Urinary F2-Isoprostanes in Cats with International Renal Interest Society Stage 1-4 Chronic Kidney Disease.
BACKGROUND
F2-isoprostanes, a biomarker of oxidant injury, increase with advancing chronic kidney disease (CKD) in humans. In cats, the relationship between CKD and oxidative stress is poorly understood.


OBJECTIVE
To determine whether cats with advancing CKD have increasing urinary F2-isoprostanes.


METHODS
Control cats without evidence of CKD (≥6 years old; n = 11), and cats with IRIS stage 1 (n = 8), 2 (n = 38), 3 (n = 21), and 4 (n = 10) CKD.


METHODS
This was a prospective observational study. Urinary F2-isoprostanes (specifically free 15-F2t-isoprostanes) normalized to urine creatinine (IsoPs) were compared among groups and tested for correlations with blood pressure, proteinuria, serum creatinine concentration, and urine specific gravity. The IsoPs also were compared between cats with and without hypertension or proteinuria, and in cats fed predominantly standard versus renal diets.


RESULTS
Urinary IsoPs were increased, but not significantly, in cats with stage 1 CKD (median 263 pg/mg creatinine; range, 211-380) compared to controls (182 pg/mg; range, 80-348) and decreased significantly from stage 1 through advancing CKD (stage 2, 144 pg/mg; range, 49-608; stage 3, 102 pg/mg; range, 25-158; stage 4, 67 pg/mg; range, 26-117; P < .01). Urinary IsoPs were inversely correlated with serum creatinine (r = -0.66, P < .0001).


CONCLUSIONS
Urinary IsoPs are significantly higher in early CKD (stage 1) compared to cats with more advanced CKD. Additional studies are warranted to characterize oxidative stress in cats with stage 1 CKD and determine whether early antioxidant treatments have a protective effect on CKD progression.
Department of Medical Sciences, University of Wisconsin-Madison, Madison, WI.
W
W
Whitehouse
College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO.
J
J
Quimby
Department of Medical Sciences, University of Wisconsin-Madison, Madison, WI.
S
S
Wan
Department of Medical Sciences, University of Wisconsin-Madison, Madison, WI.
K
K
Monaghan
Department of Medical Sciences, University of Wisconsin-Madison, Madison, WI.
R
R
Robbins
Department of Medical Sciences, University of Wisconsin-Madison, Madison, WI.
L A
LA
Trepanier
D000818:Animals; D015415:Biomarkers / Q000652:urine; D002371:Cat Diseases / Q000378:metabolism* / Q000652:urine; D002415:Cats; D003404:Creatinine / Q000097:blood; D028441:F2-Isoprostanes / Q000652:urine*; D005260:Female; D006973:Hypertension / Q000662:veterinary; D008297:Male; D018384:Oxidative Stress; D011446:Prospective Studies; D011507:Proteinuria / Q000652:urine / Q000662:veterinary; D051436:Renal Insufficiency, Chronic / Q000652:urine / Q000662:veterinary*
D015415:Biomarkers; D028441:F2-Isoprostanes; D003404:Creatinine
Biomarker; Feline; Oxidative stress; Prostanoids; Redox; Renal failure