Carotid Intima-media Thickness Is Associated With Genetic Polymorphisms Of Homocysteine Metabolism Related Enzymes In Type 2 Diabetic Patients

Objective To investigate the relationship of plasma homocysteine(Hcy) level and genetic polymorphisms of 5,10-Methylenetetrahydrofolate reductase(MTHFR) C677T related to homocysteine metabolism with carotid intima-media thickness(IMT)in type 2 diabetic (T2DM) patients.Methods 140 cases with new-onset(≤5 years) type 2 diabetes and 52 cases of normal control(NC) were enrolled in the study.cases of T2DM were divided into two groups, according to the IMT:IMT≥0.9mm.One with normal IMT(DM₁) and another with thicked IMT(DM₂).Plasma concentrations of total Hcy were measured by direct Chemiluminescence using reagents and an ACS:180 automated analyzer from Bayer Vital GmbH.MTHFR genetic C677T polymorphism was examined by polymerase chain reaction restriction fragment length polymorphisms(PCR-RFLP),Carotid intimal-medial wall thickness was determined by the use of the doppler ultrasonography.In three groups.Measurement data was expressed with mean+standard deviation((?)±s).The comparison of measurement data was adopted with t test and analysis of variance.The distribution of genetype and allele frequencies was adopted with Chi-Square Test.Bivariate Correlation was expressed with Spearman Correlation.The risk factors for diabetic nephropathy were selected with Logistic Regression.Statistical analysis use the Spssl 1.5 software.Results T he Plasma Hcy level in DM₂ group was significantly higher than that in NC group[(16.86±2.86) vs(12.50±2.05)μmol/L,P＜0.05].the plasma Hcy level in DM₂ group was significantly higher than that in DM₁ group[(16.86±2.86) vs(14.69±2.51)μmol/L,P＜0.05].the frequency of TT genotype in DM₂ was significantly higher than that in NC group (32.4%vs15.4%,x²=9.96,P=0.007),the frequency of TT genotype in DM₂ group was significantly higher than that in DM₁ group(32.4%vs20.8%,x²=11.35,P=0.023);Similarly, the frequency of T allele in DM₂ group was significantly higher than that in NC group (54.4%vs32.7%,x²=11.23,P=0.001).multivariate Logistic regression analysis showed homocysteine(OR=2.28,95%Cl 1.45～3.57,P＜0.01 ) and TT genotype(OR=1.36,95%Cl 1.21～1.52,P＜0.01) to be the main determinant of IMT variability.Conclusion Hyperhomocysteinemia and the TT genotype of MTHFR C677T seems to be the risk factors of early atherosclerosis in patients with tyPe 2 diabetes.Mutations in MTHFR were associated with elevated plasma levels of Hcy.