Postprandial glycemic control conditions in relation to urinary N-acetyl-β-D-glucosaminidase in patients with type 2 diabetes mellitus without low glomerular filtration rate.

BACKGROUND

This study assessed the relationship between the serum level of 1,5-anhydroglucitol (1,5-AG), a marker of postprandial hyperglycemia, and the ratio of the urinary activity of N-acetyl-β-D-glucosaminidase (NAG) to creatinine (NAG index) in patients with type 2 diabetes mellitus.

SUBJECTS AND

METHODS

This was a cross-sectional study with 153 patients who had an estimated glomerular filtration rate of ≥60 mL/min/1.73 m(2) and no proteinuria and who had never been treated with oral hypoglycemic agents or insulin. On the basis of 1,5-AG levels, the patients were divided into a High 1,5-AG group (>14.0 μg/mL) and a Low 1,5-AG group (≤14.0 μg/mL).

RESULTS

The logarithmically transformed NAG index was significantly higher in the Low 1,5-AG group than in the High 1,5-AG group when all glycated hemoglobin (HbA1c) levels were included. The logarithmically transformed NAG index was lowest in the High 1,5-AG group with an HbA1c level of ≤6.4% and was highest in the Low 1,5-AG group with an HbA1c level of ≥7.5%. Multivariate regression analysis showed that the NAG index had a higher independent association with 1,5-AG than with HbA1c or the fasting plasma glucose level. In all models, multivariate regression analyses showed that the NAG index was correlated with age.

CONCLUSIONS

These results suggest that postprandial hyperglycemia correlates with early renal tubule injury in type 2 diabetes mellitus.