Work stress models and diurnal cortisol variations: The SALVEO study

Area of Science:

• Occupational Health Psychology
• Endocrinology
• Stress Research

Background:

• Workplace stress models, including Job Demand-Control (JDC), Job Demand-Control-Support (JDCS), and Effort-Reward Imbalance (ERI), are widely used to understand employee well-being.
• Diurnal cortisol variation is a key biomarker for physiological stress responses.
• Previous research has explored the relationship between work stress and cortisol, but findings regarding specific model components and interactions remain debated.

Purpose of the Study:

• To investigate the association between components, subscales, and interactions of the JDC, JDCS, and ERI work stress models and diurnal cortisol variation.
• To identify which specific work stress factors are most predictive of cortisol fluctuations throughout the day.

Main Methods:

• A study involving 401 Canadian day-shift workers from 34 workplaces.
• Data collection included questionnaires on psychological demands, decision latitude, social support, effort, reward, and overcommitment.
• Salivary cortisol was measured at multiple time points over two working days: upon waking, 30 minutes post-waking, 1400h, 1600h, and bedtime.

Main Results:

• Interactions within the JDC, JDCS, and ERI models were not significantly associated with diurnal cortisol variations.
• Increased psychological demands correlated with lower bedtime cortisol.
• Increased job recognition was linked to higher cortisol levels post-waking and at bedtime.
• Higher overcommitment was associated with increased awakening cortisol and decreased cortisol later in the day.
• Sex differences were observed, particularly in men, for psychological demands, total social support, and supervisor support.

Conclusions:

• Components and subscales of work stress models, rather than their theorized interactions, are more relevant for explaining diurnal cortisol variations.
• Psychological demands, job recognition, overcommitment, and social support are significant predictors of diurnal cortisol variation.
• The overall effect sizes of these work stress subscales on cortisol concentrations were weak, suggesting a complex interplay of factors influencing stress physiology.