Workload and morning salivary cortisol in women

Abstract

Previous studies have shown a link between work-related stress and the morning level of the stress hormone cortisol. The level of cortisol in the circulation is regulated by the hypothalamic-pituitary-adrenocortical (HPA) axis, dysregulation of which plays an important role in a number of disorders including hypertension, immune deficiency and being overweight (the 'metabolic syndrome'). The aim of this study was to investigate the association between workload and morning cortisol in women. Saliva samples were obtained four times during the first 45 min after awakening (0, 15, 30 and 45 min) in the morning on a work-free day from more than 200 women in full-time work who were born in 1955 and representing a normal population of a small city in Sweden. The amount of paid and unpaid work was reported in a questionnaire. Significant positive correlations were found between the amount of overtime at work and each of the four measurements of morning salivary cortisol (varying from r = .29 to r = .38, p < .01). In addition, participants with excessive overtime (more than 10 h/week) had on average about twice as high ( p < .01) morning cortisol levels as women with moderate overtime (< 10 h/week) or normal working hours (35-40 h/week). The results are consistent with earlier findings and suggest that morning cortisol is a sensitive indicator of work overload in women. However, additional research is necessary in order to reveal the specific pathways linking work-related stress to elevated morning cortisol.