title: [Values of thyrotropin, free triiodothyronine and free thyroxine using chemiluminescence in children and adolescents in the Autonomous Community of Madrid (Spain)].
abstract: OBJECTIVE
  To establish the reference ranges of thyrotropin (TSH), free triiodothyronine (FT3) and free thyroxine (FT4) with the chemiluminescence method in healthy children and adolescents in Madrid, Spain.
  
  
  METHODS
  A total of 371 children and adolescents of both sexes, with different ages and at different pubertal stage participated in the study. Serum values of TSH, FT3, and FT4 were determined by chemiluminescence.
  
  
  RESULTS
  TSH, FT4 and FT3 reference ranges decreased inversely with chronological age. Significant differences were found between prepubertal and pubertal groups. In some groups, there were also occasional differences between sexes.
  
  
  CONCLUSIONS
  Thyroid hormone levels decrease with chronological age. Because of the differences in hormone levels between prepubertal and pubertal subjects, we believe that different pubertal stages should be included in the standard reference values of these hormones.
authors.affiliation: Servicio de Pediatría.Hospital Severo Ochoa. Madrid. España. bgarciac@hsvo.insalud.es
authors.forename: B
authors.initials: B
authors.lastname: García Cuartero
authors.forename: C
authors.initials: C
authors.lastname: García Lacalle
authors.forename: C
authors.initials: C
authors.lastname: Jiménez Lobo
authors.forename: V
authors.initials: V
authors.lastname: Nebreda Pérez
authors.forename: C
authors.initials: C
authors.lastname: Calvo Rey
authors.forename: A
authors.initials: A
authors.lastname: García Vergaz
authors.forename: N J
authors.initials: NJ
authors.lastname: Alcázar Villar
authors.forename: M
authors.initials: M
authors.lastname: de la Torre Verdú
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008163:Luminescent Measurements; D008297:Male; D013030:Spain; D013972:Thyrotropin / Q000097:blood*; D013974:Thyroxine / Q000097:blood*; D014284:Triiodothyronine / Q000097:blood*; D014505:Urban Population
chemical_list: D014284:Triiodothyronine; D013972:Thyrotropin; D013974:Thyroxine