Lipoperoxidation and antioxidant capacity in patients with poorly controlled type 2 diabetes.
Type 2 diabetes is a heterogeneous disease resulting from insulin resistance and/or from a beta-cell secretory defect. Hyperglycemia, which occurs during type 2 diabetes, causes disorders of oxidative-antioxidative balance in the cells, leading to increased free-radical formation. Reduced antioxidant capacity is supposed to be one of the causes of the occurrence of complications in type 2 diabetes. The aim of this study was to evaluate lipoperoxidation and plasma antioxidant status in patients with poorly controlled type 2 diabetes with or without complications. In this study, 15 patients with type 2 diabetes without complications and 11 patients with type 2 diabetes with complications were enrolled. The 'ferric-reducing ability of plasma' showed no differences between the two experimental groups. A small, nonsignificant, Superoxide dismutase (SOD) activity reduction was observed in patients with diabetes with complications when compared to those patients with diabetes without complications; on the contrary, we found increased lipoperoxidation in patients with diabetes with complications compared with those patients with diabetes without complications. We also observed a positive correlation between malondialdehyde levels and high density lipoprotein or vitamin E in all analyzed patients with type 2 diabetes. Data obtained from our study show that patients with poorly controlled type 2 diabetes with complications have higher lipoperoxidation than patients with complication-free diabetes, although a residual compensatory response to hyperglycemia-induced oxidative stress occurs.
Lodovici
M
M
Department of Pharmacology, University of Florence, Florence, Italy. maura.lodovici@unifi.it
Bigagli
E
E
Bardini
G
G
Rotella
C M
CM
D000368:Aged; D000369:Aged, 80 and over; D000975:Antioxidants / Q000502:physiology*; D001786:Blood Glucose / Q000378:metabolism; D008076:Cholesterol, HDL / Q000097:blood; D048909:Diabetes Complications / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000150:complications; D005260:Female; D006442:Glycated Hemoglobin; D006801:Humans; D015227:Lipid Peroxidation / Q000502:physiology*; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D008875:Middle Aged; D013482:Superoxide Dismutase / Q000096:biosynthesis; D014810:Vitamin E / Q000097:blood
D000975:Antioxidants; D001786:Blood Glucose; D008076:Cholesterol, HDL; D006442:Glycated Hemoglobin; D008315:Malondialdehyde; D013482:Superoxide Dismutase; D014810:Vitamin E