Background: Patients with type 2 diabetes mellitus are usually treated with oral antidiabetic agents but it is still not known whether these drugs have antioxidant effects in humans.
Methods: We studied 60 patients with type 2 diabetes mellitus, divided into three groups on the basis of hypoglycaemic treatment (Group A: metformin, Group B: glibenclamide, Group C: diet). All patients were followed for at least 1 year. The three subgroups had similar clinical characteristics. Twenty healthy subjects, of comparable sex and age, were enrolled as controls. In each subject, platelet production of superoxide anion (O(2)(-)) elicited by collagen, was determined by lucigenin assay.
Results: Patients with diabetes had higher platelet O(2)(-) production than controls; no correlation was observed between blood glucose and platelet O(2)(-) production. Group A patients had platelet O(2)(-) production similar to that of healthy subjects but lower than Group B and Group C patients.
Conclusion: The present findings suggest an in vivo antioxidant activity of metformin and warrant prospective studies to further explore this hypothesis.
Copyright 2002 John Wiley & Sons, Ltd.