Related Experiment Video
Updated: Mar 22, 2026

Collecting Saliva and Measuring Salivary Cortisol and Alpha-amylase in Frail Community Residing Older Adults via Family Caregivers
Published on: December 18, 2013
Shiftwork and Diurnal Salivary Cortisol Patterns Among Police Officers
Luenda E Charles1, Desta Fekedulegn, Cecil M Burchfiel
1Biostatistics and Epidemiology Branch (Drs Charles, Fekedulegn, Burchfiel, Hartley, and Andrew); Department of Epidemiology and Environmental Health, School of Public Health and Health Professions, State University of New York at Buffalo (Dr Violanti); Toxicology and Molecular Biology Branch (Dr Miller), Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia.
Objective:
To investigate associations between shiftwork and diurnal salivary cortisol among 319 police officers (77.7% men).
Methods:
Information on shiftwork was obtained from the City of Buffalo, NY electronic payroll records. Saliva was collected using Salivettes at seven time points and analyzed for free cortisol concentrations (nmol/L) using a chemiluminescence immunoassay. Mean slopes and areas under the curve were compared across shift schedule using analysis of variance (ANOVA)/analysis of covariance (ANCOVA).
Results:
Officers working primarily on the night shift had a significantly shallower slope. Mean slope (nmol/L/minutes) of the cortisol curve varied significantly across shifts (day: -0.00332 ± 0.00017, afternoon: -0.00313 ± 0.00018, night: -0.00257 ± 0.0002); adjusted P = 0.023.
Conclusions:
Our results suggest that night shiftwork is a workplace factor that may alter the response of the hypothalamic-pituitary-adrenal (HPA) axis to the circadian cues responsible for the pattern of the diurnal cortisol curve.

