Relationship Between 1,5-Anhydroglucitol and Renal Function Assessed by Dynamic Renal Scintigraphy in Type 2 Diabetes

Context: The reliability of serum 1,5-anhydroglucitol (1,5-AG) in patients with type 2 diabetes and renal insufficiency remains controversial. Objective: To evaluate the relationship between renal function and serum 1,5-AG and to assess the extent to which renal function influences 1,5-AG. Methods: A total of 5337 participants with type 2 diabetes were enrolled. The measured glomerular filtration rate (mGFR) was assayed using Tc-99m-DTPA dynamic renal scintigraphy. All subjects were stratified into 5 groups based on mGFR (>= 120 [n = 507], 90-120 [n = 2015], 60-90 [n = 2178], 30-60 [n = 604], and <30 mL/min/1.73 m(2) [n = 33]). Results: Overall, the serum 1,5-AG and mGFR levels were 3.3 (1.7-7.0) mu g/mL and 88.6 +/- 24.1 mL/min/1.73 m(2), respectively. mGFR was found to be negatively correlated with 1,5-AG levels (r = -0.189, P < .001). Multiple linear regression revealed that mGFR was independently and negatively related to serum 1,5-AG after adjusting for covariates including hemoglobin A1c (HbA1c; P < .001). In subgroups with mGFR >= 30 mL/min/1.73 m(2), the correlation coefficients between 1,5-AG and HbA1c, fasting plasma glucose, postprandial plasma glucose, and the differences between postprandial and fasting plasma glucose remained significant (range, -0.126 to -0.743, all P < .01). However, the link between 1,5-AG and traditional glycemic markers was attenuated in individuals with mGFR < 30 mL/min/1.73 m(2). Sensitivity analysis after excluding anemic patients showed similar results regarding the relationship between serum 1,5-AG and HbA1c across the mGFR subgroups. Conclusion: Although we observed a weak inverse correlation (r = -0.189) between mGFR and serum 1,5-AG in type 2 diabetes, 1,5-AG remains a valid marker for assessing glucose control in subjects with mild or moderate renal dysfunction.