Change in urinary N-acetyl-ß-d-glucosaminidase levels relevant to postprandial glycemic control conditions in subjects without diabetes mellitus.

BACKGROUND: To assess 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-ß-d-glucosaminidase to creatinine (NAG index) in subjects without diabetes mellitus (DM). METHODS: This was a cross-sectional study with 495 subjects without DM who had an estimated glomerular filtration rate≥30ml/min/1.73m(2). Subjects were divided into tertiles based on serum 1,5-AG levels: high (>21.0µg/ml), middle (14.0-21.0µg/ml), and low (<14.0µg/ml). Adjusted odds ratios for an elevated urinary NAG index (>5.8U/g creatinine) according to the HbA1c (≤5.4%, 5.5%-5.9%, and 6.0%-6.4%) and 1,5-AG tertiles were calculated. RESULTS: The NAG index was negatively correlated with the serum 1,5-AG level in all subjects. The slopes of the regression lines for these variables did not differ significantly between elderly (≥65y) and nonelderly subjects. As compared with high 1,5-AG and HbA1c≤5.4%, the odds ratios for an elevated urinary NAG index increased progressively to 7.71 across the categories of low 1,5-AG and HbA1c of 6.0% to 6.4%. CONCLUSION: Poor control of postprandial glucose is related to an elevated urinary NAG index in persons without DM.

What characteristics at baseline are associated with the glucose-lowering effect of colestimide in patients with type 2 diabetes and hypercholesterolemia according to response to treatment?

Colestimide, an anion exchange resin, reportedly improves glycemic control in patients with type 2 diabetes. However, no studies of the glucose-lowering effect of colestimide have identified responders and nonresponders. In the present study, we compared glycemic control, lipids, and body-mass index (BMI) among patients with type 2 diabetes receiving colestimide (n=59) until 24 weeks after the start of treatment. Subjects were classified as responders to treatment (n=40), who showed a 15% or greater decrease in glycated hemoglobin (HbA1c) or a 20% or greater decrease in plasma glucose level or both after 24 weeks of colestimide treatment as compared with baseline; nonresponders showed HbA1c>11.5% or fasting plasma glucose (FPG)>250 mg/dL during the course of the study and <15% decrease in HbA1c levels or <20% decrease in FPG levels or both after 24 weeks of colestimide treatment as compared with baseline. In responders, FPG decreased significantly from 196 ± 91 mg/dL to 125 ± 47 mg/dL after 24 weeks (P<0.001), and HbA1c decreased from 9.1% ± 2.0% to 7.0% ± 0.9% (P<0.001). In nonresponders, HbA1c decreased significantly from 7.7% ± 2.9% to 7.6% ± 1.2% (P<0.05). Multiple logistic regression analysis revealed that baseline HbA1c and the presence of cholelithiasis were significant determinants of the response to colestimide treatment when corrected for sex, age, triglyceride levels, and BMI at baseline and the presence of fatty liver. In conclusion, baseline HbA1c and the presence of cholelithiasis have strong and independent influences on the glucose-lowering effect of colestimide.