Objectives: This study aimed at investigating the connection between oxidative stress & oxidative DNA damage in subjects with impaired fasting glucose (IFG).
Design and methods: This is a University-based research project. Clinical data of sixty-four participants without a known history of cardiovascular disease and/or diabetes were analysed. Participants were recruited via public media announcements. Differences in the level of biochemical markers of oxidative stress (erythrocyte GSH/GSSG), and endothelial dysfunction (urinary 8-hydroxy-2-deoxy-guanosine– 8OHdG) were determined for prediabetes and control subjects.
Results & conclusion: The redox balance was significantly impaired in the prediabetes group with an increased erythrocyte GSSG (18.3±13.2 vs 25.2±13.1mg/dL) and a decreased GSH/GSSG ratio (10.6±6.7mg/dL vs 6.1±2.6) compared to the control group (p<0.05), without changes in GSH oxidation and urinary 8-OHdG. This result follows on from our previous work that indicated a complex interaction between redox balance and oxidative stress, with 8-OHdG significantly increased when GSH levels are decreasing in IFG. Increased oxidative stress as reflected by the reduced GSH/GSSG ratio is the likely link between moderate hyperglycaemia in prediabetes leading to reduced erythrocyte GSH and endothelial dysfunction. The GSH/GSSG ratio, GSH and urinary 8-OHdG offer a possible tool for the assessment of oxidative stress related vascular pathology.