Open AccessDiagnostic potential of simplified methods for measuring glomerular filtration rate to detect chronic kidney disease in dogs
Author(s) -
Pocar Paola,
Scarpa Paola,
Berrini Anna,
Cagnardi Petra,
Rizzi Rita,
Borromeo Vitaliano
Publication year - 2019
Publication title -
journal of veterinary internal medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.356
H-Index - 103
eISSN - 1939-1676
pISSN - 0891-6640
DOI - 10.1111/jvim.15573
Subject(s) - medicine , renal function , iohexol , kidney disease , receiver operating characteristic , urology , quartile , cutoff , population , area under the curve , diagnostic accuracy , concordance , creatinine , confidence interval , physics , environmental health , quantum mechanics
Background Glomerular filtration rate (GFR) is the most sensitive indicator of initial renal function decline during chronic kidney disease (CKD), but conventional protocols for measuring GFR are labor‐intensive and stressful for the dog. Objectives To assess the diagnostic potential for detecting CKD with simplified GFR protocols based on iohexol plasma clearance. Animals Seventeen CKD‐positive and 23 CKD‐negative dogs of different breeds and sex. Methods Prospective nonrandomized study. Plasma iohexol was measured 5, 15, 60, 90, and 180 minutes after injection. Glomerular filtration rate was calculated using 5 samples (GFR 5 ) or simplified protocols based on 1, 2, or 3 samples. The GFR 5 and simplified GFR were compared by Bland‐Altmann and concordance correlation coefficient (CCC) analysis, and diagnostic accuracy for CKD by receiver operating characteristic curves. A gray zone for each protocol was bounded by the fourth quartile of the CKD‐positive population (lower cutoff) and the first quartile of the CKD‐negative population (upper cutoff). Results All simplified protocols gave reliable GFR measurements, comparable to reference GFR 5 (CCC >0.92). Simplified protocols which included the 180‐minutes sampling granted the best GFR measure (CCC: 0.98), with strong diagnostic potential for CKD (area under the receiver operating characteristic curve ± SE: 0.98 ± 0.01). A double cutoff including a zone of CKD uncertainty guaranteed reliable diagnosis outside the gray area and identified borderline dogs inside it. Conclusions The simplified GFR protocols offer an accurate, hands‐on tool for CKD diagnosis in dogs. The gray zone might help decision‐making in the management of early kidney dysfunction.