The Study of Muscle and Physical Performance in African Caribbeans.

项目总结/摘要 随着年龄的增长，身体功能的下降是一个巨大的临床和公共卫生问题，导致增加 残疾、住院、保健费用、生活质量下降和过早死亡。的负担 与高加索人相比，非洲人的身体限制和残疾率更高。复配 在这一问题上，非洲老年人占人口的比例迅速增长，特别是 在美国之外。例如，预计加勒比地区60岁以上的人口数量将从2010年的100万增加到2011年的100万。 到2050年将达到5900万至1.96亿。来自加勒比海的黑人移民不同于在美国出生的非洲裔美国人， 来自非洲的黑人移民患高血压、糖尿病和肥胖症的比率。这些差异可能是 部分原因是与非洲裔相比，非裔美国人中的高加索欧洲混合物（约25%）更多 加勒比（~6%）。然而，尽管有明确的科学前提和需要-没有专门设计的研究 彻底检查非洲加勒比人的身体机能在过去的20年里，我们一直在研究 一大批来自托巴哥的非洲加勒比男女，我们对他们进行了广泛的测量， 生活习惯、家族和病史、身体成分和生物标本。我们发现非洲人 加勒比海有更多的瘦体重（估计肌肉质量），但较弱的肌肉力量和较高的水平， 肌肉脂肪比美国成年人多。我们还发现，脂肪量的变化，而不是瘦体重，是重要的 未来的行走能力。然而，许多重要的差距仍然存在，必须扩大对有形资产的计量， 在这个队列中的表现。因此，我们建议通过直接测量 骨骼肌质量（d3肌酸稀释[D3 Cr]），并进行更深入的体能表型分析 在残疾路径的每个级别的措施，以获得全面的了解物理 在这1700名非洲加勒比人的独特队列中表现出色。Aim 1将使用大量现有数据来测试 假设风险和保护因素在非洲加勒比人中更明显， 遗传非洲混合物，糖尿病和肌肉脂肪浸润-将与身体的变化， 功能老化。目标2和3将侧重于身体成分和身体表现的新措施 我们打算收集这些数据来检验以下假设：1）肌肉质量较低，肌肉脂肪较多 渗透将与更大疲劳性和更差的物理性能有关，以及2）更差的脂肪氧化 在步行过程中，将与更大的总脂肪和肌肉脂肪，以及更大的疲劳和更糟糕的 物理性能。这些目标的成功完成将提供第一个直接评估骨骼 肌肉质量和全面调查的身体表现在非洲加勒比，一个大大低于- 研究，但迅速增长的人口，并为未来的调查奠定了基础。这些数据可以 在未来的努力，以改善，预防和治疗与年龄有关的身体表现下降。

PROJECT SUMMARY/ABSTRACT Declines in physical function with aging are an enormous clinical and public health problem that lead to increased disability, institutionalization, health care costs, lower quality of life and premature mortality. The burden of physical limitations and disability is higher in African compared with Caucasian individuals. Compounding the issue, older African Ancestry populations represent a rapidly growing segment of the population, especially outside the USA. For example, the number of individuals aged ≥60 in the Caribbean is expected to increase from 59 to 196 million by 2050. Black immigrants from the Caribbean differ from U.S. born African Americans and Black immigrants from Africa in rates of high blood pressure, diabetes, and obesity. These differences may be due in part to the greater Caucasian European Admixture (~25%) in African Americans compared with African Caribbeans (~6%). Yet, despite the clear scientific premise and need – there are no studies specifically designed to thoroughly examine physical function in African Caribbeans. Over the past 20 years, we have been studying a large cohort of African Caribbean men and women from Tobago in whom we have extensive measures of lifestyle habits, family and medical history, body composition, and biospecimens. We found that African Caribbeans have more lean mass (estimated muscle mass), but weaker muscle strength and higher levels of muscle fat than US adults. We have also discovered that changes in fat mass, but not lean mass, are important for future walking ability. However, many important gaps remain, and it is critical to expand measures of physical performance in this cohort. Therefore, we are proposing to address these gaps in the field by directly measuring skeletal muscle mass (d3 creatine dilution [D3Cr]) and performing deeper phenotyping of physical performance measures at each level in the disablement pathway to gain a comprehensive understanding of physical performance in this unique cohort of 1700 African Caribbeans. Aim 1 will use a wealth of existing data to test the hypothesis that both risk and protective factors more pronounced in African Caribbeans – specifically higher genetic African admixture, diabetes, and muscle fat infiltration - will be associated with changes in physical function with aging. Aims 2 and 3 will focus on new measures of body composition and physical performance that we are proposing to collect to test the hypotheses that: 1) lower muscle mass and greater muscle fat infiltration will be related to greater fatigability and worse physical performance, and 2) that poorer fat oxidation during walking will be associated with greater total fat and muscle fat, as well as greater fatigability and worse physical performance. Successful completion of these aims will provide the first direct assessment of skeletal muscle mass and comprehensive investigation of physical performance in African Caribbeans, a vastly under- studied, but rapidly growing population and lay the foundation for future investigations. These data can be harnessed in future efforts to improve, prevention, and treatment of age-related declines in physical performance.