title: Spot urine estimations are equivalent to 24-hour urine assessments of urine protein excretion for predicting clinical outcomes.
abstract: Background. The use of spot urine protein to creatinine ratios in estimating 24 hr urine protein excretion rates for diagnosing and managing chronic kidney disease (CKD) predated the standardization of creatinine assays. The comparative predictive performance of spot urine ratios and 24 hr urine collections (of albumin or protein) for the clinical outcomes of CKD progression, end-stage renal disease (ESRD), and mortality in Asians is unclear. We compared 4 methods of assessing urine protein excretion in a multiethnic population of CKD patients. Methods. Patients with CKD (n = 232) provided 24 hr urine collections followed by spot urine samples the next morning. We created multiple linear regression models to assess the factors associated with GFR decline (median follow-up: 37 months, IQR 26-41) and constructed Cox proportional-hazards models for predicting the combined outcome of ESRD and death. Results. The linear regression models showed that 24 hr urine protein excretion was most predictive of GFR decline but all other methods were similar. For the combined outcomes of ESRD and death, the proportional hazards models had similar predictive performance. Conclusions. We showed that all methods of assessments were comparable for clinical end-points, and any method can be used in clinical practice or research.
authors: Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, 1E Kent Ridge Road, Level 10 NUHS Tower Block, Singapore 119228.
authors: Boon Wee
authors: BW
authors: Teo
authors: Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, 1E Kent Ridge Road, Level 10 NUHS Tower Block, Singapore 119228.
authors: Ping Tyug
authors: PT
authors: Loh
authors: National University Health System, Singapore 119228.
authors: Weng Kin
authors: WK
authors: Wong
authors: Department of Statistics and Applied Probability, Faculty of Science, National University of Singapore, Singapore 119228.
authors: Peh Joo
authors: PJ
authors: Ho
authors: Department of Statistics and Applied Probability, Faculty of Science, National University of Singapore, Singapore 119228.
authors: Kwok Pui
authors: KP
authors: Choi
authors: Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, 1E Kent Ridge Road, Level 10 NUHS Tower Block, Singapore 119228.
authors: Qi Chun
authors: QC
authors: Toh
authors: Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, 1E Kent Ridge Road, Level 10 NUHS Tower Block, Singapore 119228.
authors: Hui
authors: H
authors: Xu
authors: Department of Laboratory Medicine, National University Health System, Singapore 119228.
authors: Sharon
authors: S
authors: Saw
authors: Department of Medicine, National University Health System, Singapore 119228.
authors: Titus
authors: T
authors: Lau
authors: Department of Pathology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228.
authors: Sunil
authors: S
authors: Sethi
authors: Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, 1E Kent Ridge Road, Level 10 NUHS Tower Block, Singapore 119228.
authors: Evan J C
authors: EJ
authors: Lee
references: Clin Chem. 2007 Apr;53(4):766-72
references: 17332152
references: Kidney Int. 2005 Jun;67(6):2089-100
references: 15882252
references: Am J Kidney Dis. 1995 Dec;26(6):904-9
references: 7503064
references: Am J Kidney Dis. 2011 Jan;57(1):21-8
references: 20951485
references: Clin Chem. 2006 Jan;52(1):5-18
references: 16332993
references: Asia Pac J Clin Nutr. 2002;11(1):1-7
references: 11890632
references: BMJ. 1998 Feb 14;316(7130):504-9
references: 9501711
references: Am J Kidney Dis. 2002 Feb;39(2 Suppl 1):S1-266
references: 11904577
references: Am J Kidney Dis. 2014 Mar;63(3):378-81
references: 24560154
references: Am J Kidney Dis. 2011 Jul;58(1):56-63
references: 21601325
references: Clin Chem. 2009 Jan;55(1):24-38
references: 19028824
references: Am J Kidney Dis. 2014 Mar;63(3):405-14
references: 24084157
references: Med J Aust. 2012 Aug 20;197(4):224-5
references: 22900872
references: Ann Intern Med. 2009 May 5;150(9):604-12
references: 19414839
references: Kidney Int. 2011 Jul;80(1):17-28
references: 21150873
references: Kidney Int Suppl (2011). 2017 Dec;7(3):e1
references: 30681074