Meal-Generated Oxidative Stress in Type 2 Diabetic Patients

Antonio Ceriello; Nadia Bortolotti; Enrico Motz; Adriana Crescentini; Sebastiano Lizzio; Assunta Russo; Laura Tonutti; Claudio Taboga

doi:10.2337/diacare.21.9.1529

Original Articles

Meal-Generated Oxidative Stress in Type 2 Diabetic Patients

Antonio Ceriello, MD,
Nadia Bortolotti, PHD,
Enrico Motz, MD,
Adriana Crescentini, TECHN,
Sebastiano Lizzio, MD,
Assunta Russo, MD,
Laura Tonutti, MD and
Claudio Taboga, MD

Department of Medicine and Pathology, Clinical and Experimental, University of Udine Udine, Italy
Diabetology Unit, Udine General Hospital Udine, Italy

Address correspondence and reprint requests to Dr. Antonio Ceriello, Chair of Internal Medicine, University of Udine, P. le S. Maria della Misericordia, 33100 Udine, Italy. E-mail: antonio.ceriello{at}dpmsc.uniud.it.

Diabetes Care 1998 Sep; 21(9): 1529-1533. https://doi.org/10.2337/diacare.21.9.1529

Abstract

OBJECTIVE Free radical production has been reported to be increased in diabetic patients and to be involved in the pathogenesis of diabetic complications. In this study, a standardized meal was administered to 10 type 2 diabetic patients and 10 healthy matched normal subjects to evaluate its effects on plasma oxidative stress generation.

RESEARCH DESIGN AND METHODS In diabetic patients, at baseline and after the meal, plasma malondialdehyde (MDA), vitamin C, protein SH groups, uric acid, vitamin E, and total plasma radical-trapping parameter, which evaluates plasma antioxidant capacity due to known and unknown antioxidants present in the plasma as well as their mutual cooperation, were measured.

RESULTS After the meal, plasma MDA and vitamin C increased, while protein SH groups, uric acid, vitamin E, and total plasma radical-trapping parameter decreased more significantly in the diabetic subjects than in control subjects.

CONCLUSIONS This finding shows that in the absorptive phase, free radicals are produced in diabetic patients. Since plasma glucose, but not insulin, rose significantly more in diabetic subjects than in control subjects, hyperglycemia may play an important role in the generation of postprandial oxidative stress in diabetic patients.