Biobehavioral Mechanisms Linking Stress and Obesity in Low-Income Children

描述（由申请人提供）：高度压力和贫困的人群更容易肥胖，最终更容易出现与肥胖相关的合并症。预防这些不利的健康结果依赖于预防生命早期肥胖的发展，因为肥胖一旦形成，往往会持续存在，预防比治疗更有效。对于低收入家庭的儿童来说，预防肥胖是非常紧迫的，因为肥胖在这一人群的早期很常见，并可能在以后的生活中造成严重的健康差距。目前的预防方案效果有限，需要新的干预目标。压力和饮食行为之间的联系是一个潜在的新目标。我们的研究项目侧重于低收入家庭儿童的压力、饮食行为和肥胖之间的联系。我们的初步研究结果表明，在儿童早期，反映慢性压力的皮质醇分泌模式可能会促进在没有饥饿感的情况下进食，降低饱腹反应和对食物发脾气；这些饮食习惯反过来又可能导致肥胖。然而，这项早期的工作已经清楚地表明，通过饮食行为将压力与肥胖联系起来的途径是复杂的、多因素的，涉及生物和行为途径。到目前为止，我们只研究了一小部分饮食行为，它们可以调节压力和肥胖之间的联系。其他可能受压力影响的机制，如对食物作为奖励的高度敏感或延迟食物满足的能力差，尚未在该模型中进行检验。这些饮食行为是如何随着时间的推移而聚集和发展的，压力的不同方面（即慢性压力源与即时压力源）如何与这些行为相关，以及基因型如何调节这些关联仍然未知。我们建议研究这些过程是如何被压力驱动的，并最终导致儿童肥胖。本申请是为了响应RFA- HL-12-037：“连接心理社会压力和行为的机械途径”而提交的，目的是更深入地了解将心理社会压力与饮食行为和最终肥胖联系起来的心理和生物行为过程。目的1：研究低收入儿童7岁时社会心理压力（慢性和即时压力）与促进肥胖的饮食行为（包括饱腹反应、食物强化价值和延迟食物满足的能力）和体重指数（BMI） z-score之间的横断面关系。目的2：在我们的低收入儿童队列中测试压力饮食行为联系的遗传调节因子。目的3：研究慢性压力和生命早期（3岁）对压力的反应与3至7岁之间促进肥胖的饮食行为变化的纵向关联。对早期生活中特定的、表型良好的饮食行为和儿童时期体重过度增加的社会心理压力发展的更好理解，可能为低收入儿童这一高危人口群体的新型肥胖预防工作带来希望。

DESCRIPTION (provided by applicant): Highly stressed and impoverished populations are more likely to be obese, and ultimately more likely to develop obesity-associated comorbidities. Preventing these adverse health outcomes relies on preventing the development of obesity early in the life span, since obesity, once established, tends to persist and prevention is more effective than treatment. Preventing obesity is highly urgent for low-income children, since obesity is common early on in this demographic and may contribute to substantial health disparities later in life. Current prevention programs have limited effectiveness, and novel targets for intervention are needed. The association between stress and eating behavior is one potential novel target. Our research program focuses on links between stress, eating behavior, and obesity in low-income children. Our preliminary findings suggest that, in early childhood, patterns of cortisol secretion reflecting chronic stress may promote eating in the absence of hunger, reduced satiety responsiveness, and tantrums over food; these eating behaviors, in turn, may lead to obesity. This early work has made clear, however, that the pathways linking stress to obesity via eating behavior are complex and multifactorial, and involve biologic and behavioral pathways. To date we have examined only a subset of eating behaviors that could mediate links between stress and obesity. Other mechanisms that may be affected by stress, such as high sensitivity to food as a reward or poor ability to delay gratification for food, have not been examined in this model. How such eating behaviors may cluster and develop over time, how different aspects of stress (i.e., chronic vs. immediate stressors) relate to these behaviors, and how genotypes may moderate such associations remains unknown. We propose to examine how these processes may be driven by stress, and ultimately lead to obesity in children. This application is submitted in response to RFA- HL-12-037: "Mechanistic Pathways Linking Psychosocial Stress and Behavior" with the goal of providing a deeper understanding of the psychological and bio-behavioral processes that connect psychosocial stress with eating behaviors and ultimately obesity. The aims are: Aim 1: To examine the cross-sectional relationship of psychosocial stress (chronic and immediate stress) with obesity-promoting eating behaviors (including satiety responsiveness, reinforcing value of food, and the ability to delay gratification for food) and body mass index (BMI) z-score at age 7 years among low-income children. Aim 2: To test genetic moderators of stress-eating behavior links in our cohort of low-income children. Aim 3: To examine longitudinal associations of chronic stress and reactivity to stress early in life (age 3 years) with changes in obesity-promoting eating behaviors between ages 3 and 7 years. Improved understanding of the development of associations of psychosocial stress during early life with specific, well-phenotyped eating behaviors and excessive weight gain beginning in childhood may hold promise for novel obesity prevention efforts among low-income children, a demographic group at high risk. PUBLIC HEALTH RELEVANCE: Psychosocial stress is linked with overeating and the development of obesity, but the mechanisms underlying these associations are not well-understood, particularly in children. Improved understanding of the development of associations of social-contextual and interpersonal stress with eating behavior and excessive weight gain beginning in childhood may hold promise for novel targets for obesity prevention. Given that psychosocial stress and obesity are both more common among low-income children, the work may also hold particular promise for addressing socioeconomic disparities in obesity prevalence.