Protein oxidation biomarkers in plasma of type 2 diabetic patients.

OBJECTIVES To evaluate oxidative stress and the extent of oxidation of plasma proteins in type 2 diabetic patients. DESIGN AND METHODS Study was carried out on blood from 31 diabetic patients of both sexes (mean age = 58 + or - 7; duration of diabetes 12 + or - 5 years) and healthy age and sex matched normal subjects. Biomarkers of protein oxidation; plasma protein carbonyls (PCO), advanced oxidation protein products (AOPPs) and -SH group and free radical scavenging capacity of plasma was measured. RESULTS PCO and AOPPS levels were significantly (P<0.005) higher in diabetic patients in comparison to healthy volunteers. Reduced free radical scavenging capacity (P<0.001) and -SH group (P<0.05) was observed in plasma of type 2 diabetic patients. CONCLUSIONS Our data suggest that diabetics are susceptible to protein oxidation. Oxidative modulation of proteins due to reduced radical scavenging activity of plasma patients may be one of the reasons of altered physiological processes in type 2 diabetic patients.