title: Evaluation of urinary biomarkers for azotaemic chronic kidney disease in cats.
abstract: OBJECTIVE
  Evaluation of urine albumin:creatinine ratio, urine cystatin C:creatinine ratio, urine protein:creatinine ratio and urine specific gravity as screening tests for azotaemic chronic kidney disease in cats.
  
  
  METHODS
  A group of cats over eight years old were defined as either (i) healthy non-azotaemic (n=40) if they had serum creatinine concentration <153 µmol/L and no history of apparent disease or (2) having azotaemic chronic kidney disease (n=12) if they had serum creatinine concentration >153 µmol/L with urine specific gravity <1·035. Urine albumin:creatinine ratio, urine cystatin C:creatinine ratio, urine protein:creatinine ratio and urine specific gravity were compared between the two groups.
  
  
  RESULTS
  Urine cystatin C:creatinine ratio was significantly lower in cats with azotaemic chronic kidney disease than that in healthy cats [3·7 (1·4, 4·3)×10(-6) versus 13·9 (6·3, 24·7)×10(-6) ; P=0·011]. Urine specific gravity was also significantly lower in the azotaemic chronic kidney disease group than that in the healthy group [1·022 (1·017, 1·028) versus 1·043 (1·034, >1·050); P<0·001]. Urine albumin:creatinine ratio and urine protein:creatinine ratio were not significantly different between the groups (P=0·075 and P=0·965, respectively).
  
  
  CONCLUSIONS
  Urine cystatin C:creatinine ratio and urine specific gravity were significantly lower in cats with azotaemic chronic kidney disease than that in healthy cats; however, neither biomarker was an adequate sole screening test for azotaemic chronic kidney disease.
authors.affiliation: Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES.
authors.forename: T L
authors.initials: TL
authors.lastname: Williams
authors.affiliation: Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES.
authors.forename: J
authors.initials: J
authors.lastname: Archer
mesh_terms: D000419:Albuminuria / Q000662:veterinary; D000818:Animals; D015415:Biomarkers / Q000652:urine*; D002371:Cat Diseases / Q000652:urine*; D002415:Cats; D003404:Creatinine / Q000652:urine; D055316:Cystatin C / Q000652:urine; D005260:Female; D006801:Humans; D008297:Male; D009391:Nephelometry and Turbidimetry / Q000662:veterinary; D011507:Proteinuria / Q000662:veterinary; D051436:Renal Insufficiency, Chronic / Q000652:urine / Q000662:veterinary*
chemical_list: D015415:Biomarkers; D055316:Cystatin C; D003404:Creatinine