Sleep, Energetic Behaviors, and Adolescent Obesity during the Transition from Middle to High School

 描述（由申请人提供）：乔纳森·米切尔是一名流行病学家，其研究旨在解释儿童生长模式的变化。他的长期职业目标是领导一个生物行为研究项目，以测试行为和基因联合收割机如何影响青春期的身体组成和肥胖的发展。他的工作将有助于儿童肥胖预防和促进健康的骨骼发育。这个职业发展奖将为他提供睡眠方面的培训，他将发展关于儿童时期睡眠、饮食摄入和体育活动之间综合关系的专业知识。他还将接受有关儿童肥胖和骨量遗传学的培训，这将使他能够领导基因-环境相互作用研究。最后，他将接受有关在实验室环境中测量身体成分的方法的专家培训，以便他可以在研究中具体估计肥胖和骨量。他在这些领域的发展将通过一系列培训活动和研究项目来实现，由一个跨学科的资深科学家团队指导，他们在睡眠，遗传学，营养，身体活动和身体成分方面具有专业知识。他将完成课程并参加宾夕法尼亚大学的研讨会，这些研讨会将涵盖睡眠，营养和肥胖研究。他将与他的指导团队成员合作，完成实验室轮换和睡眠测量，身体成分测量和身体成分遗传学的独立研究。他将完成短期课程，涵盖身体活动研究和纵向数据分析，他将参加由美国睡眠医学学会（睡眠），美国心脏协会（流行病学和预防/生活方式和心脏代谢健康[EPI/生活方式]）和肥胖协会（肥胖周）主办的年度科学会议。他将领导一个研究项目，该项目将利用宾夕法尼亚大学、佩雷尔曼医学院和费城儿童医院（CHOP）的资源。该研究项目旨在调查睡眠、青少年肥胖与能量摄入和体育活动之间的关系。他将在基线时招募100名年龄在13至14岁（8年级）的健康青少年样本，并将在1年随访（9年级）时重新评估这些青少年。参与者已经在CHOP应用基因组学中心进行了单核苷酸多态性（SNP）基因分型，代表肥胖易感性位点。在这两个时间点，他将为每位参与者提供两个加速度计;一个将在手腕上每天佩戴24小时，持续2周，以估计总睡眠时间（TST）。第二个将在清醒时间佩戴在臀部，持续2周，以估计中度至剧烈体力活动（MVPA）和久坐行为（SB）所花费的时间。在2周佩戴期间，经过培训的Nutrition Core工作人员将三次致电每位参与者，记录过去24小时内的食物摄入量;这些数据将用于估计能量摄入量。每位参与者将参观CTRC营养中心， 通过双能X射线吸收测定法（DXA）估计质量。他假设：1）TST的下降将与较高的脂肪量相关，2）TST的下降将与增加的能量摄入相关，3）TST的下降将与MVPA花费的时间减少和SB花费的时间增加相关。该纵向研究将提供经验和必要的试点和可行性数据，以支持更大的R 01研究睡眠，饮食和身体的影响。 活动对肥胖的变化在青春期。

 DESCRIPTION (provided by applicant): Jonathan Mitchell is an epidemiologist whose research aims to explain variations in childhood growth patterns. His long-term career goal is to lead a program of biobehavioral research to test how behaviors and genes combine to affect body composition and the development of obesity during adolescence. His work will help to inform childhood obesity prevention and promote healthy bone development. This career development award will provide him with training in sleep and he will develop expert knowledge on the integrated relationships between sleep, dietary intakes and physical activity in childhood. He will also receive training on the genetics of childhood obesity and bone mass, and this will enable him to lead gene-environment interaction studies. Finally, he will receive expert training on the methodologies used to measure body composition in the lab setting so that he can specifically estimate adiposity and bone mass in his research studies. His development in these areas will be achieved through a series of training activities and a research project, guided by an interdisciplinary team of senior scientists with expertise in sleep, genetics, nutrition, physicl activity, and body composition. He will complete coursework and attend seminars at the University of Pennsylvania that will cover sleep, nutrition, and obesity research. He will collaborate with members of his mentoring team to complete laboratory rotations and independent studies on sleep measurement, body composition measurement, and the genetics of body composition. He will complete short courses that cover physical activity research and longitudinal data analysis, and he will attend annual scientific meetings hosted by the American Academy of Sleep Medicine (SLEEP), the American Heart Association (Epidemiology and Prevention/Lifestyle and Cardiometabolic Health [EPI/Lifestyle]), and the Obesity Society (Obesity Week). He will lead a research project that will use resources at the University of Pennsylvania, Perelman School of Medicine and the Children's Hospital of Philadelphia (CHOP). The research project aims to investigate the association between sleep, adolescent obesity and energy intake and physical activity. He will recruit a sample of 100 healthy adolescents aged 13 to 14 (8th grade) at baseline and will re-assess these adolescents at 1-year follow-up (9th grade. The participants have already been genotyped for single nucleotide polymorphisms (SNPs), representing obesity susceptibility loci, at the Center for Applied Genomics at CHOP. At both time points, he will provide each participant with two accelerometers; one will be worn for 24 hours per day for 2-weeks on the wrist to estimate total sleep time (TST). The second will be worn on the hip during waking hours for 2-weeks to estimate time spent in moderate-to-vigorous physical activity (MVPA) and sedentary behavior (SB). During the 2-week wear periods trained Nutrition Core staff will call each participant on three occasions to record foods consumed in the past 24 hours; these data will be used to estimate energy intakes. Each participant will visit the CTRC Nutrition Core to have his or her fat mass estimated by dual energy X-ray absorptiometry (DXA). He hypothesizes that: 1) declines in TST will be associated with higher fat mass, 2) declines in TST will be associated with increased energy intake, and 3) declines in TST will be associated with less time spent in MVPA and more time spent in SB. This longitudinal study will provide the experience and necessary pilot and feasibility data to support a larger R01 study of the effects of sleep, diet and physical activity on adiposity changes during adolescence.