Spot urinary protein/osmolality ratio as a predictor for proteinuria of nephrotic range.

A prospective study was carried out on 50 patients (age 1-15 years) with nephrotic range of proteinuria to determine the correlation of 24-hour urinary total protein with spot urinary protein/creatinine ratio and urinary protein/osmolality ratio. Another 50 patients having no proteinuria grouped as control. Twenty-four hours urine and spot urine were collected from each child and were analyzed for total volume, total protein, creatinine and osmolality level. The average 24-hour urinary total proteins in nephritic patient were 2148.6 +/- 808.7 mg and the spot urinary protein/creatinine and spot urinary protein/osmolality were 3.2332 +/- 0.4293 mg/mg and 3.2418 +/- 0.4393 mg/mOsm respectively. There was a strong positive correlation of the 24-hour urinary total protein with spot urinary protein/creatinine and protein/osmolality ratios (r=0.9846 and 0.9870, p= <0.001). But in control group, these ratios did not show any correlation with 24-hour urinary total protein. These results suggest that in pediatric patients with nephrotic range of proteinuria, the spot urinary protein/osmolality ratio can predict the 24-hour urinary total protein excretion like that of spot urinary protein/creatinine ratios.