Background: Atherosclerosis and microvascular complications in patients with non-insulin-dependent diabetes have been linked to increased oxidative stress. The glutathione redox cycle is a major determinant of the antioxidative capacity of plasma and its constituents.
Methods: We attempted to investigate plasma oxidation and plasma and erythrocyte glutathione and glutathione enzymes in 20 patients with NIDDM, compared with euglycemic matched controls. Plasma oxidation was analyzed both basally (without) and as induced by 2,2'-azobis,2-amidopropane hydrochloride measured by the generation of thiobarbituric acid reactive substances and lipid peroxides.
Results: There was a significant increase in oxidation both basally (without) and as induced by AAPH. Plasma glutathione was lowered by 50% (P<0.01) and erythrocyte glutathione peroxidase, glutathione s-transferase and glutathione reductase activities were lower by 30%, 27% and 46%, respectively (P<0.01) in the patients with NIDDM.
Conclusions: Confronted by increased oxidation, patients with NIDDM show an abnormal plasma and erythrocyte antioxidative capacity, which may result in an accelerated rate of complications.
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NIDOM= non-insulin-dependent diabetes mellitus