Job stress and sleep disorders: findings from the Helsinki Heart Study

Sleep disorders and daytime fatigue are common health problems in middle‐aged and elderly populations, and they vary greatly between occupational groups. There is widespread evidence that working hours and job stress may explain these differences. In this study the relationship of job demands and job control to sleep disorders was investigated. The subjects were 3079 middle‐aged working men. The data were collected with a questionnaire including scales on sleep quality, job stress and lifestyle. The main effects of job demands and job control on insomnia, sleep deprivation and daytime fatigue were highly significant. Some interaction effects of the stressors were also noted. Lifestyle factors were not found as significant mediators or confounders of the effects. The associations between the stressors and sleep disorders were greater in the daytime workers than in the shift workers. The main conclusion is that job stressors have a direct relationship to sleep disorders, independent of working hours and lifestyle. Copyright © 2000 John Wiley & Sons, Ltd.