Association between sleep-wake schedules and myopia among Chinese school-aged children and adolescents: a cross-sectional study

BACKGROUND: This study aimed to investigate the relationship between sleep-wake schedules and self-reported myopia in the pediatric population. METHODS: In this cross-sectional study in 2019, school-aged children and adolescents in the Baoan District of Shenzhen City were sampled using a stratified cluster sampling approach. Sleep-wake schedules of children were determined by a self-administered questionnaire. The age that participants first reported using myopia correction glasses or contact lenses was used to identify those with myopia. Pearson χ(2) test was used to examine differences in myopia prevalence among participants with different characteristics. Multivariate logistic regression, adjusted for potential confounding variables, was applied to examine the relationship between sleep-wake schedule and risk of self-reported myopia, and a stratification analysis by school grade was also performed. RESULTS: A total of 30,188 students were recruited. In this study, the overall prevalence of myopia was 49.8%, with prevalence rates of 25.6%, 62.4%, and 75.7% for primary, junior high, and senior high school students, respectively. Students with irregular sleep-wake times reported a higher prevalence of myopia than those with regular sleep-wake times. Nighttime sleep duration of < 7 hours/day (h/d) (OR = 1.27, 95%CI: 1.17–1.38), no daytime nap (OR = 1.10, 95%CI: 1.03–1.18), irregular weekday bedtime (OR = 1.11, 95%CI: 1.05–1.17), irregular weekday wake time (OR = 1.21, 95%CI: 1.12–1.30), weekend bedtime delayed > = 1 h/d (OR = 1.20, 95%CI: 1.11–1.29, P < 0.001), weekend wake time delayed > = 1 h/d (OR = 1.11, 95%CI: 1.03–1.19), irregular sleep-wake time on weekdays (OR = 1.13, 95%CI: 1.07–1.19), and social jetlag > = 1 h (OR = 1.08, 95%CI: 1.03–1.14) were likely to be associated with increased risks of self-reported myopia after adjusting age, sex, grade, parental education level, family income, parental myopia, academic record, and academic workload. When stratified by school grade, we observed that nighttime sleep duration < 7 h/d, no daytime naps, and irregular sleep-wake time on weekdays were significantly associated with self-reported myopia in primary school students. CONCLUSION: Insufficient sleep and irregular sleep-wake schedules can increase the risk of self-reported myopia in children and adolescents.