Department of Education and Counselling Psychology, McGill University, Canada.
Department of Psychology, University of Montreal, Canada.
Sleep. 2023 Nov 8;46(11). doi: 10.1093/sleep/zsad127.
Pre- and early adolescence are believed to constitute periods of important age-related changes in sleep. However, much of the research on these presumed developmental changes has used cross-sectional data or subjective measures of sleep, limiting the quality of the evidence. In addition, little is known about the development of certain features of the sleep-wake cycle pertaining to regularity (e.g. weekend-weekday differences and intra-individual variability) or circadian rhythms (e.g. sleep midpoint).
This study examined the sleep trajectories of 128 typically developing youth (69 girls) from ages 8 to 12 years on four sleep characteristics: sleep onset, sleep offset, total sleep time (TST), and sleep midpoint. For each of these characteristics, actigraphy-derived estimates of typical (i.e. mean) sleep and sleep regularity were obtained at each time point. Multilevel growth curves were modeled.
Overall, the sleep-wake cycle significantly changed between 8 and 12 years. Mean sleep onset, offset and midpoint exhibited an ascending curvilinear growth pattern that shifted later with age, while mean TST decreased linearly. Weekend-weekday differences (social jetlag) for sleep offset and midpoint became more pronounced each year. Weekday TST was longer than weekend TST, though this difference became smaller over time. Finally, intra-individual variability increased over time for all sleep characteristics, with variability in TST ascending curvilinearly. Important between-person and sex differences were also observed.
This study reveals the marked changes that occur in the sleep of typically developing pre- and early adolescents. We discuss the potential implications of these trajectories.
人们认为，青春期前和青春期早期是与睡眠相关的重要年龄变化时期。然而，许多关于这些假定的发育变化的研究都使用了横断面数据或睡眠的主观测量方法，限制了证据的质量。此外，人们对与规律性（例如周末-工作日差异和个体内可变性）或昼夜节律（例如睡眠中点）相关的某些睡眠-觉醒周期特征的发展知之甚少。
本研究通过四项睡眠特征（入睡、醒来、总睡眠时间（TST）和睡眠中点），对 128 名正常发育的青少年（69 名女孩）从 8 岁到 12 岁的睡眠轨迹进行了研究。对于每个特征，在每个时间点都使用活动记录仪获得典型（即平均）睡眠和睡眠规律性的估计值。采用多层次增长曲线模型。
总的来说，8 岁到 12 岁之间，睡眠-觉醒周期发生了显著变化。平均入睡、醒来和中点呈现出上升的曲线生长模式，随着年龄的增长而延迟，而平均 TST 则呈线性下降。睡眠终点和中点的周末-工作日差异（社交时差）每年都变得更加明显。工作日 TST 比周末 TST 长，但随着时间的推移，这种差异变得更小。最后，所有睡眠特征的个体内可变性随时间增加，TST 的可变性呈上升的曲线变化。还观察到了重要的个体间和性别差异。
本研究揭示了典型的青春期前和青春期早期发育中睡眠发生的显著变化。我们讨论了这些轨迹的潜在影响。
