Hair-Normalized Cortisol Waking Response as a Novel Biomarker of Hypothalamic-Pituitary-Adrenal Axis Activity following Acute Trauma: A Proof-of-Concept Study with Pilot Results

David M Walton; Joy C Macdermid; Evan Russell; Gideon Koren; Stan Van Uum

doi:10.1155/2013/876871

Hair-Normalized Cortisol Waking Response as a Novel Biomarker of Hypothalamic-Pituitary-Adrenal Axis Activity following Acute Trauma: A Proof-of-Concept Study with Pilot Results

Pain Res Treat. 2013:2013:876871. doi: 10.1155/2013/876871. Epub 2013 Dec 3.

Authors

David M Walton¹, Joy C Macdermid², Evan Russell³, Gideon Koren⁴, Stan Van Uum⁵

Affiliations

¹ School of Physical Therapy, Western University, London, ON, Canada N6G 1H1.
² School of Physical Therapy, McMaster University, Hamilton, ON, Canada L8S 1C7.
³ Department of Physiology and Pharmacology, Western University, London, ON, Canada N6A 5C1.
⁴ Department of Physiology and Pharmacology, Western University, London, ON, Canada N6A 5C1 ; Ivey Chair in Molecular Toxicology, Western University, London, ON, Canada N6A 5C1 ; Department of Pharmacology/Toxicology, Hospital for Sick Children, Toronto, ON, Canada M5G 1X8.
⁵ Department of Medicine, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada N6A 5C1.

Abstract

The mechanisms underlying the development of persistent posttraumatic pain and disability remain elusive. Recent evidence suggests that disordered stress-system pathway (hypothalamic-pituitary-adrenal axis) activity may be responsible for the genesis and maintenance of long-term sensory and emotional problems. However, confidence in current evidence is limited by the necessarily retrospective collection of data. Hair cortisol can serve as a calendar of HPA axis activity going back several months prior to injury. The purposes of this pilot study were to determine the feasibility of using hair cortisol and hair-normalized salivary cortisol as biomarkers of distress following traumatic injuries of whiplash or distal radius fracture. Ten subjects provided complete data within 3 weeks of injury. Hair cortisol, cortisol waking response (CWR), and mean daily cortisol (MDC) were captured at inception, as were self-report indicators of pain, disability, and pain catastrophizing. Pain and disability were also captured 3 months after injury. Results indicate that cortisol waking response may be a useful biomarker of current distress as measured using the pain catastrophizing scale, especially when normalized to 3-month hair cortisol (r = 0.77 raw, 0.93 normalized). Hair-normalized CWR may also have predictive capacity, correlating with 3-month self-reported disability at r = 0.70. While promising, the results must be viewed in light of the small sample.