Establishing equations to evaluate 24 hour urine protein excretion using routine urinalysis

• Published in: Nephrology (Carlton, Vic.) Vic.), 2014-11, Vol.19 (11), p.685-692
• Main Authors: Yang, Yang, Xie, Yuansheng, Wang, Chao, Chen, Guanglei, Kong, Deyang, Zhou, Zhuliang, Wang, Yaping, Qi, Ka, Song, Minghui, Ma, Lu
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Child; chronic kidney disease; dipstick assays; Humans; Male; Mathematical Concepts; Middle Aged; proteinuria; Proteinuria - urine; routine urinalysis; Time Factors; Urinalysis - methods; Urinalysis - statistics & numerical data; Young Adult
• ISSN: 1320-5358; 1440-1797
• DOI: 10.1111/nep.12311

Aim It is necessary to screen people at high risk for proteinuria with an economical, reliable and convenient method. The aim of this study is to establish a new approach to predict 24 h urine protein (24 h UP) by routine laboratory assays. Methods Five centres were included and a total of 4211 hospitalized patients were enrolled. All samples were assayed for dipstick protein (DSP), specific gravity (SG), 24 h UP and serum albumin (ALB) simultaneously. 4211 patients were randomly divided into two groups for establishing and testing the equations. Equations were built by multiple log‐linear regressions. Results (i) DSP is significantly correlated to 24 h UP in a logarithmic pattern; (ii) SG interprets 24 h UP for specific DSP; (iii) Equation 1 = 0.203 × 10dummy‐variable F × [100 (SG‐1)]−0.470; and (iv) Equation 2 = 13.366 × 10dummy‐variable F × [100 (SG‐1)]−0.547 × [ALB (g/L)]−1.130 The dummy‐variable F had a point‐to‐point accordance to DSP (detailed in text). Conclusion Combination of DSP and SG can interpret normal‐range proteinuria well, and helped by ALB, their interpretation for macro proteinuria is much improved. It is dependable and economical for routine urinalysis to evaluate pathological proteinuria by equation. Summary at a Glance This paper attempts to express a ‘shortcut’ approach to estimating 24 h urine protein using only dipstick results – specifically dipstick protein and dipstick specific gravity.