1,5 Anhydroglucitol and 1,5 Anhydroglucitol / Glycated Hemoglobin Ratio as a Potential Biomarker for Islet β-cell Function and Insulin Resistance Among Patients With Type 2 Diabetes Mellitus

Hyperglycemia is a major risk factor for the micro- and macro-vascular complications of diabetes . Lowering blood glucose levels has been shown to reduce the incidence of diabetes complications. Therefore, there is a need for a simple surrogate biochemical marker for glycemic variability. Glycated hemoglobin (HbA1c) is the standard clinical measurement used to monitor glycemic status and is recommended to assess control of diabetes over the preceding 2-3 months. However, being a measure of mean glucose, it does not reflect glucose variability. It is well known that insulin secretion defects of islet β cells and/or tissue insensitivity to insulin are common pathophysiological mechanisms of diabetes mellitus (DM) . The elevation in the blood glucose level usually represents the degree of glucose metabolism disorder, which is generally assessed by glycated hemoglobin A1c ( HbA1c) and indirectly reflects the extent of β-cell function damage . In the recent years, 1,5-anhydroglucitol (1,5-AG) has received attention as a short-term blood glucose index that reflects the average blood glucose level 1,5 AG reflects the average maximum blood glucose level during the past 1-2 weeks and is reported to be a more sensitive marker of glucose variability and postprandial hyperglycemia than HbA1c, even for patients with prediabetes and for those with well or moderately controlled diabetes . (1,5 AG ) is structurally similar to glucose . Due to this similarity, glucose inhibits renal reabsorption of 1,5 AG by competitive inhibition ,resulting in an inverse correlation of 1,5 AG with hyperglycemia . 1,5-AG levels are acting as an effective supplement to HbA1c. Additionally, previous study showed that 1,5-AG and HbA1c had opposite curves with increasing blood glucose levels; specifically, with the increase in HbA1c levels, 1,5-AG levels decreased significantly . Therefore, we speculate a ratio of 1,5- AG / HB A1C in relation to islet β-cell function and insulin resistance. The a