LOW LEVELS OF SERUM CYANOCOBALAMIN IN A METFORMIN-TREATED PATIENT. CASE REPORT AND COMPARISON WITH LITERATURE DATA
Abstract
Metformin is a widely used oral antidiabetic biguanide compound. According to the literature, metformin may lower the serum cyanocobalamin levels. We present the case of a 71-old-male treated with metformin for 15 years. When presenting to a periodic checkup, low serum cyanocobalamin levels where found. Laboratory tests showed levels below normal range for hemoglobin (12.7 g/dL) and hematocrit (37.8 %). After patient reevaluation, a change in antidiabetic treatment will be considered if metformin will be found the cause of low serum cyanocobalamin levels. Other cases reported in the literature support this hypothesis, justifying the study of the influence of metformin therapy on serum vitamin B12 levels in patients diagnosed with diabetes. The influence of patient age, metformin dosage, duration of treatment and time since diabetes diagnosis on serum levels of vitamin B12 also need to be determined.
References
2. Mazokopakis EE, Starakis IK. Recommendations for diagnosis and management of metformin-induced vitamin B12 (Cbl) deficiency. Diabetes Res Clin Pract 2012; 97(3): 359–367.
3. Mihai C, Prelipcean CC, Pintilie I, Nedelciuc O, Jigaranu AO, Dranga M, Mihai B. Nutrition in in-flammatory bowel diseases. Rev Med Chir Soc Med Nat Iasi 2013; 117(3): 662-669.
4. Potur RG, Gafitanu E. Formulation by design of experiments of immediate release tablets with met-formin hydrochloride and glibenclamide. Rev Med Chir Soc Med Nat Iasi 2010; 114(4): 1219-1926.
5. Melgar A, Becerril B, Gil T, Olivares J. Déficit de vitamina B12 en paciente tratado con metformina. Semergen 2008; 34(9): 463–464.
6. Lin H-Y, Chung C-Y, Chang C-S, Wang M-L, Lin J-S, Shen M-C. Hyperhomocysteinemia, Deep Vein Thrombosis and Vitamin B12 Deficiency in a Metformin-treated Diabetic Patient. J Formos Med Assoc 2007; 106(9): 774–778.
7. Tung ML, Tan LK. Long term use of metformin leading to vitamin B 12 deficiency. Diabetes Res Clin Pract 2014; 104(3): e75–76.
8. Liu KW, Dai LK, Jean W. Metformin-related vitamin B12 deficiency. Age Ageing 2006; 35(2): 200–201.
9. Gourgari E, Nella AA, Lodish M, Stratakis CA, Yanovski JA. Vitamin B12 deficiency in an adolescent girl with polycystic ovarian syndrome. Eur J Obstet Gynecol Reprod Biol 2014; 179: 254.
10. Sahin M, Tutuncu NB, Ertugrul D, Tanaci N, Guvener ND. Effects of metformin or rosiglitazone on serum concentrations of homocysteine, folate, and vitamin B12 in patients with type 2 diabetes mellitus. J Diabetes Complications 2007; 21(2): 118–123.
11. Sato Y, Ouchi K, Funase Y, Yamauchi K, Aizawa T. Relationship between metformin use, vitamin B12 deficiency, hyperhomocysteinemia and vascular complications in patients with type 2 diabetes. Endocr J 2013; 60(12): 1275–1280.
12. Stargrove MB, Treasure J, McKee DL. Herb, Nutrient, and Drug Interactions: Clinical Implications and Therapeutic Strategies. Missouri: Elsevier Health Sciences, 2008.

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