Association Analysis Of MTHFR And MTRR Gene Polymorphisms Towards The Development Of Hypertension And Type 2 Diabetes Mellitus In Dali Area Of Yunnan Province

Objective:5,10-methylenetetrahydrofolate reductase(MTHFR)and methionine synthetase reductase(MTRR)are two key enzymes involved in folic acid metabolism.Mutations in these two genes cause the decrease of enzyme activities,which will lead to the lower folate utilization rate and higher homocysteine(Hcy)level.Hyperhomocysteinemia can induce vascular endothelial injury and dysfunction,which increases the risk of cardiovascular disease,diabetes,metabolic syndrome and other diseases.The purpose of this study is to investigate the relationship between the polymorphisms of MTHFR C677T(rs1801133),MTHFR A1298C(rs1801131)and MTRR A66G(rs1801394)and the occurrence of hypertension and type 2 diabetes mellitus(T2DM)in Dali area of Yunnan Province,and provide some reference value for the prevention of hypertension and T2 DM in this area.Methods:1.470 patients with hypertension and 470 patients with T2 DM were selected as the study group,282 healthy people at the same period were selected as the control group.Their general clinical data and biochemical indicators were collected.2.Genomic DNA was extracted from the peripheral blood,and the concentration and purity were measured by Nano Drop One,the integrity was tested by agarose gel eletrophoresis.3.Genotyping of MTHFR C677 T,MTHFR A1298 C and MTRR A66 G was carried out by using the kompetitive allele specific PCR(KASP).4.Hardy-Weinberg equilibrium was used to determine whether the study subjects was representative of the population.5.SHEsis Plus online software was used for linkage disequilibrium and haplotype analysis at C677 T and A1298 C loci of MTHFR gene.6.Enzyme-linked immunosorbent assay(ELISA)was performed to detect the content of serum Hcy and inflammatory indicators(TNF-α and IL-6),chemical methods were used to detect the content of serum oxidative stress indicators(SOD and MDA).7.Statistical analyses were performed using SPSS 25.0 software.Results:1.The CT,TT genotype and T allele frequencies at MTHFR C677 T were significantly higher in the hypertension group(P<0.05),and could increase the risk of hypertension.In dominant genetic model,the risk of hypertension in CT and TT genotype carriers was 1.517 times higher than that in CC genotype carriers.The frequency of CC genotype at the MTHFR A1298 C was significantly higher in the hypertension group(P<0.05),and could increase the risk of hypertension.In recessive genetic model,the risk of hypertension in CC genotype carriers was 7.945 times higher than that in AA and AC genotype carriers.No significant difference was observed in genotype distribution of MTRR A66 G in these two groups(P>0.05).2.The MTHFR C677 T and A1298 C polymorphisms were found to be in linkage disequilibrium in the control group and hypertension group.The frequencies of T-A and C-C haplotypes were significantly higher in the hypertension group(P<0.05),and two haplotypes could increase the risk of hypertension.The ratio of people with poor utilization of folic acid was higher in the hypertension group compared to the controls.The people with average risk were significantly higher in the hypertension group(P<0.05),and could increase the risk of hypertension.3.The CT genotype of MTHFR C677 T could significantly increase the serum FMN level in hypertensive patients(P<0.05).The TT genotype of MTHFR C677 T could significantly increase the serum FBG level,and decrease the serum APOA1 level in hypertension patients(P<0.05).The CT and TT genotypes of MTHFR C677 T could significantly increase the serum Hcy level in hypertensive patients(P<0.05).The TT genotype of MTHFR C677 T could significantly increase the level of serum MDA and decrease the level of SOD in hypertensive patients(P<0.05).4.The serum FBG level of patients with grade 2 and 3 hypertension was higher than that in grade 1 hypertension patients,and the APOA1 level of patients with grade2 and 3 hypertension was lower than that in grade 1 hypertension patients(P<0.05).The CT,TT genotype and T allele frequencies of patients with grade 2 and 3hypertension were higher than those in grade 1 hypertensive patients(P<0.05).5.The TT genotype and T allele frequencies at MTHFR C677 T were significantly higher in the T2 DM group(P<0.05),and could increase the risk of T2 DM.In recessive genetic model,the risk of T2 DM in TT genotype carriers was1.754 times that in CC and CT genotype carriers.The frequency of CC genotype at the MTHFR A1298 C was significantly higher in the T2 DM group(P<0.05),and could increase the risk of T2 DM.In recessive genetic model,the risk of T2 DM in CC genotype carriers was 8.250 times higher than that in AA and AC genotype carriers.No significant difference was observed in genotype distribution of MTRR A66 G in these two groups(P>0.05).6.The MTHFR C677 T and A1298 C polymorphisms were found to be in linkage disequilibrium in the control group and T2 DM group.The frequency of T-A haplotype in the T2 DM group was significantly higher in the T2 DM group(P<0.05),and this haplotype could increase the risk of T2 DM.The ratio of people with poor utilization of folic acid was higher in the T2 DM group compared to the controls.The people with average risk were significantly higher in the T2 DM group(P<0.05),and increase the risk of T2 DM.7.The CT and TT genotypes of MTHFR C677 T and the CC genotype of MTHFR A1298 C could significantly increase the serum FBG level in T2 DM patients(P<0.05).The CT and TT genotypes of MTHFR C677 T and the AC genotype of MTHFR A1298 C could significantly increase the serum Hcy level in T2 DM patients(P<0.05).The CT and TT genotypes of MTHFR C677 T could significantly increase the serum TNF-α level in T2 DM patients(P<0.05).Conclusion:1.The polymorphisms of MTHFR C677 T and A1298 C are associated with the occurrence of hypertension in Dali area of Yunnan Province,and these two loci mutations could increase the risk of hypertension.The polymorphism of MTHFR C677 T is associated with the severity of hypertensive patients.MTHFR C677 T and A1298 C polymorphisms could cause changes in the levels of glycolipid metabolism indicators,Hcy,and oxidative stress indicators in hypertensive patients.2.The polymorphisms of MTHFR C677 T and A1298 C are associated with the occurrence of T2 DM in Dali area of Yunnan Province,and these two loci mutations could increase the risk of T2 DM.MTHFR C677 T and A1298 C polymorphisms could cause changes in the levels of glucose metabolism indicators,Hcy,and inflammatory indicators in T2 DM patients.