OGTT values in subjects with normoglycemia, prediabetes and diabetes. The findings highlighted that 1,5 AG (tested by ELISA) negatively correlates with HbA1c and plasma glucose. Approximately 20% individuals with diabetes and prediabetes (bases on HbA1c) had 1,5 AG levels above 10 μg/mL. The results suggested that 1,5 AG may detect subjects with glycemic variation over previous 1-2 weeks or those with very recent onset hyperglycemia, with more ease than HbA1c.