CLINICAL AND BIOCHEMIICAL MANIFESTATIONS OF VITAMIN B12 DEFICIENCY IN TYPE 2 DIABETIC PATIENTS TREATED WITH METFORMIN- A COMPARATIVE STUDY

Objectives: The objective of this study was to estimate the occurrence of Vitamin B12 deficiency in patients with type 2 diabetes mellitus treated with metformin, and the clinical and biochemical profile of vitamin B12 deficiency in them.

Materials and Methods: This was a cross sectional study. Type 2 Diabetics over the age of 18 years were recruited for the study. Patients were divided into two groups - one groupof 62 patients who were on metformin for more than 6 months and the other group of 62 patients who were on other oral hypoglycemic agents or insulin. Patients were interviewed using a questionnaire. Relevant blood investigations were done.

Results: The mean (+SD) age of study population was 57 (±9.8) years with an age range of 35 to 79 years. There was high prevalence of vitamin B12 deficiency in patients with type 2 diabetic mellitus treated with metformin (22.6%)(p-value<0.001). This study showed a statistically significant inverse relationship between duration of metformin use and vitamin B12 levels (p-value 0.01). There was a statistically significant correlation between the dose of metformin and vitamin B12 deficiency – the higher the dose, the lower the average vitamin B12 level (p-value 0.02). The study revealed significantly increased neuropathic symptoms in Type 2 Diabetic patients on metformin with B12 deficiency than with normal B12 levels (p-value<0.001).

Conclusions: This study demonstrated a high prevalence of vitamin B12 deficiency in patients with type 2 diabetic patients treated with metformin (22.6%). Hencethe measurement of vitamin B12 should become an essential part of the annual review in all patients with type 2 diabetic patients on metformin therapy. The study revealed significantly increased neuropathic symptoms in Type 2 Diabetic patients on metformin with B12 deficiency than with normal B12 levels.