The Factors Affecting Accurate Quantitaion of Proteinuria Using Spot Urine Protein/Creatinine Ratio in Children

ABSTRACT

PURPOSE: Many results have reported a correlation between the spot urine protein/creatinine ratio(P/C ratio) and 24-hour urinary protein(24UP) amount. This study was designed to evaluated correlation between 24UP amounts and P/C ratio in children and to find the factors that affect this correlation. METHODS: 210 patients who visited the Department of Pediatrics in Busan Paik Hospital from september 2003 to december 2007 were included in this study. All the patients were divided into I, II, III/A, B, C group[I24UP(mg/m2/day)] or =1,000, A Cr excretion(mg/kg) or =25)]. Pearson correlation analysis was performed between 24UP and P/C ratio to evaluate the relationship. We defined fractional difference between 24UP and P/C ratio, and then performed multiple regression analysis. RESULTS: There was a strong positive linear correlation between 24UP and P/C ratio in all patients, and the correlation was also good in each group. The factors affecting accurate quantitation of proteinuria using spot urine P/C ratio was creatinine excretion. CONCLUSION: Spot urine P/C ratio is a useful test to predict proteinuria roughly. Therefore, we expect that urine P/C ratio can be used as parameter instead of 24UP, if we set cutoff value of P/C ratio considered to creatinine excretion according to age and sex in large pediatric population.