[Protein/creatinine index in isolated samples of urine for evaluation of 24-hour proteinuria]

The correct determination of the 24 hours proteinuria (PU24) in the non-hospitalized patients is frequently subject to collection errors. To overcome this problem it has been proposed the use of the proteinuria ratio (PR), obtained by dividing the concentrations of protein/creatinine in random urine samples. In the present investigation PR and PU24 were correlated in 42 patients (22 male and 20 female), aged between 14 and 63 years. Each patient was submitted to a 2 hours creatinine clearance (Ccr), to determination of PU24 and to evaluation of PR in the urine samples. The measures of PU24 were correlated with the values of PR. On linear regression analysis the equation y = 0,517 + 0,759x was obtained, with r = 0,914, suggesting good correlation between PU24 and PR. Values of r greater than 0,9 were always obtained, independently of the values of Ccr and PU24. The results indicate that PR in random urine samples may be practical and reliable in the follow-up of nephrological patients.