Behavioral and Biological Rhythms in Children's Obesity-Related Health Disparities

项目总结/摘要 儿童肥胖被认为是一种流行病，其社会经济地位（SES）存在显著差异。有 因此，迫切需要确定新的、可改变的肥胖预防和治疗风险因素， 儿童，特别是那些面临更大风险的儿童。令人信服的证据是植根于昼夜节律生物学， 我们对昼夜节律的理解，以及对啮齿动物和成年人的新兴研究表明， 除了关注我们在饮食、活动和睡眠方面的参与程度， 重要的是要了解我们参与这些行为的时间和一致性（即，行为 节奏）来降低肥胖风险。越来越多的证据表明， 与潜在的昼夜节律，如在生物夜间睡觉，在生物夜间进食， 一天与改善代谢过程和体重调节有关。虽然我们知道的不多 关于行为节律如何优化儿童的体重调节， 儿科研究支持那些与啮齿动物和成人，并强调了行为的潜在重要性， 预防体重过度增加的节奏。了解行为节律在体重调节中的作用 对于来自社会经济地位较低背景的儿童来说，考虑到他们可能面临更大的风险， 由于经济逆境和邻里关系的不利， 增加了体重增加的风险。此外，了解SES之间的关联，行为 节奏和体重调节在年轻的学龄儿童集中在一个时间段时，一些 在青春期进行的健康行为是形成的，因此可能代表了一个合适的时间， 优化重量调节。因此，本研究拟招募176名5-8岁的儿童， 一项为期16个月的观察性研究。孩子们将完成5个10天 研究期间的评估（基线、4、8、12和16个月），在此期间将测量以下内容： 睡眠的时间和一致性（通过活动记录），进食的时间和分布（通过24小时饮食回忆）， 身体和久坐活动的时间和一致性（通过加速度计和自我报告）， 昼夜节律钟（暗光褪黑激素发作; DLMO），家庭和邻里环境的测量，以及 人体测量（身高、体重、肥胖）。这项拟议工作的主要目的是评估：a）如何 行为节律影响儿童的身体质量指数（BMI）轨迹，以及B）SES如何影响行为 节律和BMI轨迹。次要目标将评估昼夜因素（即，昼夜节律相位和 昼夜相位角）以及家庭和邻里环境影响行为节律。 探索性目标还将评估行为、昼夜节律和环境因素对 儿童的BMI轨迹，包括行为节律和BMI之间的关联的潜在适度 通过昼夜节律相位和相位角的轨迹。

PROJECT SUMMARY/ABSTRACT Pediatric obesity is considered an epidemic with striking disparities by socioeconomic status (SES). There is therefore a pressing need to identify novel, modifiable risk factors for obesity prevention and treatment in children, particularly those who are at greater risk. Compelling evidence that is rooted in circadian biology and our understanding of circadian rhythms, and is supported by emerging work with rodents and adults suggests that in addition to focusing on how much we engage in eating, activity and sleep behaviors, it may also be important to understand the timing and consistency with which we engage in these behaviors (i.e., behavioral rhythms) for obesity risk reduction. Mounting evidence demonstrates that behavioral rhythms that are aligned with underlying circadian rhythms, such as sleeping during the biological night and eating during the biological day are associated with improved metabolic processes and weight regulation. Although less is known regarding how behavioral rhythms may optimize weight regulation in children, findings from related lines of pediatric research support those with rodents and adults and highlight the potential importance of behavioral rhythms for excess weight gain prevention. Understanding the role of behavioral rhythms in weight regulation for children from lower SES backgrounds may be particularly important given that they may be at greater risk for disruptions to behavioral rhythms due to economic adversity and neighborhood disadvantage, placing them at increased risk for excess weight gain. Further, understanding associations between SES, behavioral rhythms and weight regulation in young school-aged children focuses on a time period when a number of health behaviors that carry through adolescence are shaped and thus may represent an opportune time for optimizing weight regulation. The present study therefore proposes to enroll 176 children 5-8 years old from diverse SES backgrounds into a 16-month observational study. Children will complete five 10-day assessments across the study (baseline, 4, 8, 12, and 16 months) during which the following will be measured: timing and consistency of sleep (via actigraphy), timing and distribution of eating (via 24-hour dietary recalls), timing and consistency of physical and sedentary activities (via accelerometry and self-report), timing of the circadian clock (dim light melatonin onset; DLMO), measures of the home and neighborhood environment, and anthropometrics (height, weight, adiposity). The primary aims of this proposed work are to assess: a) how behavioral rhythms affect body mass index (BMI) trajectories in children, and b) how SES affects behavioral rhythms and thus BMI trajectories. Secondary aims will assess how circadian factors (i.e., circadian phase and circadian phase angle) and the household and neighborhood environments affect behavioral rhythms. Exploratory aims will also assess the relative influence of behavioral, circadian and environmental factors on children's BMI trajectories, including potential moderation of associations between behavioral rhythms and BMI trajectories by circadian phase and phase angle.