Association of active and passive smoking with sleep disturbances and short sleep duration among Japanese working population

Background: The relationship between passive smoking and sleep is uncertain. Purpose: To examine the association of passive/active smoking with sleep disturbances. Method: 732 women and 1,896 men, working in a suburb of Tokyo, were surveyed using a self-administered questionnaire. Information on smoking, passive smoking exposure, and sleep was elicited. Exposure levels to passive smoking were assessed separately at work and at home as no, occasional, or regular exposure. Risk of sleep disturbances according to smoking status was estimated using logistic regression with odds ratios (OR) and 95% confidence intervals (CIs) as measures of association. Results: Compared to never smokers, odds of difficulty awakening in the morning (DAM) in current smokers were significantly higher,for women (OR 1.95) and men (OR 1.50), while increased difficulty initiating sleep (OR 1.88) and decreased early morning awakening (OR 0.31) were found only in women. Never smoking men occasionally exposed to passive smoking at work but not at home had increased odds (OR 1.81) of short sleep duration (SSD, < 6 h) than unexposed counterparts. Conclusions: The analyses suggest that exposure to passive smoking at work is associated with SSD in men, while current smoking relates to various subtypes of sleep disturbances in both sexes.