Abstract
The increased oxidative stress may play an important role on the pathogenesis of diabetes and diabetic complications, and the blood level of vitamin C and lipid peroxidation in NIDDM patients may be used as an indicator for oxidative stress. However there is only scanty evidence on the blood level of vitamin C in NIDDM patients with or without diabetic complications. The study population consisted of 90 NIDDM patients(diabetes without complication, 48, and diabetes with complications, 42) and 41 normal subjects. The 42 diabetic complications were divided into 3 groups : 15 diabetic nephropathy, 18 diabetic neuropathy, 9 diabetic retinopathy. The anthropometric data and blood biochemical data were studied. The dietary intake was determined by 24 hour recall methods and food frequency questionnaire. The plasma concentrations of MDA and vitamin C were determined by fluorophotometer and HPLC respectively. 1) In blood lipoprotein study, diabetes with complication had higher level of TG than diabetes without complications, while no significant differences in total cholesterol, HDL, and LDL were shown. Diabetic neuropathy had the highest TG level among diabetic complication groups. 2) The intakes of vitamin B complexes(vitamin B$_2$, vitamin B$_{6}$, not vitamin B$_1$) and antioxidant vitamins(vitamin A and vitamin E, not vitamin C) and certain minerals such as iron and calcium in diabetes were not sufficient but the intakes of energy, protein, niacin, and phosphorus in diabetes were sufficient. The dietary intakes between diabetes with-and without complications were not significantly different. Among diabetic complications, the diabetic retinopathy had the lowest intake of vitamin B$_2$ and B$_{6}$(p < 0.05). the diabetic neuropathy or nephropathy consumed extremely low amount of vitamin A. 3) The MDA concentrations of NIDDM was significantly higher than that in controls(p < 0. 05) while no significant difference in the MDA concentration between with and without complications was shown. Although there were no statistical differences, the diabetic nephropathy and diabetic neuropathy showed the higher concentration of MDA than the diabetes without complications or diabetic retinopathy. 4) The plasma concentration of vitamin C in controls was higher than that in diabetes(p < 0.05) while the plasma vitamin C in diabetes with and without complications were similar. In diabetic complications, no differences in plasma vitamin C concentration of three groups were shown. This study showed that the oxidative stress in NIDDM patients was highly increased and the vitamin C reserve was significantly depleted, as compared with normals, although their intakes of vitamin C met korean RDA, which means that diabetes need more vitamin C intake to decrease oxidative stress in NIDDM patients.nts.