1,5-AG as a Marker of Postprandial Hyperglycemia and Glucose Variability in Well-controlled Type 2 Diabetes Mellitus

1,5-Anhydroglucitol (AG) is a glucose analogue present in the plasma of healthy subjects. Physiologically, the plasma levels of 1,5-AG are very stable and only a small quantity is excreted in the urine. It is competitively reabsorbed with glucose in the renal tubules. Therefore, in the hyperglycemic state where glycosuria is present, glucose competitively inhibits renal tubular reabsorption of 1,5-AG and consequently the plasma 1,5-AG levels decrease. When glycemia is normalized and glycosuria is resolved, 1,5-AG levels increase.

The usefulness of 1, 5-AG in reflecting glycemic excursions have been demonstrated in moderately controlled patients to some extent, although some studies reveal controversial results.

Therefore, the aim of this study was to evaluate the association of 1,5-AG and postprandial hyperglycemia determined using the Continuous Glucose Monitoring System (CGMS) in DM patients with HbA1C<7% and evaluate the usefulness of 1,5-AG as a marker of glycemic control compared to HbA1C and fructosamine.

Inclusion criteria

• HbA1C < 7%
• HbA1c modification <0.5% in the previous 3 months
• no recent addition of oral hypoglycemic medications or change in insulin dose >10% previous 3 months

Exclusion criteria

• pregnancy
• anemia (Hb <10.0 g/dL)
• liver disease (ALT >2 UNL)
• hypoalbuminemia (albumin <3.5 g/dL)
• serum creatinine >2 mg/dL
• acute or chronic renal tubulointerstitial disease
• severe medical illness