1,5-anhydroglucitol (1,5-AG) has been suggested as a marker for short-term
glycemic control and
postprandial hyperglycemia. However, the role of 1,5-AG in glycemic variability has not been established. The aim of this study was to demonstrate the usefulness of 1,5-AG as a marker for glycemic variability in patients with
type 2 diabetes. Sixty patients with
type 2 diabetes were enrolled, and a continuous
glucose monitoring system (CGMS) was applied for 72 h. Continuous overlapping net glycemic action (CONGA), mean amplitude of glycemic excursion (MAGE), and mean of the daily differences (MODD) were calculated for the assessment of glycemic variability and compared with 1,5-AG. Urinary 8-iso
prostaglandin F2α (8-isoPGF2α) was measured to assess oxidative stress. 1,5-AG was correlated with fasting
blood glucose, HbA1c, postprandial area under the curve for
glucose above 180 mg/dL (AUC-180), and mean post-meal maximum
glucose (MPMG). However, 1,5-AG did not show significant correlation with CONGA-1, MAGE, and MODD (R = -0.053, P = 0.689; R = -0.148, P = 0.259; R = -0.123, P = 0.350). In patients with HbA1c ≤ 8.0% (n = 35), 1,5-AG was significantly correlated with HbA1c, mean
glucose, postprandial AUC-180, and MPMG. However, in patients with HbA1c > 8.0% (n = 25), 1,5-AG did not show correlation with any glycemic markers. Oxidative stress measured as urine 8-isoPGF2α showed positive correlations with CONGA-1, MAGE, AUC-180, postprandial AUC-180, and MPMG only in men. However, 1,5-AG did not correlate with oxidative stress. Our data suggested a limited usefulness of 1,5-AG in estimating glycemic variability and oxidative stress. 1,5-AG was able to represent mean
glucose and
postprandial hyperglycemia only in well-controlled diabetic patients.