Abstract
BACKGROUND: To explore the complex effects of school-day sleep patterns on elevated blood pressure (EBP), with a particular focus on the role of compensatory sleep. METHODS: Utilizing propensity score matching, 15,612 children aged 7-12 years were obtained from the Chinese National Survey on Students' Constitution and Health in 2019. School-day wake-up and bedtimes were gathered by questionnaires, categorizing sleep midpoint into morning, intermediate, and evening phenotype and classifying sleep duration as "inadequate," "moderate," or "excessive." EBP was defined as systolic blood pressure (SBP) and/or diastolic blood pressure (DBP) at or above the 95th percentile for their respective sex, age, and height. The nonlinear relationships between sleep midpoint and sleep duration with EBP were explored by restricted cubic splines. Logistic regressions were utilized to assess the school-day sleep patterns, combining sleep midpoint and duration on EBP. Stratified analyses were conducted to examine the roles of compensatory sleep, and the population attribution fraction was calculated to describe the contributions of compensatory sleep to EBP related to school-day sleep patterns. RESULTS: 15,612 children aged 7-12 from 504 schools nationwide were included. An early sleep midpoint and short sleep duration significantly increase the odds of EBP, but the risks posed by late sleep midpoint and late bedtimes should not be overlooked either (P for non-linear < 0.05). Both morning-types (odds ratio, OR = 1.10, 95% CI = 1.02-1.18) and evening-types (OR = 1.11, 95% CI = 1.02-1.21), as well as inadequate sleep duration (< 9 h), exhibited positive associations with EBP. Even "morning larks" phenotype with sufficient sleep duration was associated with EBP. Compensatory sleep may influence the odds of EBP in sleep-deprived "morning larks" and "night owls." CONCLUSIONS: Prioritize the assurance of ≥ 9 h of sleep on schooldays, promote the adoption of an intermediate-phenotype, and discourage excessively early wake-up times. Compensatory sleep appears to modify the odds of EBP in sleep-deprived "morning larks" and "night owls."