title: The effect of feeding a renal diet on plasma fibroblast growth factor 23 concentrations in cats with stable azotemic chronic kidney disease.
abstract: BACKGROUND
  Fibroblast growth factor 23 (FGF-23) is a phosphatonin, which is increased in cats with azotemic CKD. Dietary phosphate restriction decreases FGF-23 concentrations in humans and rodents, but this relationship has not previously been examined in the cat.
  
  
  OBJECTIVE
  To investigate the effect of feeding renal diet on plasma FGF-23 concentrations in cats with stable azotemic CKD.
  
  
  METHODS
  Azotemic, client-owned cats (≥ 9 years); 33 cats ate renal diet (RD group) and 11 cats did not eat renal diet (comparator group) over 28-56 days.
  
  
  METHODS
  Retrospective longitudinal study: Plasma FGF-23, PTH, and phosphate concentrations were measured at baseline and after 28-56 days. Cats in the RD group were classified as hyperphosphatemic (HP) or normophosphatemic (NP) based on the International Renal Interest Society targets for plasma phosphate concentration. Nonparametric tests were performed.
  
  
  RESULTS
  In the HP group (n = 15), feeding renal diet was associated with a significant decrease in plasma phosphate (P = .001), PTH (P = .007), and FGF-23 (P = .008), but not creatinine concentrations (P = .91). In the NP group (n = 18), feeding renal diet was associated with a significant decrease in plasma FGF-23 (P = .006), but not phosphate (P = .48), PTH (P = .35), or creatinine concentrations (P = .10). No significant changes were seen in any parameters in the comparator group during the study period.
  
  
  CONCLUSIONS
  Feeding renal diet is associated with reductions in plasma FGF-23 concentrations in hyper- and normophosphatemic cats with stable azotemic CKD, suggesting that dietary phosphate restriction may enable cats with CKD to maintain normal plasma phosphate concentrations in association with lower plasma FGF-23 concentrations.
authors.affiliation: Department of Veterinary Clinical Sciences, Royal Veterinary College, North Mymms, Hatfield, UK.
authors.forename: R F
authors.initials: RF
authors.lastname: Geddes
authors.forename: J
authors.initials: J
authors.lastname: Elliott
authors.forename: H M
authors.initials: HM
authors.lastname: Syme
mesh_terms: D000818:Animals; D053099:Azotemia / Q000178:diet therapy / Q000378:metabolism / Q000662:veterinary*; D002371:Cat Diseases / Q000178:diet therapy / Q000378:metabolism*; D002415:Cats; D003404:Creatinine / Q000097:blood; D000089703:Fibroblast Growth Factor-23; D005346:Fibroblast Growth Factors / Q000097:blood*; D008137:Longitudinal Studies; D010281:Parathyroid Hormone / Q000097:blood; D010710:Phosphates / Q000097:blood; D012016:Reference Values; D051436:Renal Insufficiency, Chronic / Q000178:diet therapy / Q000378:metabolism / Q000662:veterinary*; D012189:Retrospective Studies; D018709:Statistics, Nonparametric
chemical_list: C000717427:FGF23 protein, human; D010281:Parathyroid Hormone; D010710:Phosphates; D005346:Fibroblast Growth Factors; D000089703:Fibroblast Growth Factor-23; D003404:Creatinine
keywords: Feline; Hyperparathyroidism; PTH; Phosphate