Is Glycosylated Hemoglobin Clinically Useful?

The chemical reaction between glucose and hemoglobin is an example of a widespread biologic process called "nonenzymatic glycosylation" (more properly called "glucosylation," in reference to glucose–protein linkages, or adducts). In this instance, a protein, hemoglobin A, is modified postsynthetically by forming an adduct with glucose.1 The reaction is nonenzymatic, slow, and irreversible. The human erythrocyte is freely permeable to glucose, and within each erythrocyte, glycosylated hemoglobin is formed continuously from hemoglobin A at a rate dependent on the ambient glucose concentration.2 It is now widely accepted that measurement of glycosylated hemoglobin in a single blood sample provides an accurate index . . .