title: Relationship of thyroid function with obesity and type 2 diabetes in euthyroid Tunisian subjects.
abstract: OBJECTIVE
  Although a relationship between obesity and metabolic consequences with thyroid function has been reported, the underlying pathogenesis is not completely known. In the current study, we evaluated the thyroid function in obese and/or diabetic patients compared to healthy normal weight peers, exploring the possible association between components of metabolic syndrome and thyroid function parameters.
  
  
  METHODS
  We recruited 108 subjects (56 male and 52 female). In all subjects, thyroid stimulating hormone (TSH), free thyroxine (FT4), fasting plasma levels of insulin and glucose, homeostasis model assessment for insulin resistance, and obesity parameters were assessed.
  
  
  RESULTS
  We found that circulating levels of TSH and FT4 were significantly increased in overweight and obese subjects. However, the data do not reveal any change of these hormones in diabetics. Multivariate linear regression analysis showed that TSH was directly associated with both obesity and insulin resistance parameters (p < 0.05). FT4 was negatively associated only with obesity parameters (p < 0.05).
  
  
  CONCLUSIONS
  Our data strongly support that the changes of thyroid hormones may be influenced by adiposity and its metabolic consequences, such as insulin resistance. This relationship can be explained by a cross talk between adipose tissue release and thyroid function. Nevertheless, metformin treatment seems to affect thyroid function in diabetic patients by maintaining plasma thyrotropin levels to subnormal levels.
authors: Laboratoire de Génétique, Immunologie et Pathologies Humaines, Département de Biologie, Faculté des Sciences de Tunis, CAMPUS, Université Tunis-el Manar, Tunis, Tunisia. soumaya15@yahoo.fr
authors: Soumaya
authors: S
authors: Kouidhi
authors: Rym
authors: R
authors: Berhouma
authors: Myriam
authors: M
authors: Ammar
authors: Kamel
authors: K
authors: Rouissi
authors: Slim
authors: S
authors: Jarboui
authors: Marie-Stéphanie
authors: MS
authors: Clerget-Froidevaux
authors: Isabelle
authors: I
authors: Seugnet
authors: Hafawa
authors: H
authors: Abid
authors: Fattouma
authors: F
authors: Bchir
authors: Barbara
authors: B
authors: Demeneix
authors: Hajer
authors: H
authors: Guissouma
authors: Amel Benammar
authors: AB
authors: Elgaaied
mesh_terms: D001786:Blood Glucose / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008297:Male; D024821:Metabolic Syndrome; D008875:Middle Aged; D009765:Obesity / Q000097:blood / Q000503:physiopathology*; D013960:Thyroid Function Tests; D013961:Thyroid Gland / Q000503:physiopathology*; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D014416:Tunisia
chemical_list: D001786:Blood Glucose; D007328:Insulin; D013972:Thyrotropin; D013974:Thyroxine