Assistant Professor Purdue University West Lafayette, Indiana, United States
Abstract:
Background: Oxidative stress might be present in cats with early chronic kidney disease (CKD), but it has not been evaluated in cats with increased symmetric dimethylarginine (SDMA) concentrations as the primary index of early CKD.
Objectives: The primary objective was to determine if urinary F2-Isoprostanes (F2-IsoPs) are increased in cats with a normal serum creatinine but increased SDMA compared to healthy controls. Secondary objectives were to evaluate plasma F2-IsoPs and renal resistive index (RRI) in these cohorts. Animals: Eight cats with early CKD and 14 healthy control cats (>8 years old).
Methods: Urinary and plasma F2-IsoP concentrations were measured by gas chromatography/negative ion chemical ionization mass spectrometry. Spectral Doppler was used to acquire RRI values.
Results: Median absolute urinary F2-IsoPs were significantly lower in cats with early CKD (.402 ng/mL, range .113-.3.306) compared to controls (1.738 ng/mL, range .770-3.183; P = .029). When urinary F2-IsoPs were normalized to urine creatinine, there was no difference between early CKD cats (.286 ng/mg, range .163-1.45) and controls (.667, range .416-1.43, P = 0.057). There was no difference in median free plasma F2-IsoPs in cats with early CKD (.038, range .003-.086) compared to controls (.106 ng/mL, range .003-.198, P = .111). Left kidney RRI was higher in early CKD cats (P = .026) but not with right kidney or averaged kidney RRI values compared to controls. Conclusions and Clinical Importance: Urinary F2-IsoPs are not increased in cats with a normal serum creatinine but increased SDMA. RRI does not reliable detect early CKD.
