title: Diagnosis of subclinical central hypothyroidism in patients with hypothalamic-pituitary disease by Doppler echocardiography.
abstract: OBJECTIVE
  The diagnosis of subclinical central hypothyroidism in hypothalamic-pituitary patients cannot be established by serum markers of thyroid hormone action. Myocardial function by echocardiography has been shown to reflect thyroid hormone action in primary thyroid dysfunction. We evaluated the performance of echocardiography in diagnosing subclinical central hypothyroidism.
  
  
  METHODS
  Cross-sectional and before and after.
  
  
  METHODS
  Echocardiography and serum thyroid hormones were assessed in overt primary (n=20) and central (n=10) hypothyroidism, subclinical primary hypothyroidism (n=10), hypothalamic-pituitary disease with normal free thyroxine (FT(4); n=25), and controls (n=28). Receiver operating characteristic (ROC) curves were generated using overt hypothyroidism patients and selected cut-off values were applied to detect both primary and central subclinical hypothyroidism. After levothyroxine (l-T(4)) intervention, patients were echocardiographically reevaluated at predefined targets: normal thyrotropin (TSH) in primary hypothyroidism, normal FT(4) in overt central hypothyroidism, and higher than pretreatment FT(4) in echo-defined subclinical central hypothyroidism.
  
  
  RESULTS
  Parameters with highest areas under the ROC curves (area under the curve (AUC) ≥0.94) were as follows: isovolumic contraction time (ICT), ICT/ejection time (ET), and myocardial performance index. Highest diagnostic accuracy (93%) was obtained when at least one parameter was increased (positive and negative predictive values: 93%). Hypothyroidism was echocardiographically diagnosed in eight of ten patients with subclinical primary hypothyroidism and in 14 of 25 patients (56%) with hypothalamic-pituitary disease and normal serum FT(4). Echocardiographic abnormalities improved significantly after l-T(4) and correlated (0.05<P<0.001) with changes in FT(4) (-0.62<r<-0.55) and TSH (0.63<r<0.68) in primary hypothyroidism and with FT(4) in central hypothyroidism (-0.72<r<-0.50).
  
  
  CONCLUSIONS
  Echocardiography can be useful in diagnosing subclinical central hypothyroidism in patients with hypothalamic-pituitary disease.
authors.affiliation: Cardiology Division, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil.
authors.forename: Fabio Casanova
authors.initials: FC
authors.lastname: Doin
authors.forename: Mariana
authors.initials: M
authors.lastname: Rosa-Borges
authors.forename: Manoel R A
authors.initials: MR
authors.lastname: Martins
authors.forename: Valdir A
authors.initials: VA
authors.lastname: Moisés
authors.forename: Julio
authors.initials: J
authors.lastname: Abucham
mesh_terms: D000328:Adult; D058070:Asymptomatic Diseases; D003430:Cross-Sectional Studies; D003940:Diagnostic Techniques, Endocrine; D015150:Echocardiography, Doppler; D005260:Female; D006801:Humans; D007027:Hypothalamic Diseases / Q000150:complications / Q000000981:diagnostic imaging* / Q000188:drug therapy; D007037:Hypothyroidism / Q000150:complications / Q000000981:diagnostic imaging* / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D010900:Pituitary Diseases / Q000150:complications / Q000000981:diagnostic imaging* / Q000188:drug therapy; D012372:ROC Curve; D013963:Thyroid Hormones / Q000097:blood; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000627:therapeutic use; D055815:Young Adult
chemical_list: D013963:Thyroid Hormones; D013972:Thyrotropin; D013974:Thyroxine