The Study of Muscle and Physical Performance in African Caribbeans.

项目摘要/摘要 随着年龄的增长，身体机能的下降是一个巨大的临床和公共卫生问题，导致 残疾、住院、保健费用、较低的生活质量和过早死亡。背负着 与高加索人相比，非洲人的身体缺陷和残疾程度更高。使之复杂化 在这一问题上，非洲裔老年人口占人口的比例迅速增长，尤其是 在美国以外。例如，加勒比海地区60岁的≥人口预计将从 到2050年达到59亿至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和 来自非洲的黑人移民的高血压、糖尿病和肥胖率。这些差异可能是 部分原因是与非洲人相比，非洲裔美国人中有更多的高加索欧洲人(约25%) 加勒比海(~6%)。然而，尽管有明确的科学前提和需求，但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 一大批来自多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、身体成分和生物样本。我们发现那个非洲人 加勒比海豚有更多的瘦肉质量(估计的肌肉质量)，但肌肉力量更弱，更高的 肌肉脂肪比美国成年人多。我们还发现，脂肪质量的变化是重要的，而不是瘦质量的变化 为了将来的行走能力。然而，仍然存在许多重要差距，扩大实物措施至关重要。 在这个队列中的表现。因此，我们建议通过直接测量来解决实地的这些差距。 骨骼肌质量(d3肌酸稀释[d3cr])和进行更深层次的体能表现表型 在致残途径的每一级采取措施，以全面了解身体状况 在这个由1700名非洲加勒比人组成的独特队列中表现出色。目标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海人中更明显-特别是更高 遗传性非洲混合症、糖尿病和肌肉脂肪渗透--将与生理变化相关 随着年龄的增长而发挥作用。目标2和目标3将重点放在身体成分和身体表现的新测量上 我们建议收集这些数据来检验以下假设：1)较低的肌肉质量和较多的肌肉脂肪 渗透将与更大的疲劳性和较差的体能表现有关，以及2)较差的脂肪氧化 在步行过程中，总脂肪和肌肉脂肪更多，疲劳感更强，情况更糟 体能表现。这些目标的成功完成将提供对骨骼的第一次直接评估 肌肉质量和对非洲加勒比海人身体表现的全面调查，远远低于- 研究，但快速增长的人口，并为未来的调查奠定了基础。这些数据可以是 在今后改善、预防和治疗与年龄相关的体能下降的努力中加以利用。

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.