Abstract

Background

Socioeconomics may explain black–white differences in physical performance; few studies examine racial differences among socioeconomically similar groups. Performance is also affected by body composition and specific strength, which differ by race. We assessed whether racial differences in physical performance exist among older adults with high education and similar income and whether body composition and specific strength attenuate observed differences.

Methods

Cross-sectional analysis of 536 men (18% black) and 576 women (28% black) aged more than 60 years from the Baltimore Longitudinal Study of Aging. Body composition was evaluated using dual-energy x-ray absorptiometry. Specific strength was assessed by quadricep peak torque divided by height-normalized thigh cross-sectional area and grip strength divided by body mass index-normalized appendicular lean mass. Physical performance was assessed using usual gait speed and fast 400 m walk time. Sex-stratified linear regression models, adjusted for age, height, education, and recent income, determined whether body composition or specific strength attenuated associations between race and physical performance.

Results

Blacks were younger, with higher weight and appendicular lean mass. Black women had higher percent fat and specific strength. In both sexes, blacks had poorer physical performance after adjustment for socioeconomic factors. In women, neither body composition nor specific strength altered the association with gait speed. In men, neither body composition nor specific strength attenuated racial differences in either performance measure.

Conclusions

Poorer physical performance among black compared to white older adults persists among persons with high education and similar income and cannot generally be attributed to differences in body composition or specific strength.

中文翻译：

---

身体成分和特定强度在老年人种族与身体表现之间的关系中的作用

抽象的

背景

社会经济学可以解释身体表现的黑白差异。很少有研究检验社会经济相似群体之间的种族差异。身体的成分和比强度也会因种族而异，因此性能也会受到影响。我们评估了受过高等教育和类似收入的老年人在身体表现上是否存在种族差异，以及身体组成和比强度是否减弱了观察到的差异。

方法

根据巴尔的摩纵向老龄化研究，对年龄超过60岁的536名男性（占18％的黑人）和576名女性（占28％的黑人）进行了横断面分析。使用双能X射线吸收法评估身体成分。通过股四头肌峰值扭矩除以身高标准化的大腿横截面积和握力除以身体质量指数标准化的阑尾瘦体重来评估比强度。使用通常的步态速度和400 m的快速步行时间评估身体表现。根据年龄，身高，学历和最近的收入进行调整的按性别分层的线性回归模型确定了身体组成或特定强度是否削弱了种族与身体表现之间的关联。

结果

黑人较年轻，体重较高，阑尾偏瘦。黑人女性的脂肪和比强度更高。在调整了社会经济因素后，黑人和白人的身体机能都较差。在女性中，无论是身体成分还是特定力量都不会改变步态速度的相关性。在男性中，无论是身体成分还是特定的力量都不能减轻种族差异。

结论

黑人与白人老年人相比，身体机能较差，受教育程度较高且收入相似的人仍然存在，通常不能归因于身体组成或特定力量的差异。