Nutritional Regulation of Bone

在美国，少数民族人口正在迅速增长。预期的人口增长 从2010到2015年，亚裔占37%，黑人/非裔美国人(AA)占20% 到只有13%的白人/高加索人(C)。众所周知，内分泌特征可能会在 这些民族，这可能与不同于Cs的脂肪库有关。为 例如，AA的肥胖率比Cs高，代谢综合征更多 与其他民族相比，流行于南亚人(SA)。而骨矿物质 SAS的骨密度(BMD)与Cs相似，骨折风险开始于较早的年龄，目前尚不清楚 如果这与他们较低的肌肉质量，较高的内脏脂肪组织或改变了 内分泌侧写。AAS具有更高的肌肉质量、BMD和更低的骨折风险 在所有种族中，脆弱性断裂的数量都在增加，最近，它 已有研究表明，肥胖者较高的骨密度并不具有保护作用。减肥就是 建议减少与肥胖和代谢综合征相关的风险，但有 此外，骨密度和几何形状的变化以及骨折风险的增加。以前的减肥研究 已经表明，绝经后的女性特别容易失去BMD，然而这些 研究反映了C级女性的反应。减肥还可以不同程度地降低BMD 和骨骼肌群在不同的解剖位置，而这些相同的位置显示出不同的 按种族划分的骨折风险。由于内脏肥胖症与骨密度受损有关， 这也可能会对不同种族的骨骼产生不同的影响。更重要的是， 不同种族之间的激素和细胞因子可能解释不同的骨骼反应 这些人群的WT变化。此外，在卡路里过程中，钙的吸收会受到影响 限制，因此确定它是否是减肥的风险因素是很重要的 导致不同种族的骨质流失。中心假设是会有骨密度的损失 在所有民族中，由于体重损失，这将部分解释为病例的减少 吸收，而特定部位的骨密度损失将在种族之间有所不同并相关 肌肉质量的区域性变化。在拟议的研究中，我们将研究3个民族 绝经后超重/肥胖妇女前后分组(SA、AA和C) 减肥：1)确定对骨密度、骨骼几何形状和强度的影响；2)确定 骨密度的变化如何与总和局部肌肉质量和脂肪储存的变化相关；以及 3)检查钙吸收是否对体重下降时骨密度的变化有贡献。理解 骨骼和软组织对减肥的种族特异性反应是新的和重要的 这些民族独特的代谢特征和疾病风险。最终目标是 制定和鼓励健康的体重控制战略，以解决种族问题 预防肥胖和骨质疏松症的多样性。

In the USA, minority populations are growing rapidly. The expected population increase from 2010 to 2015 is 37% for Asians and 20% for Black/African Americans (AA) compared to only 13% for White/Caucasians (C). It is well known that endocrine profiles may vary in these ethnic groups, and this may be associated with adipose depots that differ from Cs. For example, AA’s have higher rates of obesity than Cs, and metabolic syndrome is more prevalent in South Asians (SAs) as compared to other ethnic groups. While bone mineral density (BMD) in SAs is similar to Cs, fracture risk begins at an earlier age, and it is unclear if this is related to their lower muscle mass, higher visceral adipose tissue or altered an endocrine profile. AAs have higher muscle mass, BMD and lower fracture risk, compared to C. There are a rising number of fragility fractures in all ethnicities, and more recently, it has been shown that higher BMD in the obese is not protective. Weight loss is recommended to reduce risks associated with obesity and metabolic syndrome, but there are also changes in BMD and geometry and increased fracture risk. Previous weight loss studies have shown that postmenopausal women are particularly vulnerable to BMD loss, yet these studies reflect the response in C women. Weight loss also differentially attenuates BMD and skeletal muscle mass at different anatomical sites and these same sites show variation in fracture risk by ethnicity. Since visceral adiposity is associated with compromised BMD, this too may affect bone differently across ethnic groups. Moreover, the variations in hormones and cytokines among ethnic groups may explain a differential bone response to wt change in these populations. In addition, Ca absorption is compromised during caloric restriction, and therefore it is important to determine if it is a risk factor for weight loss induced bone loss across ethnicities. The central hypothesis is that there will be BMD loss in all ethnic groups due to wt loss that will be partially explained by a reduction in Ca absorption, whereas site specific BMD loss will differ between ethnic groups and be related to the regional changes in muscle mass. In the proposed studies, we will study 3 ethnic groups (SA, AA and C) of postmenopausal overweight/obese women before and after weight loss to: 1) determine the effect on BMD, bone geometry and strength; 2) determine how BMD changes relate to changes in total and regional muscle mass and fat depots; and 3) examine if Ca absorption contributes to BMD changes with weight loss. Understanding ethnic-specific responses of bone and soft tissue to weight loss is novel and important due the unique metabolic profiles and disease risks in these ethnic groups. The ultimate goal is to develop and encourage healthy weight control strategies that are tailored to address ethnic diversity in the prevention of obesity and osteoporosis.