Background and Objectives: Metformin is a cornerstone in the treatment of type 2 DM (type 2 diabetes mellitus) and is used as 1st line therapy. Studies showed that an average of 10-30% of patients on metformin for longer duration and at higher dosage had Vit. B12 deficiency. Sr.(Serum) Vit. B12 levels were studied and correlated with presence of peripheral neuropathy in type 2 DM patients on long term Metformin, attending OPD of our hospital.

Methods: 100 consecutive type 2 DM patients on Metformin for >3 years, aged >18 years attending OPD of the Dept. of Medicine from 1st January - 31st December 2017, were included in our study after the informed consent. Estimation of Sr. Vit. B12 levels was done and correlated with monofilament testing in all the study participants and metformin doses of 1 gm/day and >1 gm/day were classified.

Results: In our study, 35% of Diabetic patients on Metformin had Vit. B12 deficiency with mean 168.2 ± 17.9 pg/ml which also correlated with the abnormalities in the monofilament testing, graded on a scale of 1-10, 1 being severe peripheral neuropathy and 10 being normal. The mean monofilament score was found to be 6 out of 10. The remaining 65% had a mean Vit. B12 level of 502.3 ± 16.8 and a mean monofilament score of 8 out of 10. Total mean Vit. B12 level was found to be 619.2. By applying Chi square test as test of significance, odds of positive outcome for monofilament test in Vit. B12 deficient person is 25.5 and p value is significant (P<0.001). Degree of dosage of metformin did not have any significant correlation with Sr. Vit. B12 levels and monofilament score. We also found evidence of Megaloblastic anemia in study participants, with 29% of patients having high MCV with a mean of 98.4 ± 2.1 fl, and dimorphic (23%) and macrocytic (6%) picture on peripheral smear. The mean Hb range was 11.1 to 14.0 g/dL.

Conclusion: There is higher prevalence of Vit. B12 deficiency and linear correlation with peripheral neuropathy with long term Metformin use in type 2 DM patients which needs to be diagnosed and treated.


V. Kothiwale: None. N.D. Chafekar: None. P. Babaliche: None. N.A. Chougule: None.

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