title: High uric acid level is a risk factor for progression of IgA nephropathy with chronic kidney disease stage G3a.
abstract: BACKGROUND
  High uric acid level is a known risk factor for deterioration of renal function in chronic kidney disease (CKD), but its influence on the progression of IgA nephropathy (IgAN) remains unclear.
  
  
  METHODS
  Adult IgAN patients (n = 611) were classified according to CKD stage. Renal survival rates and clinical and histological findings were compared between patients with high (H-UA) and normal (N-UA) uric acid levels in different CKD stages.
  
  
  RESULTS
  The proportion of patients with H-UA increased significantly with increasing CKD stage (stage G1, 12.3%; stage G2, 19.0%; stage G3a, 43.7%; stage G3b-4, 69.0%; P < 0.001). The 30-year renal survival rate was similar in patients with H-UA and N-UA in CKD stages G1, G2, and G3b-4, but was significantly lower in patients with H-UA than with N-UA in CKD stage G3a (24.7 vs. 51.9%; P = 0.0205). The clinical findings were similar in patients with H-UA and N-UA, but the interval from onset to biopsy differed between groups. The proportion of patients with global sclerosis was significantly higher in patients with H-UA than with N-UA in CKD stage G3a (33.3 vs. 11.4%; P = 0.0005), but the Oxford classifications were similar between groups. Multivariate Cox regression analysis identified H-UA (HR 1.36, 95% CI 1.07-1.72, P = 0.011) and a large amount of proteinuria (HR 1.38, 95% CI 1.09-1.74, P = 0.0084) as independent predictors of end-stage renal disease.
  
  
  CONCLUSIONS
  H-UA induced global glomerular sclerosis and accelerated the progression of IgAN in CKD stage G3a.
authors.affiliation: Department of Medicine, Kidney Center, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan, takamori@kc.twmu.ac.jp.
authors.forename: Takahito
authors.initials: T
authors.lastname: Moriyama
authors.forename: Mitsuyo
authors.initials: M
authors.lastname: Itabashi
authors.forename: Takashi
authors.initials: T
authors.lastname: Takei
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kataoka
authors.forename: Masayo
authors.initials: M
authors.lastname: Sato
authors.forename: Ari
authors.initials: A
authors.lastname: Shimizu
authors.forename: Yuko
authors.initials: Y
authors.lastname: Iwabuchi
authors.forename: Miki
authors.initials: M
authors.lastname: Nishida
authors.forename: Keiko
authors.initials: K
authors.lastname: Uchida
authors.forename: Kosaku
authors.initials: K
authors.lastname: Nitta
mesh_terms: D015415:Biomarkers / Q000097:blood; D001706:Biopsy; D016009:Chi-Square Distribution; D018450:Disease Progression; D005260:Female; D005922:Glomerulonephritis, IGA / Q000150:complications* / Q000175:diagnosis / Q000401:mortality; D006801:Humans; D033461:Hyperuricemia / Q000097:blood / Q000150:complications* / Q000175:diagnosis / Q000401:mortality; D053208:Kaplan-Meier Estimate; D007676:Kidney Failure, Chronic / Q000175:diagnosis / Q000209:etiology; D008297:Male; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D051436:Renal Insufficiency, Chronic / Q000175:diagnosis / Q000209:etiology* / Q000401:mortality / Q000628:therapy; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D013997:Time Factors; D015854:Up-Regulation; D014527:Uric Acid / Q000097:blood*
chemical_list: D015415:Biomarkers; D014527:Uric Acid