Performance of chronic kidney disease epidemiology... : Hepatology (original) (raw)

Liver Failure, Cirrhosis and Portal Hypertension

Performance of chronic kidney disease epidemiology collaboration creatinine-cystatin C equation for estimating kidney function in cirrhosis

Mindikoglu, Ayse L.1; Dowling, Thomas C.2; Weir, Matthew R.3; Seliger, Stephen L.3; Christenson, Robert H.4; Magder, Laurence S.5

1_Department of Medicine, Division of Gastroenterology and Hepatology, University of Maryland School of Medicine, Baltimore, MD,_

2_University of Maryland School of Pharmacy, Baltimore, MD,_

3_Department of Medicine, Division of Nephrology, University of Maryland School of Medicine, Baltimore, MD,_

4_Department of Pathology, University of Maryland School of Medicine, Baltimore, MD,_

5_Department of Epidemiology and Public Health, Division of Biostatistics and Bioinformatics, University of Maryland School of Medicine, Baltimore, MD,_

Received 10 January 2013; Accepted 22 May 2013

Address reprint requests to: Ayse L. Mindikoglu, M.D., M.P.H., Assistant Professor of Medicine, Division of Gastroenterology and Hepatology, University of Maryland School of Medicine, 22 S. Greene St., N3W50, Baltimore, MD 21201. E-mail: [email protected]; fax: 410-328-1897.

Grant sponsor: The National Institutes of Health (NIH) National Institute of Diabetes and Digestive and Kidney Diseases (to Ayse L. Mindikoglu, M.D., M.P.H.) and its contents are solely the responsibility of the authors and do not necessarily represent the official views of the National Institute of Diabetes and Digestive and Kidney Diseases or the NIH; Grant Number: 5 K23 DK089008-03.

See Editorial on Page 1242

Potential conflict of interest: Dr. Weir consults for Amgen, Janssen, Novartis, Sanofi, and Otsuka. Dr. Christenson consults for Siemens and Instrumentation Laboratory.

Abstract

Conventional creatinine-based glomerular filtration rate (GFR) equations are insufficiently accurate for estimating GFR in cirrhosis. The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) recently proposed an equation to estimate GFR in subjects without cirrhosis using both serum creatinine and cystatin C levels. Performance of the new CKD-EPI creatinine-cystatin C equation (2012) was superior to previous creatinine- or cystatin C-based GFR equations. To evaluate the performance of the CKD-EPI creatinine-cystatin C equation in subjects with cirrhosis, we compared it to GFR measured by nonradiolabeled iothalamate plasma clearance (mGFR) in 72 subjects with cirrhosis. We compared the “bias,” “precision,” and “accuracy” of the new CKD-EPI creatinine-cystatin C equation to that of 24-hour urinary creatinine clearance (CrCl), Cockcroft-Gault (CG), and previously reported creatinine- and/or cystatin C-based GFR-estimating equations. Accuracy of CKD-EPI creatinine-cystatin C equation as quantified by root mean squared error of difference scores (differences between mGFR and estimated GFR [eGFR] or between mGFR and CrCl, or between mGFR and CG equation for each subject) (RMSE = 23.56) was significantly better than that of CrCl (37.69, P = 0.001), CG (RMSE = 36.12, P = 0.002), and GFR-estimating equations based on cystatin C only. Its accuracy as quantified by percentage of eGFRs that differed by greater than 30% with respect to mGFR was significantly better compared to CrCl (P = 0.024), CG (P = 0.0001), 4-variable MDRD (P = 0.027), and CKD-EPI creatinine 2009 (P = 0.012) equations. However, for 23.61% of the subjects, GFR estimated by CKD-EPI creatinine-cystatin C equation differed from the mGFR by more than 30%. Conclusion: The diagnostic performance of CKD-EPI creatinine-cystatin C equation (2012) in patients with cirrhosis was superior to conventional equations in clinical practice for estimating GFR. However, its diagnostic performance was substantially worse than reported in subjects without cirrhosis. (HEPATOLOGY 2014;59:1532-1542)