Changes in superoxide dismutase activities and concentrations and myeloperoxidase activities in leukocytes from patients with diabetes mellitus

To investigate whether the two free-radical scavengers, Cu, Zn- and Mn-supe roxide dismutase (SOD), are changed in leukocytes of diabetic patients, and the alteration of these enzymes correlates with the diabetic state, we mea sured the activity and concentration of these enzymes in leukocytes from di abetic patients. Both Cu, Zn-SOD and Mn-SOD activities in neutrophils and l ymphocytes were significantly lower in patients with non-insulin-depend ent diabetes mellitus than in healthy controls. The concentrations of these en zymes in leukocytes from diabetic patients, however, did not differ from th ose in controls. Cu, Zn-SOD and Mn-SOD activities in neutrophils inversely correlated with HbA(1c) concentrations. Myeloperoxidase activity in leukocy tes was significantly reduced in NIDDM patients. These findings suggest tha t changes in these enzymes may affect the susceptibility to infection and i mmunocompetence of patients with diabetes. (C) 2000 Elsevier Science Inc.