title: [Non-thyroid illness" or changed thyroid hormone parameter syndrome with non-thyroid illnesses].
abstract: BACKGROUND
  The multiple effects of systemic illness on thyroid economy are commonly referred to "non-thyroidal illness" (NTI) or "sick euthyroid syndrome". The various aspects of this common syndrome are summarized in this article.
  
  
  METHODS
  Results of the relevant studies published during the past 25 years were evaluated. The influence of the underlying illness and of drug administration was especially emphasized.
  
  
  RESULTS
  The most common abnormalities in NTI are 1. the "low-T3 syndrome" due to a decreased T3 generation from T4 by a reduced activity of 5'-deiodinase (a selenoprotein); 2. the "low-T3 low-T4 state", which is associated with a poor prognosis. The low T4-levels are related to a binding inhibitor that displaces T4 from its binding proteins. However, there exists some controversy regarding the character of this binding inhibitor. 3. The high-T4 state is often found in acute psychiatric and liver diseases. The nutritional status of the patients and drugs known to influence thyroid hormone parameters have to be considered when patients with NTI are evaluated. Some difficulties may arise, when there is evidence of coexisting thyroid disease. Here aside from further biochemical evaluation such as thyroid antibodies, thyroid ultrasound and a thyroid scan have to be performed.
  
  
  CONCLUSIONS
  NTI is associated with various alterations in thyroid hormone parameters when no intrinsic thyroid hormone disease exists. The severity of NTI reflects clinical outcome and clinical amelioration is associated with normalization of thyroid hormone parameters. There is no need for specific therapeutic intervention such as the administration of thyroid hormones in patients with the various forms of the NTI-syndrome.
authors.affiliation: Abteilung für Endokrinologie, Zentrum für Innere Medizin, Universitätsklinikum Essen. F.W.Reinhardt@netscape.net
authors.forename: W
authors.initials: W
authors.lastname: Reinhardt
authors.forename: K
authors.initials: K
authors.lastname: Mann
mesh_terms: D003937:Diagnosis, Differential; D005067:Euthyroid Sick Syndromes / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D006801:Humans; D013960:Thyroid Function Tests; D013963:Thyroid Hormones / Q000097:blood*
chemical_list: D013963:Thyroid Hormones
vernacular_title: "Non-Thyroidal Illness" oder Syndrom veränderter Schilddrüsenhormonparameter bei Patienten mit nichtthyreoidalen Erkrankungen.