[Non-enzymatic glycosylation. Biology. Pathology].

Enzymatic glycosylation of proteins should be clearly distinguished from non-enzymatic glycosylation or glycation. Both processes occur in normal subjects but are enhanced in patients with hyperglycemia. Increased enzymatic glycation in patients with diabetes mellitus is responsible for thickening and weakening of capillary membranes, resulting in microangiopathy with microaneurisms, bleeding, and circulatory exclusion. Non-enzymatic glycosylation (glycation) affects all the proteins in the body and, if intense enough, may modify the activity or effectiveness of some molecules (apolipoproteins, membrane receptors, or even insulin itself). In everyday practice, glycated serum albumin and, above all, glycated hemoglobin serve as markers to evaluate the effectiveness of therapy in patients with diabetes mellitus.