title: Fatigue and fatigue-related symptoms in patients treated for different causes of hypothyroidism.
abstract: OBJECTIVE
  Research on determinants of well-being in patients on thyroid hormone replacement therapy is warranted, as persistent fatigue-related complaints are common in this population. In this study, we evaluated the impact of different states of hypothyroidism on fatigue and fatigue-related symptoms. Furthermore, the relationship between fatigue and the TSH receptor (TSHR)-Asp727Glu polymorphism, a common genetic variant of the TSHR, was analyzed.
  
  
  METHODS
  A cross-sectional study was performed in 278 patients (140 patients treated for differentiated thyroid carcinoma (DTC) and 138 with autoimmune hypothyroidism (AIH)) genotyped for the TSHR-Asp727Glu polymorphism.
  
  
  METHODS
  The multidimensional fatigue inventory (MFI-20) was used to assess fatigue, with higher MFI-20 scores indicating more fatigue-related complaints. MFI-20 scores were related to disease status and Asp727Glu polymorphism status.
  
  
  RESULTS
  AIH patients scored significantly higher than DTC patients on all five MFI-20 subscales (P<0.001), independent of clinical and thyroid hormone parameters. The frequency of the TSHR-Glu727 allele was 7.2%. Heterozygous DTC patients had more favorable MFI-20 scores than wild-type DTC patients on four of five subscales. The modest effect of the TSHR-Asp727Glu polymorphism on fatigue was found in DTC patients only.
  
  
  CONCLUSIONS
  AIH patients had significantly higher levels of fatigue compared with DTC patients, which could not be attributed to clinical or thyroid hormone parameters. The modest effect of the TSHR-Asp727Glu polymorphism on fatigue in DTC patients should be confirmed in other cohorts.
authors.affiliation: Department of Endocrinology, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands.
authors.forename: Marloes
authors.initials: M
authors.lastname: Louwerens
authors.forename: Bente C
authors.initials: BC
authors.lastname: Appelhof
authors.forename: Herman
authors.initials: H
authors.lastname: Verloop
authors.forename: Marco
authors.initials: M
authors.lastname: Medici
authors.forename: Robin P
authors.initials: RP
authors.lastname: Peeters
authors.forename: Theo J
authors.initials: TJ
authors.lastname: Visser
authors.forename: Anita
authors.initials: A
authors.lastname: Boelen
authors.forename: Eric
authors.initials: E
authors.lastname: Fliers
authors.forename: Johannes W A
authors.initials: JW
authors.lastname: Smit
authors.forename: Olaf M
authors.initials: OM
authors.lastname: Dekkers
mesh_terms: D000328:Adult; D000483:Alleles; D003430:Cross-Sectional Studies; D005221:Fatigue / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology*; D005260:Female; D005838:Genotype; D006801:Humans; D007037:Hypothyroidism / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic / Q000235:genetics; D011989:Receptors, Thyrotropin / Q000235:genetics; D013964:Thyroid Neoplasms / Q000378:metabolism / Q000503:physiopathology
chemical_list: D011989:Receptors, Thyrotropin