Depletion of total antioxidant capacity in type 2 diabetes

The purpose of the study was to examine the relationship between antioxidan t depletion, glycemic control, and development of chronic complications in a controlled population of type 2 diabetic patients. Fifty age-matched type 2 diabetic patients receiving sulfonylureas but not insulin treatment were screened and assigned to two groups based on the presence or absence of pr oteinuria. A third group of normal subjects without diabetes were also enro lled in the study. All subjects in the three groups were Egyptians who were matched for body weight, and the two diabetic groups were also age-matched , plasma glucose and fructosamine levels were higher in the two groups of d iabetic patients versus the control group, but lipid peroxide levers were h igher only in the patients with proteinuria. Compared with the control grou p, the total antioxidant capacity was depleted in the two diabetic groups, but the depletion was more severe in patients with proteinuria. Thus, the m ean Trolox equivalent antioxidant capacity (TEAC) of the control group was 2.7 +/- 0.45, versus 1.7 +/- 0.5 (P < .001) in the patients without protein uria. Furthermore, the TEAC measured in patients with proteinuria, who also had more diabetic complications, was lower (1.4 +/- 0.5, P < .001) than th e TEAC in patients without urinary protein. In conclusion, a depletion of t he total antioxidant capacity is associated with a higher incidence of diab etic complications. Copyright (C) 1999 by W.B. Saunders Company.