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 type 2 diabetic patients with 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 99mTc-DTPA dynamic renal scintigraphy. All subjects were stratified into five 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 m2 [n = 33]).

Results: Overall, the serum 1,5-AG and mGFR levels were 3.3 (1.7-7.0) μg/mL and 88.6 ± 24.1 mL/min/1.73 m2, respectively. mGFR was found to be negatively correlated with 1,5-AG levels (r = -0.189, P < 0.001). Multiple linear regression revealed that mGFR was independently and negatively related to serum 1,5-AG after adjusting for covariates including HbA1c (P < 0.001). In subgroups with mGFR ≥ 30 mL/min/1.73 m2, 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 from -0.126 to -0.743, all P < 0.01). However, the link between 1,5-AG and traditional glycemic markers was attenuated in individuals with mGFR < 30 mL/min/1.73 m2. Sensitivity analysis after excluding anemic patients showed similar results regarding the relationship between serum 1,5-AG and HbA1c across the mGFR subgroups.

Conclusions: 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.