Hair cortisol as a biomarker of stress among a first nation in Canada.
BACKGROUND
Cortisol level in hair is increasingly being used as a biomarker of chronic stress. Members of First Nation communities in Canada are experiencing stress related to a higher incidence of chronic diseases, socioeconomic factors, the state of their environment, and cultural oppression. This study aimed to investigate hair cortisol as a biomarker of stress in this population.


METHODS
Hair samples were collected from the posterior vertex of 55 Walpole Island First Nation (WIFN) volunteers and compared with white volunteers living in and around London, ON, Canada. An enzyme-linked immunosorbent assay technique was used to measure cortisol content in 1 cm of hair, considered to represent 1 month of growth. In parallel, the Perceived Stress Scale (PSS), which measures short-term stress, was also completed.


RESULTS
Median hair cortisol level (range) in WIFN volunteers was 177 (93-273) ng/g, significantly higher than the median hair cortisol in the healthy white controls of 116 (26-204) ng/g (P < 0.0001, Mann-Whitney U test). Hair cortisol correlated positively with gender, smoking status, and self-reported diabetes. Unlike hair cortisol, the Perceived Stress Scale did not differentiate between the First Nation and control population.


CONCLUSIONS
The increased hair cortisol concentrations among WIFN volunteers compared with volunteers from a non-First Nation community suggests higher levels of chronic stress. The causes for this apparent increased stress are likely due to factors such as socioeconomic and poorer health and are worthy of further evaluation. The results highlight the difference between acute stress measured for short periods of time compared with chronic stress, measured by hair analysis.
*Ecosystem Health Research Program, †Department of Pathology, ‡Ivey Chair in Molecular Toxicology, §Department of Physiology and Pharmacology, and ¶Department of Anthropology, Western University, Canada; ‖Walpole Island First Nation Heritage Centre and **Health Centre, Ontario, Canada; ††Division of Endocrinology, ‡‡Department of Pediatrics, and §§Department of Medicine, Western University, Canada; ¶¶Motherisk Program and ‖‖Division of Clinical Pharmacology, Hospital for Sick Children, University of Toronto, Canada.
Phaedra
P
Henley
Zahra
Z
Jahedmotlagh
Steven
S
Thomson
Julie
J
Hill
Regna
R
Darnell
Dean
D
Jacobs
Joyce
J
Johnson
Naomi C
NC
Williams
Rosemary M
RM
Williams
Stan
S
Van Uum
John R
JR
Bend
Gideon
G
Koren
D015415:Biomarkers / Q000737:chemistry* / Q000378:metabolism*; D002170:Canada; D002908:Chronic Disease; D005260:Female; D006197:Hair / Q000737:chemistry* / Q000378:metabolism*; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism*; D008297:Male
D015415:Biomarkers; D006854:Hydrocortisone