title: Momentary relationship between cortisol secretion and symptoms in patients with fibromyalgia.
abstract: OBJECTIVE
  To compare the momentary association between salivary cortisol levels and pain, fatigue, and stress symptoms in patients with fibromyalgia (FM), and to compare diurnal cycles of cortisol secretion in patients with FM and healthy control subjects in a naturalistic environment.
  
  
  METHODS
  Twenty-eight patients with FM and 27 healthy control subjects completed assessments on salivary cortisol levels and pain, fatigue, and stress symptoms, 5 times a day for 2 consecutive days, while engaging in usual daily activities. Only those participants who adhered to the protocol (assessed via activity monitor) were included in the final analyses.
  
  
  RESULTS
  Twenty FM patients and 16 healthy control subjects adhered to the protocol. There were no significant differences in cortisol levels or diurnal cortisol variation between FM patients and healthy controls. Among women with FM, a strong relationship between cortisol level and current pain symptoms was observed at the waking time point (t = 3.35, P = 0.008) and 1 hour after waking (t = 2.97, P = 0.011), but not at the later 3 time points. This association was not due to differences in age, number of symptoms of depression, or self-reported history of physical or sexual abuse. Cortisol levels alone explained 38% and 14% of the variation in pain at the waking and 1 hour time points, respectively. No relationship was observed between cortisol level and fatigue or stress symptoms at any of the 5 time points.
  
  
  CONCLUSIONS
  Among women with FM, pain symptoms early in the day are associated with variations in function of the hypothalamic-pituitary-adrenal axis.
authors.affiliation: Chronic Pain and Fatigue Research Center, University of Michigan Medical Center, 24 Frank Lloyd Wright Drive, PO Box 385, Ann Arbor, MI 48106, USA. samclean@umich.edu
authors.forename: Samuel A
authors.initials: SA
authors.lastname: McLean
authors.forename: David A
authors.initials: DA
authors.lastname: Williams
authors.forename: Richard E
authors.initials: RE
authors.lastname: Harris
authors.forename: Willem J
authors.initials: WJ
authors.lastname: Kop
authors.forename: Kimberly H
authors.initials: KH
authors.lastname: Groner
authors.forename: Kirsten
authors.initials: K
authors.lastname: Ambrose
authors.forename: Angela K
authors.initials: AK
authors.lastname: Lyden
authors.forename: Richard H
authors.initials: RH
authors.lastname: Gracely
authors.forename: Leslie J
authors.initials: LJ
authors.lastname: Crofford
authors.forename: Michael E
authors.initials: ME
authors.lastname: Geisser
authors.forename: Ananda
authors.initials: A
authors.lastname: Sen
authors.forename: Pinaki
authors.initials: P
authors.lastname: Biswas
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Clauw
mesh_terms: D000328:Adult; D002940:Circadian Rhythm; D005221:Fatigue / Q000209:etiology / Q000378:metabolism* / Q000503:physiopathology; D005260:Female; D005356:Fibromyalgia / Q000150:complications / Q000378:metabolism* / Q000503:physiopathology; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis / Q000378:metabolism*; D007030:Hypothalamo-Hypophyseal System; D008297:Male; D010146:Pain / Q000209:etiology / Q000378:metabolism* / Q000503:physiopathology; D010913:Pituitary-Adrenal System; D012463:Saliva / Q000737:chemistry / Q000378:metabolism*; D013315:Stress, Psychological / Q000209:etiology / Q000378:metabolism* / Q000503:physiopathology
chemical_list: D006854:Hydrocortisone