Urinary oxidative stress markers in young patients with type 1 diabetes

Background: Involvement of oxidative stress in the pathogenesis of diabetic vascular complications has been proposed. However, there are few methods to determine the status of oxidative stress both directly and quantitatively in young patients with type 1 diabetes. Methods: A total of 27 young patients with type 1 diabetes (mean age ± SD, 12.6 ± 4.2 years) with normal renal function and 38 healthy control subjects (13.0 ± 4.6 years) were investigated. Early morning voiding urine samples were collected. The concentrations of acrolein-lysine adducts, 8-hydroxy-2′-deoxyguanosine (8-OHdG) were determined using competitive enzyme-linked immunosorbent assay, and nitric oxide metabolites were measured using the colorimetric, non-enzymatic assay. Results: Urinary concentrations of 8-OHdG, but not acrolein-lysine adducts and nitric oxide metabolites, were significantly increased in the diabetic group. For diabetic patients, microalbuminuria was significantly correlated with higher concentrations of all three markers. Hemoglobin A _1c values were significantly correlated with 8-OHdG values. Conclusions: These findings indicate that increased oxidative stress and the risk of vascular complications may be present at early stages of type 1 diabetes.