title: TSH reference values for adult Brazilian population.
abstract: OBJECTIVE
  To establish limits of normal serum TSH for the adult (18 to 60 years) Brazilian population according to recommendations of the National Academy of Clinical Biochemistry.
  
  
  METHODS
  Healthy volunteers were evaluated and those fulfilling the following clinical criteria were selected: absence of known thyroid disease; no use of any interfering medications; no history of head and neck external radiotherapy, type 1 diabetes or autoimmune disease; no family history of thyroid disease, and absence of goiter or palpable nodules. Subjects with anti-thyroperoxidase antibodies and/or altered free T4 were excluded. The sample consisted of 960 subjects (480 males and 480 females).
  
  
  RESULTS
  TSH values corresponding to the 2.5th and 97.5th percentiles of the sample were 0.43 and 3.24 mIU/L, respectively. TSH values > 2.5 mIU/L were observed in 9.15% of the volunteers and levels > 3 mIU/L in 3.11%.
  
  
  CONCLUSIONS
  The present study suggests an upper limit of normal TSH of approximately 3.5 mIU/L.
authors.affiliation: Santa Casa de Belo Horizonte, MG, Brazil. pedrorosario@globo.com
authors.forename: Pedro Weslley
authors.initials: PW
authors.lastname: Rosario
authors.forename: Arthur Cezar Malard
authors.initials: AC
authors.lastname: Xavier
authors.forename: Maria Regina
authors.initials: MR
authors.lastname: Calsolari
mesh_terms: D000047:Academies and Institutes; D000293:Adolescent; D000328:Adult; D001938:Brazil; D005260:Female; D006801:Humans; D008163:Luminescent Measurements; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D013972:Thyrotropin / Q000097:blood*; D055815:Young Adult
chemical_list: D013972:Thyrotropin