Meal-generated oxidative stress in type 2 diabetic patients.
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.


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.
Ceriello
A
A
Department of Medicine and Pathology, Clinical and Experimental, University of Udine, Italy.
Bortolotti
N
N
Motz
E
E
Crescentini
A
A
Lizzio
S
S
Russo
A
A
Tonutti
L
L
Taboga
C
C
D000704:Analysis of Variance; D000975:Antioxidants / Q000378:metabolism; D001205:Ascorbic Acid / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000503:physiopathology*; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D005609:Free Radicals; D006801:Humans; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D008875:Middle Aged; D018384:Oxidative Stress; D019518:Postprandial Period; D014527:Uric Acid / Q000097:blood; D014810:Vitamin E / Q000097:blood
D000975:Antioxidants; D001786:Blood Glucose; D005230:Fatty Acids, Nonesterified; D005609:Free Radicals; D014810:Vitamin E; D014527:Uric Acid; D008315:Malondialdehyde; D001205:Ascorbic Acid