Neurobiology of Childhood Obesity: An MRI study

描述(申请人提供)：儿童肥胖症是一个严重的公共卫生问题，正在迅速增加。使用成瘾模型来研究儿童肥胖症患者大脑对食物线索的反应，我们预测，线索诱导的大脑激活差异在儿童暴饮暴食行为和在试图限制食物摄入量的过程中复发起着关键作用。我们建议使用功能磁共振成像来检查肥胖儿童对食物提示的反应，并与正常体重儿童的反应进行比较。目前还没有关于其他健康肥胖儿童的神经成像研究结果发表。对我们实验室对肥胖和正常体重儿童进行的一项初步研究的功能磁共振成像(FMRI)数据的初步分析表明，与正常体重儿童相比，肥胖儿童在大脑关键区域对食物线索的反应更活跃，包括岛区、海马区和眼眶额叶皮质。我们假设，与正常体重的儿童相比，超重儿童对食物提示的反应不同，根据功能磁共振成像的测量，包括禁食状态下大脑区域更大的激活和对食物的迟钝反应。我们的具体目标是确定：(1)当食物线索与非食物线索相比较时，肥胖儿童和正常体重儿童的大脑区域激活模式是否不同？(2)禁食和饮食状态是否会不同地改变肥胖儿童对食物线索的反应？我们将使用3.0特斯拉的功能磁共振成像对20名肥胖和20名8-12岁正常体重的健康儿童进行探索性研究，以检查与肥胖相关的局部大脑活动的差异。受试者将在禁食4小时后和摄入标准餐后进行研究。在正常体重和肥胖儿童中，大脑对视觉显示的食物图像的反应将与在禁食和进食条件下对非食物的反应进行对比。这项研究承诺阐明肥胖儿童对食物暗示反应的神经基础，并为成瘾方法与暴饮暴食行为的相关性提供洞察力。这些知识对于制定预防和治疗儿童肥胖症的循证方法至关重要。肥胖是发病率和死亡率的主要和日益重要的原因，接触到食物的视觉图像可能会极大地导致暴饮暴食和肥胖。这项大脑研究将提高我们对食物线索处理过程的理解，并有助于制定行为、心理和环境干预措施，促进健康选择和行为。

DESCRIPTION (provided by applicant): Childhood obesity is a serious public health problem that is rapidly increasing. Using an addiction model to examine brain activation in response to food cues in childhood obesity, we predict that cue-induced brain activation differences play a critical role in childhood over-eating behavior and relapse during attempts to limit food intake. We propose to use fMRI to examine the response of obese children to food cues as compared to the response of normal weight children. No neuroimaging studies have been published with findings for otherwise healthy obese children. Preliminary analysis of functional magnetic resonance imaging (fMRI) data from a pilot study conducted by our lab in obese and normal weight children show that obese children, compared with normal weight children, have greater activation in response to food cues in key regions of the brain, including the insular region, the hippocampal gyrus region, and the orbitofrontal cortex. We hypothesize that in contrast to normal weight children, overweight children respond differently to food cues as measured by fMRI, including greater regional brain activation in the fasting state and a blunted response to feeding. Our specific aims are to determine: (1) Does the pattern of regional brain activation differ between obese versus normal weight children when food cues are compared to non- food cues? (2) Does fasting versus fed status differentially alter the response to food cues in obese children? We will use fMRI at 3.0 Tesla to conduct an exploratory study in 20 obese and 20 normal weight healthy children ages 8-12 to examine for differences in regional brain activity associated with obesity. Subjects will be studied after a 4-hour fast and following ingestion of a standardized meal. Brain response to visually displayed food images will be contrasted with response to non-food items across fasted and fed conditions in normal weight and obese children. This study promises to elucidate the neural substrates of the response of obese children to food cues and provide insight to the relevance of an addiction approach to overeating behavior. Such knowledge is essential in development of evidence-based methods for prevention and treatment of childhood obesity. Obesity is a major and increasingly important cause of morbidity and mortality, and exposure to visual images of food may contribute greatly to overeating and obesity. This brain study will improve our understanding of the process by which food cues undergo processing and help in the development of behavioral, psychosocial, and environmental interventions and promotions of healthy choices and behavior.