title: Effect of intravenous saccharated ferric oxide on serum FGF23 and mineral metabolism in hemodialysis patients.
abstract: OBJECTIVE
  Fibroblast growth factor-23 (FGF23) plays a central role in the development of hypophosphatemia and inappropriately low 1,25-dihydroxyvitamin D induced by iron therapy for iron-deficiency anemia. The aim of this study was to examine the effect of intravenous saccharated ferric oxide on serum FGF23 levels and mineral metabolism in hemodialysis patients.
  
  
  METHODS
  This prospective study enrolled 27 hemodialysis patients who had iron-deficiency anemia defined by a hemoglobin concentration < 10.5 g/dl and serum ferritin < 100 ng/ml. Intravenous saccharated ferric oxide at a dose of 40 mg was administered three times weekly over 3 weeks. The dose of active vitamin D and phosphate binders was kept unchanged. Serum FGF23, intact parathyroid hormone (PTH) and other parameters were prospectively monitored for 5 weeks.
  
  
  RESULTS
  Serum FGF23 levels were markedly elevated [3,453 (338-6,383) pg/ml] at baseline. After 3 weeks of intravenous saccharated ferric oxide treatment, serum FGF23 further increased to 4,701 (1,251-14,396) pg/ml, and returned to the baseline values after 2 weeks of observation. There was also a significant decrease in intact PTH but no changes in serum calcium and phosphorus.
  
  
  CONCLUSIONS
  Intravenous saccharated ferric oxide induces further increase in elevated FGF23 levels in hemodialysis patients. This increase does not induce hypophosphatemia and inappropriately low 1,25-dihydroxyvitamin D in the absence of functioning kidney, but may result in transient PTH suppression - possibly by directly acting on the parathyroid.
authors.affiliation: Division of Nephrology and Kidney Center, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Takeda
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Komaba
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Goto
authors.forename: Hideki
authors.initials: H
authors.lastname: Fujii
authors.forename: Michio
authors.initials: M
authors.lastname: Umezu
authors.forename: Hirohito
authors.initials: H
authors.lastname: Hasegawa
authors.forename: Akira
authors.initials: A
authors.lastname: Fujimori
authors.forename: Masato
authors.initials: M
authors.lastname: Nishioka
authors.forename: Shinichi
authors.initials: S
authors.lastname: Nishi
authors.forename: Masafumi
authors.initials: M
authors.lastname: Fukagawa
mesh_terms: D000368:Aged; D005260:Female; D005290:Ferric Compounds / Q000008:administration & dosage* / Q000494:pharmacology*; D000077605:Ferric Oxide, Saccharated; D000089703:Fibroblast Growth Factor-23; D005346:Fibroblast Growth Factors / Q000097:blood*; D005937:Glucaric Acid; D006801:Humans; D007262:Infusions, Intravenous; D007676:Kidney Failure, Chronic / Q000628:therapy; D008297:Male; D008875:Middle Aged; D010280:Parathyroid Glands / Q000378:metabolism; D010281:Parathyroid Hormone / Q000378:metabolism; D010710:Phosphates / Q000737:chemistry; D011446:Prospective Studies; D006435:Renal Dialysis / Q000379:methods*; D014807:Vitamin D / Q000378:metabolism
chemical_list: C000717427:FGF23 protein, human; D005290:Ferric Compounds; D010281:Parathyroid Hormone; D010710:Phosphates; D014807:Vitamin D; D005346:Fibroblast Growth Factors; D000089703:Fibroblast Growth Factor-23; D000077605:Ferric Oxide, Saccharated; D005937:Glucaric Acid