Association of hostility with sleep duration and sleep disturbances in an employee population

Background: Sleep disturbances are common among the general population, and hostile persons have been proposed to be at greater risk of several serious health problems and diseases. Purpose: This study examined the relationships between hostility, sleep disturbances, and sleep duration in a large non-clinical sample of 5,433 employees working in 12 Finnish hospitals. Method: Data were collected by questionnaire surveys in 1998 and 2000. Results: Higher hostility was cross-sectionally associated with increased sleep disturbances but not with sleep duration after adjustment for gender, age, marital status, education, shift work, smoking, alcohol consumption, physical activity, body mass index, psychiatric morbidity, and somatic disease. A stratified analysis distinguishing individuals with stable hostility across the two measurements and those with transient hostility (>0.5 SD difference between measurements) replicated the association with increased sleep disturbance in both groups, but among those with transient hostility, there additionally was a cross-sectional association between higher hostility and shorter sleep duration. Conclusion: Our evidence suggests that hostility is an independent risk factor for sleep disturbances and that transient hostility may also predispose shorter sleep duration. However, the effect sizes for all these associations were small, suggesting limited clinical significance for our findings.