title: Fibroblast growth factor 23 and Inflammation in CKD.
abstract: OBJECTIVE
  Levels of fibroblast growth factor 23 (FGF23) and inflammatory markers are commonly elevated in CKD, and each is associated with adverse clinical outcomes. This study tested the hypothesis that FGF23 is independently associated with inflammation in CKD.
  
  
  METHODS
  The association between levels of FGF23 and the inflammatory markers IL-6, C-reactive protein (CRP), TNF-α, and fibrinogen was assessed in a cross-sectional analysis of 3879 participants enrolled in the Chronic Renal Insufficiency Cohort (CRIC) study between June 2003 and September 2008.
  
  
  RESULTS
  FGF23 correlated directly with IL-6 (r=0.4), CRP (r=0.2), TNF-α (r=0.4), and fibrinogen (r=0.3; P<0.001 for each). In univariate and multivariable-adjusted linear regression analyses, natural log (ln) transformed FGF23 was significantly associated with lnIL-6, lnCRP, lnTNF-α, and fibrinogen (P<0.001 for each). Each unit higher lnFGF23 was associated with severe inflammation, defined as levels of all inflammatory markers in the highest 25th percentile, in univariate (odds ratio [OR], 2.4 [95% confidence interval (CI), 2.0-2.9]) and multivariable-adjusted (OR, 2.0 [95% CI, 1.6-2.5]) logistic regression analyses. Ascending FGF23 quartiles were independently associated with severe inflammation (OR, 5.6 for the highest versus lowest FGF23 quartile [95% CI, 2.3-13.9]; P for trend < 0.001).
  
  
  CONCLUSIONS
  Higher FGF23 levels are independently associated with higher levels of inflammatory markers in patients with CKD and with significantly greater odds of severe inflammation. Future studies should evaluate whether inflammation modifies the association between FGF23 and adverse outcomes in CKD.
authors.affiliation: Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miller School of Medicine, Miami, FL 33136, USA.
authors.forename: Jair
authors.initials: J
authors.lastname: Munoz Mendoza
authors.forename: Tamara
authors.initials: T
authors.lastname: Isakova
authors.forename: Ana C
authors.initials: AC
authors.lastname: Ricardo
authors.forename: Huiliang
authors.initials: H
authors.lastname: Xie
authors.forename: Sankar D
authors.initials: SD
authors.lastname: Navaneethan
authors.forename: Amanda H
authors.initials: AH
authors.lastname: Anderson
authors.forename: Lydia A
authors.initials: LA
authors.lastname: Bazzano
authors.forename: Dawei
authors.initials: D
authors.lastname: Xie
authors.forename: Matthias
authors.initials: M
authors.lastname: Kretzler
authors.forename: Lisa
authors.initials: L
authors.lastname: Nessel
authors.forename: L Lee
authors.initials: LL
authors.lastname: Hamm
authors.forename: Lavinia
authors.initials: L
authors.lastname: Negrea
authors.forename: Mary B
authors.initials: MB
authors.lastname: Leonard
authors.forename: Dominic
authors.initials: D
authors.lastname: Raj
authors.forename: Myles
authors.initials: M
authors.lastname: Wolf
mesh_terms: D002097:C-Reactive Protein / Q000032:analysis; D003430:Cross-Sectional Studies; D005260:Female; D000089703:Fibroblast Growth Factor-23; D005346:Fibroblast Growth Factors / Q000097:blood / Q000502:physiology*; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D051436:Renal Insufficiency, Chronic / Q000097:blood / Q000150:complications*
chemical_list: C000717427:FGF23 protein, human; D005346:Fibroblast Growth Factors; D000089703:Fibroblast Growth Factor-23; D002097:C-Reactive Protein