Ascorbyl free radical release in diabetic patients

The objective of this study was to verify the presence of oxidative stress in type 1 and type 2 diabetic patients and to provide evidences for an use of ascorbyl free radical (AFR) / vitamin C ratios as tools exploring the le vel of oxidative stress in diabetic patients. TEARS levels, oxygen-radical absorbing capacity assay and AFR release assessed by electron paramagnetic resonance (EPR) were used to explore the existence of oxidative stress in d iabetes. Endogenous antioxidants (alpha-tocopherol, vitamin C and uric acid ) were also measured. Scavenging capacities of plasma were decreased in dia betic patients. A significant decrease of plasma vitamin C and an increase of AFR / vitamin C ratios were noted in type 2 diabetic patients. Uricemia was decreased in type 1 diabetic patients. Our results suggest a possible u se of AFR / vitamin C ratios as indicators of oxidative stress in diabetes mellitus.