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Updated: Jan 23, 2026

Human Circadian Phenotyping and Diurnal Performance Testing in the Real World
Published on: April 7, 2020
Diurnal Cortisol Variation According to High-Risk Occupational Specialty Within Police: Comparisons Between
Kyle Planche1, Jennifer F Chan, Paula M Di Nota
1Department of Psychology, University of Toronto Mississauga, Mississauga, Ontario, Canada (Planche, Chan, Boychuk, Dr Andersen, Dr Di Nota, Dr Beston), and Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada (Dr Collins).
Objective:
The aim of this study was to compare diurnal salivary cortisol among high-risk occupational police specialties and the general population (n = 18,698).
Methods:
Tactical and frontline officers provided salivary cortisol samples for 2 days (four times: wake, 30 minutes, 11 hours, and 17 hours post-awakening) and were compared with a general population sample of group field studies utilizing similar methodology. Samples were analyzed for free cortisol concentrations (nmol/L) using chemiluminescence immunoassay.
Results:
Repeated-measures mixed-model analysis of variance (ANOVA) revealed significantly greater salivary diurnal cortisol among tactical than frontline officers. Furthermore, both tactical and frontline officers had higher cortisol levels on average at all time points than the general population sample.
Conclusion:
Results suggest that diurnal cortisol response may be associated with level of risk exposure in hazardous occupational subspecialties within policing compared with the general population.
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