Sources of oxidative stress Sources of vascular oxidative stress Acute and chronic hyperglycaemia; Lipoprotein abnormalities; Hypertension; OS; Inflammation and AGEs accumulation; Glycation; Glycoxidation; Lipoxidation; Extracellular metal ions; Superoxide and HOCl; NADPH/NADH oxidase; NO synthase; Cyclooxygenase; Lipoxygenase; Myeloperoxidase; P450 monooxygenases; Enzymes of mitochondrial oxidative phosphorylation; Increased generation of ROS Autoxidation of carbohydrates, fatty acids, triglycerides, phospholipids and cholesteryl esters; Acute and chronic hyperglycemia; Glycation, advanced glycation and glycoxidation; Alterations in enzymatic pathways Increased polyol pathway activity; Decreased glyoxalase pathway activity; Alteration in mitochondrial oxidative metabolism; Altered prostaglandin and leukotriene metabolism; Other mechanisms Ischemia-reperfusion injury, hypoxia and pseudohypoxia;

Table 1: Possible conditions that may be sources of oxidative stress in diabetes mellitus (modified from ref. [46]).