Adolescent circadian phase shifts: novel time-of-day targets for bright light

青少年昼夜节律相移：新的亮光时间目标

• 批准号: 10224325
• 负责人: Stephanie Crowley McWilliam
• 金额: $ 50.2万
• 依托单位: RUSH UNIVERSITY MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10224325
• 关键词: Address; Adolescence; Adolescent; Adult; Alcohol consumption; Anxiety; Biological; Chronic; Circadian Rhythms; Circadian desynchrony; Conflict (Psychology); Control Groups; Cues; Data; Depressed mood; Development; Drowsiness; Emotions; Feeling suicidal; Future; Goals; Home; Individual; Insulin Resistance; Laboratories; Lead; Light; Measures; Melatonin; Obesity; Outcome; Overweight; Participant; Performance; Phase; Phase response curves; Phototherapy; Protocols documentation; Psychosocial Factor; Puberty; Publishing; Randomized; Recommendation; Risk; Risk Behaviors; Schedule; Schools; Sleep; Sleep Deprivation; Sunlight; System; Teenagers; Testing; Time; Work; aged; awake; base; circadian; circadian pacemaker; conduct problem; design; experience; falls; follow-up; novel; response; sleep onset; substance use

PROJECT SUMMARY A majority of older adolescents in the U.S. are chronically sleep deprived, getting 1- 2 h less sleep than recommended. The circadian (~24-h) system shifts later (delay) with the progression of puberty; this shift contributes to late sleep onsets in older adolescents. Early school start times force teenagers awake earlier than their spontaneous wake time. Thus, the opportunity for sleep shortens. Many adolescents are also waking for school at the “wrong” circadian time. Chronic circadian misalignment and sleep restriction are at their peak during late adolescence, and are associated with morning daytime sleepiness, poor academic performance, conduct problems, depressed mood, suicidal ideation, substance use, insulin resistance, and obesity. Bright light exposure from light boxes can shift rhythms earlier (phase advance) to facilitate earlier sleep onset, and reduce morning circadian misalignment and the associated risks. We constructed the first phase response curves (PRCs) to bright light in older adolescents. To phase advance circadian rhythms, our PRCs showed that the ideal time to begin light exposure was slightly before wake-up time and light should be avoided around bedtime because this is when light produces maximum phase delay shifts. An unexpected finding from our results, however, was a second advancing region in the afternoon (~6 to 9 h after habitual wake-up time) suggesting that afternoon light may have more circadian phase advancing ability than traditionally thought. The overall goal of this mechanistic study is to follow-up on our unexpected PRC findings and test whether individually-timed afternoon light alone and in combination with morning bright light can shift circadian rhythms earlier in older adolescents aged 14 to 17 years. Four groups will be compared in a randomized parallel group design: afternoon bright light, morning bright light, morning + afternoon bright light, and a dim room light control. Adolescents will complete a 2-week protocol. After a baseline week with a stable sleep schedule, adolescents will live in our laboratory for 4 days. Sleep/dark and the time of bright light exposure will gradually shift earlier. Bright light (~5000 lux) will be timed individually based on his/her stable baseline sleep schedule. The first 3-h morning bright light exposure will begin 1 h before wake on the first morning. The first 3-h afternoon bright light exposure will begin 6 h after wake. The morning + afternoon exposures will begin at the same times, but each exposure will be 1.5 h so that a total of 3 h of bright light per day will be given to each group except the dim light control group. Phase shifts of the circadian clocks marked by the dim light melatonin onset (DLMO) is the main outcome. We hypothesize that afternoon bright light will advance DLMO more than dim room light and afternoon bright light will work synergistically with morning bright light to produce larger shifts than morning or afternoon bright light alone. If our hypotheses are supported, these data will challenge the current understanding of how to use bright light to shift the circadian system earlier.

项目摘要 美国大多数年长的青少年长期睡眠不足，睡眠1-2小时比 受到推崇的。随着青春期的发展，昼夜节律（〜24-h）系统在后来移动（延迟）；这种转变 在年长的青少年中有助于晚期入睡。早期入学时间强迫青少年早起 比他们的赞助唤醒时间。那就缩短了睡眠的机会。许多青少年也是 在“错误”的昼夜节律时间醒来。慢性昼夜节律的未对准和睡眠限制是 它们在青少年后期的峰 绩效，行为问题，情绪低落，自杀想法，使用物质，胰岛素抵抗和 肥胖。光盒中明亮的光线暴露会更早地改变节奏（阶段进步），以促进早期 睡眠发作，减少早间昼夜节律的未对准和相关的风险。我们构建了第一个 相位响应曲线（PRC）对老年青少年的明亮光。为了提高昼夜节律，我们的 PRC表明，开始唤醒时间和光应该是稍微开始曝光的理想时间 避免在就寝时间避免，因为这是光产生最大相位延迟移动的时候。意外 然而，从我们的结果中发现是下午的第二个前进区域（习惯后约6至9小时 唤醒时间）暗示下午的灯光可能具有比 传统上思考。这项机械研究的总体目标是跟进我们意外的PRC发现 并测试单独定时的下午光线单独并与早晨明亮的光线相结合可以改变 在14至17岁的老年青少年早期的昼夜节律。将在A中比较四组 随机平行组设计：下午明亮的光线，明亮的灯光，早晨 +下午明亮的光线， 和一个昏暗的房间控制。青少年将完成2周的协议。在基准周后与马stable 睡眠时间表，青少年将在我们的实验室生活4天。睡眠/黑暗和明亮光的时间 曝光将逐渐改变。明亮的光（〜5000 lux）将根据他/她的稳定而单独定时 基线睡眠时间表。前3-H早晨明亮的光线曝光将开始1小时，然后在第一次醒来 早晨。醒来后6小时，前3-H下午明亮的光线曝光将开始。早上 +下午 曝光将在同一时间开始，但每次暴露均为1.5 h 除了昏暗的光对照组以外，每组都会给予一天。标记的昼夜节律的相移 通过昏暗的光褪黑激素发作（DLMO）是主要结果。我们假设那个下午明亮的光将 前进的dlmo不仅仅是昏暗的房间灯光和午后明亮的光线将与早晨明亮协同作用 光线可以比早晨或午后明亮的光线产生更大的变化。如果支持我们的假设， 这些数据将挑战当前对如何使用明亮光转移昼夜节律系统的理解 较早。