Associations Between Occupational Status, Support at Work, and Salivary Cortisol Levels

OBJECTIVE The present study investigated associations between occupation, job stress, and salivary cortisol levels after psychological tasks. METHODS We examined 766 (273 men and 493 women) healthy employed Japanese participants aged 21 to 68 years (mean age = 46.4 years, standard deviation = 8.5) with three types of occupation: manager, teacher, and general worker. The Brief Job Stress Questionnaire was used to evaluate participants' job stress levels, including job demand, job control, support from supervisors, and support from coworkers. Salivary cortisol levels were measured at pre-session, post-stressful tasks, and post-relaxation. All samples were assayed using an enzyme-linked immunosorbent assay test. Natural log transformation was applied before statistical analyses. A multiple regression analysis and a repeated measures analysis of covariance were conducted to test associations between occupation and salivary cortisol levels, adjusting for confounding factors. Statistical analyses were conducted separately for men and women. RESULTS Among both men and women, general workers had higher cortisol levels than managers throughout the experimental session (men 0.6 μg/dL and 0.4 μg/dL, respectively; women 0.5 μg/dL and 0.4 μg/dL, respectively). Job control was positively associated with cortisol levels measured in all sessions, after adjusting for confounding factors (standardized beta 0.15, 0.21, and 0.18 for pre-session, post-stressful-tasks, and post-relaxation, respectively, all p < 0.05). Men with low support from coworkers had higher cortisol levels than those with high support through the sessions (0.6 μg/dL and 0.4 μg/dL, respectively). CONCLUSION Socioeconomic disparity according to occupational status was related to cortisol levels in Japanese workers. Support from coworkers may be effective for reducing cortisol secretion in men.