2020 Volume 2020 Issue 89 Pages 12-21
Internationally, it is said that the “era of sleeping difficulty” has arrived, and for Japanese children, this is no exception. On the other hand, it is well-established that daytime light reception promotes phase advances in melatonin secretion. Thus, it is undeniable that the sleep situation and melatonin secretion patterns of schoolchildren may depend on whether the classroom seat where they spend a relatively long time during a school day is on the window side of the classroom. This study examined the relationship between classroom seat location and children's sleep situation and melatonin secretion patterns. Our subjects were 88 elementary school children (47 boys and 41 girls) from the 5th to 6th grades enrolled in public elementary schools in Tokyo; we analyzed the data of 73 (37 boys and 36 girls) with whom there was no data loss. The study was carried out on weekdays from September to October 2018. From the analysis, a 1.7-times difference in the average illuminance median was observed between seats that were on the window side and those on the corridor side (window side group: 362.2 lx, control group: 207.7 lx) In addition, the odds ratio of children with high melatonin (night to morning) was 10-times higher in the window side group than in the control group (OR＝10.179, 95％ CI＝1.492-69.455).
Based on our findings, we conclude that the sleep situation of children should be an important determinant in classroom seating.
