Endocrine Abstracts

JOINT594

Background: Vitamin B12 deficiency, which inevitably occurs during lifelong metformin therapy in patients with type 2 diabetes, requires timely and adequate vitamin replacement. Moreover, vitamin B12 deficiency mimics the symptoms of diabetic polyneuropathy. However, there are no clear recommendations on the dose and duration of vitamin B12 intake in such patients.

Materials and methods: We conducted a comparative study among 28 patients with type 2 diabetes mellitus with clinical manifestations of diabetic neuropathy. The average age of patients was 60.7±10.0 years, the average duration of diabetes was 7.2±5.4 years, the duration of Metformin intake was 5.5±4.7 years, the average dose of Metformin was 1466.7±544.9 mg, vitamin B12 deficiency was detected in 100% of patients (vitamin B12 level below 197 pg/ml, average level 103.0±19.3 pg/ml). All patients were prescribed vitamin B12. 20 patients took the vitamin in a total course dose below 150 g (up to 1500 mg per day for 3 months). 8 patients received a total course dose above 150 g (maximum 190 g). NSS and NDSS, as well as vitamin B12 levels, were assessed 6 months after the treatment.

Results: Of the symptoms of the NSS and NDSS, a significant difference after treatment was obtained only for the criterion of "burning sensation" (1.46±0.19 points vs 0.88±0.13 points, P = 0.022) between the groups; a significantly greater reduction in paresthesia was noted in the group of patients who received a higher course dose of vitamin B12 (87.5% vs 15.0%, P = 0.005). No significant difference was found between the groups in terms of other symptoms of peripheral neuropathy.

Conclusion: To reduce neuropathic symptoms associated with vitamin B12 deficiency in patients with type 2 diabetes mellitus receiving long-term metformin, vitamin B12 supplementation at a dose of at least 150 g per course of therapy is necessary.