title: Increased prevalence of thyroid autoimmunity and hypothyroidism in patients with glycogen storage disease type I.
abstract: OBJECTIVE
  To investigate the hypothalamus-pituitary-thyroid axis in patients with glycogen storage disease type 1(GSD1).
  
  
  METHODS
  Ten patients with GSD1a, 7 patients with GSD1b, and 34 sex- and age-matched healthy control subjects were enrolled in the study.
  
  
  RESULTS
  The levels of serum-free thyroxine (FT4) were significantly lower in patients with GSD1a and GSD1b (P < .05), whereas thyrotropin was significantly higher compared with control subjects only in patients with GSD1b (P < .005). Thyroglobulin and thyroperoxidase auto-antibodies were significantly higher in patients with GSD1b than in patients with GSD1a and control subjects (P < .005). After thyrotropin-releasing hormone stimulation, an enhanced thyrotropin response was found in patients with GSD1a and patients with GSD1b (P < .005) compared with control subjects. The presence of a subclinical or overt hypothyroidism was found in 4 of 7 patients with GSD1b and in no patient with GSD1a (chi2 = 7.47, P < .005) or control subject (chi2 = 27.2, P < .0001).
  
  
  CONCLUSIONS
  Patients with GSD1b have an increased prevalence of thyroid autoimmunity and hypothyroidism, although patients with GSD1a have little evidence of thyroid abnormalities. Concomitant damage at the level of the hypothalamus or pituitary gland might be hypothesized on the basis of the slightly elevated thyrotropin levels, even in patients with overt hypothyroidism.
authors.affiliation: Department of Pediatrics, Federico II University, Naples, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Melis
authors.forename: Rosario
authors.initials: R
authors.lastname: Pivonello
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Parenti
authors.forename: Roberto
authors.initials: R
authors.lastname: Della Casa
authors.forename: Mariacarolina
authors.initials: M
authors.lastname: Salerno
authors.forename: Gaetano
authors.initials: G
authors.lastname: Lombardi
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Sebastio
authors.forename: Annamaria
authors.initials: A
authors.lastname: Colao
authors.forename: Generoso
authors.initials: G
authors.lastname: Andria
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D016022:Case-Control Studies; D002648:Child; D015897:Comorbidity; D005260:Female; D005953:Glycogen Storage Disease Type I / Q000175:diagnosis / Q000453:epidemiology*; D006801:Humans; D007037:Hypothyroidism / Q000175:diagnosis / Q000453:epidemiology*; D008297:Male; D015995:Prevalence; D011336:Probability; D011379:Prognosis; D011446:Prospective Studies; D012016:Reference Values; D018570:Risk Assessment; D017678:Sex Distribution; D018709:Statistics, Nonparametric; D013960:Thyroid Function Tests; D013967:Thyroiditis, Autoimmune / Q000175:diagnosis / Q000453:epidemiology*; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood
chemical_list: D013972:Thyrotropin; D013974:Thyroxine