SKELETAL MUSCLE--NEW BODY COMPOSITION MODELS

肥胖及其相关的医学并发症代表了一种 黑人妇女的主要健康问题。 评估患病率 和黑人女性肥胖的潜在发病机制， 准确估计身体脂肪和代谢活性 组织块 目前，体重被细分为脂肪和 通过基于假设密度K的模型计算无脂肪分数 浓度，或无脂体重（FFM）的水合作用。 虽然水密度测定，全身计数的K，和总 身体水方法被认为是研究水平的技术， 其它针对它们校准的方法广泛用于临床 实践或实地调查。 人体评价 因此，组合物在很大程度上依赖于两个- 基于或验证n个相对有效的隔室模型 几具白色男性尸体 直到最近， 一些体内尸体研究受到以下因素的限制： 他需要方法论。 如今的重大技术进步， 然而，提供了重新校准双室的机会， 方法学和探索以前无法测量的身体 隔间 在我们资助的研究的初始阶段， 结合独特的资源（流体密度测定法，双光子 吸收法，放射性同位素，中子非弹性 散射、延迟和瞬发伽马中子活化）， 估计身体密度，骨灰，H2O，交换性钠，和总 体K、Na、Cl、N、P、Ca和C。 通过应用这些技术 我们：1）开发或显着改善三室多室 身体成分模型，2）评估了四种估计方法， 体内FFM密度; 3）验证DPA在骨衍生中的使用 矿物质、骨骼肌和全身脂肪， 在匹配的（年龄，体重， 身高）妇女的骨矿物质、全身K和FFM密度; 和5）观察到水合作用的相对增加和 肥胖黑人女性与匹配的瘦女性的FFM密度比较 对照 这次更新的目的是1）扩大我们的主题 合并液（n-7），以提供两室的确定系数 女性模型作为年龄、种族和体脂的函数; 2） 模型静息代谢率与广泛体 在这个不同的主题组的组成测量;和 3)批判性地评估身体组成方法和模型， 跟踪肥胖女性减肥的间隔变化， 低热量饮食超过三个月。

Obesity and its associated medical complications represent a major health problem in black women. Evaluating the prevalence and underlying pathogenesis of obesity in black women requires accurate estimates of body fat and the metabolically active tissue mass. At present body weight is subdivided into fat and fat-free fractions through models based on an assumed density, K concentration, or hydration of the fat-free body mass (FFM). Although hydrodensitometry, whole body counting for K, and total body water methods are considered research level techniques, other methods calibrated against them are widely used in clinical practice or in field surveys. The evaluation of human body composition thus relies to a very large extent on the two- compartment models which are based on or validated n relatively few white male cadavers. Until recently , pushing beyond these few cadaver studies in vivo was limited by the unavailability of he required methodology. Major technological advances now, however, provide the opportunity to recalibrate two-compartment methodology and to explore previously unmeasurable body compartments. In the initial phase of our funded study we combined unique resources (hydrodensitometry, dual photon absorptiometry (DPA), radioactive isotopes, neutron inelastic scattering, and delayed and prompt gamma neutron activation) to estimate body density, bone ash, H2O, exchangeable Na, and total body K, Na, Cl, N, P, Ca, and C. By applying these techniques we: 1) developed or markedly improved three-multicompartment body composition models, 2) evaluated four methods of estimating FFM density in vivo, 3) validated the use of DPA in deriving bone mineral, appendicular skeletal muscle, and total body fat, to demonstrate black-white differences in matched (age, weight, height) women for bone mineral, total body K, and FFM density; and 5) observed a relative increase in hydration and lowering of FFM density in obese black women compared to matched lean controls. The aims of this renewal are to 1) expand our subject pool (n-7) to provide definitive coefficients for two-compartment models in women as a function of age, ethnicity, and body fat; 2) model resting metabolic rate in relation to extensive body composition measurements in this diverse group of subjects; and 3) critically evaluate body composition methodology and models in tracking compartmental changes in obese women losing weight on a hypocaloric diet over three months.