Sensitivity of the circadian system to evening bright light in preschool-age children.
Sensitivity of the circadian system to evening bright light in preschool-age children.
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DOI：
10.14814/phy2.13617
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发表时间：
2018-03
影响因子：
2.5
通讯作者：
LeBourgeois MK
中科院分区：
文献类型：
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作者：
Akacem LD;Wright KP Jr;LeBourgeois MK
尽管光诱导的褪黑激素抑制反应在成人中得到了很好的表征，但研究儿童中这种效应的动态的研究很少。本研究的目的是量化学龄前儿童夜间光诱导的褪黑激素抑制的程度。健康儿童（n = 10; 7名女性; 4.3 ± 1.1岁）参加了7天方案。在第1-5天，孩子们遵循严格的睡眠时间表。在第6天，儿童进入昏暗的光照环境（<15 lux）1 h，然后从下午开始每20 - 30分钟提供一次唾液样本，直到预定就寝时间后50分钟。在第7天，受试者保持在昏暗的光线条件下，直到睡前1小时，此时他们暴露于强光刺激（约1000 lux）1小时，然后重新进入昏暗的光线条件。在强光暴露之前、期间和之后获得唾液样品，并将其时间锚定到前一天晚上采集的样品。我们发现强烈的褪黑激素抑制（87.6 ± 10.0%）在响应于明亮的光刺激。褪黑激素水平在光刺激终止后50分钟内保持衰减（P < 0.008）。此外，7/10的儿童在光照后50分钟的褪黑激素水平没有恢复到昏暗光线条件下观察到的褪黑激素水平的50%。我们的研究结果表明，学龄前儿童存在强烈的光诱导褪黑激素抑制反应。这些发现对理解夜间光照在夜间解决困难的发展中的作用具有影响，并可作为实验证据，支持有关儿童早期光照和睡眠卫生习惯的建议。
Although the light‐induced melatonin suppression response is well characterized in adults, studies examining the dynamics of this effect in children are scarce. The purpose of this study was to quantify the magnitude of evening light‐induced melatonin suppression in preschool‐age children. Healthy children (n = 10; 7 females; 4.3 ± 1.1 years) participated in a 7‐day protocol. On days 1–5, children followed a strict sleep schedule. On day 6, children entered a dim light environment (<15 lux) for 1‐h before providing salivary samples every 20‐ to 30‐min from the afternoon until 50‐min after scheduled bedtime. On day 7, subjects remained in dim light conditions until 1‐h before bedtime, at which time they were exposed to a bright light stimulus (~1000 lux) for 1‐h and then re‐entered dim light conditions. Saliva samples were obtained before, during, and after bright light exposure and were time anchored to samples taken the previous evening. We found robust melatonin suppression (87.6 ± 10.0%) in response to the bright light stimulus. Melatonin levels remained attenuated for 50‐min after termination of the light stimulus (P < 0.008). Furthermore, melatonin levels did not return to 50% of those observed in the dim light condition 50‐min after the light exposure for 7/10 children. Our findings demonstrate a robust light‐induced melatonin suppression response in preschool‐age children. These findings have implications for understanding the role of evening light exposure in the development of evening settling difficulties and may serve as experimental evidence to support recommendations regarding light exposure and sleep hygiene practices in early childhood.