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

Wondwossen Wale Tesega; Solomon Genet; Gnanasekaran Natesan; Getahun Tarekegn; Fitsum Girma; Dinkinesh Chalchisa; Yohannes Belay; Zeleke Geto; Tadesse Asmamaw Dejenie

doi:10.2147/DMSO.S306433

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

Diabetes Metab Syndr Obes. 2021 May 3:14:2011-2018. doi: 10.2147/DMSO.S306433. eCollection 2021.

Authors

Wondwossen Wale Tesega¹, Solomon Genet², Gnanasekaran Natesan², Getahun Tarekegn², Fitsum Girma³, Dinkinesh Chalchisa³, Yohannes Belay³, Zeleke Geto⁴, Tadesse Asmamaw Dejenie⁵

Affiliations

¹ Department of Biomedical Sciences, School of Medicine, College of Health Sciences, Arbaminch University, Arba Minch, Ethiopia.
² Department of Medical Biochemistry, School of Medicine, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia.
³ National Reference Laboratory for Immunohematology, Ethiopian Public Health Institute, Addis Ababa, Ethiopia.
⁴ Department of Biomedical Science, College of Medicine and Health Science, Wollo University, Dessie, Ethiopia.
⁵ Department of Biochemistry, School of Medicine, College of Medicine and Health Science, University of Gondar, Gondar, Ethiopia.

Abstract

Background: Metformin is the first-line drug in the treatment of type 2 diabetes mellitus. Monitoring vitamin B₁₂ 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 B₁₂ 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 B₁₂ and folate levels were quantified by chemiluminescent immunoassays. Mean corpuscular volume was determined by complete blood count. Differences in vitamin B₁₂ and folate levels and mean corpuscular volume between different groups were assessed using Kruskal-Wallis H and Mann-Whitney U tests.

Results: Vitamin B₁₂ and folate deficiency were documented in 5% and 23.8% of participants, respectively, and 6.2% of patients were macrocytic. Levels of vitamin B₁₂ 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 B₁₂ and folate levels and macrocytosis were found to be associated with prolonged metformin treatment.

Keywords: folate; macrocytosis; metformin; type 2 diabetes mellitus; vitamin B12.

Grants and funding

This work was supported both financially and materially by the Ethiopian Public Health Institution (EPHI) in collaboration with Addis Ababa University.