Obesity and Free Fatty Acid Flux

肥胖和游离脂肪酸通量

• 批准号: 7334651
• 负责人: Anne E Sumner
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF DIABETES AND DIGESTIVE AND KIDNEY DISEASES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7334651
• 关键词: Obesity; Free; Fatty; Acid; Flux; Obesity; Free; Fatty; Acid; Flux

Thirty percent of Americans are obese. Women are more severely affected than men. African-Americans are more severely affected than Caucasians. To understand the metabolic consequences of obesity, it is essential to know the rate at which free fatty acids (FFA) are released from adipose tissue. Circulating FFA contribute to the complications of obesity particularly diabetes and heart disease. As there are sex and race differences in the prevalence of all these conditions there may be sex and race differences in FFA flux. FFA flux represents the rate at which FFA circulate. FFA flux is the result of three processes going on at the same time, (1) the rate FFA are released from adipose tissue, (2) the rate circulating FFA are used for energy, and (3) the rate FFA leaves the circulation to re-enter adipose tissue. No data is available on whether sex and race differences in FFA flux exist. Further, when comparing subjects of different size, sex and race, it is unknown whether FFA flux should be corrected for lean body mass or resting energy expenditure. To determine if there are sex and race differences in FFA flux and to ensure adequate enrollment of both African American and Caucasians, this investigation is a collaborative effort between the National Institutes of Health (NIH) in Bethesda, Maryland and the Mayo Clinic in Olmsted County, Minnesota. The greater Washington, DC, metropolitan area, where NIH is located, has a large African-American community whereas over 90% of residents of Olmsted County are Caucasians. Therefore, sex differences in FFA flux in African Americans will be studied at the National Institutes of Health. Sex differences in in FFA flux Caucasians will be studied at the Mayo Clinic. The results of the two studies will be combined to determine if there are race differences in FFA flux. At NIH, 50 African-Americans (25M, 25W, age range 18-49 years) will be enrolled. Equal numbers of normal weight, overweight and obese subjects will be recruited. As outpatients, participants will be placed on weight maintaining diets for two weeks and then admitted for a two-day hospital stay. On each in-hospital morning, resting energy expenditure will be measured and stable isotopes infused to measure FFA flux. Stable isotopes are naturally occurring forms of elements, which are safe and non-radioactive. From the study of African-Americans at NIH it will be possible to determine if (a) the rate of FFA release in African-Americans is more highly related to lean body mass or to resting energy expenditure, and (b) if there is a sex difference in this relationship. Then as described above, the results from the Mayo Clinic and NIH will be combined to determine if there are race differences in the FFA flux.

30％的美国人肥胖。女性比男性受到严重影响。与高加索人相比，非裔美国人受到严重影响。 为了了解肥胖的代谢后果，必须了解从脂肪组织中释放出游离脂肪酸（FFA）的速率。循环FFA导致肥胖症的并发症，特别是糖尿病和心脏病。由于所有这些条件的患病率存在​​性别和种族差异，因此FFA通量可能存在性别和种族差异。 FFA通量代表FFA循环的速率。 FFA通量是同时进行的三个过程的结果，（1）速率FFA从脂肪组织中释放出来，（2）循环FFA的速率用于能量，并且（3）速率FFA使循环循环以重新输入脂肪组织。没有有关FFA通量中是否存在性别和种族差异的数据。此外，在比较不同大小，性别和种族的受试者时，尚不清楚FFA通量是否应纠正瘦体重或静息能量消耗。 为了确定FFA通量中是否存在性别和种族差异，并确保非洲裔美国人和高加索人都足够入学，这项调查是贝塞斯达，马里兰州的美国国立卫生研究院（NIH）与明尼苏达州奥尔姆斯特县的梅奥诊所之间的合作努力。 NIH所在的大华盛顿特区，大都市地区拥有大型的非裔美国人社区，而奥尔姆斯特德县（Olmsted County）的90％以上的居民是高加索人。因此，将在美国国立卫生研究院研究非洲裔美国人的FFA通量的性别差异。 FFA通量高加索人的性别差异将在Mayo诊所进行研究。两项研究的结果将合并，以确定FFA通量中的种族差异。 在NIH，将招募50名非裔美国人（25m，25W，年龄范围18-49岁）。将招募相等数量的正常体重，超重和肥胖受试者。作为门诊患者，将参加两个星期的体重维持饮食，然后承认为期两天的住院住院。在每个院内早晨，将测量静息能量消耗，并注入稳定的同位素以测量FFA通量。稳定的同位素是自然存在的元素形式，它们是安全且非放射性活性的。 从NIH的非裔美国人的研究可以确定（a）（a）非裔美国人的FFA释放率是否与瘦体重或静息能量消耗更高度相关，以及（b）这种关系中的性别差异。然后如上所述，将合并Mayo诊所和NIH的结果，以确定FFA通量中是否存在种族差异。