BACKGROUND Metformin is the cornerstone medication in the management of type 2 diabetes mellitus (T2DM) with estimates that it is routinely prescribed to 120 million type 2 diabetes patients around the world. Preceding studies say long term use of metformin in T2DM lowers vitamin-B12 levels and its clinical manifestations can be misdiagnosed as diabetic peripheral neuropathy. The aim of this study is to correlate haematological parameters with estimated serum Vit. B12 levels in T2DM patients on long term metformin in patient subjects and healthy volunteers. MATERIALS AND METHODS A total of 34 T2DM patients (cases) and 34 healthy volunteers (controls) were enrolled in the study from the outpatient department and in-patient wards of RVM Hospital, for over a period of 6 months. Serum vitamin-B12, HbA1c and haematological parameters were measured. RESULTS The clinical characteristics and serum vitamin-B12 levels of the study population were compared using chi-square cross tabulation. Vitamin-B12 deficiency was higher in T2DM patients taking daily dose of metformin >1000 mg/day. Hematological parameters estimation and peripheral smear study was done in all cases to identify macrocytic anaemia and hyper segmented polymorphs.

Introduction:Metformin is the cornerstone medication in the management of Type 2 diabetes mellitus with estimates that it is prescribed to 120 million patients with diabetes around the world. Several studies reported that the long-term use of metformin lowers vitamin -B12 levels and its clinical manifestation can be misdiagnosed as diabetic peripheral neuropathy. Thereby, the present study was undertaken to assess the vitamin-b12 deficiency in type II Diabetic patients with long-term use of metformin, an association between vitamin B12 and peripheral neuropathy and evaluating the quality of life in (T2DM) patients. Material and Methods: A prospective observational casecontrol study was conducted at the outpatient and inpatient departments of RVM Hospital. Total 34 (controls) healthy volunteers and 34 (cases) Type 2 diabetes patients using metformin for more than six months were recruited for the study. Data was collected using designed profile form, structured questionnaires and venous blood samples were collected in K2 EDTA vacutainers from the patients and centrifuged at 1500 rpm for 10 minutes, settled plasma was transferred into cryovials, estimating the parameters such as Vitamin-B12, HbA1c and CBP. The statistical analysis was done using SPSS (v25) software. Results: The prevalence of serum vitamin B12 deficiency and borderline deficiency in T2DM patients is 20.5%, the mean HbA1C levels in our study T2DM subjects is < 9.07% which is showing either poor control of diabetes and lack of compliance with metformin medication. 83% of T2DM patients with 1-10 years of metformin use resulted in Vitamin-B12 deficiency. Conclusion: Vitamin-B12 deficiency and Borderline deficiency prevalence in Type II Diabetes patients was found to be slightly high in our study population when compared to control subjects. The reliability test was done to evaluate their quality of life which concludes that the quality of life was poor amongst the study participants. Considering the regular screening of vitamin-B12 as a cost factor, the peripheral smear can be done in T2DM patients on long-term metformin to detect macrocytic anaemia followed by biochemical analysis periodically.