Insulin Resistance and Declining Physical Activity Levels in African American and

总体目标：确定身体素质下降的生理和心理决定因素 拉丁裔和非裔美国女孩在青春期的活动。理由：体力活动的减少 发生在青春期的这种情况在性别、种族和国籍方面都一致地被发现 人类研究，以及动物研究中的跨物种研究，表明了生物学基础。青春期 拉丁裔和非裔美国女孩的转变代表着一个发展的“关键时期” 已经注意到胰岛素抵抗的增加和体力活动的减少。这些“危险的”代谢 这一易感人群的行为变化可能在一定程度上解释了他们患癌症风险增加的原因。 肥胖。青春期体力活动的减少也会增加乳房、子宫内膜和 结肠癌。具体目标和方法：目标1(纵向研究)：确定直接 拉美裔和非裔美国少女青春期胰岛素抵抗对体力活动的影响 从晒黑阶段1-3的青春期过渡期间体力活动的情绪和意义。目标2：TC 确定青春期诱导的胰岛素抵抗对体力活动的影响是如何通过模拟实验来调节的 以及体力活动的含义。目的3：研究种族差异对胰岛素的影响 抗拒情绪，体力活动和体力活动的意义。我们将招募50名拉丁裔女孩 和50名9-11岁的非裔美国女孩在坦纳阶段1。年度新陈代谢评估和 每季度进行一次加速测量和心理社会评价，为期三年。一个 路径模型和增长曲线模型的组合将被用来理解纵向影响 拉丁裔和非洲人青春期胰岛素抵抗对情绪、动机和体力活动水平的影响 成熟的美国女孩。中心假设：青春期胰岛素抵抗导致青春期 体力活动。女孩体力活动的减少在一定程度上是生物程序化的， 与体力活动的情感决定因素有关的胰岛素抵抗的“诱因” 包括情绪和能量水平，这些新陈代谢和心理变化有助于 青春期体力活动明显减少。这项研究将是第一个检查 青春期胰岛素抵抗与体力活动锐减的时间关系 拉丁裔和非裔美国女孩在青春期经历的。

Overall goal: To determine physiological and psychological determinants of the decline in physical activity in Latina and African American girls during puberty. Rationale: The decline in physical activity that occurs during adolescence has been found consistently across gender, ethnicity and nationality in human studies, and across species in animal studies, suggesting a biological basis. The pubertal transition in Latina and African American girls represents a "critical period" of development in which increased insulin resistance and decreased physical activity have been noted. These "risky" metabolic and behavioral changes in this susceptible ethnic group may explain, in part, their increased risk for obesity. This pubertal decrease in physical activity also raises future risk of breast, endometrial and colon cancer. Specific aims and Approach: Aim 1 (Longitudinal Study): To determine the direct impact of pubertal insulin resistance in Latina and African American adolescent girls on physical activity, mood and meanings of physical activity across the pubertal transition from Tanner Stage 1-3. Aim 2: Tc determine how the impact of puberty induced insulin resistance on physical activity is mediated by moot and meanings of physical activity. Aim 3: To investigate ethnic differences in the impact of insulin resistance on mood, meanings of physical activity and physical activity. We will recruit 50 Latina girls and 50 African American girls 9-11 years of age at Tanner Stage 1. Yearly metabolic evaluations and quarterly accelerometry and psychosocial evaluations will be completed for a period of three years. A combination of path models and growth curve models will be used to understand the longitudinal impact of pubertal insulin resistance on mood, motivation and physical activity levels in Latina and African American girls as they mature. Central hypotheses: Pubertal insulin resistance leads to a decline in physical activity. The decline in physical activity in girls is partially biologically programmed, emanating from the "trigger" of insulin resistance, which is linked to affective determinants of physical activity including mood and energy levels, and these metabolic and psychological changes contribute to the marked decline in physical activity that occurs during puberty. This study will be the first to examine the temporal relationship between pubertal insulin resistance and the sharp decline in physical activity experienced by Latina and African American girls during puberty.