Influence of methylcobalamin on the vitamin B12 level and manifestations of neuropathy in patients with type 2 diabetes mellitus and metformin-associated vitamin B12 deficiency
Keywords:type 2 diabetes mellitus, metformin, B12 hypovitaminosis, neuropathy, methylcobalamin
Background. Adverse side effect of metformin is disturbance in vitamin B12 metabolism associated with low serum vitamin B12 level. B12 hypovitaminosis is accompanied by peripheral neuropathy. The aim of the study was to determine the effectiveness of methylcobalamin (Diacobal preparation manufactured by Kusum Pharm LLC, Ukraine) in correcting vitamin B12 deficiency in diabetic patients with metforminassociated vitamin B12 deficiency, and to establish its effect on manifestations of diabetic neuropathy. Materials and methods. Thirty patients with type 2 diabetes mellitus and metforminassociated vitamin B12 deficiency (< 190 pg/ml) were examined. Duration of metformin administration was 6.1 years on average, the average dose was 2100 mg/day. Methylcobalamin was administered at a dose of 500 mg three times a day for three months. Determination of vitamin B12 content and assessment of neuropathy manifestations was carried out before and after the course of treatment. Results. After the course of treatment, it was found that the average content of vitamin B12 in the blood serum reached the reference values (312.4 ± 39.8 pg/ml). The positive effect of therapy on the severity of clinical manifestations of peripheral sensory motor neuropathy in the examined patients was revealed: in 17 (56.7 %) patients, the severity of numbness in feet significantly decreased, in 6 (20 %) persons, there was a complete disappearance of numbness. The intensity of the pain syndrome decreased in 19 (63.3 %) patients, the pain syndrome was completely removed in 3 (10 %) persons. Conclusions. The relationship between metformin and B12 hypovitaminosis has been confirmed. Diacobal is an effective and safe drug for the prevention and treatment of metformininduced vitamin B12 deficiency and diabetic neuropathy.
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