Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway.
Norwegian Competence Center for Sleep Disorders, Haukeland University Hospital, Bergen, Norway.
J Sleep Res. 2023 Aug;32(4):e13840. doi: 10.1111/jsr.13840. Epub 2023 Mar 2.
The present study explored the associations between school start time and sleep habits among older adolescents, and whether these associations depended on circadian preference. The sample comprised 4010 high school students aged 16-17 years who completed a web-based survey on habitual school start time, sleep, and health. The survey included the Munich ChronoType Questionnaire, and the short version of the Horne-Östberg Morningness-Eveningness Questionnaire. Students were categorised according to habitual school start time (before 08:00 hours, 08:00 hours, 08:15 hours, 08:30 hours or after 08:30 hours) and circadian preference (morning, intermediate or evening). Data were analysed using two-way analyses of variance (school start time × circadian preference) and linear regression analyses. Results showed an overall effect of school start time on school day sleep duration (main effect, p < 0.001), with the latest school starters having the longest, and the earliest school starters having the shortest sleep duration (7:03 hr versus 6:16 hr; Tukey HSD p < 0.001). Similarly, later school starters generally reported shorter social jetlag and later school day wake-up times than earlier starting students (both main effect p < 0.001). Circadian preference did not modify these associations (interaction effects p > 0.05). In the crude regression analysis, 15 min later school start was associated with 7.2 min more sleep (p < 0.001). School start time remained a significant predictor of school day sleep duration when adjusted for sex, parental educational level and circadian preference (p < 0.001). Results suggest that school start time is a significant predictor of school day sleep duration among adolescents.
本研究探讨了高中生的上学时间与睡眠习惯之间的关联，以及这些关联是否取决于昼夜节律偏好。样本包括 4010 名 16-17 岁的高中生，他们完成了一项关于习惯性上学时间、睡眠和健康的网络调查。该调查包括慕尼黑昼夜类型问卷和霍恩-奥斯特伯格早晨-傍晚型问卷的简短版本。学生根据习惯性上学时间（08:00 点之前、08:00 点、08:15 点、08:30 点或 08:30 点之后）和昼夜节律偏好（早晨型、中间型或傍晚型）进行分类。使用双向方差分析（上学时间×昼夜节律偏好）和线性回归分析对数据进行分析。结果显示，上学时间对上学日睡眠持续时间有总体影响（主效应，p<0.001），最晚上学的学生睡眠时间最长，最早上学的学生睡眠时间最短（7:03 小时对 6:16 小时；Tukey HSD p<0.001）。同样，较晚上学的学生通常报告社交时差较小，上学日醒来时间较晚（主效应 p<0.001）。昼夜节律偏好没有改变这些关联（交互效应 p>0.05）。在未经调整的回归分析中，上学时间每推迟 15 分钟，睡眠时间就会增加 7.2 分钟（p<0.001）。当调整性别、父母教育水平和昼夜节律偏好后，上学时间仍然是上学日睡眠持续时间的显著预测因素（p<0.001）。结果表明，上学时间是青少年上学日睡眠持续时间的重要预测因素。
