Dr. K. Vijaya Lakshmi
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 out-patient 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. CONCLUSION The prevalence of vitamin-B12 deficiency in T2DM patients was found to be high in our study population when compared to control subjects. Peripheral smear study revealed macrocytic anaemia in 22.7% and hyper-segmented polymorphs in 50% of cases with B12 deficiency. Considering the regular screening of vitamin-B12 as cost factor, the peripheral smear can be done frequently in T2DM patients on long term metformin to detect macrocytic anaemia followed by biochemical analysis periodically in a rural areas.
