Department of Integrative Physiology, University of Colorado Boulder, Boulder, Colorado, USA.
Division of Preclinical Innovation, National Center for Advancing Translational Sciences, Rockville, Maryland, USA.
J Sleep Res. 2023 Apr;32(2):e13635. doi: 10.1111/jsr.13635. Epub 2022 May 14.
In adults, recent evidence demonstrates that sleep and circadian physiology change across lunar phases, including findings that endogenous melatonin levels are lower near the full moon compared to the new moon. Here, we extend these results to early childhood by examining circalunar fluctuations in children's evening melatonin levels. We analysed extant data on young children's circadian rhythms (n = 46, aged 3.0-5.9 years, 59% female). After following a strict sleep schedule for 5-7 days, children completed an in-home, dim-light circadian assessment (<10 lux). Salivary melatonin was assessed at regular 20- to 30-min intervals until 1 h past each child's scheduled bedtime. Melatonin levels varied significantly across lunar phases, such that melatonin was lower in participants assessed near the full moon as compared to near the new moon. Significant differences were observed at 50 min (mean = 2.5 pg/ml; mean = 5.4 pg/ml) and 10 min (mean = 7.3 pg/ml; mean = 15.8 pg/ml) before children's scheduled bedtime, as well as at 20 min (mean = 15.5 pg/ml; mean = 26.1 pg/ml) and 50 min (mean = 19.9 pg/ml; mean = 34.3 pg/ml) after bedtime. To our knowledge, these are the first data demonstrating that melatonin secretion, a process regulated by the human circadian system, is sensitive to changes in lunar phase at an early age. Future research is needed to understand the mechanisms underlying this association (e.g., an endogenous circalunar rhythm) and its potential influence on children's sleep and circadian health.
在成年人中，最近的证据表明，睡眠和昼夜生理节律会随着月相变化，包括内源性褪黑素水平在满月时比新月时更低的发现。在这里，我们通过检查儿童傍晚褪黑素水平的月周期波动，将这些结果扩展到幼儿期。我们分析了现有关于幼儿昼夜节律的数据集（n=46，年龄 3.0-5.9 岁，59%为女性）。在遵循严格的睡眠时间表 5-7 天后，儿童在家中进行暗光昼夜节律评估（<10 勒克斯）。唾液褪黑素在每个孩子预定就寝时间后 1 小时内，每隔 20-30 分钟进行定期评估。褪黑素水平在月相之间有显著差异，因此在接近满月时参与者的褪黑素水平低于接近新月时。在儿童预定就寝时间前 50 分钟（平均值为 2.5pg/ml；平均值为 5.4pg/ml）和 10 分钟（平均值为 7.3pg/ml；平均值为 15.8pg/ml），以及在儿童预定就寝时间后 20 分钟（平均值为 15.5pg/ml；平均值为 26.1pg/ml）和 50 分钟（平均值为 19.9pg/ml；平均值为 34.3pg/ml）观察到显著差异。据我们所知，这些是首批表明褪黑素分泌（受人体昼夜节律系统调节的过程）对早期月相变化敏感的数据。需要进一步研究来了解这种关联的机制（例如，内源性月周期节律）及其对儿童睡眠和昼夜节律健康的潜在影响。
