The state of reduced glutathione in patients with impaired glycemic states and coronary heart disease

Abstract

Antioxidative mechanisms prevent human body from the damaging action of free radicals and reactive oxygen species. Glutathione and related to it enzyme systems detoxicate H2O2 and hyperoxide and from there, reduced glutathione is a potential marker of oxidative stress level. Purpose: To investigete glutathione of erythrocytes in patients with prediabetes (IGT & IFG) and type 2 diabetes and concomitant coronary heart disease (CHD). Matherial and methods: We examined 25 patients with T2D and concomitant CHD and atherosclerosis (group 1), 20 patients with prediabetes (IGT & IFG) newly diagnosed and the same co-morbidity (group 2) and 47 almost healthy person (group 3). Examinations included clinical laboratory evaluation, fasting glicose, HbA1c. Total glutathione (GSHt) and oxidized glutathione (GSSG) were measered by use of glutathione reductase reaction. Redox potential (Eh) of glutathione was evaluated by use of Nernst equation. Results: Concentrations of GSHt and GSH were greater in group 2 to compare with groups 1 and 3 (by 4,2 times, p=0,012 and by 3,1 times, p=0,005 respectively). Increase of concentration of GSSG in group 1 may change extracellular redox condition. Calculation of Eh revealed its change to oxidized condition in group 1 to compare with group 2 (19,0 mV greater) and group 3 (15,4 mV greater). Conclusion: Antioxidant defense in red-cells is overactivated during prediabetes (IGT & IFG) with concomitant CHD and atherosclerosis while in patients with T2D was noticed depletion of compensatory mechanisms with increased GSSG and Eh. Reduction in 2GSH/GSSG suggests that intracellular antioxidant is lost; herewith cells become sensitive to oxidative stress.