LIPID-PEROXIDATION IN INSULIN-DEPENDENT DIABETIC-PATIENTS WITH EARLY RETINA DEGENERATIVE LESIONS - EFFECTS OF AN ORAL ZINC SUPPLEMENTATION

Design: Placebo for 3 months, followed by 30 mg/day zinc gluconate in identical capsules. Setting: Diabetic out patients clinic at the Unive rsity Hospital, Grenoble. Subjects: Diabetic patients cared for type I diabetes mellitus. 22 patients began the study, 4 dropped out. 10 pat ients suffered of an early retinopathy, 8 patients had no retinopathy. Interventions: In this order: T0 biological measurements, 3 months pl acebo treatment, T1 biological measurements, 3 months zinc gluconate t reatment, T2 biological measurements. Plasma Zn, Cu, Se, thiobarbituri c acid reactants and antioxidant enzymes were measured [plasma and red glutathione peroxidase (Se-GPx), red cell superoxide dismutase (Cu-Zn -SOD)]. Results: Lower plasma zinc level in the two groups. An increas e in zinc level was observed and was more important in diabetic patien ts with no retinopathy (P = 0.05). The thiobarbituric acid reactants w ere above the reference values in all the patients, and were decreased at T2 (P < 0.05). Increase of GPx activity after zinc supplementation in patients with retinopathy. Conclusions: Zinc deficiency in insulin -dependent diabetic patients is corrected by a zinc supplementation. M oreover this supplementation decreases lipid peroxidation. The effects of zinc are different in diabetic patients with or without retinopath y. The increase in Se-GPx activity observed in patients with retinopat hy could be Linked to the protective effect of zinc on the protein its elf. Sponsorship: Aguettant pharmaceuticals (Lyon) purchased the place bo and the zinc treatment.