Effects of morning- and evening-shift work on the sleep, dietary intake, and psycho-physiological healthconditions of Japanese female workers

Abstract

Objectives: Occupational health research on shift work has been conducted for night-shift work exclusively. This study aimed to evaluate the impact of morning- and evening-shift works, which have been common among Japanese female shift workers except nurses, on their sleep and dietary patterns, fatigue and gastrointestinal complaints, and psychological well-being. We alsoconsidered the inter-variable relationships. Methods: A 4-day questionnaire survey was conducted for 36 daytime workers and 67weekly-rotating two-shift workers. Of the 67 shift workers, 34 worked in the morning-shift and 33in the evening-shift during the survey week. Results: Early awakening time was observed in the morning-shift workers, and this was relatedto sleep disturbance. Further, late awakening time was observed in the evening-shift workers, and this was related to skipping breakfast. Worsened quality of sleep triggered the feeling of fatigue, while skipping breakfast led to gastrointestinal complaints. These health complaints wererelated to the GHQ-28 score, which reflected relatively long-term somatic and psychological illbeing. Conclusions: The effects of shift work differed between the morning-shift and evening-shift workers. Based on the cross-sectional data, this study disclosed the plausible relationships among the behavioral and health variables of female shift workers.