Short or Irregular Sleep Duration in Early Childhood Increases Risk of Injury for Primary School-Age Children: A Nationwide Longitudinal Birth Cohort in Japan.

Takafumi Obara,Atsunori Nakao,Naomi Matsumoto,Takashi Yorifuji,Kohei Tsukahara,Hirotsugu Yamamoto,Hiromichi Naito

doi:10.3390/ijerph18189512

Takafumi Obara, Atsunori Nakao + Show 5 more

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https://doi.org/10.3390/ijerph18189512

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Abstract

The aim of this study was to investigate the longitudinal relationship between shorter or irregular sleep duration (SD) in early childhood and increased risk of injury at primary school age using data from a nationwide survey in Japan. We categorized SD into seven groups: 6 h, 7 h, 8 h, 9 hrs, 10 or 11 h, >12 h, and irregular, based on questionnaire responses collected at 5.5 years old. The relationship between SD and incidence of injury at 5.5–nine years of age is shown. In addition, we completed a stratified analysis on children with or without problematic behavior at eight years old. We included 32,044 children, of which 6369 were classified as having an injury and 25,675 as not having an injury. Logistic regression model showed that shorter or irregular SD categories were associated with an increased adjusted odds ratio (aOR) for injuries (6 h: aOR 1.40, 95% confidence interval (CI) 1.19–1.66, 7 h: aOR 1.10, 95% CI, 0.98–1.23, 8 h: aOR 1.13, 95% CI, 1.02–1.26, irregular: aOR 1.26, 95% CI 1.10–1.43). The same tendency was observed with shorter or irregular SD in subgroups with or without behavioral problems. Shorter or irregular sleep habits during early childhood are associated with injury during primary school age.

Highlights

Short or irregular sleep causes decreased activity of the prefrontal cortex and inhibits concentration and behavioral and emotional control, leading to hyperactivity, depression, and poor communication [1,2]
The present study demonstrates that shorter or irregular sleep duration (SD) in early childhood was closely associated with a higher risk of injury at school age using data from a nationwide
Our results indicate that the whole living environment, including appropriate sleep habits in early childhood, may have significant implications for child health and public health

Summary

Introduction

Short or irregular sleep causes decreased activity of the prefrontal cortex and inhibits concentration and behavioral and emotional control, leading to hyperactivity, depression, and poor communication [1,2]. Insufficient sleep or bedtime delay in adolescents and children is associated with a higher risk of poor academic performance due to early memory and cognitive decline [3,4,5]. Multiple cohort studies demonstrate that shorter sleep duration (SD) is associated with a higher risk of overweight/obesity and hypertension, as well as migraine and tension-type headaches in children and adolescents [6,7,8,9]. Previous studies have shown that insufficient/irregular sleep influences many factors, including mental and physical condition, life, and behavioral problems in children and adolescents [10,11,12]. The relationship between short or irregular SD in childhood and risk of injury has not been fully elucidated due to various confounding factors involved in studies on injury in children and the limited sample sizes of single-center, cross-sectional studies [10]

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