Circadian phase advances in children during camping life according to the natural light-dark cycle
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 t...
| Main Authors: | , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
BMC
2022-12-01
|
| Series: | Journal of Physiological Anthropology |
| Subjects: | |
| Online Access: | https://doi.org/10.1186/s40101-022-00316-x |
| _version_ | 1797980438858301440 |
|---|---|
| author | Taisuke Eto Shingo Kitamura Kana Nishimura Kota Takeoka Yuki Nishimura Sang-il Lee Michihiro Ohashi Akiko Shikano Shingo Noi Shigekazu Higuchi |
| author_facet | Taisuke Eto Shingo Kitamura Kana Nishimura Kota Takeoka Yuki Nishimura Sang-il Lee Michihiro Ohashi Akiko Shikano Shingo Noi Shigekazu Higuchi |
| author_sort | Taisuke Eto |
| collection | DOAJ |
| description | 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. |
| first_indexed | 2024-04-11T05:54:37Z |
| format | Article |
| id | doaj.art-a0b90cb14ce445bbb02d943e67f6dfa9 |
| institution | Directory Open Access Journal |
| issn | 1880-6805 |
| language | English |
| last_indexed | 2024-04-11T05:54:37Z |
| publishDate | 2022-12-01 |
| publisher | BMC |
| record_format | Article |
| series | Journal of Physiological Anthropology |
| spelling | doaj.art-a0b90cb14ce445bbb02d943e67f6dfa92022-12-22T04:41:56ZengBMCJournal of Physiological Anthropology1880-68052022-12-0141111010.1186/s40101-022-00316-xCircadian phase advances in children during camping life according to the natural light-dark cycleTaisuke Eto0Shingo Kitamura1Kana Nishimura2Kota Takeoka3Yuki Nishimura4Sang-il Lee5Michihiro Ohashi6Akiko Shikano7Shingo Noi8Shigekazu Higuchi9Graduate School of Integrated Frontier Sciences, Kyushu UniversityDepartment of Sleep-Wake Disorders, National Institute of Mental Health, National Center of Neurology and PsychiatryGraduate School of Integrated Frontier Sciences, Kyushu UniversityGraduate School of Integrated Frontier Sciences, Kyushu UniversityGraduate School of Integrated Frontier Sciences, Kyushu UniversityDepartment of Human Science, Faculty of Design, Kyushu UniversityGraduate School of Integrated Frontier Sciences, Kyushu UniversityFaculty of Sport Science, Nippon Sport Science UniversityFaculty of Sport Science, Nippon Sport Science UniversityDepartment of Human Science, Faculty of Design, Kyushu UniversityAbstract 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.https://doi.org/10.1186/s40101-022-00316-xCircadian rhythmMelatoninChildrenSleepCampingLighting |
| spellingShingle | Taisuke Eto Shingo Kitamura Kana Nishimura Kota Takeoka Yuki Nishimura Sang-il Lee Michihiro Ohashi Akiko Shikano Shingo Noi Shigekazu Higuchi Circadian phase advances in children during camping life according to the natural light-dark cycle Journal of Physiological Anthropology Circadian rhythm Melatonin Children Sleep Camping Lighting |
| title | Circadian phase advances in children during camping life according to the natural light-dark cycle |
| title_full | Circadian phase advances in children during camping life according to the natural light-dark cycle |
| title_fullStr | Circadian phase advances in children during camping life according to the natural light-dark cycle |
| title_full_unstemmed | Circadian phase advances in children during camping life according to the natural light-dark cycle |
| title_short | Circadian phase advances in children during camping life according to the natural light-dark cycle |
| title_sort | circadian phase advances in children during camping life according to the natural light dark cycle |
| topic | Circadian rhythm Melatonin Children Sleep Camping Lighting |
| url | https://doi.org/10.1186/s40101-022-00316-x |
| work_keys_str_mv | AT taisukeeto circadianphaseadvancesinchildrenduringcampinglifeaccordingtothenaturallightdarkcycle AT shingokitamura circadianphaseadvancesinchildrenduringcampinglifeaccordingtothenaturallightdarkcycle AT kananishimura circadianphaseadvancesinchildrenduringcampinglifeaccordingtothenaturallightdarkcycle AT kotatakeoka circadianphaseadvancesinchildrenduringcampinglifeaccordingtothenaturallightdarkcycle AT yukinishimura circadianphaseadvancesinchildrenduringcampinglifeaccordingtothenaturallightdarkcycle AT sangillee circadianphaseadvancesinchildrenduringcampinglifeaccordingtothenaturallightdarkcycle AT michihiroohashi circadianphaseadvancesinchildrenduringcampinglifeaccordingtothenaturallightdarkcycle AT akikoshikano circadianphaseadvancesinchildrenduringcampinglifeaccordingtothenaturallightdarkcycle AT shingonoi circadianphaseadvancesinchildrenduringcampinglifeaccordingtothenaturallightdarkcycle AT shigekazuhiguchi circadianphaseadvancesinchildrenduringcampinglifeaccordingtothenaturallightdarkcycle |