Does metformin increase the serum total homocysteine level in non-insulin-dependent diabetes mellitus?
OBJECTIVE: The aim of this study was to estimate the effect of metformin on the serum total homocysteine level in non-insulin-dependent diabetes mellitus (NIDDM) patients. An elevated serum total homocysteine level is a risk factor for atherosclerosis. Metformin decreases serum vitamin B12, and may thereby indirectly increase the serum total homocysteine level. DESIGN: A cross-sectional study in a primary care setting. SUBJECTS, MAIN OUTCOME MEASURES: Fasting serum total homocysteine level was measured in 40 NIDDM patients who had received treatment with metformin (500-2550 mg per day) for at least six months, and in 71 NIDDM patients not treated with metformin and matched for sex, age (+/- 5 years), serum creatinine (+/- 5 micromol L[-1]) and current smoking habits. ‘Exposed’ patients were matched with ‘nonexposed’ patients. A two-way analysis of variance was performed. RESULTS: The mean serum total homocysteine level was 11.5 micromol L(-1) in the metformin-exposed patients and 10.6
