Sensitivity of the Circadian Clock to the Spectrum of Evening Light in Early Childhood

幼儿时期昼夜节律钟对夜间光线光谱的敏感性

• 批准号: 10616666
• 负责人: Lauren Hartstein
• 金额: $ 7.61万
• 依托单位: UNIVERSITY OF COLORADO
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-05-01 至 2024-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10616666
• 关键词: Adolescent; Adult; Attention; Award; Behavioral; Characteristics; Child; Chronic; Circadian Rhythms; Color; Crossover Design; Cues; Data; Development; Devices; Educational workshop; Elderly; Electronics; Emotional; Environment; Exposure to; Goals; Grant; Health; High School Student; Home; Hormones; Knowledge; Light; Lighting; Manuscripts; Measurement; Measures; Melatonin; Mental Health; Methods; National Heart, Lung, and Blood Institute; Nursery Schools; Outcome; Parents; Participant; Pathway interactions; Phase; Physiological; Physiology; Preschool Child; Problem behavior; Production; Protocols documentation; Pupil; Recommendation; Research; Research Project Grants; Resistance; Risk; Role; Saliva; Schedule; School-Age Population; Scientist; Sleep; Sleep Deprivation; Sleep Disorders; Sleep disturbances; Source; Stimulus; Substance abuse problem; System; Temperature; Time; Training; United States National Institutes of Health; Writing; aged; circadian; circadian pacemaker; digital media; early childhood; experience; falls; interest; lens; light emission; novel; obesity risk; poor health outcome; programs; sleep health; sociodemographic factors

PROJECT SUMMARY Late sleep timing and evening sleep problems in early childhood increase the risk for poor behavioral and health outcomes. Light is the primary zeitgeber of the circadian system, and even small amounts of evening light can suppress production of the sleep-promoting hormone melatonin and delay circadian timing. The spectrum of light – not just the intensity – may be a particularly relevant factor for determining sleep and circadian timing in early childhood for several reasons: (1) children are more sensitive to evening light exposure than adults due to differences in ophthalmological features, including larger pupils and clearer lenses that increase light transmittance; (2) young children show robust melatonin suppression (~90%) following evening bright light exposure; and (3) media use in preschoolers has increased dramatically in the last decade and is associated with late sleep timing and bedtime resistance. Central to this research are also data from older children, adolescents, and adults indicating the circadian system shows high sensitivity to short- wavelength blue light. To date, however, the role of light spectrum in young children’s sensitivity to evening light exposure and its differential impact on circadian physiology is unknown. This is the primary purpose of this F32 research project. In a within-subjects crossover design, participants complete a 10-day protocol twice. Healthy, good sleeping children aged 3.0-4.9 years maintain a stable sleep schedule for 7 days, followed by a 3-day in-home circadian assessment performed in dim-light conditions. Children experience two counterbalanced experimental conditions: a high CCT (5000K; blue-enriched) or low CCT (2700K; red-enriched) light exposure of 100 lux for 1-h before their scheduled bedtime. Following a 1-2 week “washout period”, the protocol is repeated with the remaining condition. We will examine the impact of light spectrum on melatonin suppression (Aim 1) and circadian phase shift (Aim 2). Dim light melatonin onset is assessed through saliva using our established protocol to determine % melatonin suppression and circadian phase delay. The results of this proposal will identify modifiable components of children’s evening light exposure (e.g. light spectrum and timing) to help parents set limits and make healthy choices about their children’s lighting environment. Results are likely to have high impact, as they will provide behavioral change recommendations that can minimize the negative impacts of evening light exposure on children’s sleep duration and quality. In addition to these research aims, this F32 Award will incorporate training in the measurement and analysis of physiological measures, advanced statistical approaches, grant and manuscript writing, dissemination of findings to the public, and lab management. The research and training proposed will be an important step in facilitating Dr. Hartstein’s transition into an independent scientist with a research program committed to further examining the impacts of the lighting environment on children’s sleep, circadian rhythms, and development.

项目总结 儿童早期的晚睡时间和晚间睡眠问题增加了行为不良和 健康结果。光是昼夜节律系统的主要驱动力，甚至是少量的夜晚。 光可以抑制促进睡眠的荷尔蒙褪黑激素的产生，并推迟昼夜节律。这个 光谱--不仅仅是强度--可能是决定睡眠和睡眠的一个特别相关的因素 儿童早期的昼夜节律有几个原因：(1)儿童对傍晚的光线更敏感 由于眼科特征的差异，包括更大的瞳孔和更清晰的晶状体，暴露于成年人 增加光的透射率；(2)幼儿表现出强烈的褪黑素抑制(~90%) 在过去的十年里，学龄前儿童对媒体的使用急剧增加 并与晚睡时间和睡前抵抗力有关。这项研究的核心数据也来自 年龄较大的儿童、青少年和成年人表明，昼夜节律系统对短时间表现出高度的敏感性 波长为蓝色的光。然而，到目前为止，光谱在幼儿对夜晚的敏感性中所起的作用 光暴露及其对昼夜生理学的不同影响尚不清楚。这就是这个的主要目的。 F32研究项目。 在受试者内部的交叉设计中，参与者完成两次为期10天的方案。健康，良好的睡眠 3.0-4.9岁的儿童保持7天的稳定睡眠时间表，然后是3天的家庭昼夜节律 在昏暗的光线条件下进行的评估。儿童经历两次平衡实验 条件：高CCT(5000K；蓝光)或低CCT(2700K；红光)曝光量为100勒克斯 在他们预定的就寝时间前1小时。在1-2周的“冲洗期”之后，重复该方案 剩下的情况。我们将研究光谱对褪黑素抑制的影响(目标1)和 昼夜相移(目标2)。暗光褪黑素的开始是通过唾液来评估的，使用我们已经建立的 测定褪黑素抑制率和昼夜相位延迟的方案。这项提议的结果将是 确定儿童夜间光线暴露的可修改成分(例如光谱和时间)，以帮助 父母对孩子的照明环境设定限制，并做出健康的选择。结果很可能是 影响很大，因为他们将提供行为改变建议，将负面影响降至最低 晚光暴露对儿童睡眠时间和睡眠质量的影响 除了这些研究目标之外，这个F32奖还将包括在测量和分析 生理测量、高级统计方法、赠款和手稿写作、传播 向公众公布调查结果，以及实验室管理。拟议的研究和培训将是 通过一个致力于进一步发展的研究计划，促进哈特斯坦博士向独立科学家的转变 研究照明环境对儿童睡眠、昼夜节律和发育的影响。