title: Aortic stiffness and left ventricular function in patients with differentiated thyroid cancer.
abstract: OBJECTIVE
  The aim of this study was to investigate aortic stiffness and left ventricular (LV) systolic and diastolic function in patients with differentiated thyroid cancer (DTC) on thyroxine (L-T4) therapy and after L-T4 withdrawal to assess the cardiovascular impact of long-term subclinical hyperthyroidism and short-term overt hypothyroidism.
  
  
  METHODS
  Twenty-four patients who had had total thyroidectomy and radioiodine ablation for differentiated thyroid cancer were studied on two occasions: on TSH suppressive L-T4 therapy (sTSH 0.24 ± 0.11 mU/L), and 4 weeks after L-T4 withdrawal (sTSH 89.82 ± 29.36 mU/L). Echocardiography was performed and thyroid function, serum thyroglobulin, lipid parameters, homocystine, C-reactive protein, fibrinogen and von Willebrand factor activity (vWF) were measured. Twenty-two healthy volunteers matched for age and sex served as euthyroid controls.
  
  
  RESULTS
  Aortic stiffness was increased both in hypothyroidism (6.04 ± 2.88 cm(2)/dyn/10(3), p < 0.05) and subclinical hyperthyroidism (9.27 ± 4.81 cm(2)/dyn/10(3), p < 0.05) vs. controls (3.92 ± 1.84 cm(2)/dyn/10(3)). Subclinical hyperthyroidism had a more marked effect (p < 0.05). LV dimensions and ejection fractions were similar before and after L-T4 withdrawal. The E'/A' was higher in euthyroid controls (1.34 ± 1.02) as compared to both subclinical hyperthyroidism (1.0 ± 0.14, p < 0.05) and overt hypothyroidism (1.13 ± 0.98, p < 0.05). Change of aortic stiffness correlated with change of free-thyroxine (fT4), vWF and fibrinogen levels in a positive manner.
  
  
  CONCLUSIONS
  Long-term thyrotropin-suppression therapy has continuous adverse effects on the arterial wall. The degree of TSH suppression in patients with DTC should be kept at the possible minimum, based on individually determined potential benefits and risks of treatment, especially in patients with cardiovascular co-morbidities.
authors.affiliation: Division of Endocrinology, Department of Medicine, Faculty of Medicine, University of Debrecen, P.O.B. 19, Debrecen, 4012, Hungary. annamaria.gazdag@gmail.com.
authors.forename: A
authors.initials: A
authors.lastname: Gazdag
authors.affiliation: Division of Endocrinology, Department of Medicine, Faculty of Medicine, University of Debrecen, P.O.B. 19, Debrecen, 4012, Hungary.
authors.forename: E V
authors.initials: EV
authors.lastname: Nagy
authors.affiliation: Division of Endocrinology, Department of Medicine, Faculty of Medicine, University of Debrecen, P.O.B. 19, Debrecen, 4012, Hungary.
authors.forename: A
authors.initials: A
authors.lastname: Erdei
authors.affiliation: Division of Endocrinology, Department of Medicine, Faculty of Medicine, University of Debrecen, P.O.B. 19, Debrecen, 4012, Hungary.
authors.forename: M
authors.initials: M
authors.lastname: Bodor
authors.affiliation: Division of Endocrinology, Department of Medicine, Faculty of Medicine, University of Debrecen, P.O.B. 19, Debrecen, 4012, Hungary.
authors.forename: E
authors.initials: E
authors.lastname: Berta
authors.affiliation: Division of Endocrinology, Department of Medicine, Faculty of Medicine, University of Debrecen, P.O.B. 19, Debrecen, 4012, Hungary.
authors.forename: Z
authors.initials: Z
authors.lastname: Szabó
authors.affiliation: Division of Endocrinology, Department of Medicine, Faculty of Medicine, University of Debrecen, P.O.B. 19, Debrecen, 4012, Hungary.
authors.forename: Z
authors.initials: Z
authors.lastname: Jenei
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D006980:Hyperthyroidism / Q000097:blood / Q000209:etiology; D007037:Hypothyroidism / Q000097:blood / Q000209:etiology; D007457:Iodine Radioisotopes / Q000008:administration & dosage / Q000009:adverse effects; D008875:Middle Aged; D013964:Thyroid Neoplasms / Q000097:blood* / Q000628:therapy*; D013965:Thyroidectomy / Q000009:adverse effects / Q000639:trends; D013972:Thyrotropin / Q000037:antagonists & inhibitors / Q000097:blood*; D013974:Thyroxine / Q000008:administration & dosage / Q000009:adverse effects; D059289:Vascular Stiffness / Q000187:drug effects / Q000502:physiology*; D016277:Ventricular Function, Left / Q000187:drug effects / Q000502:physiology*
chemical_list: D007457:Iodine Radioisotopes; D013972:Thyrotropin; D013974:Thyroxine
keywords: Aortic stiffness; Cardiovascular risk; Differentiated thyroid cancer; Subclinical hyperthyroidism