BACKGROUND: Random urine protein-to-creatinine (PCR) and albumin-to-creatinine (ACR) ratios have been proposed as alternatives to 24 h urine measurements to simplify sample collection and overcome errors. The aim of this study was to examine the ability of PCR and ACR to predict urinary 24 h protein and albumin loss, respectively, in patients with kidney disease, and determine the most appropriate time of collection. METHODS: Eighty-three patients were recruited from a renal outpatient clinic. In a 24 h period, each collected an early-morning urine (EMU), second and third voids, and the remaining urine passed that day. PCR and ACR were determined in random urines and compared with the 24 h loss of protein and albumin, respectively. RESULTS: For all patients, median (range) 24 h urine protein and albumin losses were 220 (30-15600) and 60 (<8-10,557) mg, respectively. Ratios derived from each of three random urines correlated well with 24 h protein or albumin loss (Spearman's r(s) > 0.87, P < 0.0001). Receiver operator characteristic (ROC) curve analysis showed PCR accurately predicted both an abnormal 24 h urine protein > or =150 mg/24 h (areas under curves [AUC] 0.90-0.92) and significant proteinuria above 300 mg/24 h (AUC between 0.97 and 1.00). ACR accurately predicted both an abnormal 24 h urine albumin > or =30 mg/24 h (AUC 0.98 to 0.99) and frank albuminuria at > or =300 mg/24 h or > or =700 mg/24 h (AUC between 0.99 and 1.00). EMU and random urines performed equally well in predicting proteinuria and albuminuria from PCR and ACR, respectively. CONCLUSIONS: By careful choice of cut-offs, both PCR and ACR can be used in patients with kidney disease to rule in or rule out abnormal 24 h losses of protein and albumin. EMU and, importantly, random samples can be used as surrogates for 24 h urine collections.
BACKGROUND: Random urine protein-to-creatinine (PCR) and albumin-to-creatinine (ACR) ratios have been proposed as alternatives to 24 h urine measurements to simplify sample collection and overcome errors. The aim of this study was to examine the ability of PCR and ACR to predict urinary 24 h protein and albumin loss, respectively, in patients with kidney disease, and determine the most appropriate time of collection. METHODS: Eighty-three patients were recruited from a renal outpatient clinic. In a 24 h period, each collected an early-morning urine (EMU), second and third voids, and the remaining urine passed that day. PCR and ACR were determined in random urines and compared with the 24 h loss of protein and albumin, respectively. RESULTS: For all patients, median (range) 24 h urine protein and albumin losses were 220 (30-15600) and 60 (<8-10,557) mg, respectively. Ratios derived from each of three random urines correlated well with 24 h protein or albumin loss (Spearman's r(s) > 0.87, P < 0.0001). Receiver operator characteristic (ROC) curve analysis showed PCR accurately predicted both an abnormal 24 h urine protein > or =150 mg/24 h (areas under curves [AUC] 0.90-0.92) and significant proteinuria above 300 mg/24 h (AUC between 0.97 and 1.00). ACR accurately predicted both an abnormal 24 h urine albumin > or =30 mg/24 h (AUC 0.98 to 0.99) and frank albuminuria at > or =300 mg/24 h or > or =700 mg/24 h (AUC between 0.99 and 1.00). EMU and random urines performed equally well in predicting proteinuria and albuminuria from PCR and ACR, respectively. CONCLUSIONS: By careful choice of cut-offs, both PCR and ACR can be used in patients with kidney disease to rule in or rule out abnormal 24 h losses of protein and albumin. EMU and, importantly, random samples can be used as surrogates for 24 h urine collections.
Authors: Hiddo J Lambers Heerspink; Ron T Gansevoort; Barry M Brenner; Mark E Cooper; Hans Henrik Parving; Shahnaz Shahinfar; Dick de Zeeuw Journal: J Am Soc Nephrol Date: 2010-07-15 Impact factor: 10.121
Authors: Eric S Sobel; Todd M Brusko; Ed J Butfiloski; Wei Hou; Shiwu Li; Carla M Cuda; Ariana N Abid; Westley H Reeves; Laurence Morel Journal: Arthritis Res Ther Date: 2011-06-27 Impact factor: 5.156
Authors: Keiichi Sumida; Girish N Nadkarni; Morgan E Grams; Yingying Sang; Shoshana H Ballew; Josef Coresh; Kunihiro Matsushita; Aditya Surapaneni; Nigel Brunskill; Steve J Chadban; Alex R Chang; Massimo Cirillo; Kenn B Daratha; Ron T Gansevoort; Amit X Garg; Licia Iacoviello; Takamasa Kayama; Tsuneo Konta; Csaba P Kovesdy; James Lash; Brian J Lee; Rupert W Major; Marie Metzger; Katsuyuki Miura; David M J Naimark; Robert G Nelson; Simon Sawhney; Nikita Stempniewicz; Mila Tang; Raymond R Townsend; Jamie P Traynor; José M Valdivielso; Jack Wetzels; Kevan R Polkinghorne; Hiddo J L Heerspink Journal: Ann Intern Med Date: 2020-07-14 Impact factor: 25.391