Difference of sleep time and screen time in preschool children in rural and urban settings in natural living conditions in Japan.

Abstract

The amount of sleep for children has been decreasing in the past decades. Artificial light at night in home and community settings is linked with increased sleep disturbances. Recently, smartphone and tablet use has increased among children and in childcare settings. We investigated the neighborhood environment (urban vs. rural) affects sleep time, screen time usage, and melatonin and cortisol concentration in real living conditions of preschool children in Japan. In this study, 26 children aged 3-6 years from urban and rural areas in Japan were participated. We collected saliva samples for melatonin and cortisol for three times. A questionnaire was given to the parents of the children to assess smartphone and television usage, and sleep duration for two weeks. We found that television watching time was significantly longer in urban area than in rural area (181 ± 82 min/day in urban vs. 112 ± 80 min/day in rural). However, melatonin and cortisol concentrations and sleep time were not significantly different between the rural and the urban areas. These results show that urban preschool children may engage in more screen time behavior than their rural counterparts. Finally, these findings may suggest the need for education and quality improvement initiatives to promote a healthy balance between sleep and sedentary screen time in both communities.