A clinical exam of 110 patients of young age with combined chronic diseases of gastrointestinal tract and chronic obstructive lung diseases was carried out. Regularities of compensatory reactions of antioxidant protection are studied; it is proved that during prolonged course of combined diseases the accumulation of the products of oxidative modification of proteins happens mainly at the account of aldehyde products and their oxidative destruction. Increase of reserves of oxidative modification of proteins in induced reactions is shown, which can be used for diagnostics and prognosis of the disease course.
