Related Experiment Videos
Quantification of proteinuria in children using the urinary protein-osmolality ratio
1Department of Pediatrics, Korea University, Guro Hospital, 80 Guro-Dong, Guro-Gu, Seoul 152-703, Korea.
Insights
Early morning urinary protein/osmolality ratio is a reliable indicator for assessing 24-hour protein excretion in children. This simple test can help evaluate the degree of proteinuria, aiding in diagnosis and management.
Area of Science:
- Pediatric Nephrology
- Clinical Chemistry
- Diagnostic Testing
Background:
- Accurate assessment of 24-hour urinary protein excretion is crucial for diagnosing and monitoring kidney disease in children.
- Traditional 24-hour urine collection can be cumbersome and prone to errors.
- Exploring simpler, reliable biomarkers for proteinuria is essential.
Purpose of the Study:
- To evaluate the correlation between the early morning urinary protein/osmolality ratio (Uprot/Uosm) and 24-hour urinary protein excretion in children.
- To determine if Uprot/Uosm can serve as a practical alternative for assessing proteinuria severity.
Main Methods:
- Prospective study involving 53 children (1 month to 15 years).
- Collection and analysis of early morning and 24-hour urine samples.
- Calculation of urinary protein/osmolality ratio (Uprot/Uosm) and protein/creatinine ratio (Uprot/Ucr).
Main Results:
- In children with proteinuria, Uprot/Uosm showed a highly significant correlation with 24-hour urinary protein excretion (r = 0.87, P < 0.001).
- The Uprot/Uosm ratio of 1.9 corresponds to the nephrotic level of proteinuria (40 mg/m²/h).
- No significant correlation was found in children without proteinuria.
Conclusions:
- The early morning urinary protein/osmolality ratio is a simple, potentially useful, and reliable test for estimating 24-hour urinary protein excretion in children.
- Uprot/Uosm may be safely used to assess the degree of proteinuria, offering a more convenient diagnostic approach.
Abstract:
A prospective study was conducted to determine the correlation of early morning urinary protein/osmolality ratio (mg/l/mosmol/kg) with 24-h urinary protein excretion (mg/m2/day). Study patients consisted of 53 children (aged 1 month to 15 years). Early morning urine samples and 24-h urine samples were collected and analyzed. In group 1 (children without proteinuria), early morning urinary protein/creatinine ratio (Uprot/Ucr, mg/mg) was 0.061 +/- 0.011 and the protein/osmolality ratio (Uprot/Uosm, mg/l/mosmol/kg) was 0.073 +/- 0.014. Twenty-four hour urinary protein excretion in group 1 had no significant correlation with Uprot/Ucr or Uprot/Uosm. In group II (children with proteinuria), Uprot/Ucr was 5.78 +/- 1.10 and Uprot/Uosm was 4.42 +/- 1.34. Twenty-four hour urinary protein excretion in group 2 was 1483.6 +/- 303.7 mg/m2/day and its correlation with both Uprot/Uosm and Uprot/Ucr was highly significant (r = 0.87, P < 0.001 and r = 0.88, P < 0.001, respectively). The accepted nephrotic level of proteinuria of 40 mg/m2/h coincides with a Uprot/Uosm ratio of 1.9. In conclusion, early morning urinary Uprot/Uosm is a simple and potentially useful test for 24-h urinary protein excretion, and possibly could be used safely for the assessment of the degree of proteinuria in children.