Effect of metformin and folic acid on plasma homocysteine level in type 2 diabetic patients

Hyperhomocysteinemia is associated with an increased risk of cardiovascular disease in diabetic patients. The aim of this study was to evaluate effects of metformin and folic acid on plasma homocysteine level in diabetic patients. In this clinical trial 47 new cases of type 2 diabetes were randomized to two groups. We treated patients in trial group with metformin and 1 mg folic acid, whereas patients in control group treated with metformin and placebo for 16 weeks. There was no significant difference in plasma homocysteine level and glycosylated hemoglobin (HbA1c) between two groups at the start of study. After 16 weeks plasma homocysteine level in the trial group did not change. In contrast plasma homocysteine level increased in the placebo group. There was significant difference in mean plasma homocysteine level between two groups (P-value < 0.01). This difference was highly significant in males (P-value < 0.0001). Correlation between glycosylated hemoglobin and plasma homocysteine level at start and end of study was not significant. This finding indicated that metformin increases plasma homocysteine level in diabetic patients especially males, whereas administration of folic acid with metformin can prevent this process.