title: [Clinical usefulness of the determination of fibroblast growth factor 23 in the evaluation of patients with osteomalacia].
abstract: OBJECTIVE
  The aim of the present study was to analyze the usefulness of the determination of fibroblast growth factor 23 (FGF23), a regulatory hormone of phosphate metabolism, in the evaluation of patients with osteomalacia of different causes.
  
  
  METHODS
  Seventeen patients with osteomalacia were included: 12 hypophosphatemic osteomalacia (by several causes), 4 vitamin D-deficiency osteomalacia and one with hypophosphatasia. Plasma C-terminal FGF23 was determined in all patients.
  
  
  RESULTS
  FGF23 levels were increased in 6/12 (50%) of patients with hypophosphatemic osteomalacia (2 X-linked, one autosomal dominant, one related HIV therapy and 2 not elucidated). No patient with vitamin D-deficiency osteomalacia or hypophosphatasia presented increased FGF23 levels.
  
  
  CONCLUSIONS
  The determination of FGF23 could be useful in the evaluation of the different types of hypophosphatemic osteomalacia and also in the identification of their associated etiopathogenic mechanisms. Thus, depending on the cause, 50% of the patients with hypophosphatemic osteomalacia showed increased FGF23 values, whereas in vitamin D-deficiency osteomalacia and in hypophosphatasia FGF23 levels were normal.
authors.affiliation: Unidad de Patología Metabólica Ósea, Servicio de Reumatología, Hospital Clínic de Barcelona, Barcelona, España. Electronic address: lgifre@clinic.ub.es.
authors.forename: Laia
authors.initials: L
authors.lastname: Gifre
authors.affiliation: Laboratorio de Hormonal, Hospital Clínic de Barcelona, Barcelona, España.
authors.forename: Maria Jesús
authors.initials: MJ
authors.lastname: Martínez de Osaba
authors.affiliation: Unidad de Patología Metabólica Ósea, Servicio de Reumatología, Hospital Clínic de Barcelona, Barcelona, España.
authors.forename: Ana
authors.initials: A
authors.lastname: Monegal
authors.affiliation: Unidad de Patología Metabólica Ósea, Servicio de Reumatología, Hospital Clínic de Barcelona, Barcelona, España; Centro de Investigación Biomédica en Red: Enfermedades Hepáticas y Digestivas (CIBERehd), Hospital Clínic de Barcelona, Barcelona, España.
authors.forename: Núria
authors.initials: N
authors.lastname: Guañabens
authors.affiliation: Unidad de Patología Metabólica Ósea, Servicio de Reumatología, Hospital Clínic de Barcelona, Barcelona, España; Centro de Investigación Biomédica en Red: Enfermedades Hepáticas y Digestivas (CIBERehd), Hospital Clínic de Barcelona, Barcelona, España.
authors.forename: Pilar
authors.initials: P
authors.lastname: Peris
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D003937:Diagnosis, Differential; D005260:Female; D000089703:Fibroblast Growth Factor-23; D005346:Fibroblast Growth Factors / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010018:Osteomalacia / Q000097:blood / Q000175:diagnosis* / Q000209:etiology
chemical_list: D015415:Biomarkers; C000717427:FGF23 protein, human; D005346:Fibroblast Growth Factors; D000089703:Fibroblast Growth Factor-23
keywords: Factor de crecimiento de los fibroblastos 23; Fibroblast growth factor 23; Fosfatonina; Hipofosfatemia; Hypophosphatemia; Osteomalacia; Phosphatonin