Relationship between plasma glycation with membrane modification, oxidative stress and expression of glucose trasporter-1 in type 2 diabetes patients with vascular complications.

BACKGROUND OF STUDY: Enhanced protein glycation in diabetes causes irreversible cellular damage through membrane modifications. Erythrocytes are persistently exposed to plasma glycated proteins; however, little are known about its consequences on membrane. Aim of this study was to examine the relationship between plasma protein glycation with erythrocyte membrane modifications in type 2 diabetes patients with and without vascular complications. METHOD: We recruited 60 healthy controls, 85 type 2 diabetic mellitus (DM) and 75 type 2 diabetic patients with complications (DMC). Levels of plasma glycation adduct with antioxidants (fructosamine, protein carbonyl, ß-amyloids, thiol groups, total antioxidant status), erythrocyte membrane modifications (protein carbonyls, ß-amyloids, free amino groups, erythrocyte fragility), antioxidant profile (GSH, catalase, lipid peroxidation) and Glut-1 expression were quantified. RESULT: Compared with controls, DM and DMC patients had significantly higher level of glycation adducts, erythrocyte fragility, lipid peroxidation and Glut-1 expression whereas declined levels of plasma and cellular antioxidants. Correlation studies revealed positive association of membrane modifications with erythrocyte sedimentation rate, fragility, peroxidation whereas negative association with free amino groups, glutathione and catalase. CONCLUSION: Our data suggest that plasma glycation is associated with oxidative stress, Glut-1 expression and erythrocyte fragility in DM patients. This may further contribute to progression of vascular complications.