THE EFFECT OF HYPERGLYCEMIA AND OXIDATIVE STRESS ON THE DEVELOPMENT AND PROGRESS OF VASCULAR COMPLICATIONS IN TYPE 2 DIABETES

Oxidative stress is the result of increased production of free radicals, which impair the cell function and cause many pathological conditions and diseases. The development of diabetes, its course and complications are closely associated with an imbalance in pro-antioxidative cell state and change of redox potential. Prolonged exposure to hyperglycemia is currently considered the major factor of the pathogenesis of atherosclerosis in diabetes. Atherosclerosis is the cause of about 80% of mortality in diabetics, and over 75% of all hospitalized diabetic patients have associated cardiovascular complications. Hyperglycemia induces different vascular tissue damage at the cellular level, which potentially accelerates the atherosclerotic processes. The most significant mechanisms responsible for acceleration of atherosclerotic processes in diabetic patients are: a) non-enzymatic protein and lipid glycosylation which interferes with normal function, in the way that it deranges molecular conformation, impairs enzymatic function, reduces the capacity of breakdown and interferes with recognition of protein structures by receptors; b) interaction of glycosylated proteins with their receptors resulting in induction of oxidative stress and pro inflammatory reactions; c) polyol pathway; d) hexosamine pathway and e) activation of protein kinase C and impaired growth factor expression.