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: 10684645
• 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/10684645
• 关键词: Adolescence; Adolescent; Adult; Alcohol consumption; Anxiety; Biological; Chronic; Circadian Rhythms; Circadian desynchrony; Conflict (Psychology); Control Groups; Cues; Darkness; Data; Depressed mood; Development; Drowsiness; Feeling suicidal; Future; Goals; Home; Human; Individual; Insulin Resistance; Laboratories; Light; Mammals; 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; circadian; circadian pacemaker; conduct problem; design; emotion regulation; experience; falls; follow-up; novel; permissiveness; 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.

项目概要 美国大多数年龄较大的青少年都长期睡眠不足，睡眠时间比正常青少年少 1 至 2 小时 昼夜节律（~24 小时）系统会随着青春期的进展而改变（延迟）； 导致年龄较大的青少年入睡较晚。上学时间过早迫使青少年较早起床。 因此，许多青少年的睡眠时间也缩短了。 在“错误的”昼夜节律时间起床去上学是慢性昼夜节律失调和睡眠限制的原因。 它们在青春期后期达到顶峰，并与早晨白天困倦、学业成绩不佳有关 表现、行为问题、情绪低落、自杀意念、药物滥用、胰岛素抵抗，以及 灯箱的强光照射可以提前改变节律（相位提前）以促进早期肥胖。 睡眠开始，并减少早晨昼夜节律失调和相关风险我们构建了第一个。 老年青少年对强光的相位响应曲线（PRC） 为了相位提前昼夜节律，我们 PRCs 表明，开始光照的理想时间是在醒来时间之前，并且光照应该是 避免在就寝时间前后进行，因为这是光产生最大相位延迟偏移的时间。 然而，从我们的结果中发现，第二个前进区域是在下午（习惯性训练后约 6 至 9 小时） 唤醒时间）表明下午的光可能比白天有更多的环昼夜相位提前能力 传统上认为，这项机制研究的总体目标是跟进我们意想不到的 PRC 研究结果。 并测试单独定时的下午光以及与早晨明亮光的结合是否可以改变 14 至 17 岁青少年的昼夜节律较早，将分四组进行比较。 随机平行组设计：下午强光、上午强光、上午+下午强光、 青少年将在稳定的基线周后完成为期 2 周的方案。 睡眠时间表，青少年将在我们的实验室中生活4天的睡眠/黑暗和强光时间。 明亮的光线（~5000 lux）将根据他/她的稳定情况单独调整。 第一次 3 小时早晨强光照射将在第一次醒来前 1 小时开始。 早上起床后 6 小时开始下午第一个 3 小时的强光照射。 曝光将同时开始，但每次曝光时间为 1.5 小时，因此每次亮光总共 3 小时 除暗光对照组外，每组都将被给予标记生物钟的相移。 由昏暗光线褪黑激素发作（DLMO）是我们捕捉到的下午明亮光线的主要结果。 DLMO 不仅仅是昏暗的提前房间灯光和午后明亮的灯光，将与早晨明亮的灯光协同工作 如果我们的假设得到支持，那么光会比早上或下午的强光产生更大的变化 这些数据将挑战目前对如何利用强光改变昼夜节律系统的理解 早些时候。