title: Elevated content of cortisol in hair of patients with severe chronic pain: a novel biomarker for stress.
abstract: Hair analysis has been used to reflect long-term systemic exposure to exogenous drugs and toxins. Several studies have demonstrated the feasibility of measuring endogenous steroid hormones, e.g. cortisol, in hair. Recently, a study in macaques showed a significant increase in hair cortisol levels induced by stress. We explored whether hair cortisol levels may be used as a biomarker for long-term stress in humans. Patients with severe chronic pain, aged 18 years or older, receiving opioid treatment for at least one year were recruited. Controls were non-obese (body mass index, BMI < 30 mg/kg(2)) adults. The Perceived Stress Scale (PSS) questionnaire was used to assess perceived stress over the last 4 weeks. A hair sample was obtained from the vertex posterior. Cortisol was measured using an enzyme-linked immunosorbent assay. We included fifteen patients (nine females and six males) and 39 non-obese control subjects (20 females, 19 males). PSS scores (median and range) were significantly higher in chronic pain patients (24: 12-28) than in controls (12: 3-31)(P < 0.001). Hair cortisol contents (median and range) were significantly greater in chronic pain patients (83.1: 33.0-205 g/mg) than in controls (46.1: 27.2-200 pg/mg) (P < 0.01). We conclude that hair cortisol contents are increased in patients with major chronic stress. Measurement of cortisol levels in hair constitutes a novel biomarker of prolonged stress.
authors.affiliation: Division of Endocrinology and Metabolism, University of Western Ontario, Ontario, Canada. Stan.VanUum@sjhc.london.on.ca
authors.forename: S H M
authors.initials: SH
authors.lastname: Van Uum
authors.forename: B
authors.initials: B
authors.lastname: Sauvé
authors.forename: L A
authors.initials: LA
authors.lastname: Fraser
authors.forename: P
authors.initials: P
authors.lastname: Morley-Forster
authors.forename: T L
authors.initials: TL
authors.lastname: Paul
authors.forename: G
authors.initials: G
authors.lastname: Koren
mesh_terms: D000328:Adult; D000701:Analgesics, Opioid / Q000627:therapeutic use; D015415:Biomarkers / Q000032:analysis*; D002908:Chronic Disease; D005260:Female; D006197:Hair / Q000737:chemistry*; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000175:diagnosis* / Q000188:drug therapy; D013315:Stress, Psychological / Q000378:metabolism*
chemical_list: D000701:Analgesics, Opioid; D015415:Biomarkers; D006854:Hydrocortisone