There is little epidemiological evidence linking subjective stress to objective etiologic indicators. To clarify an association between work-related stress and autonomic nervous function, we examined call center employees (167 males and 371 females) undergoing electrocardiography (ECG) at the time of annual health checkups. The questionnaire was composed of the Brief Job Stress Questionnaire based on the demand-control-support model and the Social Readjustment Rating Scale including detailed contents of home stress. The Bazett's corrected QT (QTc) interval, QT index, and heart rate were obtained from the ECG data. The male employees showed significantly higher scores of job demand, job control, and supervisor support than the female ones. In the male employees, QT index indicating the extent of autonomic imbalance and heart rate were associated with high score of supervisor support and low score of coworker support (P < 0.05), but no significant relationships were seen between QTc interval and either job strain (i.e., job demand and job control) or home stress. By contrast, the female employees showed no significant links between any autonomic indicators and either work-related stress or home stress. These data suggest that work-related stress affected QT index in male employees suffering specific occupational stressors such as emotional abuse from unsatisfied customers. Specifically, supports from supervisors and coworkers were paradoxically associated with QT index, implying that supervisors may have failed to effectively support such male employees. Also, autonomic nervous function in male employees appears to be more vulnerable to work-related stress than that in female ones.Keywords: autonomic nervous function; call center employees; demand-control-support model; electrocardiography; subjective job stress Tohoku J. Exp. Med., 2017 December, 243 (4), 321-328. © 2017 Tohoku University Medical Press
IntroductionWith regard to the epidemiological evidence linking work-related stress to cardiovascular disease, the stress and cardiovascular disease are not directly tied but mediated by a certain etiologic mechanism. However, there is less research on the etiological pathways of the disease causation (Schnall et al. 1994). Collins et al. (2005) examined electrocardiographic QT intervals for 36 healthy men wearing 48-h Holter-monitor, and one mechanism suggested by them was the disturbed cardiovascular regulatory pattern associated with job strain in a pathogenic manner. In this case, it may not be easy to examine a large number of workers with 48-h monitor. Another mechanism was concerning autonomic imbalance induced by home stress (Maeda et al. 2015), but not work-related stress. For the earlier prevention of work-related cardiovascular events and a better understanding of the pathophysiology, it is important to investigate the association between workrelated stress and autonomic outcomes by using simpler tools.As a measure of work-related stress, the job demandcontrol-support (DCS) model with three dimensions (i...