Obesity and Free Fatty Acid Flux

为了确定FFA通量是否存在性别和种族差异，并确保非裔美国人和白人都有足够的入组，这项调查是马里兰州贝塞斯达的美国国立卫生研究院（NIH）和明尼苏达州奥姆斯特德县的梅奥诊所合作开展的。美国国立卫生研究院所在的大华盛顿特区大都市区有一个庞大的非洲裔美国人社区，而奥姆斯特德县90%以上的居民是白人。因此，非裔美国人FFA通量的性别差异将主要在美国国立卫生研究院进行研究。白人游离脂肪酸通量的性别差异将主要在梅奥诊所进行研究。这两项研究的结果将结合起来，以确定FFA通量是否存在种族差异。为了确保结果归因于种族差异（非裔美国人与白人）而不是地点差异（NIH与Mayo），一些白人将被NIH录取，而一些非裔美国人将被Mayo录取。

To determine if there are sex and ethnic differences in FFA flux and to ensure adequate enrollment of both African American and whites, 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 whites. Therefore, sex differences in FFA flux in African Americans will be mainly studied at the National Institutes of Health. Sex differences in FFA flux in whites will be mainly studied at the Mayo Clinic. The results of the two studies will be combined to determine if there are ethnic differences in FFA flux. To ensure results are attributable to ethnic differences (African American versus white) rather than site differences (NIH versus Mayo) some whites will be enrolled at NIH and some African Americans at Mayo. At NIH, 50 African-Americans (25M, 25W) and 14 whites (7M, 7W) 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. At NIH 7 African-American men, 14 African-American women and 3 white women have completed the protocol and analyses are underway.