[Indicators of glycemic control --hemoglobin A1c (HbA1c), glycated albumin (GA), and 1,5-anhydroglucitol (1,5-AG)].

The clinical goal of diabetes management is a good quality of life that is not different from that of a healthy subjects. To fulfill the goal, prevention of complications is needed under good glycemic control. Although blood glucose measurement is essential for glycemic control, there are diurnal variations in blood glucose levels. An indicator of long-term glycemic control is necessary. HbA1c is the gold standard measurement for the assessment of glycemic control, and worldwide large scale clinical studies of diabetes complications have greatly valued HbA1c as an indicator of glycemic control. In addition, recently, HbA1c was recommended for use in the diagnosis of diabetes in Japan and in the United States. Although HbA1c is used widely and internationally, international standardization of the HbA1c value has not been achieved. In Japan, from April 2014, it has been decided to adopt the National Glycohemoglobin Standardization Program (NGSP) value, which is used by many countries globally, as the first step toward internationalization. Recently, cardiovascular disease in diabetic patients has been increasing in Japan. Relationships between postprandial hyperglycemia and cardiovascular disease have been noted. Therefore, the correction of postprandial hyperglycemia is one of the important goals of glycemic control to prevent cardiovascular disease. HbA1c or glycated albumin (GA) results from the glycation of hemoglobin or serum albumin and represents 2-month or 2-week glycemia, respectively. In addition, the glycation speed of GA is ten times faster than HbA1c, so GA is likely to reflect the variation in blood glucose and postprandial hyperglycemia in combination with HbA1c and its value. 1,5-anhydroglucitol (AG) is a marker of glycemia-induced glycosuria, since reabsorption of filtered 1,5-AG in the proximal tubule is competitively inhibited by glucose. It is an indicator to identify rapid changes in hyperglycemia. Understanding the characteristics of the indicators above, it is important to use them suitably for each diabetes subject and to recognize glycemic control conditions more accurately.