[Recent progress in evaluation of glycemic control by glycated protein and 1,5-AG]

The aim of treatment of diabetes is to prevent the progress of diabetic complications. A recent report by the DCCT (Diabetes Control and Complications Trial) clearly shows the importance of strict glycemic control for prevention of diabetic complications. For this purpose, some markers for long-term glycemic control other than glucose concentration will be helpful, because glucose levels fluctuate too severely to assess whether they are precise. HbA1c is the longest established marker for glycemic control but still large interlaboratory variation is present. The standardized procedure for measurement of HbA1c was just proposed by the Japan Diabetes Society. Fructosamine is measured by a simpler procedure but many deoxidizing materials in serum especially superoxide may interfere with the reaction. Glycated albumin should be more reliable than fructosamine but a standard method of measurement has not been established yet. Future measurement of advanced glycation end product (AGE) should prove to be good marker for not only glycemic control but also diabetic complications or diagnosis of diabetes. The decrease in serum 1,5-anhydro-D-glucitol(1,5-AG) is very sensitive to urinary glucose excretion and may be useful as a marker of glycemic control and diagnosis of diabetes.