Multiple positive outcomes of a later school starting time for adolescents

Author(s)

de Araujo, Laura Bruna Gomes ; Bianchin, Sandieli ; Pedrazzoli, Mario ; Louzada, Fernando M. ; Beijamini, Felipe

• Document type: Journal article
• Source: SLEEP HEALTH; v. 8, n. 5, p. 7-pg., 2022-10-01.

Abstract

Objective: We tested the effect of later school start time (LSST) by 1 hour during 1 week on sleep, sleepiness, and mood profile using within-subject design. Design: A within-subject 3-weeks-long interventional study. A baseline week with school starting at 7:30 AM (week A), followed by an intervention week with school starting at 8:30 AM (week B), and a recovery week with school start time back to 7:30 AM (week C). Mixed model for repeated measures analysis was applied to test for the LSST effect between weeks. Setting: A private high school with high level of socioeconomic status. Participants: Forty-eight adolescents from 3 different high school years. Measurements: Participants were invited to wear actigraphs continuously during the 3 experimental weeks. Somnolence was obtained every school day twice, at arrival and before departure of school. Sleep quality and mood profile were evaluated by standard measures by the end of each school week, resulting in 3 repeated measures for each variable. Results: Thirty-eight adolescents completed the study. Adolescents woke up later during week B (7:42 +/- 00:30) in comparison to weeks A (6:54 +/- 00:12) and C (6:46 +/- 00:15) (p < .001), with no significant change on sleep onset between weeks (p = .657), resulting in a longer sleep duration in week B (p < .001). Significant improvements on sleepiness and mood profile were also reported during week B. Conclusions: Starting school later was effective in improving multiple aspects from sleep patterns, subjective sleepiness, and mood profile. (c) 2022 National Sleep Foundation. Published by Elsevier Inc. All rights reserved. (AU)

• FAPESP's process: 11/05804-5 - Phenotypic characterization of circadian rhythms in different genotype individuals for clock gene polymorphisms in different regions in Brazil: an emphasis on the effect of the gene PER3 and latitude
• Grantee: Mario Pedrazzoli Neto
• Support Opportunities: Regular Research Grants