The Influence of School Start Time on Sleep, Academic Achievement, and Behavioral Outcomes in Adolescents

项目总结 尽管国家睡眠基金会建议青少年每晚睡眠8.5至9.25小时，但更多 不到一半的美国16岁青少年的睡眠时间通常不到7个小时；此外，女孩和弱势青少年的睡眠时间 睡眠时间短的风险更大。“睡眠债”的后果远远超出了阻碍 日常运作，因为它对多个领域的健康和福祉有害。虽然各种力量，如 屏幕时间、家庭作业期望和其他因素可能会阻碍美国青少年的学习 睡眠，研究表明，高中早期的开始时间与青春期的生物学是不同步的， 是年轻人获得充足睡眠的最大障碍之一。当孩子们开始 青春期，昼夜节律变化，褪黑激素在晚上分泌较晚，很难下降 晚上11点前睡着了这种神经生物学的变化意味着参加“早起”(之前)的青少年 早上8：30)高中，即使是那些努力争取早点睡觉的人，也会努力获得充足的睡眠。天然 实验清楚地表明，较晚的开学使青少年有更多的机会积累知识 充足的睡眠，但不幸的是，大多数美国学校在早上8：30之前开始上课我们假设这样的好处 较晚的高中开始时间可能会延伸到促进学校的成功，这反过来可能会有无数的长期- 任期福利，因为低教育程度是人口水平发病率和 心血管疾病死亡率(CVD)。我们建议对START研究中的数据进行二次分析 (R01 HD088176)。START是一个现有的队列，旨在评估一项自然实验在 学校课程表修改对体重和体重相关行为随时间的变化。在基线(春季 2016)，START从五所开学时间较早的明尼苏达州高中招募九年级学生(7：30或 上午7：45)。在研究的第二年和第三年(2016/17学年和2017/18学年)，五所学校中的两所 已经将开始时间推迟了50到55分钟，而有三个人仍然在早上7：30对全样本的调查(n =2,422)，每年收集对象睡眠测量子样本(n=455)。在计划开始数据之后 收集工作完成后，我们从学校获得了更多关于学生学习成绩的数据，并 可单独链接到开始数据的行为。我们的具体目标是：1)确定高风险的影响 学校开学时间对学校的表现和行为随着时间的推移。2)确定如何客观衡量 睡眠的特征(持续时间、时间和质量)与学校的表现和随着时间推移的行为有关。这个 这一系列研究的产品具有潜在的公共健康影响，因为它们将 睡眠政策与学校成功之间的联系。它还可以提供证据，证明某些学校 课程表可能会放大学生的表现和幸福感，从而减少长期的 心血管风险。如果有效，推迟开学时间，这项政策可以在广泛的 在美国各地的社区，可以提高教育促进健康的有效性。

PROJECT SUMMARY Although the National Sleep Foundation recommends 8.5 to 9.25 hours of sleep per night for adolescents, more than half of US 16-year-olds regularly get less than seven hours; further, girls and disadvantaged youth are at even greater risk for short sleep duration. “Sleep debt” has consequences that extend far beyond hampering day-to-day functioning as it is deleterious to multiple areas health and wellbeing. While a variety of forces such as screen time, homework expectations, and other factors can be implicated in stymying American teenagers’ sleep, studies have revealed that early high school start times, which are asynchronous with adolescent biology, are one of the most significant obstacles to youth being able to net sufficient sleep. When children begin puberty, circadian rhythms shift such that melatonin is secreted later in the evening making it difficult to fall asleep before 11pm. This neurobiological change means that adolescents who attend “early-start” (prior to 8:30am) high schools, even those who strive for an early bedtime, will struggle to get sufficient sleep. Natural experiments have clearly shown that later school starts allow adolescents a greater opportunity to accumulate adequate sleep, but unfortunately most US schools start before 8:30am. We hypothesize that the benefits of later high school start times may extend to promoting school success, which in turn could have numerous long- term benefits as low educational attainment is a profound contributor to population-level morbidity and mortality from cardiovascular disease (CVD). We propose secondary analyses of data from the START study (R01 HD088176). START is an existing cohort designed to evaluate the impact of a natural experiment in school schedule modification on weight and weight-related behavior change over time. At baseline (Spring 2016), START recruited ninth grade students from five Minnesota high schools with early start times (7:30 or 7:45am). In the second and third years of the study (school years 2016/17 and 2017/18), two of the five schools had delayed their start time by 50 or 55 minutes while three remained at 7:30am. Surveys on the full sample (n = 2,422) and an object sleep measures subsample (n = 455) were collected annually. After planned START data collection was completed, we obtained additional data from schools on student academic achievement and behaviors that was individually linkable to START data. Our specific aims are: 1) Identify the impact of high school start time on school performance and behaviors over time. 2) Determine how objectively measured features of sleep (duration, timing, and quality) relate to school performance and behaviors over time. The products of this line of research have potential for public health impact because they will characterize associations between sleep policy and school success. It may also provide evidence for whether certain school schedules might amplify student performance and wellbeing in ways that could reduce long-term cardiovascular risk. If effective, later school start times, a policy that is deployable in a wide range of communities across the US, could enhance the health-promoting effectiveness of education.