Clinical characteristics of vitamin B12 deficiency predictors in metformin-treated type-2 diabetes mellitus

Características clínicas predictoras de déficit de vitamina B12 de diabetes mellitus 2 tratada con metformina

Introduction: metformin use is related to vitamin B12 deficiency. Objective: to identify the clinical characteristics that predict B12 deficiency in metformin-treated type-2 diabetes mellitus (T2DM) patients, aged 18 years or older. Materials and methods: analytical cross-sectional study including 100 T2DM patients aged between 50 and 85 years, on metformin for more than 3 months, with vitamin B12 levels recorded in their clinical record, seen in a family medicine diabetes program in Bogotá DC, Colombia. Results: the median duration of the disease was 9.6 years, metformin use ranged between 1 and 5 years (32%), the most commonly used dose ranged between 1001 and 2000 mg (65%), polypharmacy was evidenced in 45% and B12 deficiency prevalence was 27%. The logistic regression analysis showed that time of metformin use behaved as a predictor of vitamin B12 deficiency (OR=0.01 CI95% 0.01-0.03) (p<0.05). Polypharmacy (OR=1.21 CI95% -0.06-2.5) and diabetes duration (OR=1.14 CI95% 0.99-1.32) emerged as predictor factors, but with no statistically significant difference. Conclusion:  duration of metformin use is a clinical variable that can be a predictor of vitamin B12 deficiency. Prevalence of B12 deficiency was high in our study. We recommend an active search of this deficiency in clinical practice.

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