Antioxidant and oxidative stress status in type 2 diabetes and diabetic foot ulcer

Abstract

ABSTRACT
Objectives: Oxidative stress (OS) has been implicated in the aetiology and progression of diabetic complications including diabetic foot ulcer. In the present study, the levels of lipid peroxides (LPO), a marker of lipid peroxidation and 8-hydroxy-2’-deoxyguanosine (8-OHdG), a marker of DNA damage as well as the enzymatic antioxidant activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx) in type 2 diabetes mellitus and diabetic foot ulcer subjects were assessed and compared with apparently healthy normal subjects in order to understand the involvement of OS in diabetic foot ulcer subject.
Design: The above-mentioned OS markers were measured in 50 subjects for each of the following groups: type 2 diabetes mellitus (DM), diabetic foot ulcer (DF) and non diabetic control (NC).
Results: Significant elevated values of LPO and 8-OHdG were found in DM subjects: 39.86% and 45.53% increase respectively compared to the NC subjects. This increase in both parameters was greater for DF subjects: 80.23% and 53.91% respectively. SOD activities were significantly reduced in DM (14.82%) and DF (4.09%) subjects in contrast with elevated activities of GPx observed in DM (21.87%) and DF (20.94%) subjects. In this study, positive correlations between glycated hemoglobin/fasting plasma glucose (HbA1c/FPG) and the following OS parameters: LPO, 8-OHdG and GPx were observed. However, correlation between the above glycemic components and SOD was found to be negative.
Conclusion: Increased oxidation subsequent to diabetic conditions induces an overexpression of GPx activity suggesting a compensatory mechanism by the body to prevent further tissue damage in these subjects.