Abstract:
Background. Metformin is the most widely used
oral antihyperglycaemic drug, but it may lower B12
status, which could have important clinical implications.
There are limited data about the effect of metformin
use on serum vitamin B12 levels in type 2 diabetes
mellitus (DM) patients.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 and discussion. 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.
