Assessment of Serum Vitamin B12 and Folate Levels and Macrocytosis in Patients with Type 2 Diabetes Mellitus on Metformin Attending Tikur Anbessa Specialized Hospital, Addis Ababa, Ethiopia: A Cross-Sectional Study

Abstract

Background Metformin is the first-line drug in the treatment of type 2 diabetes mellitus. Monitoring vitamin B 12 deficiency associated with long-term and high-dose therapy is not a common practice in many clinical settings in Ethiopia. Objective The study aimed to measure levels of serum vitamin B 12 and folate and to assess the macrocytic status of type 2 diabetes mellitus patients on metformin. Methods A cross-sectional study was conducted on 80 type 2 diabetes mellitus patients who had been on metformin for 5 months or more at the diabetic clinic of Tikur Anbessa Specialized Teaching Hospital. Serum vitamin B 12 and folate levels were quantified by chemiluminescent immunoassays. Mean corpuscular volume was determined by complete blood count. Differences in vitamin B 12 and folate levels and mean corpuscular volume between different groups were assessed using Kruskal–Wallis H and Mann–Whitney U tests. Results Vitamin B 12 and folate deficiency were documented in 5% and 23.8% of participants, respectively, and 6.2% of patients were macrocytic. Levels of vitamin B 12 and folate in patients who had been on metformin >1,500 mg/day ≥4 years were significantly lower those who had been on metformin 1,000–1,500 mg/day and <1,000 mg/day <4 years, respectively. Conclusion Low serum vitamin B 12 and folate levels and macrocytosis were found to be associated with prolonged metformin treatment.

Does Metformin in different doses cause vitamin B12 deficiency? A cross-sectional study

“…The results of examining the mean age variable in patients showed that the mean age in patients with a normal range of vitamin B12 and patients with vitamin deficiency is higher compared to other studies. So that in the study of W Wale Tesega et al (2021) (28). The mean age of the patients was 56 years, which is lower than the mean age of the present study.…”