An inverse relationship between plasma glutathione concentration and fasting glycemia in patients with coronary artery disease and concomitant type 2 diabetes: A pilot study

Abstract

Background. There have been occasional reports indicating that plasma concentrations of reduced glutathione (GSH) may be associated in some way with blood glucose. This relationship, however, has not hitherto been explored in the blood plasma of patients with coronary artery disease (CAD). Objectives. The aim of this study was to evaluate potential associations of fasting glycemia and peripheral blood plasma GSH concentrations in CAD-free and CAD-affected subjects. Material and methods. In blood samples obtained from patients with CAD, defined by coronary angiography and/or echocardiography, and from an age-matched control group of patients with a confirmation of no coronary artery occlusion and with no history of cardiovascular events, plasma concentrations of glucose and reduced glutathione were analyzed by routine laboratory diagnostic methods and high performance liquid chromatography (HPLC), respectively. Results. The results showed that in the CAD patients, but not in the non-CAD controls, fasting glycemia is negatively associated with plasma levels of GSH (r = -0.328; p = 0.011). Moreover, in the CAD-affected subjects (but not in the controls) the presence of type 2 diabetes mellitus significantly discriminated plasma levels of GSH (rP = -0.125; p = 0.350, between GSH and glucose adjusted for the occurrence of diabetes). Conclusions. The study suggests that GSH may be an important factor contributing to glucose metabolism in CAD patients. Hence, it may be considered a significant therapeutic target in strategies aimed at improving glycemic control in CAD-affected subjects.