Circadian phase advances in children during camping life according to the natural light-dark cycle.

IF 3.1 4区医学 Q1 Social Sciences

Journal of Physiological Anthropology Pub Date : 2022-12-16 DOI:10.1186/s40101-022-00316-x

Taisuke Eto, Shingo Kitamura, Kana Nishimura, Kota Takeoka, Yuki Nishimura, Sang-Il Lee, Michihiro Ohashi, Akiko Shikano, Shingo Noi, Shigekazu Higuchi

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引用次数: 4

Abstract

Background: It is known that the circadian rhythm phase in adults can be advanced in a natural light-dark cycle without electrical lighting. However, the effect of advanced sleep-wake timing according to the natural light-dark cycle on children's circadian phase is unclear. We investigated the effects of approximately 2 weeks of camping life with little access to artificial lighting on children's circadian phases. We also conducted an exploratory examination on the effects of wake time according to natural sunrise time on the manner of the advance of their circadian phases.

Methods: Twenty-one healthy children (mean ± SD age, 10.6 ± 1.4 years) participated in a camping program with wake time (4:00) being earlier than sunrise time (EW condition), and 21 healthy children (10.4 ± 1.1 years) participated in a camping program with wake time (5:00) being almost matched to sunrise time (SW condition). Salivary dim light melatonin onset (DLMO) before the camping program and that after approximately 2 weeks of camping were compared.

Results: DLMO was advanced by approximately 2 h after the camping program compared with the circadian phase in daily life in both conditions. In addition, the advances in DLMO were significantly correlated with mid-sleep points before the camp in both conditions (EW: r = 0.72, p < 0.01, SW: r = 0.70, p < 0.01). These correlations mean that the phase advance was greater for the children with delayed sleep habits in daily life. Furthermore, in the EW condition, mean DLMO after the camp (18:09 ± 0:33 h) was earlier than natural sunset time and there was no significant decrease in interindividual variability in DLMO. On the other hand, in the SW condition, mean DLMO after the camp (18:43 ± 0:20 h) matched natural sunset time and interindividual variability in DLMO was significantly lower than that before the camp.

Conclusions: Camping with advanced sleep and wake timing under natural sunlight advances children's circadian phases. However, DLMO earlier than sunset in an early waking condition may lead to large interindividual variability in the circadian rhythm phase.

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露营期间，儿童的昼夜节律根据自然的光-暗循环而变化。

背景:众所周知，成年人的昼夜节律阶段可以在没有电照明的自然光-暗循环中提前。然而，根据自然光暗周期提前睡眠-觉醒时间对儿童昼夜节律阶段的影响尚不清楚。我们调查了大约两周的露营生活对儿童昼夜节律阶段的影响，几乎没有人工照明。我们还对自然日出时间对其昼夜节律阶段推进方式的唤醒时间的影响进行了探索性检查。方法:21名健康儿童(平均±SD年龄，10.6±1.4岁)参加起床时间(4:00)早于日出时间(EW组)的露营活动，21名健康儿童(10.4±1.1岁)参加起床时间(5:00)几乎与日出时间(SW组)一致的露营活动。比较了露营前和露营约2周后唾液暗光褪黑素(DLMO)的变化。结果:与日常生活中的昼夜节律相比较，两种情况下露营活动后DLMO均提前约2小时。此外，在两种情况下，DLMO的进展与营地前的中期睡眠点显著相关(EW: r = 0.72, p < 0.01, SW: r = 0.70, p < 0.01)。这些相关性意味着，在日常生活中有延迟睡眠习惯的儿童，阶段提前更大。此外，在EW条件下，营地后平均DLMO(18:09±0:33 h)早于自然日落时间，DLMO的个体间变异性无显著降低。另一方面，在SW条件下，营地后平均DLMO(18:43±0:20 h)符合自然日落时间，DLMO的个体间变异性显著低于营地前。结论:在自然阳光下露营，提前睡眠和醒来时间会提前儿童的昼夜节律阶段。然而，在早醒状态下，早于日落的DLMO可能会导致昼夜节律阶段的大个体间差异。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Journal of Physiological Anthropology Social Sciences-Human Factors and Ergonomics

CiteScore

4.80

自引率

6.50%

发文量

审稿时长

>12 weeks

期刊介绍： Journal of Physiological Anthropology (JPA) is an open access, peer-reviewed journal that publishes research on the physiological functions of modern mankind, with an emphasis on the physical and bio-cultural effects on human adaptability to the current environment. The objective of JPA is to evaluate physiological adaptations to modern living environments, and to publish research from different scientific fields concerned with environmental impact on human life. Topic areas include, but are not limited to: environmental physiology bio-cultural environment living environment epigenetic adaptation development and growth age and sex differences nutrition and morphology physical fitness and health Journal of Physiological Anthropology is the official journal of the Japan Society of Physiological Anthropology.