Longitudinal study on sleep and its problem through preschool and elementary school period

在日本的幼儿园里，午睡已经成为一种惯例。在之前的一项研究中，我们发现常规的午睡有延迟后续夜间睡眠开始的效果。与没有固定午睡时间表的幼儿园儿童相比，幼儿园儿童的“入睡困难”、“熬夜”的频率更高、“睡眠不足”的情况更少、“起床情绪更差”、“不愿上学”的情况也更少。本研究旨在探讨学龄前上幼儿园的儿童在进入小学后，其睡眠模式是否持续。采用问卷调查的方法，对各年级1 ~ 5年级幼儿的睡眠模式进行了调查。调查显示，在幼儿期（即一至四年级）的学童中，尽管午睡时间已经停止，但睡眠时间延迟和夜间睡眠时间短的睡眠模式仍然存在。然而，“经常熬夜”和“起床时心情不好”的症状严重程度在幼儿园和幼儿园前的孩子之间没有区别。这些结果表明，学龄前儿童的睡眠模式对其后续学龄期睡眠模式的发展有显著影响。

Afternoon nap is being conducted as a routine at Japanese nursery schools. In a previous study, we found a routine afternoon nap has the effect of delaying the onset of the subsequent nighttime sleep. Nursery school children also reported having more 'difficulty to fall asleep,' more frequent 'staying-up at late night,' less 'not getting enough sleep,' worse 'mood at rising,' and more 'unwillingness to go to their school' compared with kindergartners who have no routine nap schedule. This study investigated whether the sleeping pattern of children who attended nursery schools during preschool age period persists after they entered elementary schools. Sleeping pattern was investigated by a questionnaire with ex-kindergartens and ex-nursery school children through the 1st to 5th grade year by year. Survey revealed that sleeping pattern of delayed sleep onset and short nighttime sleep persisted during younger age grades (i.e., the 1st to 4th) of elementary school in ex-nursery school children, in spite that the nap schedule had already been discontinued. However the severity of the symptoms 'frequent staying-up at late night' and 'bad mood at rising' were not different between ex-kindergartners and ex-nursery school children. These results suggest that sleep pattern of preschool age has significant effect on the development of sleep pattern in the subsequent school ages.