Determination of the glomerular filtration rate in patients with type 2 diabetes: An assessment of the agreement between 51Cr-EDTA plasma clearance and 99mTc-DTPA plasma clearance, 99mTc-DTPA renography and plasma creatinine prediction equation

Aims: To investigate the agreement of glomerular filtration rate (GFR) determination between Cr-51- ethylenediaminetetraacetic acid (Cr-51- EDTA) plasma clearance (GFR(EDTA)) and Tc-99m-diethylenetriaminepentaacetic acid (Tc-99m-DTPA) plasma clearance (GFR(DTPA)), the Gates Tc-99m- DTPA renographic method (GFRGates) and the serum creatinine Chronic Kidney Disease Epidemiology Collaboration equation (CKD-EPI, GFR(SCr)) in patients with type 2 diabetes mellitus (T2DM). Methods: Ninety-nine T2DM patients underwent GFR determinations simultaneously with Cr-51-EDTA and Tc-99m-DTPA (using the slope-intercept technique and the Brochner-Mortensen correction) and also with GFR(Gates) and GFR(SCr). Results: In the comparison between GFR(EDTA) versus GFR(DTPA), GFR(Gates) and GFR(SCr), the Bland-Altman statistic provided 0.0 +/- 13.2, 17.4* +/- 28.8 and -5.9* +/- 30.1 (*p < 0.001 for the difference from 0). Lin's concordance correlation coefficient showed substantial (0.976), poor (0.737) and poor (0.872) agreement, respectively. The proportion of the index results within the 30% and 10% of GFR(EDTA) measurements were 95% and 74% for GFR(DTPA), 53% and 19% for GFR(Gates), and 83% and 26% for GFR(SCr), respectively. Conclusion: In T2DM patients, a clinically acceptable agreement is demonstrated between Cr-51-EDTA and Tc-99m-DTPA plasma clearance for GFR measurements, suggesting conditional interchangeability between those compounds. Both the CKD-EPI prediction equation and the Gates' renographic method cannot assess GFR reliably, the latter appearing less unfailing than the former. (C) 2020 Elsevier B.V. All rights reserved.