title: Attenuated morning salivary cortisol concentrations in a population-based study of persons with chronic fatigue syndrome and well controls.
abstract: BACKGROUND
  A substantial body of research on the pathophysiology of chronic fatigue syndrome (CFS) has focused on hypothalamic-pituitary-adrenal axis dysregulation. The cortisol awakening response has received particular attention as a marker of hypothalamic-pituitary-adrenal axis dysregulation.
  
  
  OBJECTIVE
  The objective of the current study was to evaluate morning salivary cortisol profiles in persons with CFS and well controls identified from the general population.
  
  
  METHODS
  We conducted a case-control study at an outpatient research clinic. CASES AND OTHER PARTICIPANTS: We screened a sample of 19,381 residents of Georgia and identified those with CFS and a matched sample of well controls. Seventy-five medication-free CFS cases and 110 medication-free well controls provided complete sets of saliva samples.
  
  
  METHODS
  We assessed free cortisol concentrations in saliva collected on a regular workday immediately upon awakening and 30 and 60 min after awakening.
  
  
  RESULTS
  There was a significant interaction effect, indicating different profiles of cortisol concentrations over time between groups, with the CFS group showing an attenuated morning cortisol profile. Notably, we observed a sex difference in this effect. Women with CFS exhibited significantly attenuated morning cortisol profiles compared with well women. In contrast, cortisol profiles were similar in men with CFS and male controls.
  
  
  CONCLUSIONS
  CFS was associated with an attenuated morning cortisol response, but the effect was limited to women. Our results suggest that a sex difference in hypocortisolism may contribute to increased risk of CFS in women.
authors.affiliation: Chronic Viral Diseases Branch, Coordinating Center for Infectious Diseases, Centers for Disease Control and Prevention, Mail Stop A-15, Atlanta, Georgia 30333, USA.
authors.forename: Urs M
authors.initials: UM
authors.lastname: Nater
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Maloney
authors.forename: Roumiana S
authors.initials: RS
authors.lastname: Boneva
authors.forename: Brian M
authors.initials: BM
authors.lastname: Gurbaxani
authors.forename: Jin-Mann
authors.initials: JM
authors.lastname: Lin
authors.forename: James F
authors.initials: JF
authors.lastname: Jones
authors.forename: William C
authors.initials: WC
authors.lastname: Reeves
authors.forename: Christine
authors.initials: C
authors.lastname: Heim
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D015673:Fatigue Syndrome, Chronic / Q000378:metabolism*; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D012463:Saliva / Q000737:chemistry*; D012727:Sex Characteristics
chemical_list: D006854:Hydrocortisone