Increased oxidative damage to all DNA bases in patients with type II diabetes mellitus

Gas chromatography-mass spectrometry was used to measure the oxidative DNA damage in diabetic subjects and controls. Levels of multiple DNA base oxida tion products, but not DNA base de-amination or chlorination products, were found to be elevated in white blood cell DNA from patients with type II di abetes as compared with age-matched controls. The chemical pattern of base damage is characteristic of that caused by an attack on DNA by hydroxyl rad ical. An increased formation of the highly reactive hydroxyl radical could account for many of the reports of oxidative stress in diabetic subjects. T here was no evidence of an increased DNA damage by reactive nitrogen or chl orine species. (C) 1999 Federation of European Biochemical Societies.