title: The natural history of the hyperthyrotropinemia of children born prematurely.
abstract: OBJECTIVE
  Non-autoimmune hyperthyrotropinemia has been previously reported among children born prematurely. The aim of this study was to follow up their thyroid function, volume, and structure and to investigate the relationship with growth, IGF-I, lipid profile, and insulin sensitivity.
  
  
  METHODS
  Seventy-two children born prematurely (33.2±2.2 weeks), 26 appropriate (AGA) and 46 small for gestational age (SGA), were evaluated at the age of 7.6±2.3 yr (time 1) and at the age of 11.4±2.3 yr (time 2). We also measured TSH, free T(3) (fT(3)), free T(4) (fT(4)), thyroperoxidase antibodies (TPO-Ab), thyroglobulin antibodies (TG-Ab), thyroid ultrasound, auxological parameters, lipid profile, glucose, and insulin level.
  
  
  RESULTS
  In the AGA group TSH was similar in both times (2.7±1.0 vs 3.0±0.9 mU/l) and above the upper normal limit in 4 (15.4%) subjects at time 1 and in 6 (23.7%) subjects at time 2 (ns). In the SGA group, TSH was similar in both times (2.8±1.2 vs 2.5±1.0 mU/l) and above the upper normal limit in 11 (23.9%) subjects at time 1 and 5 (10.8%) subjects at time 2 (ns). fT(4) and fT(3) were always normal and TPO- and TG-Ab absent. Thyroid volume increased progressively, but significantly only in the AGA group (p=0.0005). The thyroid structure was always normal and there was no influence on the growth and the biochemical profile.
  
  
  CONCLUSIONS
  Some ex-premature babies show a mild and variable thyroid dysfunction, which does not seem to evolve toward an overt thyroid dysfunction.
authors.affiliation: Department of Pediatrics, Regional Hospital of Bolzano, Bolzano, Italy.
authors.forename: A Y
authors.initials: AY
authors.lastname: Leitner
authors.forename: F
authors.initials: F
authors.lastname: Pellegrini
authors.forename: P
authors.initials: P
authors.lastname: Beck-Peccoz
authors.forename: P
authors.initials: P
authors.lastname: Wanker
authors.forename: L
authors.initials: L
authors.lastname: Persani
authors.forename: G
authors.initials: G
authors.lastname: Radetti
mesh_terms: D000293:Adolescent; D001323:Autoantibodies / Q000097:blood; D001324:Autoantigens / Q000276:immunology; D001786:Blood Glucose / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D003409:Congenital Hypothyroidism / Q000000981:diagnostic imaging / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age / Q000378:metabolism*; D007328:Insulin / Q000097:blood; D007453:Iodide Peroxidase / Q000276:immunology; D033862:Iron-Binding Proteins / Q000276:immunology; D008055:Lipids / Q000097:blood; D047928:Premature Birth / Q000378:metabolism*; D013960:Thyroid Function Tests; D013961:Thyroid Gland / Q000000981:diagnostic imaging / Q000502:physiology*; D013972:Thyrotropin / Q000097:blood*; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood; D014463:Ultrasonography
chemical_list: D001323:Autoantibodies; D001324:Autoantigens; D001786:Blood Glucose; D007328:Insulin; D033862:Iron-Binding Proteins; D008055:Lipids; D014284:Triiodothyronine; D013972:Thyrotropin; C056658:TPO protein, human; D007453:Iodide Peroxidase; D013974:Thyroxine