title: Poor glycemic control is a major factor in the overestimation of glomerular filtration rate in diabetic patients.
abstract: OBJECTIVE Serum creatinine levels are lower in diabetic patients compared with their nondiabetic counterparts. Therefore, estimated glomerular filtration rate (eGFR) is higher in the former than in the latter group. Factors associated with overestimation of renal function in diabetic patients were examined, and new formulae reflecting precise eGFR were created. RESEARCH DESIGN AND METHODS Eighty subjects (age 56.5 ± 15.4 years; 35 males [43.8%]; 40 patients with diabetes and 40 nondiabetic subjects) were enrolled. GFR was evaluated by inulin clearance (Cin). eGFR values were calculated based on serum creatinine and/or serum cystatin C levels. The factors related to the dissociation between eGFR and Cin in diabetic patients and the agreement among each of three eGFR and Cin were compared. RESULTS Although Cin was not significantly different between the diabetic and nondiabetic subjects (P = 0.2866), each of three eGFR measures from the diabetic patients was significantly higher than that of the nondiabetic subjects (P < 0.01). There were significant and positive correlations between the ratio of each eGFR/Cin, hemoglobin A1c, and glycated albumin. The intraclass correlation coefficients in diabetic patients were weaker than those in the nondiabetic subjects, and the intercepts of the regression lines between each eGFR measure and Cin in the diabetic patients were significantly higher than those of the nondiabetic subjects. New formulae for the calculation of eGFR corrected by the glycemic control indices were better than the original eGFR, particularly in diabetic patients. CONCLUSIONS eGFR overestimates Cin as glycemic controls worsen. eGFR corrected by hemoglobin A1c is considered to be clinically useful and feasible.
authors.affiliation: Corresponding author: Eiji Ishimura, ish@med.osaka-cu.ac.jp.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Tsuda
authors.forename: Eiji
authors.initials: E
authors.lastname: Ishimura
authors.forename: Yoshiteru
authors.initials: Y
authors.lastname: Ohno
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Ichii
authors.forename: Shinya
authors.initials: S
authors.lastname: Nakatani
authors.forename: Yuuichi
authors.initials: Y
authors.lastname: Machida
authors.forename: Katsuhito
authors.initials: K
authors.lastname: Mori
authors.forename: Junji
authors.initials: J
authors.lastname: Uchida
authors.forename: Shinya
authors.initials: S
authors.lastname: Fukumoto
authors.forename: Masanori
authors.initials: M
authors.lastname: Emoto
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Nakatani
authors.forename: Masaaki
authors.initials: M
authors.lastname: Inaba
mesh_terms: D001786:Blood Glucose / Q000378:metabolism; D055316:Cystatin C / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000503:physiopathology*; D005240:Feasibility Studies; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology*; D006442:Glycated Hemoglobin / Q000378:metabolism; D017127:Glycation End Products, Advanced; D006801:Humans; D007677:Kidney Function Tests; D008297:Male; D008875:Middle Aged; D012709:Serum Albumin / Q000378:metabolism; D000093423:Glycated Serum Albumin
chemical_list: D001786:Blood Glucose; D055316:Cystatin C; D006442:Glycated Hemoglobin; D017127:Glycation End Products, Advanced; D012709:Serum Albumin; D000093423:Glycated Serum Albumin