ABSTRACT
The ratio of urine protein to urine osmolality has recently been suggested as an accurate method to determine proteinuria. We studied the correlation of urine protein to urine osmolality ratio with 24-hr urinary protein excretion. 150 children aged 0.11-17 years admitted to the Department of Pediatric Nephrology were included in this study. Early morning urine samples and 24-hr urine specimens were collected and analyzed for protein, creatinine, and osmolality. The patients with chronic renal failure were not excluded. Two groups were established: Children with no proteinuria [group 1] and those with proteinuria [group 2]. The optimal cutoff value of abnormal proteinuria and nephrotic range proteinuria was determined to be a protein-osmolality ratio [Up/Uosm] 0.27 and 1.59 mg/1/mOsm respectively. The correlation of 24-hr urinary protein excretion withboth urinary protein/creatinine ratio [Up/Ucr] and Up/Uosm was highly significant [p<0.001]. According to the receiver operator characteristic [ROC] curves analysis, we found no differences between Up/Uosm and Up/Ucr ratios in detecting either abnormal proteinuria or nephrotic syndrome. Urine protein to urine osmolality ratio seems to be a simple and a valuable test for the assessment of the degree of proteinuria in children