title: Renal function in gout: long-term treatment effects of febuxostat.
abstract: BACKGROUND
  The association between hyperuricemia, gout, and impaired renal function has long been recognized. Recent data provide evidence for the causal relationship between elevated serum urate (sUA) and renal changes, leading to declines in glomerular filtration rates. In healthy adults, glomerular filtration rate wanes with age. Urate-lowering therapy (ULT) with allopurinol has been shown to stabilize or reverse this.
  
  
  OBJECTIVE
  Here we examine the long-term effects of ULT with febuxostat on estimated glomerular filtration rate (eGFR).
  
  
  METHODS
  This is a post hoc analysis of the Febuxostat Open-label Clinical trial of Urate-lowering efficacy and Safety study, during which 116 hyperuricemic gout subjects received daily doses of febuxostat (40, 80, or 120 mg) for up to 5 years. sUA concentrations and eGFR were assessed regularly. Results were stratified by mean change in sUA from baseline. Mathematical modeling was used to predict the effect of sUA reduction on eGFR.
  
  
  RESULTS
  Maintenance or improvement in eGFR was inversely correlated with the quantitative reduction in sUA from baseline. For every 1 mg/dL decrease in sUA, the model projected an expected improvement in eGFR of 1 mL/min from the untreated value.
  
  
  CONCLUSIONS
  Individuals with the greatest reductions in sUA may experience reduced rates of renal deterioration or even stabilization of renal function. Further studies examining the impact of long-term ULT on renal function in hyperuricemic gout patients are needed to both confirm our results and verify if improvements in renal function are feasible in such patients.
authors.affiliation: Universal Clinical Research Center, Inc., 1737 Beaver Brook Lane, Hunt Valley, MD 21030-1603, USA. huntvalley@aol.com
authors.forename: Andrew
authors.initials: A
authors.lastname: Whelton
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Macdonald
authors.forename: Lin
authors.initials: L
authors.lastname: Zhao
authors.forename: Barbara
authors.initials: B
authors.lastname: Hunt
authors.forename: Lhanoo
authors.initials: L
authors.lastname: Gunawardhana
mesh_terms: D000328:Adult; D000368:Aged; D004311:Double-Blind Method; D000069465:Febuxostat; D005260:Female; D005919:Glomerular Filtration Rate / Q000187:drug effects*; D006073:Gout / Q000503:physiopathology*; D006074:Gout Suppressants / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D006801:Humans; D033461:Hyperuricemia / Q000188:drug therapy / Q000503:physiopathology; D007668:Kidney / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D013844:Thiazoles / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D055815:Young Adult
chemical_list: D006074:Gout Suppressants; D013844:Thiazoles; D000069465:Febuxostat