ABSTRACT

Each cell can mobilize an armory of antioxidant defense systems. Under nor­ mal metabolic conditions, the production of free radicals and the antioxidant capacity are balanced. Hyperglycemia in diabetes mellitus is associated with an increased production of free radicals. Furthermore, observational studies indicate lower levels of antioxidants like vitamin E, vitamin C, carotene, ascor­ bate, and thiols in patients with diabetes mellitus (1,2). Imbalance between free radical production and the antioxidant defense system leads to oxidative stress. In diabetic patients, oxidative stress can be demonstrated by increased levels of lipid peroxidation products (3-8). There is a body of evidence that vascular and neurological complications in patients with diabetes mellitus are a consequence of oxidative stress (9-12).