title: Atypical celiac disease as cause of increased need for thyroxine: a systematic study.
abstract: OBJECTIVE
  Replacement T4 dose in hypothyroid patients bearing both chronic autoimmune thyroiditis and atypical celiac disease (CD) has been analyzed.
  
  
  METHODS
  Replacement T4 dose has been analyzed in 35 hypothyroid patients with Hashimoto's thyroiditis (HT) and atypical CD, as defined by the American Gastroenterological Association. We have evaluated the ability of the same dose of T4 to reach target TSH in 21 patients before and during gluten-free diet (GFD). In the remaining 14 patients, noncompliant with GFD, we analyzed replacement T4 dose and compared it with that in a similar group consisting of 68 patients with hypothyroid HT but no evidence of celiac sprue or other conditions interfering with T4 absorption.
  
  
  RESULTS
  In patients with isolated HT, the desired serum TSH (median=1.02 mU/liter) was reached in all patients after 5±2 months of treatment at a median T4 dose of 1.31 μg/kg·d. After a similar period and dose of T4, higher levels of TSH (median=4.20 mU/liter) were observed in patients with HT and CD. In 21 CD patients, target TSH (median TSH=1.25 mU/liter) has been attained after 11±3 months of GFD without increasing T4 dose (1.32 μg/kg·d). In the remaining 14 patients, who were noncompliant with GFD, target TSH has also been achieved but at a higher T4 dose (median=1.96 μg/kg·d; +49%; P=0.0002) than in hypothyroid patients without CD.
  
  
  CONCLUSIONS
  Atypical CD increases the need for T4. The effect was reversed by GFD or by increasing T4 dose. Malabsorption of T4 may provide the opportunity to detect CD that was overlooked until the patients were put under T4 therapy.
authors.affiliation: Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome, Viale Regina Elena 324, 00161 Rome, Italy.
authors.forename: Camilla
authors.initials: C
authors.lastname: Virili
authors.forename: Giulia
authors.initials: G
authors.lastname: Bassotti
authors.forename: Maria Giulia
authors.initials: MG
authors.lastname: Santaguida
authors.forename: Raffaella
authors.initials: R
authors.lastname: Iuorio
authors.forename: Susanna Carlotta
authors.initials: SC
authors.lastname: Del Duca
authors.forename: Valeria
authors.initials: V
authors.lastname: Mercuri
authors.forename: Antonio
authors.initials: A
authors.lastname: Picarelli
authors.forename: Patrizia
authors.initials: P
authors.lastname: Gargiulo
authors.forename: Lucilla
authors.initials: L
authors.lastname: Gargano
authors.forename: Marco
authors.initials: M
authors.lastname: Centanni
mesh_terms: D000328:Adult; D002446:Celiac Disease / Q000097:blood / Q000150:complications / Q000178:diet therapy / Q000188:drug therapy*; D015331:Cohort Studies; D055050:Diet, Gluten-Free; D005260:Female; D050031:Hashimoto Disease / Q000097:blood / Q000150:complications / Q000188:drug therapy*; D006801:Humans; D007037:Hypothyroidism / Q000097:blood / Q000150:complications / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000627:therapeutic use*
chemical_list: D013972:Thyrotropin; D013974:Thyroxine