title: Cardiovascular responses to an acute psychological stressor are associated with the cortisol awakening response in individuals with chronic neck pain.
abstract: BACKGROUND
  Dysregulation of the hypothalamic-pituitary-adrenal axis (HPA-axis) is common in individuals who experience chronic psychological stress, as well as individuals with chronic pain. Changes in cortisol availability in the presence of a chronic stressor such as pain may influence the sympathetic-adrenal-medullary (SAM) system, which contributes to cardiovascular responses to stress and also exhibits altered responsiveness in the presence of pain. The purpose of this study was to investigate the relationship between HPA activity during the cortisol awakening response and cardiovascular reactivity during exposure to an acute psychological stressor in individuals with chronic neck pain.
  
  
  METHODS
  Area under the curve (AUC) of the salivary cortisol awakening response was assessed in 41 individuals with chronic neck pain aged 19-80 years (22 men, 23 women). Slopes representing the change in mean arterial pressure and heart rate during a baseline quiet sitting condition, a low stress condition with mental concentration, and a high stress condition combining mental concentration with social evaluative threat were calculated for each individual as an index of cardiovascular responsiveness to the acute stressor. Cardiovascular responses were regressed on cortisol awakening AUC and pain duration, adjusting for age and sex.
  
  
  RESULTS
  Greater mean arterial pressure (β = -0.33, p = 0.02) and heart rate responses (β = -0.41, p = 0.007) to the acute psychological stressor were associated with lower cortisol awakening responses after adjusting for age and sex. Individuals with a shorter duration of chronic pain also demonstrated a larger increase in mean arterial pressure during the laboratory stressor (β = -0.39, p = 0.01), but there was no relationship between pain duration and changes in heart rate (p = 0.25).
  
  
  CONCLUSIONS
  Individuals with a shorter duration of chronic neck pain who demonstrate heightened cardiovascular responsiveness to an acute psychological stressor also exhibit lower cortisol awakening response. These results are consistent with time-dependent adaptations across the two major stress systems in the presence of chronic pain.
authors: University of Colorado Denver, Rehabilitation Science Program, Department of Physical Medicine and Rehabilitation, Aurora, CO, USA.
authors: Bahar
authors: B
authors: Shahidi
authors: University of Colorado Denver, Department of Psychiatry, Aurora, CO, USA.
authors: Timothy
authors: T
authors: Sannes
authors: University of Colorado Denver, Department of Psychiatry, Aurora, CO, USA.
authors: Mark
authors: M
authors: Laudenslager
authors: University of Colorado Denver, Rehabilitation Science Program, Department of Physical Medicine and Rehabilitation, Aurora, CO, USA; San Diego State University, Physical Therapy Program, School of Exercise and Nutritional Sciences, San Diego, CA, USA. Electronic address: kmaluf@mail.sdsu.edu.
authors: Katrina S
authors: KS
authors: Maluf
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D001794:Blood Pressure / Q000502:physiology*; D002908:Chronic Disease; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D019547:Neck Pain / Q000150:complications*; D010147:Pain Measurement; D012463:Saliva / Q000378:metabolism; D013315:Stress, Psychological / Q000097:blood / Q000209:etiology*; D014851:Wakefulness / Q000502:physiology*; D055815:Young Adult
chemical_list: D006854:Hydrocortisone
keywords: Cardiovascular; Chronic pain; HPA; Stress