Evaluation of Gestational Diabetes Mellitus Risk in South Indian Women Based on MTHFR (C677T) and FVL (G1691A) Mutations

Serum folate mediates the associations of MTHFR rs1801133 polymorphism with blood glucose levels and gestational diabetes mellitus in Chinese Han pregnant women

This study aimed to explore the mediation effects of one-carbon metabolism (OCM) related nutrients on the association between MTHFR rs1801133 polymorphism and gestational diabetes mellitus (GDM). Folate, vitamin B12 and homocysteine (Hcy) were measured in the serum of 1254 pregnant women. Linear and logistic regressions were used to estimate the associations of OCM nutrients and MTHFR rs1801133 polymorphism with blood glucose levels and GDM risk. Mediation analysis was applied to test the mediation effects of folate, vitamin B12 and Hcy on the association of MTHFR rs1801133 polymorphism with blood glucose concentrations and GDM. Pregnant women with MTHFR rs1801133 CC genotype had higher serum folate (10·75 v. 8·90 and 9·40 ng/ml) and lower serum Hcy (4·84 v. 4·93 and 5·20 μmol/l) than those with CT and TT genotypes. Folate concentrations were positively associated with fasting plasma glucose (FPG), 1-h plasma glucose (1-h PG), 2-h plasma glucose (2-h PG) and GDM risk. Vitamin B12 levels were negatively correlated with FPG and GDM. Although no direct association was found between MTHFR rs1801133 genotypes and GDM, there were significant indirect effects of MTHFR rs1801133 CC genotype on FPG (β: 0·005; 95 % CI: 0·001, 0·013), 1-h PG (β: 0·006; 95 % CI: 0·001, 0·014), 2-h PG (β: 0·007; 95 % CI: 0·001, 0·015) and GDM (β: 0·006; 95 % CI: 0·001, 0·014) via folate. In conclusion, serum folate mediates the effect of MTHFR rs1801133 on blood glucose levels and GDM. Our findings potentially provide a feasible GDM prevention strategy via individualised folate supplementation according to the MTHFR genotypes.

Associations of MTHFR Polymorphisms and Cytosine Modifications with Early-Gestational Diabetes Mellitus in Chinese Pregnant Women

Early-Gestational Diabetes Mellitus (Early-GDM) is a complex condition that may cause complications in infants of affected mothers. The aim of this case-control study was to analyze the effects of genetic-epigenetic interaction on Early-GDM and fetal development with respect to cytosine modifications (i.e., 5mC, 5-methylcytosines; and 5hmC, 5-hydroxymethylcytosines) and single nucleotide polymorphisms (SNPs) of MTHFR, a key gene involving cytosine modifications. Peripheral blood samples were collected from 92 women in their first or second trimester of pregnancy (Early-GDM, n = 14; Controls, n = 78). Global DNA 5mC and 5hmC were quantified by HPLC-MS/MS, and MTHFR SNPs (rs1801133 C > T and rs1801131 A > C) were determined by TaqMan-qPCR. Association analysis suggested that MTHFR rs1801133 TT genotype was a risk factor of Early-GDM (OR [odds ratio] = 4.00; 95% CI [confidence interval]: 1.24, 12.86; p = 0.02). The C allele of rs1801131 appeared to be a protective factor for the 2-h OGTT (oral glucose tolerance test) (OR = -0.79; 95% CI: -1.48, -0.10; p = 0.03). Patients with Early-GDM had higher global 5mC and lower global 5hmC. The reduction of global 5hmC and the TT genotype of rs1801133 were associated with higher level of the 1st-FBG (fasting blood glucose in the first trimester) (p < 0.05). Additionally, global 5mC showed a positive correlation with birth weight, body length and head circumference of newborns, while global 5hmC showed a negative correlation with birth weight. The current study implicated MTHFR SNPs and cytosine modifications in the development of Early-GDM and potential complications in their newborns.

Associations of Maternal rs1801131 Genotype in MTHFR and Serum Folate and Vitamin B12 with Gestational Diabetes Mellitus in Chinese Pregnant Women

Circumstantial evidence links one-carbon metabolism (OCM) related nutrients, such as folate and vitamin B₁₂, with gestational diabetes mellitus (GDM). However, few studies have evaluated the combined effects of these nutrients with OCM related gene polymorphisms on GDM. This study investigated whether OCM related genetic variants modified the associations of folate and B₁₂ with GDM. Logistic regression was used to estimate odds ratios (ORs) for OCM related nutrients and single nucleotide polymorphisms (SNPs) in genes encoding main OCM related enzymes (MTHFR, MTR, and MTRR) on GDM. Higher folate concentrations were associated with increased GDM risk (OR: 1.59; 95% CI: 1.22, 2.13). However, higher B₁₂ concentrations were associated with reduced GDM risk (OR: 0.76; 95% CI: 0.65, 0.92). Pregnancies with MTHFR rs1801131 G alleles had a significantly lower risk of GDM than pregnancies with T alleles (OR: 0.65; 95% CI: 0.47, 0.91) under the dominant model. The genotype-stratified analysis revealed the association between folate and GDM (OR: 1.66, 95% CI: 1.20, 2.30) or B₁₂ and GDM (OR: 0.80, 95% CI: 0.65, 0.98) was more evident in pregnancies with TT genotype. Higher folate and lower B₁₂ are associated with GDM. Pregnancies with MTHFR rs1801131 TT genotype are more susceptible to OCM nutrient-related GDM.

The prevalence of Factor V Leiden (Arg506Gln) mutation in King Khalid University Hospital patients, 2017-2019

Arg506Gln mutation is responsible for one of the procoagulant factors and most common inherited thrombophilia in the Factor V Leiden (FVL) family. The replacement of the missense mutation for Arg506Gln / R506Q is at 1691st position from Guanine to Adenine with the modification of the amino acid from arginine to glutamine. The aim of this study was to investigate the current prevalence of the G1691A mutation in the FVL gene in the capital city’s King Khalid University Hospitals (KKUH). Since 2017–2019 we have recruited 482 patients in these cross-sectional studies to test the G1691A mutation in KKUH’s FVL gene. DNA was extracted using 2mL of the EDTA blood and genotyping was performed with polymerase chain reaction and the data was analyzed using Sanger sequencing. In this study, 4.4% of the G1691A mutation was found to be positive (combined heterozygous-GA and homozygous-AA variants) and 95.6% of them with negative, i.e., homozygous normal-GG genotypes. Our study concludes that with the advances in genetic testing and their recent availability, early mutation detection could approve the genotype risks for many patients and this mutation is not as rare as previously believed in the Saudi region as our study has established with a 4.4 percent prevalence.

Peripheral Vascular Disease Susceptibility Based on Diabetes Mellitus and rs17367504 Polymorphism of the MTHFR Gene

PURPOSE

Peripheral vascular disease (PVD) is a life-threatening condition affecting the lower extremities. Common risk factors include type 2 diabetes (T2D), hypertension, dyslipidemia, smoking, and older age. There is a little-documented research on the genetic basis of the disease in Taiwan. We examined the impact of T2D and the blood pressure-associated rs17367504 variant of the Methylenetetrahydrofolate reductase (MTHFR) gene on PVD risk.

MATERIALS AND METHODS

In this population-based association study, we linked data from 8992 participants in Taiwan Biobank (TWB) to their medical records in the National Health Insurance Research Database (NHIRD). Participants were 30 to 70 years old at recruitment and included those assessed between 2008 and 2015. We tested for association of PVD with rs17367504 and T2D using multiple logistic regression models. The rs17367504 variant was assessed using the Axiom-Taiwan Biobank Array Plate (TWB chip: Affymetrix, Inc., Santa Clara, CA, USA).

RESULTS

Among cases with T2D (n = 1294), 158 (12.21%) were identified with PVD. T2D was associated with PVD (odds ratio [OR], 1.52; 95% confidence interval [CI], 1.21-1.91; p<0.001) whereas rs17367504 variant was not (OR, 0.96; CI, 0.76-1.21; p = 0.728 in AG/GG compared to AA homozygotes). However, T2D and rs17367504 had an interactive effect on PVD (p for interaction = 0.0076). Results from our stratified analyses displayed OR of 1.75 (CI, 1.35-2.26; p<0.001) in AA individuals with DM and 0.94 (CI, 0.56-1.58; p = 0.811) in AG+GG individuals with T2D. Using the AA genotype and no T2D as the reference group, the respective OR of PVD was 1.77 (CI, 1.38-2.28; p<0.001) in AA individuals with T2D; 1.18 (CI, 0.91-1.55; p = 0.215) in AG+GG individuals with no T2D, and 1.03 (CI, 0.66-1.60; p = 0.892) in AG+GG individuals with T2D .

CONCLUSION

We found that type 2 diabetes was associated with increased risk of peripheral vascular disease, particularly in AA genotype carriers of the rs17367504 variant in Taiwan.

No Association Between ADIPOQ or MTHFR Polymorphisms and Gestational Diabetes Mellitus in South African Women

PURPOSE

Gestational diabetes mellitus (GDM) is a growing public health concern. GDM affects approximately 14% of pregnancies globally, and without effective treatment, is associated with short- and long-term complications in mother and child. Lower serum adiponectin (ADIPOQ) concentrations and aberrant DNA methylation have been reported during GDM. The aim of this study was to investigate the association between the ADIPOQ -11377C>G and -11391G>A, and methylenetetrahydrofolate reductase (MTHFR) 677C>T polymorphisms and GDM in a population of black South African women.

MATERIALS AND METHODS

DNA was isolated from the peripheral blood of 447 pregnant women with (n=116) or without (n=331) GDM, where after ADIPOQ (rs266729 and rs17300539) and MTHFR (rs1801133) polymorphisms were genotyped using TaqMan Quantitative Real-Time PCR analysis.

RESULTS

Women with GDM had a higher body mass index (p=0.012), were more insulin resistant (p<0.001) and had lower adiponectin levels (p=0.013) compared to pregnant women with normoglycemia. Genotypic, dominant and recessive genetic models showed no association between ADIPOQ rs266729 and rs17300539 and MTHFR rs1801133 polymorphisms and GDM. Intriguingly, the risk G allele of ADIPOQ rs266729 was associated with higher fasting glucose and insulin concentrations, while the T allele in MTHFR rs1801133 was associated with higher fasting insulin concentrations only.

CONCLUSION

ADIPOQ rs266729 and rs17300539 and MTHFR rs1801133 polymorphisms are not associated with GDM in a population of black South African women. These findings suggest that these single nucleotide polymorphisms (SNPs) do not individually increase GDM risk in the African population. However, the role of these SNPs in possible gene-gene or gene-environment interactions remain to be established.

Associations Between Gestational Diabetes Mellitus Risk and Folate Status in Early Pregnancy and MTHFR C677T Polymorphisms in Chinese Women

PURPOSE

Red blood cell (RBC) folate indicates long-term folate intake, and methylenetetrahydrofolate reductase (MTHFR) gene is the main gene affecting folate status. Increasing evidence suggests an association between gestational diabetes mellitus (GDM) and increased folate levels. Whether RBC folate concentrations in the first trimester of pregnancy or polymorphisms of MTHFR C677T (rs1801133) affect GDM risk in Chinese pregnant women remains unknown. Therefore, we analyzed the associations of RBC folate concentrations and rs1801133 polymorphisms with GDM risk among pregnant women in China.

METHODS

A total of 366 women with a singleton pregnancy were followed prospectively from their first prenatal visit to delivery. RBC folate concentrations and rs1801133 polymorphisms were assessed during the first trimester of pregnancy. Binary logistic regression analyses were performed to determine the odds ratios (ORs) of GDM and 95% confidence intervals (CIs) by using the RBC folate concentration quartiles and rs1801133 polymorphisms.

RESULTS

Participants with the TT genotype had the highest RBC folate concentrations. Those with heterozygous or homozygous variants did not have a significantly higher risk of GDM than did women with C alleles. After adjustments for covariates, women in the highest quartile for RBC folate concentration had a higher risk of GDM (adjusted OR = 2.473, 95% CI = 1.013-6.037, P = 0.047) than did those in the lowest quartile, but this association was nonsignificant after adjustment for rs1801133 polymorphisms.

CONCLUSION

Higher RBC folate, partly caused by MTHFR 677C→T, may be associated with increased GDM risk, even in early pregnancy. Assessing RBC folate status and appropriately supplementing folate during early pregnancy, particularly for patients with MTHFR 677C→T, may prevent GDM. Further studies with larger populations are warranted.

Genetic confirmation of T2DM meta-analysis variants studied in gestational diabetes mellitus in an Indian population

BACKGROUND

Meta-analysis is useful for combining the results of different studies statistically to confirm genuine associations in genetics. Based on earlier reports, we aimed to investigate the association between type 2 diabetes mellitus (T2DM) genetic variants identified in a previous meta-analysis in gestational diabetes mellitus (GDM) in an Indian woman.

MATERIAL AND METHODS

In this study, 137 pregnant women with GDM and 150 pregnant women were selected on the basis of their serum glucose levels. The six single nucleotide polymorphisms (SNPs) of different genes studied had known involvement in pancreatic β-cell function, particular pathways linked to T2DM, and other biological functions. Genomic DNA was isolated from the 287 women for polymerase chain reaction and restriction fragment length polymorphism analyses.

RESULTS

The rs7903146, rs13266634, rs2283228, rs5210 and rs179881 SNPs were found to be positively associated with GDM when calculated for genotype and allele frequencies (p < 0.05), but rs680 (ApaI) variant did not show statistically significant association (p = 0.31). The rs7903146, rs2283228, rs5210 and rs680 variants showed a strong association with oral glucose tolerance test values.

CONCLUSION

The SNPs studied in this GDM had the same role as those identified in a previous T2DM meta-analysis, and showed positive association in the Indian women. Meta-analyses should be implemented to assess the IGF2 gene in GDM subjects.

The CDKN2A polymorphisms and the susceptibility of HBV-related gestational diabetes mellitus

BACKGROUND

Single-nucleotide polymorphisms (SNPs) were discovered in HBV-related gestational diabetes mellitus, but it still unclear whether these SNPs are associated with the susceptibility of HBV-related gestational diabetes mellitus.

METHODS

The investigation of the association between CDKN2A polymorphisms and occurrence of HBV-related gestational diabetes mellitus (GDM) in Chinese was assessed in the case-control study. A total of 480 pregnant patients with HBV and 530 pregnant controls were consecutively recruited from January 2015 to December 2016. Polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP) method was applied to measure genotyping for the detection of CDKN2A.

RESULTS

The significant differences in the frequency of CDKN2A genotype distributions, rs10811661 and rs564398, were found by Chi-square test. Using conditional logistic analysis, individuals carrying the CDKN2A rs10811661 TC and TT genotypes and CDKN2A rs564398 AA and AG genotypes were related to a greater risk of HBV-related GDM compared with the genotype.

CONCLUSIONS

In conclusion, the CDKN2A rs10811661 and rs564398 polymorphisms showed association with a greater risk of HBV-related GDM in a Chinese population.

Importance of glucokinase -258G/A polymorphism in Asian Indians with post-transplant and type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) and post-transplant diabetes mellitus (PTDM) are non-synonymous forms of diabetes. Glucokinase (GCK) plays a key role in glucose metabolism. The relationship between the GCK promoter and specific types of diabetes, such as PTDM and T2DM, in the Asian Indian population is unknown. We examined the occurrence of a specific GCK promoter variant (-258G/A) in patients with T2DM and PTDM. The case-control study enrolled 640 Asian Indian subjects, including controls (n = 250) and T2DM (n = 250), PTDM (n = 42), and non-post-transplant diabetes mellitus (non-PTDM) (n = 98) patients. Purified Deoxyribonucleic acid (DNA) was genotyped with the polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis. The digested PCR products were analyzed on 12% polyacrylamide gels. The anthropometric, biochemical, and clinical details of each group were documented. GCK -258G/A alleles and genotypes were not associated with T2DM. However, among PTDM subjects, we detected a higher frequency of heterozygotes (52.4%) and a positive association with alleles/genotypes. The results suggest that the promoter region (-258G/A) of GCK plays an important role in PTDM in Asian Indians.

Association of GSTs polymorphisms with risk of gestational diabetes mellitus

We conducted a case-control study to investigate the association between GSTM1, GSTT1 and GSTP1 IIe105Val polymorphisms and development of gestational diabetes mellitus in a Chinese population. A total of 320 patients with gestational diabetes mellitus and 358 pregnancy subjects were consecutively collected between January 2013 and December 2014. Genotyping for detection of GSTM1, GSTT1 and GSTP1 IIe105Val was conducted by using PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphisms) method. By Fisher's exact test, we found that the genotype distributions of GSTP1 IIe105Val were in line with the Hardy-Weinberg equilibrium in control subjects (P=0.57). By Chi-square test, we found significant differences in the genotype distributions of GSTM1 (χ(2)=11.49, P=0.001) and GSTT1 (χ(2)=18.50, P<0.001). Using unconditional logistic analysis, individuals carrying the null genotypes of GSTM1 and GSTT1 were associated with an increased risk of gestational diabetes mellitus when compared with the present genotype, and the adjusted Ors (95% CI) were 1.71 (1.24-2.36) and 2.00 (1.44-2.79), respectively. However, the GSTP1 IIe105Val polymorphism was not associated with an elevated risk of gestational diabetes mellitus. In conclusion, we suggest that the GSTM1 null genotype and GSTT1 null genotype are correlated with an increased risk of gestational diabetes mellitus in a Chinese population.