title: Effects of uric acid-lowering therapy on renal outcomes: a systematic review and meta-analysis.
abstract: BACKGROUND
  Non-randomized studies suggest an association between serum uric acid levels and progression of chronic kidney disease (CKD). The aim of this systematic review is to summarize evidence from randomized controlled trials (RCTs) concerning the benefits and risks of uric acid-lowering therapy on renal outcomes.
  
  
  METHODS
  Medline, Excerpta Medical Database and Cochrane Central Register of Controlled Trials were searched with English language restriction for RCTs comparing the effect of uric acid-lowering therapy with placebo/no treatment on renal outcomes. Treatment effects were summarized using random-effects meta-analysis.
  
  
  RESULTS
  Eight trials (476 participants) evaluating allopurinol treatment were eligible for inclusion. There was substantial heterogeneity in baseline kidney function, cause of CKD and duration of follow-up across these studies. In five trials, there was no significant difference in change in glomerular filtration rate from baseline between the allopurinol and control arms [mean difference (MD) 3.1 mL/min/1.73 m2, 95% confidence intervals (CI) -0.9, 7.1; heterogeneity χ2=1.9, I2=0%, P=0.75]. In three trials, allopurinol treatment abrogated increases in serum creatinine from baseline (MD -0.4 mg/dL, 95% CI -0.8, -0.0 mg/dL; heterogeneity χ2=3, I2=34%, P=0.22). Allopurinol had no effect on proteinuria and blood pressure. Data for effects of allopurinol therapy on progression to end-stage kidney disease and death were scant. Allopurinol had uncertain effects on the risks of adverse events.
  
  
  CONCLUSIONS
  Uric acid-lowering therapy with allopurinol may retard the progression of CKD. However, adequately powered randomized trials are required to evaluate the benefits and risks of uric acid-lowering therapy in CKD.
authors.affiliation: Department of Nephrology, University of Queensland at Princess Alexandra Hospital, Brisbane, Australia.
authors.forename: Bhadran
authors.initials: B
authors.lastname: Bose
authors.forename: Sunil V
authors.initials: SV
authors.lastname: Badve
authors.forename: Swapnil S
authors.initials: SS
authors.lastname: Hiremath
authors.forename: Neil
authors.initials: N
authors.lastname: Boudville
authors.forename: Fiona G
authors.initials: FG
authors.lastname: Brown
authors.forename: Alan
authors.initials: A
authors.lastname: Cass
authors.forename: Janak R
authors.initials: JR
authors.lastname: de Zoysa
authors.forename: Robert G
authors.initials: RG
authors.lastname: Fassett
authors.forename: Randall
authors.initials: R
authors.lastname: Faull
authors.forename: David C
authors.initials: DC
authors.lastname: Harris
authors.forename: Carmel M
authors.initials: CM
authors.lastname: Hawley
authors.forename: John
authors.initials: J
authors.lastname: Kanellis
authors.forename: Suetonia C
authors.initials: SC
authors.lastname: Palmer
authors.forename: Vlado
authors.initials: V
authors.lastname: Perkovic
authors.forename: Elaine M
authors.initials: EM
authors.lastname: Pascoe
authors.forename: Gopala K
authors.initials: GK
authors.lastname: Rangan
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Walker
authors.forename: Giles
authors.initials: G
authors.lastname: Walters
authors.forename: David W
authors.initials: DW
authors.lastname: Johnson
mesh_terms: D000493:Allopurinol / Q000627:therapeutic use*; D018450:Disease Progression; D006074:Gout Suppressants / Q000627:therapeutic use; D006801:Humans; D051436:Renal Insufficiency, Chronic / Q000097:blood / Q000188:drug therapy*; D014527:Uric Acid / Q000097:blood*
chemical_list: D006074:Gout Suppressants; D014527:Uric Acid; D000493:Allopurinol
keywords: chronic kidney disease; clinical trial; kidney function test; renal dialysis; uric acid