title: Effects of dietary phosphate restriction and phosphate binders on FGF23 levels in CKD.
abstract: BACKGROUND
  Elevated levels of fibroblast growth factor 23 (FGF23) are associated with increased risk of adverse outcomes in patients with CKD. Reducing dietary phosphate intake or absorption may decrease FGF23 levels, but data on the combined effects of dietary phosphate restriction and phosphate binders in CKD are limited.
  
  
  METHODS
  In this 2×2 factorial, single-blinded, placebo-controlled, 3-month study, conducted between July 2009 and March 2012, 39 patients with CKD stages 3 or 4 and normal serum phosphate levels were randomly assigned to one of four groups: ad libitum diet plus lanthanum carbonate (LC) placebo (n=10), 900-mg phosphate diet plus LC placebo (n=10), ad libitum diet plus LC (n=11), or 900-mg phosphate diet plus LC (n=8). The dose of LC was 1000 mg three times daily with meals. Dietary restriction was accomplished with outpatient counseling. The primary end point was change in FGF23 levels from baseline.
  
  
  RESULTS
  Compared with ad libitum diet, the 900-mg phosphate diet did not significantly reduce FGF23 levels (diet × time interaction, P=0.05). Compared with placebo, LC alone also did not significantly reduce FGF23 levels (LC × time interaction, P=0.21). However, the dual intervention significantly decreased FGF23 levels throughout the study period (diet × LC × time interaction, P=0.02), resulting in a 35% (95% confidence interval, 8%-62%) reduction by study end.
  
  
  CONCLUSIONS
  The combination of LC plus counseling for a phosphate-restricted diet decreased FGF23 levels in patients with CKD stages 3-4 and normal serum phosphate levels.
authors.affiliation: Division of Nephrology and Hypertension, Department of Medicine, Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, Florida 33136, USA.
authors.forename: Tamara
authors.initials: T
authors.lastname: Isakova
authors.forename: Allison
authors.initials: A
authors.lastname: Barchi-Chung
authors.forename: Gwen
authors.initials: G
authors.lastname: Enfield
authors.forename: Kelsey
authors.initials: K
authors.lastname: Smith
authors.forename: Gabriella
authors.initials: G
authors.lastname: Vargas
authors.forename: Jessica
authors.initials: J
authors.lastname: Houston
authors.forename: Huiliang
authors.initials: H
authors.lastname: Xie
authors.forename: Patricia
authors.initials: P
authors.lastname: Wahl
authors.forename: Eva
authors.initials: E
authors.lastname: Schiavenato
authors.forename: Austin
authors.initials: A
authors.lastname: Dosch
authors.forename: Orlando M
authors.initials: OM
authors.lastname: Gutiérrez
authors.forename: Jorge
authors.initials: J
authors.lastname: Diego
authors.forename: Oliver
authors.initials: O
authors.lastname: Lenz
authors.forename: Gabriel
authors.initials: G
authors.lastname: Contreras
authors.forename: Armando
authors.initials: A
authors.lastname: Mendez
authors.forename: Rory B
authors.initials: RB
authors.lastname: Weiner
authors.forename: Myles
authors.initials: M
authors.lastname: Wolf
mesh_terms: D000328:Adult; D000368:Aged; D002614:Chelating Agents / Q000627:therapeutic use*; D003131:Combined Modality Therapy; D015536:Down-Regulation; D005260:Female; D000089703:Fibroblast Growth Factor-23; D005346:Fibroblast Growth Factors / Q000097:blood*; D005431:Florida; D006801:Humans; D007811:Lanthanum / Q000627:therapeutic use*; D016018:Least-Squares Analysis; D008297:Male; D008875:Middle Aged; D010710:Phosphates / Q000008:administration & dosage / Q000097:blood*; D016226:Phosphorus, Dietary / Q000097:blood*; D051436:Renal Insufficiency, Chronic / Q000097:blood / Q000175:diagnosis / Q000178:diet therapy* / Q000188:drug therapy*; D016037:Single-Blind Method; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D002614:Chelating Agents; C000717427:FGF23 protein, human; D010710:Phosphates; D016226:Phosphorus, Dietary; C119467:lanthanum carbonate; D005346:Fibroblast Growth Factors; D007811:Lanthanum; D000089703:Fibroblast Growth Factor-23