Reduction in CVD risk in children by physical activity

通过体力活动降低儿童心血管疾病风险

• 批准号: 7026895
• 负责人: ROBERT C HICKNER
• 金额: $ 30.31万
• 依托单位: EAST CAROLINA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-05-01 至 2011-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7026895
• 关键词: African American; adipose tissue; aerobic exercise; behavioral /social science research tag; blood flow measurement; body physical activity; cardiovascular disorder risk; caucasian American; child physical development; clinical research; controlled environment; early experience; eating; enzyme activity; glucose metabolism; human subject; interstitial; lipolysis; longitudinal human study; metabolic syndrome; microdialysis; middle childhood (6-11); nitric oxide synthase; obesity; racial /ethnic difference

DESCRIPTION (provided by applicant): Childhood overweight is a strong predictor of adult obesity. Abnormalities in glucose and lipid homeostasis are associated with body weight gain and many o f the alterations found in the Metabolic Syndrome. Obese sedentary adults, in particular obese African Americans, are more prone to hyperglycemia, hyperinsulinemia, lower rates of post- absorptive adipose tissue lipolysis per unit fat mass, poor post- prandial suppression of lipolysis and reduced blood flow. We propose to implement the novel use of microdialysis to assess interstitial glucose and glycerol concentrations as indices of blood glucose and adipose tissue lipolysis, respectively, and adipose tissue blood flow in lean and obese prepubescent children continuously over 24 hours. The hypothesis is that overweight children exhibit higher interstitial glucose concentrations throughout the day, reduced rates of basal lipolysis and poor postprandial suppression of lipolysis compared to lean children, and that these abnormalities will be associated with a higher prevalence of cardiovascular disease risk factors. Furthermore, 16- weeks of physical activity will normalize, or bring closer to lean, the glucose and lipolytic profiles of overweight children and will result in an improved cardiovascular disease risk profile. We will investigate lean and overweight African American and Caucasian children (8- 10 yr; n=80) before and after 16 weeks of increased physical activity. Subcutaneous abdominal adipose tissue lipolysis and glucose profiles will by monitored using microdialysis under resting fasting and fed conditions as well as in response to exercise. Microdialysis probes will be perfused with either a control solution, an inhibitor of nitric oxide synthase (L- NMMA), or an activator of nitric oxide synthase (acetylcholine) to investigate the mechanism of the proposed reduction of basal lipolysis in obese and African American children. These investigations will determine if acute and chronic aerobic physical activity improves the lipolytic and glucose profiles in lean and overweight children, and whether these beneficial changes will be accompanied by improvements in cardiovascular disease risk factors. The long- term objectives are: 1) to identify the relevant in- vivo metabolic and circulatory parameters that are deficient in overweight children and adults that place them at risk for metabolic and cardiovascular disease; and 2) to find practical means of reversing metabolic and circulatory insufficiencies in obese individuals, thereby reducing the incidence of metabolic and cardiovascular diseases.

描述（由申请人提供）：儿童期超重是成人肥胖的一个强有力的预测因素。葡萄糖和脂质稳态的异常与体重增加和代谢综合征中发现的许多改变相关。肥胖的久坐不动的成年人，特别是肥胖的非裔美国人，更倾向于高血糖症、高胰岛素血症、每单位脂肪质量的吸收后脂肪组织脂解速率较低、脂解的餐后抑制较差和血流减少.我们建议实施新的使用微透析评估间质葡萄糖和甘油浓度的血糖和脂肪组织脂解，分别为指标，脂肪组织血流量在瘦和肥胖的青春期前儿童连续超过24小时。假设超重儿童全天间质葡萄糖浓度较高，基础脂解率降低，餐后脂解抑制较差，与瘦儿童相比，这些异常与心血管疾病危险因素的患病率较高相关。此外，16周的体力活动将使超重儿童的葡萄糖和脂肪分解状况正常化或接近精益，并将导致心血管疾病风险状况的改善。我们将调查瘦和超重的非洲裔美国人和白人儿童（8- 10岁; n=80）之前和之后16周的增加体力活动。在静息禁食和进食条件下以及运动后，将使用微透析监测皮下腹部脂肪组织的脂解和葡萄糖谱。微透析探针将用对照溶液、一氧化氮合酶抑制剂（L-NMMA）或一氧化氮合酶激活剂（乙酰胆碱）灌注，以研究肥胖和非裔美国儿童中基础脂解拟定减少的机制。这些研究将确定急性和慢性有氧体力活动是否能改善瘦和超重儿童的脂肪分解和葡萄糖代谢，以及这些有益的变化是否会伴随着心血管疾病风险因素的改善。长期目标是：1）确定超重儿童和成人中缺乏的相关体内代谢和循环参数，这些参数使他们处于代谢和心血管疾病的风险中;和2）找到逆转肥胖个体中代谢和循环障碍的实用方法，从而降低代谢和心血管疾病的发病率.