Is there an association between work stress and diurnal cortisol patterns? Findings from the whitehall II study

Abstract

Objective: The evidence on whether there is work stress related dysregulation of the hypothalamic-pituitary-adrenal axis is equivocal. This study assessed the relation between work stress and diurnal cortisol rhythm in a large-scale occupational cohort, the Whitehall II study. Methods: Work stress was assessed in two ways, using the job-demand-control (JDC) and the effort-reward-imbalance (ERI) models. Salivary cortisol samples were collected six times over a normal day in 2002-2004. The cortisol awakening response (CAR) and diurnal cortisol decline (slope) were calculated. Results: In this large occupational cohort (N = 2,126, mean age 57.1), modest differences in cortisol patterns were found for ERI models only, showing lower reward (β = 20.001, P-value = 0.04) and higher ERI (β = 0.002, P-value = 0.05) were related to a flatter slope in cortisol across the day. Meanwhile, moderate gender interactions were observed regarding CAR and JDC model. Conclusions: We conclude that the associations of work stress with cortisol are modest, with associations apparent for ERI model rather than JDC model. © 2013 Liao et al.