BACKGROUND: This cross-sectional study was conducted to determine whether a spot urine protein/creatinine ratio (UPr/UCr) provides accurate quantitation of 24-hr urinary protein excretion (24-hr Prot) in out-patients with primary glomerulonephritis (GN) and different renal function levels. METHODS: Patients were classified into three groups according to creatinine (Cr) clearance (ml/min) and into five categories according to morning UPr/UCr. Correlation between 24-hr Prot and UPr/UCr was calculated according to the three renal function levels. The Bland and Altman method was used to assess agreement between 24-hr Prot and UPr/UCr. Agreement limits were obtained calculating the mean difference between 24-hr Prot and morning UPr/UCr +/- 2SD. Sensitivity and specificity were determined for different renal function levels and UPr/UCr cut-off values. RESULTS: High correlation coefficients (r=0.91, 0.95 and 0.98) were observed in patients with normal, reduced and severely reduced renal function. Differences and variability between 24-hr Prot and UPr/UCr tended to increase with higher proteinuria levels, and this trend was observed for the three renal function levels. The best UPr/UCrcut-off values to detect abnormal or nephrotic proteinuria were, respectively, 0.3 and 2.6. CONCLUSIONS: Correlation and agreement between UPr/UCr and 24-hr Prot was good for all renal function levels, but demonstrated more marked differences as urinary protein excretion increased. Morning UPr/UCr had good sensitivity and specificity for the diagnosis of 24-hr Prot, even in patients with reduced renal function.
BACKGROUND: This cross-sectional study was conducted to determine whether a spot urine protein/creatinine ratio (UPr/UCr) provides accurate quantitation of 24-hr urinary protein excretion (24-hr Prot) in out-patients with primary glomerulonephritis (GN) and different renal function levels. METHODS:Patients were classified into three groups according to creatinine (Cr) clearance (ml/min) and into five categories according to morning UPr/UCr. Correlation between 24-hr Prot and UPr/UCr was calculated according to the three renal function levels. The Bland and Altman method was used to assess agreement between 24-hr Prot and UPr/UCr. Agreement limits were obtained calculating the mean difference between 24-hr Prot and morning UPr/UCr +/- 2SD. Sensitivity and specificity were determined for different renal function levels and UPr/UCr cut-off values. RESULTS: High correlation coefficients (r=0.91, 0.95 and 0.98) were observed in patients with normal, reduced and severely reduced renal function. Differences and variability between 24-hr Prot and UPr/UCr tended to increase with higher proteinuria levels, and this trend was observed for the three renal function levels. The best UPr/UCrcut-off values to detect abnormal or nephrotic proteinuria were, respectively, 0.3 and 2.6. CONCLUSIONS: Correlation and agreement between UPr/UCr and 24-hr Prot was good for all renal function levels, but demonstrated more marked differences as urinary protein excretion increased. Morning UPr/UCr had good sensitivity and specificity for the diagnosis of 24-hr Prot, even in patients with reduced renal function.
Authors: Debbie S Gipson; Hyunsook Chin; Trevor P Presler; Caroline Jennette; Maria E Ferris; Susan Massengill; Keisha Gibson; David B Thomas Journal: Pediatr Nephrol Date: 2006-01-05 Impact factor: 3.714
Authors: Maria Teresa Rocchetti; Massimo Papale; Anna Maria d'Apollo; Ida Valentina Suriano; Anna Maria Di Palma; Grazia Vocino; Eustacchio Montemurno; Leonarda Varraso; Giuseppe Grandaliano; Salvatore Di Paolo; Loreto Gesualdo Journal: Clin J Am Soc Nephrol Date: 2013-04-18 Impact factor: 8.237