 0.285) and cholesterol levels at delivery (P = 0.015, β = 0.341). Multivariate logistic regression analysis showed that baseline serum 25(OH)D levels (OR = 1.23, 95%CI: 1.04-1.44), maternal VDR Cdx2 TT (OR = 0.09, 95%CI: 0.01-0.88) and cholesterol levels at delivery (OR = 0.39, 95%CI: 0.17-0.87) were associated with targeted antiviral effects (maternal HBV DNA levels < 2 × 10⁵ at delivery).

CONCLUSION

Maternal VD levels and VDR SNPs may be associated with the efficacy of antiviral therapy in pregnant women with high HBV viral loads. Future studies to evaluate the therapeutic value of VD and its analogs in reducing the MTCT of HBV may be justified.

Effects of Vitamin D Receptor Genotype on Lipid Profiles and Retinopathy Risk in Type 2 Diabetes Patients: A Pilot Study

Genetic polymorphisms affect lipid profiles and are associated with disease complications. Genetic variants in the vitamin D receptor (VDR) gene are associated with type 2 diabetes mellitus (T2DM). In this study, we investigated the effects of VDR genotypes on the lipid profile and disease complications of T2DM patients in a Jordanian population. Ninety T2DM patients were genotyped for four major functional VDR genetic variants, rs2228570 C > T (FokI), rs7975232 A > C (ApaI), rs731236 T > C (TaqI), and rs1544410 C > T (BsmI), using the polymerase chain reaction−restriction fragment length polymorphism method. Lipid profiles and diabetes complications were analyzed and correlated with VDR genotypes. We found that the VDR rs7975232 and rs1544410 alleles were significantly (p = 0.008−0.04) associated with high-density lipoprotein (HDL) levels and retinopathy among patients. Carriers of the rs7975232 A/A genotype exhibited higher levels (49.68 ± 15.86 mg/dL) of HDL than patients with the A/C (44.73 ± 13.38 mg/dL) and C/C (37.93 ± 9.22 mg/dL) genotypes. Moreover, carriers of the rs1544410 T/T genotype had higher levels of HDL (54.31 ± 16.45 mg/dL) than patients with the C/T (43.57 ± 13.24 mg/dL) and C/C (43.98 ± 13.17 mg/dL) genotypes. T2DM patients who carry the rs7975232 C/C genotype were at higher risk (odds ratio [OR] = 7.88) of developing retinopathy compared with carriers of the rs7975232 C/A and A/A genotypes. In addition, T2DM patients with the rs1544410 C/C genotype had a higher risk (OR = 4.21) of developing retinopathy than patients with the rs1544410 C/T and T/T genotypes. Therefore, we concluded that the VDR rs7975232 and rs1544410 alleles were associated with HDL levels and retinopathy and can be considered as potential genetic biomarkers for the lipid profile and retinopathy complication among T2DM patients in a Jordanian population of Arabic origin. Further studies with larger sample sizes are needed to confirm our findings.

Association of Lipids’ Metabolism with Vitamin D Receptor (rs10735810, rs222857) and Angiotensinogen (rs699) Genes Polymorphism in Essential Hypertensive Patients

BACKGROUND: Cardiovascular (CV) diseases are the most spread cause of mortality in the world. Essential arterial hypertension (EAH), as a major risk factor for the development of CV diseases, is a multifactorial disease involving environmental and genetic factors together with risk-conferring behaviors. AIM: The purpose of this study was to analyze lipid metabolism changes in patients with EAH depending on the Vitamin D receptor (VDR rs2228570 (aka rs10735810)) and angiotensinogen (AGT rs699) genes polymorphism. MATERIALS AND METHODS: The single-stage study involved 100 patients suffering from Stage 2 EAH, 1–3 degrees of blood pressure increase, high and very high CV risks, 21% (21) men, and 79% (79) women. The average age of patients was 59.86 ± 6.22 years old. The control group included 60 practically healthy individuals of an appropriate age and sex distribution. To examine the VDR gene (rs10735810, rs2228570) and AGT gene (rs699) polymorphism, a qualitative real-time polymerase chain reaction was made. The lipid metabolism was studied by determining the blood plasma content of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglycerides (TGs). RESULTS: Т allele of AGT gene is associated with reduced HDL-C level in men and increased TGs level in women. The EAH risk increases 4.5 times as much among the ТС-genotype carriers and lowered HDL-C level (odds ratio [OR] = 6.43; p = 0.01). The EAH risk increases as far as the HDL-C level reduction, irrespective of the VDR gene alleles condition 1.83 times (OR = 2.37; OR 95% confidence interval [CI]: 1.02–5.51; p = 0.04) and 1.9 times (OR=2.43; OR 95% CI: 0.99–5.97; p = 0.04). HDL-C reduction and LDL-C elevation in women increase the EAH risk 2.4 times (OR = 3.27; p = 0.01) and 1.24 times (OR = 3.67; p = 0.01), respectively. CONCLUSIONS: The EAH risk increases with a reduced HDL-C level in the TC genotype carriers of the AGT gene and irrespective of VDR gene polymorphic variants.

Vitamin D deficiency is a risk factor for delayed tooth eruption associated with persistent primary tooth

OBJECTIVE

To verify the association between 25(OH)D level and polymorphisms in the vitamin D receptor gene (VDR) with the disturbance in the dental development and eruption.

DESIGN

A total of 183 children from two datasets were evaluated. The first dataset was a case-control (15:15) designed to assess if persistent primary tooth (PPT) is associate with serum 25(OH)D level and with genetic polymorphisms in VDR. The second dataset of genomic DNA samples from 54 children with delayed tooth eruption (DTE) and 99 controls were analysed to verify if genetic polymorphisms in VDR (rs2228570 and rs739837) are associated with DTE. The 25(OH)D and the genotyping/allele distribution were analysed using the T-test and chi-square test, respectively.

RESULTS

The level of 25(OH)D in the PPT group (24.9 ± 6.4 mg/mL) was significantly lower than the control (30.0 ± 7.0 mg/mL) (p=.047). Our data show that children with 25(OH)D deficiency are more likely to present PPT (OR = 2.36; 95%CI: 1.51, 3.70). The rs739837 and rs2228570 polymorphisms were not associated with DTE (OR = 1.44; 95%CI: 0.87, 2.39 and OR = 0.80; 95%CI: 0.45, 1.44, respectively).

CONCLUSIONS

Vitamin D deficiency is a risk factor for PPT.

Vitamin D receptor gene polymorphisms in atopy

Background

The occurrence of allergic conditions, for example allergic asthma, rhinitis, and atopic dermatitis, is rising worldwide. These allergic conditions are associated with poor life quality. Vitamin D is proposed to be linked with increased risk and severe forms of allergic diseases.

Aims

This review article aimed to evaluate the vitamin D level role and polymorphisms of vitamin D receptor gene (VDR) in atopy.

Methods & Materials

We analyzed publications that were focusing on levels of vitamin D and/or polymorphism analysis of vitamin D receptor gene in allergic asthma, rhinitis, and atopic dermatitis patients.

Results

We noticed that levels of vitamin D are extensively studied in atopy by many research groups, however, polymorphisms of vitamin D receptor gene and their link with levels of vitamin D lack comprehensive data. There is evidence that vitamin D may be associated with anti‐inflammatory effects in allergic diseases. Some of VDR polymorphisms also may play a role in pathogenesis of these diseases. However, the data from different studies are controversial.

Discussion

The results of different studies are usually inconsistent, most probably due to populational bias or differences in methodology. Even though, more evidence shows a positive impact of vitamin D on the risk and outcomes of allergic diseases, especially atopic dermatitis, and asthma.

Conclusions

There is controversial data about the level of vitamin D and its role in atopy; however, more evidence shows a positive impact on the risk and outcomes of allergic diseases.

Vitamin D levels and vitamin D receptor genetic variants in Egyptian cardiovascular disease patients with and without diabetes

Background

25-Hydroxyvitamin D (Vit.D) levels associated with cardiovascular disease (CVD) may vary according to genetic variants in the vitamin D receptor (VDR) gene. However, the existing results are not conclusive in the Egyptian population, where diabetes mellitus is a common CVD risk factor. The purpose of the study was to evaluate the role of VDR polymorphism in Egyptian patients with CVD by studying the association of the rs2228570 (FokI) and rs1544410 (BsmI) single nucleotide polymorphisms (SNPs) of the VDR gene and serum levels of Vit.D with several CVD risk factors in patients with and without diabetes mellitus. We studied the genotypes for rs2228570 (FokI) and rs1544410 (BsmI) SNPs of the VDR gene in 382 Egyptian patients (120 CVD patients with diabetes, 124 CVD patients without diabetes, 69 diabetic patients without CVD and 69 healthy individuals). We also determined the serum levels of Vit.D, insulin, lipids, fasting blood glucose (FBG), and the body mass index (BMI).

Results

The distribution of genotypes and allelic frequencies of the rs2228570 (FokI) and rs1544410 (BsmI) SNPs of the VDR gene was significant in CVD patients (p < 0.001). The level of Vit.D was significantly lower in patients with CVD and diabetes compared to those without diabetes (p < 0.001). Moreover, there was a significant association between Vit.D level and the selected SNPs with serum lipids, BMI, FBG, and insulin levels in CVD patients with or without diabetes.

Conclusion

The level of Vit.D and the distribution of VDR polymorphisms are associated with risk of CVD in Egyptian patients with or without diabetes. These results suggest that VDR polymorphisms may be potential diagnostic biomarkers for CVD susceptibility.

The association between vitamin D receptor polymorphisms and tissue-specific insulin resistance in human obesity

BACKGROUND/OBJECTIVES

To investigate (1) the association of four VDR polymorphisms (TaqI/rs731236, ApaI/rs7975232, FokI/rs10735810, and Bsml/rs1544410) with markers of adiposity and tissue-specific insulin resistance at baseline, after weight loss and weight maintenance; (2) the effect of the VDR polymorphisms in the SAT transcriptome in overweight/obese Caucasians of the DiOGenes cohort.

METHODS

We included 553 adult obese individuals (mean BMI 34.8 kg/m²), men (n = 197) and women (n = 356) at baseline, following an 8-week weight loss intervention and 26 weeks weight maintenance. Genotyping was performed using an Illumina 660W-Quad SNP chip on the Illumina iScan Genotyping System. Tissue-specific IR was determined using Hepatic Insulin Resistance Index (HIRI), Muscle Insulin Sensitivity Index (MISI), and Adipose Tissue Insulin Resistance Index (Adipo-IR). Expression quantitative trait loci (eQTL) analysis was performed to determine the effect of SNPs on SAT gene expression.

RESULTS

None of the VDR polymorphisms were associated with HIRI or MISI. Interestingly, carriers of the G allele of VDR FokI showed higher Adipo-IR (GG + GA 7.8 ± 0.4 vs. AA 5.6 ± 0.5, P = 0.010) and higher systemic FFA (GG + GA: 637.8 ± 13.4 vs. AA: 547.9 ± 24.7 µmol/L, P = 0.011), even after adjustment with age, sex, center, and FM. However, eQTL analysis showed minor to no effect of these genotypes on the transcriptional level in SAT. Also, VDR polymorphisms were not related to changes in body weight and IR as result of dietary intervention (P > 0.05 for all parameters).

CONCLUSIONS

The VDR Fokl variant is associated with elevated circulating FFA and Adipo-IR at baseline. Nevertheless, minor to no effect of VDR SNPs on the transcriptional level in SAT, indicating that putative mechanisms of action remain to be determined. Finally, VDR SNPs did not affect dietary intervention outcome in the present cohort.

Association of Vitamin D Receptor Gene Polymorphisms with Metabolic Syndrome in Chinese Children

Purpose

To investigate the association between vitamin D receptor (VDR) gene polymorphisms and vitamin D deficiency, overweightness/obesity, and metabolic syndrome (MetS) in a cohort of Han children residing in Hangzhou, China.

Patients and Methods

This study assessed 106 overweight/obese and 86 healthy (control) children. Five single-nucleotide polymorphisms (SNPs) in the VDR gene, namely, TaqI (rs731236 T > C), ApaI (rs7975232 C > A), BsmI (rs1544410 G > A), FokI (rs2228570 G >A), and Cdx2 (rs11568820 G > A), were genotyped by sequencing the total polymerase chain reaction products. The distributions of different genotypes and alleles were compared among different groups.

Results

The serum 25-hydroxyvitamin D (25(OH)D) concentration was significantly lower in overweight/obese children, while the AA genotype of ApaI SNP exhibited higher frequencies in the overweight/obese group than in the control. Furthermore, children with the ApaI AA genotype showed higher levels of Glu-60min, Glu-90min, Glu-120min and triglyceride. The AA genotype of FokI SNP was significantly associated with MetS. However, no association was observed between the five VDR SNPs and the risk of vitamin D deficiency.

Conclusion

VDR ApaI polymorphisms appear to be correlated with overweightness/obesity and glucose intolerance. FokI polymorphisms may be linked to a higher susceptibility toward MetS in Chinese children.

Vitamin D receptor gene ApaI and FokI polymorphisms and its association with inflammation and oxidative stress in vitamin D sufficient Caucasian Spanish children

BACKGROUND

Vitamin D has gone from being just one vitamin to being an important prohormone with multiple effects on different tissue types. The mechanism of action of the active form or calcitriol is mediated by the intracellular vitamin D receptor (VDR). The interaction of the VDR with calcitriol modulates the expression of target genes involved in cell proliferation and cytokine production. Several studies have explored the effects of vitamin D deficiency in inflammatory disorders. Furthermore, some mutations in the VDR can affect its functionality. The focus of this study was to explore associations between VDR single nucleotide polymorphisms (SNPs) and markers of inflammation and oxidative stress in vitamin D sufficient children.

METHODS

This is a cross-sectional study of a Caucasian Spanish population including 155 healthy children (87 males, 68 females) aged 10 to 14 years. FokI, ApaI and TaqI SNPs of the VDR gene were genotyped. Routine biochemistry, serum levels of interleukin-6, tumor necrosis factor-α, interferon-γ, 8-isoprostaglandin F2α and nitrates were determined.

RESULTS

The homozygous major allele AA in the FokI SNP was associated with increased levels of high-density lipoprotein cholesterol in a recessive inheritance mode (P=0.025). The minor allele A of ApaI was significantly associated with decreased serum tumor necrosis factor-α and 8-isoprostaglandin F2α in an additive mode (P=0.016 and P=0.020 respectively). No significant associations were observed between the TaqI SNP and any of the parameters evaluated. Haplotype analysis confirmed the significance of the relationships between ApaI and FokI SNPs and parameters associated with inflammation and oxidative stress.

CONCLUSIONS

Genetic variations of VDR are associated with subtle changes in metabolic, inflammatory and oxidative stress markers. These results may provide a better understanding of the relationships between vitamin D and these clinical parameters.

Vitamin D receptor gene methylation in patients with hand, foot, and mouth disease caused by enterovirus 71

To evaluate the epigenetic regulation of the VDR gene in enterovirus 71 (EV71)-associated severe hand, foot, and mouth disease (HFMD), a total of 116 patients with EV71-HFMD, including 58 with mild EV71-HFMD and 58 with severe EV71-HFMD, as well as 60 healthy controls, were enrolled in this study. Quantitative real-time PCR was used to measure the relative levels of VDR mRNA expression, and the methylation status of the VDR promoter was assessed using a MethylTarget™ assay. The DNA methylation levels of the VDR promoter in children with EV71-associated severe HFMD were lower than those in the healthy controls and in children with mild HFMD (P < 0.05). Hypomethylation at CpG site 133 and hypermethylation at the CpG 42 sites and 68 downregulated VDR expression. Moreover, the methylation level of VDR could be used for differential diagnosis of mild and severe EV71-associated HFMD (AUC₅₆, 0.73; AUC₆₈, 0.699; AUC₄₂, 0.694; AUC₆₆, 0.693). VDR expression and promoter methylation were associated with the progression of EV71 infection. Determining the VDR promoter status might help clinicians initiate the appropriate strategy for treatment of EV71-associated HFMD.

Association Between Single Nucleotide Polymorphisms in the Vitamin D Receptor and Incidence of Dry Eye Disease in Chinese Han Population

Background

Dry eye disease (DED) is a chronic dysfunction of the ocular surface and has become an important public problem. Vitamin D receptor (VDR) gene polymorphism has been found to be associated with different kinds of diseases. The relationship between single nucleotide polymorphisms (SNPs) in the VDR gene should be studied.

Material/Methods

In the present case-control study, we investigated the association of VDR gene polymorphism with DED risk. Clinical data including age, gender, body mass index (BMI, kg/m²), smoking history, diabetes, and blood pressure were recorded. Serum 25-hydroxy vitamin D (25[OH]D) was chosen as the main parameter that reflected the level of vitamin D. We identified SNPs of VDR gene Apa-1, Bsm-1, Fok-1, and Taq-1 in both DED cases and healthy controls.

Results

A total of 124 DED cases and 135 healthy controls were included in this study. It was reported that aa in Apa-1 (OR=2.803, 95% CI, 1.350–5.820) and tt in Taq-1 (OR=0.362, 95% CI, 0.141–0.930) were associated with increased the risk of DED. Analysis of the allele frequencies of VDR gene polymorphisms among DED patients and healthy controls showed that allele differences in Apa-1 were significantly associated with higher risk.

Conclusions

SNPs of VDR gene (Apa-1 and Taq-1) were associated with the risk of DED. No significant association of Bsm-1 and Fok-1 in VDR gene demonstrated significant effect in the incidence of DED. Thus, we found that several SNPs of VDR gene could provide significant pathogenic effects in the risk of DED.

Vitamin D receptor gene polymorphisms are associated with triceps skin fold thickness and body fat percentage but not with body mass index or waist circumference in Han Chinese

Background

Evidence shows that low serum vitamin D concentrations account for an increased risk of obesity by inducing vitamin D receptor (VDR) hypofunction. Although the correlation between single nucleotide polymorphisms (SNPs) of VDR gene and obesity-related anthropometric measures (such as body mass index [BMI] and waist circumference[WC]) has already been tested, there are only few studies on the association between direct measures of body fat percentage (BFP) and triceps skinfold thickness and the SNPs of VDR. The aim of the present study was to evaluate the effect of VDR gene polymorphism on multiple obesity indexes in Han Chinese, including BMI, WC, BFP and triceps skinfold thickness.

Methods

In this cross-sectional study, five hundred and seventeen healthy Chinese adults were enrolled in the trial. Four loci in VDR gene (rs2228570 [FokI], rs2189480, rs2239179 and rs7975232[ApaI]) were genotyped by TaqMan probe assays. Obesity indexes including BMI, WC, BFP and triceps skinfold thickness were used to evaluate the relationship to the VDR SNPs. Multiple logistic regression, linear regression and general multifactor dimensionality reduction (GMDR) were performed to analyze the correlation of VDR gene and obesity indexes.

Results

None of the VDR SNPs were associated with BMI and WC, the C allele of FokI and the T allele of ApaI were associated with an increase in BFP (β = 0.069,P = 0.007; β = 0.087, P = 0.022 respectively); the G allele of rs2239179 and the T allele of ApaI were associated with an increase in triceps skin fold thickness (β = 0.074, P = 0.001; β = 0.122, P < 0.001 respectively). In regards to adiposity-related metabolic parameters, we found that the GT genotype of ApaI was associated with higher level of total cholesterol (TC) (P = 0.013) and Low-density lipoprotein cholesterol (LDL-C) (P = 0.001).

Conclusions

Though we failed to prove that VDR SNPs were in correlation with BMI and WC, we did establish the association between VDR variants and BFP, as well as triceps skinfold thickness. Data obtained suggested that the VDR variants play an important role in regulating adipose tissue activity and adiposity among Han Chinese.

Electronic supplementary material

The online version of this article (10.1186/s12944-019-1027-2) contains supplementary material, which is available to authorized users.

Association of polymorphisms in the vitamin D receptor gene with severity of hand, foot, and mouth disease caused by enterovirus 71

Severe hand, foot, and mouth disease (HFMD) is sometimes associated with critical complications that can cause substantial child mortality. Activity of the vitamin D receptor (VDR) may influence the outcomes of enterovirus 71 (EV71) infection. This case-control study aimed to assess the association of single-nucleotide polymorphisms (SNPs) in the gene encoding the VDR with the severity of EV71-associated HFMD. We selected four VDR SNPs based on linkage disequilibrium and functional prediction, and we tested them using the SNPscan multiple SNP typing method for potential association with severity of EV71-associated HFMD. We found a significant association in the case of rs11574129 (G vs A: odds ratio (OR), 0.3439; 95% confidence intervals (CI), 0.1778-0.6653) and rs739837 (T vs G: OR, 0.5580; 95%CI, 0.3352-0.9291). Our results suggest that these two SNPs may influence the severity of EV71-associated HFMD.