title: Enhanced cortisol increase upon awakening is associated with greater pain ratings but not salivary cortisol or soluble tumor necrosis factor-α receptor II responses to acute pain.
abstract: OBJECTIVE
  The cortisol awakening response (CAR) is related to psychosocial factors and health in potentially significant ways, suggesting that it may be a distinctive marker of hypothalamic-pituitary-adrenal axis function and dysfunction. This study sought to expand upon previous work that examined the association between CAR and ratings of laboratory-evoked acute pain stimulation. In addition to evoked pain ratings, this study also tested whether CAR was prospectively related with salivary cortisol and soluble tumor necrosis factor-α receptor II responses to acute pain stimulation.
  
  
  METHODS
  This study included 36 healthy, pain-free volunteers of both sexes recruited through posted study flyers. Prior to completion of laboratory pain testing, salivary cortisol samples were obtained at home over the course of a single morning according to the following time frame: upon awakening, and 15, 30, and 60 minute after awakening. After collection of saliva, study participants brought their home saliva samples to the laboratory for assay and subsequently completed acute experimental pain testing procedures.
  
  
  RESULTS
  Cluster analysis of CAR revealed two distinct groups with similar patterns of cortisol response to awakening; increased and flattened. Relative to flattened CAR, increased CAR was associated with greater ratings of pain intensity and unpleasantness. Salivary cortisol was significantly increased and soluble tumor necrosis factor-α receptor II significantly decreased after pain testing, but neither of these responses differed as a function of increased versus flattened CAR.
  
  
  CONCLUSIONS
  CAR may be a marker for stress sensitivity and/or the anticipation of impending stress, which could explain why the increased CAR cohort reported greater acute pain ratings.
authors: University of Florida, Comprehensive Center for Pain Research, Gainesville, FL 32610, USA. bgoodin1@ufl.edu
authors: Burel R
authors: BR
authors: Goodin
authors: Noel B
authors: NB
authors: Quinn
authors: Christopher D
authors: CD
authors: King
authors: Gayle G
authors: GG
authors: Page
authors: Jennifer A
authors: JA
authors: Haythornthwaite
authors: Robert R
authors: RR
authors: Edwards
authors: Laura M
authors: LM
authors: Stapleton
authors: Lynanne
authors: L
authors: McGuire
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000502:physiology; D003080:Cold Temperature / Q000009:adverse effects; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism*; D008297:Male; D010146:Pain / Q000209:etiology / Q000378:metabolism* / Q000523:psychology; D010147:Pain Measurement; D010912:Pituitary-Adrenal Function Tests / Q000379:methods*; D011312:Pressure / Q000009:adverse effects; D012463:Saliva / Q000378:metabolism*; D057566:Self Report; D047992:TNF Receptor-Associated Factor 2 / Q000378:metabolism*; D014851:Wakefulness / Q000502:physiology*; D055815:Young Adult
chemical_list: D047992:TNF Receptor-Associated Factor 2; D006854:Hydrocortisone