Metformin intake among geriatric patients may predispose to vitamin B12 deficiency: Polish population-based study

Introduction Vitamin B₁₂ deficiency is becoming a major problem among geriatric population worldwide. It may contribute to higher prevalence of cognitive impairment and depression, and may occur as a side effect of commonly prescribed anti-diabetic and anti-acid treatments. However, the scale of this phenomenon in Poland remains unknown. Aim We investigated the scale of vitamin B₁₂ deficiency across population of geriatric patients over 70 years old. Additionally, we examined the association between vitamin B₁₂ deficiency, cognitive impairment or depression prevalence, and metformin or proton pump inhibitors intake. Material and methods Based on the measured vitamin B₁₂ serum level, we divided patients into 3 groups: (1) normal (≥300 pg/mL); (2) borderline (191–300 pg/mL), and (3) low (≤191 pg/mL). The assessment of cognitive impairment or depression was performed by using 5 distinct tests (mini-mental state examination, abbreviated mental test score, clock drawing test, and 4-item or 15-item geriatric depression scale). For statistical analysis, we used χ² and ANOVA tests. Results and discussion We showed no differences in the frequency of cognitive impairment, depression, and vitamin among characterized groups. Importantly, we found that metformin intake was associated with vitamin B₁₂ deficiency (P = 0.009), contrary to proton pump inhibitor (P = 0.53) and combined these drugs (P = 0.24). Conclusions We showed a relatively high prevalence of vitamin B₁₂ deficiency across a population of geriatric patients. A preventive vitamin B₁₂ supplementation should be considered when treating, especially geriatric diabetic patients. Due to conflicting results of retrospective studies, prospective clinical trial should be undertaken to describe the association between vitamin B₁₂ deficiency and prevalence of cognitive impairment or depression.