Haematological Parameters and Vitamin B12 Levels in Type Ii Diabetic Patients on Metformin- A Prospective Case Control Study

Abstract

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.

The Frequency of Vitamin B12 Deficiency in Patients With Type 2 Diabetes Mellitus Treated With Metformin for at Least Five Years

“…This result is consistent with those reported in other studies [4,19]. In contrast, some authors have shown that the reduction of serum vitamin B 12 concentration is associated with duration of metformin therapy and is induced in a dose-dependent manner [16,18,20,38] The complex interaction between the oxidative stress and inflammation in T2DM patients contribute to the alteration of erythrocyte homeostasis and cause an increase in RDW values [1,23,26]. Vitamin B 12 possesses antioxidant properties, and subclinical vitamin B 12 deficiency may contribute to oxidative stress through various mechanisms [36].…”

“…By multiple linear regression analysis, we found that older patients had statistically significantly lower serum vitamin B 12 levels. A significant negative relationship between age and vitamin B 12 level in T2DM patients using metformin for 1 -10 years was reported by Koduri et al [18]. The vitamin B 12 status depends on both the amount ingested and the proper functioning of the gastrointestinal tract.…”