Endocrine Abstracts

Background: Metformin is the most widely used oral antihyperglycaemic drug, but it may lower B₁₂ status, which could have important clinical implications.

Aim: To study serum Vitamin B₁₂ levels in patients with type 2 diabetes mellitus who were receiving metformin and compared them to those never treated with metformin.

Materials and methods: A total of 60 patients with type 2 DM (group 1, n = 35, receiving metformin and group 2, n = 25, never treated with metformin) from the endocrinology clinic in Chernivtsi were studied. Serum vitamin B₁₂ levels were measured in all patients.

Results: The serum vitamin B₁₂ levels were 239.6 ± 37.4 pg/ml in metformin group and 293.6 ± 42.3 pg/ml in the no metformin group (P = 0.37). When adjusted for duration of DM, metformin use was associated with a 57.2 ± 7.3 pg/ml (P = 0.03) lower serum vitamin B₁₂ levels. Serum vitamin B₁₂ levels were higher by 41.4 pg/ml in patients with DM of 1–5 years compared to those with recently diagnosed diabetes (P = 0.41). Serum vitamin B₁₂ levels were higher by 119.4 pg/ml in patients with duration of DM > 5 years compared to those with recently diagnosed diabetes (P < 0.02). Similarly, serum vitamin B₁₂ levels were 77.1 pg/ml higher in > 5 years DM duration group compared to 1–5 year duration of DM group (P = 0.03). Serum vitamin B₁₂ levels for the entire cohort were higher by 11.8 ± 1.7 pg/ml (P < 0.01) for every 1 year increase in the DM duration.

Conclusions: Metformin use was associated with a lower serum vitamin B₁₂ levels when adjusted for duration of DM. Increasing duration of DM was associated with higher serum vitamin B₁₂ levels.