Metformin induces reductions in plasma cobalamin and haptocorrin bound cobalamin levels in elderly diabetic patients

Abstract

ObjectiveTo study the effect of short term metformin therapy on plasma levels of cobalamin, cobalamin related metabolites and cobalamin binding proteins in elderly patients. Design and methodsTwenty patients with type 2 diabetes were assigned to receive metformin or not for 3months. Cobalamin and its metabolites were measured before and after metformin therapy. ResultsAs compared to baseline measures, there was a metformin therapy specific significant decrease in plasma levels of total cobalamin, total haptocorrin and haptocorrin bound cobalamin. ConclusionsPlasma total cobalamin and haptocorrin bound cobalamin levels are reduced by short term metformin therapy in an elderly diabetic population. Larger scale, longer term studies are necessary to determine if there is an unequivocal decrease in functional measures of cobalamin status.