Abstract

A COMPARATIVE STUDY OF ESTIMATED GFR VERSUS MEASURED CREATININE CLEARANCE IN REFERENCE POPULATION OF INDIAN ORIGIN

Madhuri M C* and Radhika Krishnaswamy

ABSTRACT

Objective: The aim of this study was to compare the GFR (glomerular filtration rate) estimating equations with 24hrs creatinine clearance to predict renal function in healthy individuals and kidney donors. Methods: A descriptive study was conducted at St. Johns Medical College Hospital, Bangalore during the period of December 2013- December 2014. 30 male and 30 female kidney donors/ volunteers aged between 20 – 30 years were enrolled and categorised into four groups based on serum creatinine. Serum creatinine (SCr), urine creatinine (Ucr) and 24hrs creatinine clearance (24 hr urine-CrCl) where measured. Estimated GFR (eGFR) was calculated using Cockcroft-Gault formula (CG/ eGFRCG), the Modification of Diet in Renal Disease equation ((MDRD/ eGFRMDRD), and the Chronic Kidney Disease Epidemiology Collaboration equation (CKD-EPI/ eGFRCKD-EPI) equations, their performance was compared with 24 hr urine-CrCl (24 hr urine-CrCl). Results: The eGFRCKD-EPI showed significant correlation with measured GFR in three groups. The Bias was 4.5, 15.16, and 16.66 ml/min/1.73m2 for CKD-EPI eGFR for group I (SCr >0.9), group II (SCr 0.7) as seen in the Bland Altman plot. Conclusion: The eGFRCKD-EPI showed higher correlation with measured GFR (24 hr urine-CrCl ) compared to eGFRMDRD and eGFRCG equations when serum creatinine levels were more than 0.7 mg/dl in females and 0.9 mg/dl in males.

Keywords: 24hrs creatinine clearance (24 hr urine-CrCl) , Cockcroft-Gault (CG/ eGFRCG), eGFR estimated Glomerular filtration rate, GFR= Glomerular filtration rate, Modification of Diet in Renal Disease (MDRD/ eGFRMDRD) equation, The Chronic Kidney Disease Epidemiol