title: Combined dexamethasone/corticotropin-releasing factor test in chronic fatigue syndrome.
abstract: BACKGROUND
  Studies of hypothalamic-pituitary-adrenal (HPA) axis function in chronic fatigue syndrome (CFS) point to hypofunction, although there are negative reports. Suggested mechanisms include a reduced hypothalamic or supra-hypothalamic stimulus to the HPA axis and enhanced sensitivity to the negative feedback of glucocorticoids. The aim of the current study was to investigate HPA axis function in CFS with the dexamethasone/corticotropin-releasing factor (Dex/CRF) test, in analogy with research in affective disorders.
  
  
  METHODS
  Thirty-four well-characterized female CFS patients and 25 healthy control subjects participated in the low-dose Dex/CRF test. Current major depressive episode was an exclusion criterion. History of early-life stress (ELS) was assessed with the Structured Trauma Interview.
  
  
  RESULTS
  Salivary cortisol responses after 0.5 mg Dex were lower in CFS patients than in controls (before 100 microg CRF, p=0.038; after 100 microg CRF, p=0.015). A secondary analysis revealed an influence of early-life stress and of oestrogen intake. After removal of the 10 participants who were taking an oral oestrogen, patients without a history of ELS showed lower cortisol responses than patients with ELS and controls (before CRF, p=0.005; after CRF, p=0.008).
  
  
  CONCLUSIONS
  CFS is globally associated with reduced cortisol responses in the combined low-dose Dex/CRF test, but this effect is only clearly present in CFS patients without a history of ELS. This study provides further support for an enhanced glucocorticoid negative feedback and/or a reduced central HPA axis drive in CFS. Furthermore, it demonstrates that ELS is an important variable to consider in CFS research.
authors.affiliation: Department of Psychiatry, Antwerp University Hospital, Edegem, Belgium.
authors.forename: F
authors.initials: F
authors.lastname: Van Den Eede
authors.forename: G
authors.initials: G
authors.lastname: Moorkens
authors.forename: W
authors.initials: W
authors.lastname: Hulstijn
authors.forename: B
authors.initials: B
authors.lastname: Van Houdenhove
authors.forename: P
authors.initials: P
authors.lastname: Cosyns
authors.forename: B G C
authors.initials: BG
authors.lastname: Sabbe
authors.forename: S J
authors.initials: SJ
authors.lastname: Claes
mesh_terms: D000302:Adrenal Cortex / Q000503:physiopathology; D000304:Adrenal Cortex Function Tests; D000328:Adult; D016022:Case-Control Studies; D003346:Corticotropin-Releasing Hormone / Q000494:pharmacology*; D003865:Major Depressive Disorder / Q000503:physiopathology; D003907:Dexamethasone / Q000494:pharmacology*; D015673:Fatigue Syndrome, Chronic / Q000503:physiopathology*; D005260:Female; D005938:Glucocorticoids / Q000494:pharmacology; D006728:Hormones / Q000494:pharmacology; D006801:Humans; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects / Q000503:physiopathology; D010913:Pituitary-Adrenal System / Q000187:drug effects / Q000503:physiopathology*; D012463:Saliva; D013315:Stress, Psychological