Frequency of Vitamin B12 deficiency in patients with type 2 diabetes mellitus taking metformin

Abstract

Aim: To determine the frequency of vitamin B12 deficiency in patients with type 2 Diabetes Mellitus taking metformin. Place & duration of study: The study was conducted from 1 Oct 2013 to 31 Mar 2014 at Department of Medicine Combined Military Hospital (CMH) Multan Methods: A total of 135 cases with Type 2 Diabetes Mellitus, aged 40 or more, taking metformin for at least one year presenting to medical OPD were included in the study. Results: Mean age as 54.53+8.56 years, 75(54.7%) were male and 62(45.3%) were females. HbA1C of patients were between 6.6 and 12.1% with a mean of 8.5% and standard deviation of 0.87. Mean fasting plasma glucose was calculated to be 208+46.3mg/dL, the duration of metformin use was between 1.5 years and 8.4 years with a mean of 5.1+1.9 years. The mean dose of metformin was calculated to be 1970 mg/day with a standard deviation of 727.0 Mean vitamin B12 levels among 137 patients taking metformin were found to be 311.6pmol/L. The standard deviation was 141.5. Serum vitamin B12 levels were found to be deficient (<150 pmol/L) in 19 patients (13.9%). Conclusion: We concluded that a considerable percentage of diabetic patients treated with metformin have low vitamin B12 levels. So, physicians must recognize this important association of metformin with B12 deficiency.