LIPID-PEROXIDATION IN TYPE-2 NORMOLIPIDEMIC DIABETIC-PATIENTS

Vascular complications, as a consequence of atherosclerosis, are the m ain causes of morbidity and mortality in diabetes. Low density lipopro tein (LDL) oxidation is accepted as a relevant pathogenic mechanism in atherogenesis. The aim of this work was to study the relationship bet ween lipid peroxidation (LPO) and metabolic control. LPO was evaluated in 40 type 2 normolipidemic diabetic patients by measuring thiobarbit uric acid reactive substances (TEARS), in the plasma, using malondiald ehyde (MDA), end product of the oxidation of polyunsaturated fatty aci ds, as a standard. Fast blood glucose (FBG), serum total cholesterol ( TC) and serum triglycerides (TG) were evaluated by routine methods. Fr uctosamine (FR) was measured by the nitroblue tetrazolium (NET) colori metric test. An elevated level of lipid peroxides (P < 0.001) was obse rved in the plasma of diabetic patients (4.51 +/- 1.29 nmol/ml) as com pared to normal subjects (3.54 +/- 1.00 nmol/ml). Lipid peroxides did not correlate with the FR levels, nor with FBG, TC and TG. These resul ts show an increase of LPO in type 2 normolipidemic diabetic patients. Probably the mechanism for higher lipid peroxide levels in diabetes i s multifactorial. Our study supports the hypothesis of a role of oxida tive stress in diabetes independently of the lipid serum content. (C) 1997 Elsevier Science Ireland Ltd.