[Hemoglobin glycosylation in prolonged hyperglycemic episodes. Interpretation of results using mathematical modeling]

Using a mathematical model, the authors analyze the relationship between glycemia and glycated haemoglobin concentration (GHb). This relationship is more complex that it seems at first sight as GHb concentration in erythrocytes is the outcome of two processes: glucose binding to haemoglobin and continuous turnover of erythrocytes in blood. Old erythrocytes carry information on glycemia of longer duration than do the younger ones. The result is that hyperglycemias which occurred immediately before to GHb estimation have a greater effect on GHb concentration than those that occurred former. Due to the fact that behind a certain value of GHb different hyperglycemic periods can be hidden, the compensation of a patient with diabetes mellitus cannot be assessed only on the basis of GHb concentration. The assessment can only be made when using criteria which take into consideration glycemia, glycated plasmatic protein, and glycated haemoglobin values in a complex way.