Publication: Comparison of Different Estimating Equations for Prediction of Glomerular Filtration Rate in Living Kidney Donors
Date
2017
Journal Title
Journal ISSN
Volume Title
Publisher
Institute of Medicine
Abstract
Abstract
Introduction: Assessment of renal function is a crucial step in evaluation of living kidney donors. The standard method for determining renal function is measurement of glomerular filtration rate (GFR) using I-123 iothalamate, Tc-99m Diethylene Triamine Pentaacetic Acid (DTPA) and 51Cr-Ethylene Diamine Tetraacetic Acid. As these methods are expensive and cannot be used in all clinical settings, it is common practice to estimate GFR by creatinine-based equations. The objective of this study is to compare commonly used estimating equations for the prediction of GFR in Living Kidney Donors.
Methods: In 75 healthy kidney donors, GFR estimated by Modification of Diet in Renal Disease Study equation (MDRD), Cockcroft-Gault formula(CG), Chronic Kidney Disease Epidemiology Collaboration(CKD- EPI) equation and 24 hour urinary creatinine clearance were compared to GFR measured by Tc-99m DTPA. Statistical analysis was done using Dunnett’s test and Bland-Altman plot. Similarly, accuracy, precision and bias of each equation were assessed.
Results: Mean GFR calculated by DTPA clearance, CG, MDRD, CKD-EPI equations and 24 hour urine creatinine clearance were 83.35±8.59, 78.99±17.17, 93.30±17.12, 96.34±13.36 and 137.96±43.65 ml/min/1.73m2 respectively. Applying Dunnett’s test, GFR by CG equation minimally underestimated GFR measured by DTPA (p=0.612) whereas GFR estimated by MDRD (p=0.034), CKD-EPI(p=0.03) and 24 hour urine creatinine clearance(p<0.001) were statistically significant. CG equation had the highest accuracy. Using Bland-Altman plot, the precision of CKD-EPI equation was the highest among all.
Conclusion: There is no single creatinine-based estimating equation to assess GFR with utmost accuracy and precision at the same time.
Keywords: creatinine clearance, Diethylene Triamine Pentaacetic Acid, living kidney donors
Description
S Poudyal
Department of Urology and Kidney Transplant Surgery, Tribhuvan University Teaching Hospital, Kathmandu, Nepal
M Pradhan
Department of Urology and Kidney Transplant Surgery, Tribhuvan University Teaching Hospital, Kathmandu, Nepal
S Chapagain
Department of Urology and Kidney Transplant Surgery, Tribhuvan University Teaching Hospital, Kathmandu, Nepal
BR Luitel
Department of Urology and Kidney Transplant Surgery, Tribhuvan University Teaching Hospital, Kathmandu, Nepal
PR Chalise
Department of Urology and Kidney Transplant Surgery, Tribhuvan University Teaching Hospital, Kathmandu, Nepal
UK Sharma
Department of Urology and Kidney Transplant Surgery, Tribhuvan University Teaching Hospital, Kathmandu, Nepal
PR Gyawali
Department of Urology and Kidney Transplant Surgery, Tribhuvan University Teaching Hospital, Kathmandu, Nepal
Keywords
creatinine clearance, Diethylene Triamine Pentaacetic Acid, living kidney donors