Evaluation of the level of plasma homocysteine in patients with type 2 diabetes mellitus under metformin treatment and its correlation with serum total antioxidant capacity, malondialdehyde, creatinine, insulin resistance and glycemic control

Abstract

Background and Objective: In patients with diabetes, elevated homocysteine levels have been reported to be associated with endothelial dysfunction, insulin resistance, dyslipidemia, poor control of disease, nephropathy, macroangiopathy and oxidative stress. Thus, this observational study was performed to determine the plasma homocysteine level and its correlation with clinical, biochemical and nutritional variables. Materials and Methods: This study was performed on 70 men with type 2 diabetes under metformin (at least 1500 mg daily) treatment. Regarding plasma homocysteine, patients were divided into two groups: 31patients with normal homocysteine (group 1: Hcy<15 ?mol/L) and 39 patients with hyperhomocysteinemia (group 2: Hcy>15 ?mol/L). Results: 55.1% patients had hyperhomocysteinemia but none of them had folate and B12 deficiency. Significant differences between the two groups, were found for serum folate, total antioxidant capacity and creatinine. No differences were found for insulin resistance and glycemic control. Multiple stepwise linear regression analysis using plasma homocysteine as a dependent variable and all other clinical and laboratory parameters as independent variables indicated that age (?=0.344), creatinine (?=0.351), vitamin B12 (?=0.235), total antioxidant capacity (?=0.285) and malondialdehyde (?=0.245) were independently associated with homocysteine concentration. No correlation was found between the homocysteine and glycemic control, HOMA-IR and intake of B vitamins and caffeine. Conclusion: Further studies with a large sample size are required to assess the association of plasma homocysteine with total antioxidant capacity and other biomarkers of oxidative stress in type2 diabetes.