title: Urinary protein/creatinine ratio weighted by estimated urinary creatinine improves the accuracy of predicting daily proteinuria.
abstract: BACKGROUND
  The spot urine protein/creatinine ratio (UPCR) is proposed to be a substitute for 24-hour urinary protein (24h-UP). This study is aimed to determine whether the predictive accuracy of 24h-UP using UPCR can be improved by simply multiplying estimated daily urine creatinine excretion (eUCr) and UPCR together.
  
  
  METHODS
  This study enrolled 120 participants to investigate the correlation between spot UPCR and 24h-UP. Three sets of spot urine samples were randomly collected throughout the day and night, along with the first morning void. UPCR was weighted by eUCr to investigate the improvement of accuracy in using spot urine samples to predict 24h-UP.
  
  
  RESULTS
  There were strong correlation and concordance between UPCR and 24h-UP irrespective of the time of spot urine sampling, and the correlation, concordance and agreement were improved after multiplying the UPCR value by the eUCr. Greater improvement was found in the subgroups with measured daily urine creatinine excretion ≤ 0.8 g/d and ≥ 1.2 g/d.
  
  
  CONCLUSIONS
  This investigation demonstrated that multiplying UPCR by eUCr can improve the accuracy of only using UPCR to predict 24h-UP.
authors.affiliation: School of Medicine (C-FC, W-CY, C-YY, S-YL, S-MO, Y-TC, C-JS, Y-JW, C-CL), National Yang-Ming University, Taipei, Taiwan; Division of Nephrology (C-FC), Department of Medicine, National Yang-Ming University Hospital (C-FC), Yilan, Taiwan; Division of Nephrology (W-CY, C-YY, S-YL, S-MO, Y-JW, C-CL), Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Division of Nephrology (Y-TC), Department of Medicine, Taipei City Hospital, He-Ping Branch, Taipei, Taiwan; Division of Nephrology (C-JS), Department of Medicine, Yuan-Shan Branch, Taipei Veterans General Hospital, Yilan, Taiwan; Department of Nephrology (C-CC), Department of Medical Research, Chi-Mei Medical Center, Tainan, Taiwan; Department of Food Nutrition (C-CC), Chung Hwa University of Medical Technology, Tainan, Taiwan; and Department of Public Health (M-CC), Biostatistics Consulting Center, School of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Chun-Fan
authors.initials: CF
authors.lastname: Chen
authors.forename: Wu-Chang
authors.initials: WC
authors.lastname: Yang
authors.forename: Chih-Yu
authors.initials: CY
authors.lastname: Yang
authors.forename: Szu-Yuan
authors.initials: SY
authors.lastname: Li
authors.forename: Shuo-Ming
authors.initials: SM
authors.lastname: Ou
authors.forename: Yung-Tai
authors.initials: YT
authors.lastname: Chen
authors.forename: Chia-Jen
authors.initials: CJ
authors.lastname: Shih
authors.forename: Chih-Chiang
authors.initials: CC
authors.lastname: Chien
authors.forename: Min-Chi
authors.initials: MC
authors.lastname: Chen
authors.forename: Yu-Jen
authors.initials: YJ
authors.lastname: Wang
authors.forename: Chih-Ching
authors.initials: CC
authors.lastname: Lin
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003404:Creatinine / Q000652:urine*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011507:Proteinuria / Q000652:urine*; D051436:Renal Insufficiency, Chronic / Q000652:urine*
chemical_list: D003404:Creatinine