Folate metabolism: Impact of involved genetic variants on homocycteine and folate levels in type 2 diabetic patients with coronary artery disease

Abstract

BackgroundType2 diabetes mellitus (T2DM) has severe impacts on quality of life throughout the world. Coronary artery disease (CAD) is one of the most serious microvascular complications of T2DM. ObjectiveTo explore the relationship between plasma homocysteine (Hcy) and folate levels, and their related methylenetetrahydrofolate reductase (MTHFR) C677T and reduced folate carrier-1 (RFC-1) A80G genes polymorphism in T2DM accompanied by CAD. MethodsThis case-control study enrolled 120 T2DM patients, 60 of them had CAD, and 60 healthy control subjects. Plasma Hcy and folate were measured by ELISA and genotyping was performed by PCR-RFLP. Lipid profile was analyzed by spectrophotometer. ResultsPlasma Hcy was increased and folate was decreased in both diabetic groups in relation to control group. T2DM with CAD showed significant difference with T2DM group. Hcy level was positively correlated with total cholesterol and triglycerides in T2DM and with LDL in T2DM with CAD patients. MTHFR TT and TC genotypes had significantly higher risk of CAD in T2DM. RFC-1 GG and AG genotypes were significantly higher in diabetic groups. Hcy was significantly higher and folate was lower in MTHFR677 TT + TC than that in CC genotype in T2DM with CAD. In RFC-1 GG + GA, Hcy level was higher and folate was lower than that of AA. ConclusionMTHFR and RFC-1 genetic variants are associated with high Hcy and low folate levels in T2DM with CAD patients and are related to dyslipidemia.