The Protective Effects of Physical Activity on AdolescentSmoking Progression

描述(申请人提供)：在美国，吸烟是导致发病率和死亡率的首要可预防原因。约23%的青少年是经常吸烟的人。为了进一步减少青少年吸烟，需要确定防止青少年吸烟的因素，并随后将其纳入青少年吸烟预防计划。体力活动可能是防止青少年吸烟开始和发展的重要保护因素。尽管对吸烟和体力活动的纵向研究表明，较高的体力活动水平会降低青少年吸烟开始和发展的几率，但这种关系的性质、解释这种保护关系的机制、提供保护作用所需的体力活动量以及由于体力活动水平而面临吸烟风险的青少年仍不清楚。我们建议通过建立1000名青少年(14岁)队列并在四年内(18岁)对他们进行跟踪来解决这一差距。将收集社会环境、行为和心理对吸烟和缺乏运动的影响。这项研究的目的是：(1)阐明吸烟和身体活动之间关系的性质；(2)评估解释身体不活动和吸烟关系的机制；(3)从经验上确定不同的纵向路径或吸烟-身体不活动轨迹，以确定最佳干预时机和防止吸烟所需的身体活动量；以及(4)通过社会环境、行为和心理变量来表征这些轨迹，以根据青少年的身体活动习惯确定吸烟的风险。令人感兴趣的具体结果包括(A)进展为规律吸烟和缺乏体育活动的几率和比率，以及(B)纵向模式或吸烟-体育缺乏活动的轨迹。这将是第一个同时和全面评估吸烟和青春期中后期体育活动的研究之一，以阐明和量化保护关系，并探索基于理论的机制如何与吸烟习惯养成的临界点有关，吸烟习惯通常会持续到成年。这项研究的结果可用于为青少年吸烟预防和干预计划提供时间、类型、体力活动数量、目标变量和重要亚群的信息。吸烟和缺乏运动是两种经常在青春期形成并带入成年的健康危害行为。尽管现有的吸烟和体力活动的纵向研究表明，较高水平的体力活动可将青少年吸烟开始和发展的几率降低50%，但这种关系的性质、为什么体力活动具有保护作用以及授予保护作用所需的体力活动量尚不清楚。这些信息对于确定青少年预防吸烟干预的内容、时机和目标至关重要，该干预措施包含了体育活动的组成部分。

DESCRIPTION (provided by applicant): Cigarette smoking is the leading preventable cause of morbidity and mortality in the U.S. About 23% of adolescents are regular smokers. To further reduce adolescent smoking, factors that protect against adolescent smoking need to be identified and subsequently incorporated into youth smoking prevention programs. Physical activity may be an important protective factor against youth smoking initiation and progression. Although longitudinal studies of smoking and physical activity indicate that higher levels of physical activity reduce the odds of adolescent smoking initiation and progression, the nature of this relationship, the mechanisms explaining this protective relationship, the amount of physical activity needed to confer a protective effect, and the adolescents at risk for smoking due to their levels of physical activity remain unclear. We propose to address this gap by creating a cohort of 1,000 adolescents (age 14 years) and following them over a four-year period (age 18 years). Socio-environmental, behavioral and psychological influences on smoking and physical inactivity will be collected. The aims of the proposed study are to (1) clarify the nature of the relationship between smoking and physical activity, (2) evaluate the mechanisms explaining the physical inactivity and smoking relationship, (3) empirically identify distinct longitudinal paths or smoking-physical inactivity trajectories to determine optimal intervention timing and the amount of physical activity needed to protect against smoking, and (4) characterize these trajectories by socio-environmental, behavioral and psychological variables to identify adolescents at risk for smoking within the context of their physical activity habits. Specific outcomes of interest include (a) odds and rates of progression to regular smoking and physical inactivity, and (b) longitudinal patterns or smoking-physical inactivity trajectories. This will be one of the first studies to concurrently and comprehensively evaluate smoking and physical activity from mid to late adolescence, to elucidate and quantify the protective relationship, and to explore how theory-based mechanisms relate to critical points in the development of a smoking habit often carried into adulthood. Results from this study can be used to inform the timing, type, amount of physical activity, target variables and important subpopulations for adolescent smoking prevention and intervention programs. Smoking and physical inactivity are two health risk behaviors often formed in adolescence and carried into adulthood. Although, the available longitudinal studies of smoking and physical activity indicate that higher levels of physical activity reduce the odds of adolescent smoking initiation and progression by 50%, the nature of this relationship, why physical activity is protective, and the amount of physical activity needed to confer a protective effect are unclear. This information is critical to for determining the content, timing, and targets for youth smoking prevention intervention that incorporates a physical activity component.