title: Assessments of factors that affect glomerular filtration rate and indirect markers of renal function in dogs and cats.
abstract: Chronic kidney disease is one of the most common disorders in dogs and cats. The plasma urea nitrogen (P-UN) and creatinine (P-Cre) concentrations are not sufficiently sensitive for early diagnosis of renal dysfunction. Although urine and plasma clearance methods allow earlier detection of reductions in the GFR, it is difficult to estimate a mildly reduced GFR from the values obtained by these methods, as they are also affected by physiological factors, such as body weight (BW) and age. The present study is a retrospective survey designed to assess the factors that affect markers of kidney function and to revaluate the clinical utility of the markers, including P-UN, P-Cre and GFR determined by plasma iohexol clearance (PCio) in dogs and cats. The P-UN, P-Cre and PCio values in dogs and the P-Cre and PCio values in cats were significantly correlated with BW (P<0.001). PCio in smaller dogs (≤ 15.0 kg) was significantly and inversely correlated with age. In smaller dogs, increase of P-UN alone might warrant a suspicion of a decreased GFR, but in contrast, P-Cre may be inefficient for detecting renal dysfunction or determining the severity of CKD compared with that in larger dogs (≥ 15.1 kg). P-Cre in larger dogs correlated better with PCio than in smaller dogs, suggesting that P-Cre in larger dogs was a more sensitive marker of reduced GFR.
authors.affiliation: Laboratory of Veterinary Integrative Medicine, School of Veterinary Medicine, Faculty of Veterinary Science, Nippon Veterinary and Life Science University, Musashino City, Tokyo, Japan. newichi.new@hotmail.co.jp
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Miyagawa
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Takemura
authors.forename: Hisashi
authors.initials: H
authors.lastname: Hirose
mesh_terms: D000375:Aging / Q000502:physiology; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D001835:Body Weight; D002371:Cat Diseases / Q000453:epidemiology / Q000401:mortality; D002415:Cats; D003404:Creatinine / Q000097:blood; D004283:Dog Diseases / Q000453:epidemiology / Q000401:mortality; D004285:Dogs; D005919:Glomerular Filtration Rate / Q000502:physiology*; D007472:Iohexol / Q000378:metabolism; D007674:Kidney Diseases / Q000453:epidemiology / Q000401:mortality / Q000662:veterinary; D007677:Kidney Function Tests / Q000662:veterinary*; D008657:Metabolic Clearance Rate; D014508:Urea / Q000097:blood
chemical_list: D015415:Biomarkers; D007472:Iohexol; D014508:Urea; D003404:Creatinine