Antioxidant vitamins and Lipid Peroxidation in Patients with Type 1 Diabetes Mellitus

It has been postulated that oxidative stress may be increased and antioxidant defenses reduced in diabetes patients. Twenty-four patients with type 1 diabetes melitus (DM) (12.8$\pm$1.7 years) and 24 nondiabetics (12.5$\pm$2.1 years) were included in this study. Serum total cholesterol and LDL -cholesterol levels were significantly higher in diabetic than in nondiabetic control subjects, but serum levels of triglyceride , retinol , tocopherol, and $\beta$-carotene were significantly lower. Both $\beta$carotene and tocopherol levels inversely correlated with HbAlc, suggesting perhaps that low serum antioxidant level enhance theglycosylation of hemoglobin. Subjects with type 1 DM had lipid peroxide levels similar to those of nondiabetics control subjects, suggesting that per-oxdation of circulating lipid is not increased in uncomplicated diabeteics. The correlation between antioxidants and serum lipids were as follows ; retinol and LDL (r--0.36, p=0.019) ; retinol and total cholesterol(r=-0.35, p=0.020), tocopherol and LDL(r=-0.47, p=0.002) ; tocopherol and cholesterol (r=-0.49, p=0.001) ; $\beta$-carotene and LDL (r=-0.51, p=0.001). Overall , the results of this study were that serum lipid peroxide in patients with type 1 DM was similar to those of control subjects and antioxidants such as retinol, tocopherol and $\beta$-carotene were lower than those of nondiabetic cotnrol subjects, and negatively correlated with serum total cholesterol and LDL-cholesterol.