Work stress, socioeconomic status and neuroendocrine activation over the working day

Socioeconomic status (SES) differences in cardiovascular and metabolic disease risk may be mediated in part by differential activation of neuroendocrine pathways. We have previously found that salivary cortisol levels over the working day are greater in lower than higher SES men, but that cortisol output is greater in higher than lower SES women. This study investigated the role of work stress in generating these patterns, analysing cortisol output in relation to job demands and job control. Participants were 97 men and 84 woman from the Whitehall II cohort, London, UK, recruited from higher and lower grades of employment. Saliva samples were obtained on waking and 30 min later to assess the cortisol waking responses, and at two hourly intervals over a typical working day. Cortisol responses to waking were positively associated with high job demands, but this effect was attenuated by higher SES. In women but not men, cortisol levels over the remainder of the day were elevated in lower SES participants who experienced high job demands, but depressed in lower status women who reported low job demands. Job control did not influence cortisol responses to waking, but in men cortisol levels over the remainder of the day were inversely related to job control. These cortisol differences were independent of age, smoking status and time of waking up. Subjectively, the most stress was reported by higher SES individuals who experienced low job control. We conclude that work stress and SES are related differently to cortisol responses to waking and cortisol output over the day. Job control may partly mediate SES differences in cortisol in men, while job demands are more relevant for women. Analyses of psychobiological pathways must take account of variations in exposure to chronic stressors as well as differences in responsivity to stressors.