GFR in Healthy Adult Population Pak Armed Forces Med J2016; 66(3):407-13 407 ESTIMATION OF GLOMERULAR FILTRATION RATE IN HEALTHY ADULT PAKISTANI POPULATION: A COMPARISON OF COCKCROFT GAULT AND MODIFIED DIET IN RENAL DISEASE Zahid Farooq Baig, Tariq Bashir Tareen, Asif Ali Combined Military Hospital Pano Aqil Pakistan ABSTRACT Objective: To compare the Cockcroft-Gault (CG) and Modification of Diet in Renal Disease (MDRD) equations of Glomerular filtration rate (GFR) estimation with 24 hours urine creatinine clearance so as to assess their application in clinical practice as a suitable alternative. Study Design: Cross sectional study. Place and Duration of Study: This study was carried out at CMH Pano Aqil in 2013. M aterial and M ethods: This was a cross sectional study conducted to compare results of GFR estimation using 24 hour urine with that of prediction equations based on samples obtained from healthy young adult volunteers. Urine creatinine clearance was measured (mGFR) from 24 hours collected urine sample and serum creatinine of the study subjects. GFR was estimated (eGFR) using standard 4 variable MDRD equation, CG creatinine clearance and CG GFR. The performance of these equations was compared with reference to measured GFR. Results: Out of 480 persons who consented for evaluation, 426 were included in the study. The subjects were healthy male adults with mean age of 27.86 ± 5.97 years. Mean measured 24 hours urine creatinine clearance was 93.38 ± 13.21 (ml/ min/ 1.73m2). Results showed that MDRD and Cockcroft Gault’s GFR equation underestimated GFR as compared to 24 hour urine evaluation (-0.7 ml/ min/ 1.73m 2 and -4.2 ml/ min/ 1.73m 2 respectively), while Cockcroft–Gault creatinine clearance equation over estimated by 12.2 ml/ min/ 1.73m 2 . Overall, MDRD equation fared better with 24 hours urine creatinine clearance than the rest, having a strong correlation (r 0.8795, p<0.0001 and 95% CI of r 0.8561 to 0.8994) and least difference of mean (-0.7 ml/ min/ 1.73m 2 ) by Bland Altman Plots. Conclusion: We recommend MDRD equation in preference to Cockcroft Gault’s equations to be used for estimation of GFR in clinical practice in young adult Pakistani population. The mean GFR of Pakistani population as of other south Asian is lower than the western population likely due to the racial difference between the two. Keywords: Cockcroft Gault equation, Creatinine clearance, GFR, MDRD equation, Pakistani population. INTRODUCTION The burden of end stage renal disease (ESRD) is causing a lot of impact on the health care system throughout the globe. The exact incidence of chronic kidney disease (CKD) in Pakistan is lacking but data from community based studies reveal alarmingly high burden of the disease 1 . Thus rigorous screening for major risk factors like hypertension and diabetes mellitus, application of preventive measures and early detection and treatment of CKD can help reduce this burden 2 . For the early detection of renal disease, accurate assessment of renal functions is required. Renal inulin clearance is regarded as the gold standard test for estimation of glomerular filtration rate (GFR), but it is cumbersome, costly and not readily available 3,4 . The 99mTcdiethylenetriamine penta-acetic acid (DTPA) and iothalamate clearance correlate well with the results of inulin clearance and are being used in clinical practice 5-7 . These tests are also expensive, not widely available and these cannot be used repeatedly and for screening of large population. Urinary creatinine clearance is often used for estimation of GFR but it is time This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http:/ / creativecommons.org/ licenses/ by/ 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Correspondence: Dr Zahid Farooq Baig, Classified Medical Specialist & Nephrologist CMH, Peshawar, Pakistan Email:zhd.frq@gmail.com Received: 22 Nov 2013; revised received: 03 Apr 2014; accepted: 08 Apr 2014 Original Article