A STUDY ON EGFR, CREATININE CLEARANCE & URINARY PROTEIN TO CREATININE RATIO IN CKD

Abstract

There was a good correlation between Glomerular Filtration Rate (GFR) values estimated by any of the 3 methods. Crcl correlated better with Cockcroft-Gault (CG eGFR) than Modification of Diet in Renal Disease (MDRD eGFR) and there was also a very good correlation between CG eGFR and MDRD eGFR. Based on this result we feel that in advanced CKD all 3 methods give similar GFR estimates but in earlier stages of Chronic Kidney Disease (CKD) Creatinine clearance (Crcl) gives higher estimate of GFR. Thus use of Crcl may wrongly classify patients into less severe stages of CKD which might lead to delay in initiation of proper treatment. MATERIALS AND METHODS: CKD patients were selected on the basis of serum creatinine levels. S.C > 2.5 mg/dl values were considered to be having CKD. 75 Samples were tested. Both males & females patients are taken in this study. Serum Creatinine & Urinary Creatinine by Jaffe's method, Blood Urea by Urease method, Urinary Protein by Pyrogallol red method, estimation of GFR by three methods. Creatinine Clearance &eGFR by using Cockcroft-Gault& MDRD equations. RESULT: A total of 75 patients attending the nephrology department (P.E.S Medical College, Kuppam)for treatment and monitoring for chronic kidney disease where included in the present study. Serum creatinine, serum urea and creatinine clearance were measured in all these patients as per methods described under materials and methods. Estimated GFR (eGFR) using CG (Cock croft) and MDRD (Modification of Diet in renal disease) formulae were calculated. Majority of the cases were complications due to long standing diabetes mellitus or hypertension. CONCLUSION: Creatinine Clearance over estimates GFR in early stages of CKD. Use of Crcl to assess GFR may not be proper to classify CKD into different stages. Any of the 3 methods (Crcl, CG eGFR and MDRD eGFR) can be used as markers of GFR in advanced stages of CKD. MDRD eGFR is a better indicator of eGFR for staging CKD in early stages of CKD. All patients included in the present study had gross proteinuria even in early stages of CKD. There was no correlation between protein: creatinine ratio and CKD stages. We recommend a larger study reporting eGFR using MDRD equation along with serum creatinine for evaluation of renal function and confirm our findings. Estimated Glomerular Filtration Rate (eGFR), Glomerular Filtration Rate (GFR), Cockcroft-Gault (CG eGFR), Modification of Diet in Renal Disease (MDRD eGFR), Creatinine clearance (Crcl), Chronic Kidney Disease (CKD).