Coen Paul M, Yi Fanchao, Lui Li-Yung, Distefano Giovanna, Ramos Sofhia V, Goodpaster Bret H, Cawthon Peggy M, Hepple Russell T, Kritchevsky Stephen B, Cummings Steven R, Tranah Gregory J, Newman Anne B, DeLany James P
Translational Research Institute, AdventHealth, Orlando, Florida, USA.
California Pacific Medical Center Research Institute, San Francisco, California, USA.
Aging Cell. 2025 Jun;24(6):e70040. doi: 10.1111/acel.70040. Epub 2025 Mar 27.
In the United States, older adults who self-identify as Black have a disproportionately higher incidence of mobility disability compared to those who are White. Whether older adults who are Black also have lower fitness and mitochondrial energetics has not been adequately investigated. The study of muscle, mobility and aging (SOMMA) examined 879 participants aged ≥ 70 years old, including 116 who self-identified as Black. Mitochondrial respiration (Max OXPHOS) was measured in permeabilized fibers from muscle biopsies. Cardiorespiratory fitness (VO peak) was determined by a cardiopulmonary exercise test. Education, income, financial resources, race, sex, and age were determined by self-report. We used propensity score matching to match Blacks with Whites with a 1:1 ratio. Black (n = 90) and White (n = 90) groups were matched for age, sex, SOMMA multimorbidity index, BMI, muscle mass, physical activity, marital status, educational achievement, and whether financial needs were met (all p > 0.05). Despite being well matched for these variables, those who identified as Black had a slower 400-m walking speed (0.97 vs. 1.03 m/s, p = 0.014), lower Max OXPHOS (50.8 vs. 60.9 (pmol/(s*mg)), p = 0.0002), and lower cardiorespiratory fitness (1391 vs. 1566 mL/min, p = 0.007) when compared to those who identified as White. Multivariate regression showed that VO peak and Max OXPHOS, but not socioeconomic factors, attenuated the race difference in 400-m walking speed. In conclusion, while the etiology of race differences in mobility is multifactorial, our data indicate that muscle mitochondrial respiration and cardiorespiratory fitness may contribute to the slower walking speed of individuals who identify as Black compared to White.
在美国，自我认定为黑人的老年人与白人相比，行动不便的发生率出奇地高。自我认定为黑人的老年人是否也有较低的体能和线粒体能量代谢尚未得到充分研究。肌肉、行动能力与衰老研究（SOMMA）调查了879名年龄≥70岁的参与者，其中116人自我认定为黑人。通过肌肉活检的透化纤维测量线粒体呼吸（最大氧化磷酸化）。通过心肺运动试验测定心肺适能（最大摄氧量）。教育程度、收入、财务状况、种族、性别和年龄通过自我报告确定。我们使用倾向评分匹配法以1:1的比例将黑人和白人进行匹配。黑人组（n = 90）和白人组（n = 90）在年龄、性别、SOMMA多种疾病指数、体重指数、肌肉量、身体活动、婚姻状况、教育程度以及财务需求是否得到满足方面进行了匹配（所有p>0.05）。尽管在这些变量上匹配良好，但与自我认定为白人的人相比，自我认定为黑人的人400米步行速度较慢（0.97对1.03米/秒，p = 0.014），最大氧化磷酸化较低（50.8对60.9（皮摩尔/（秒·毫克）），p = 0.0002），心肺适能较低（1391对1566毫升/分钟，p = 0.007）。多变量回归显示，最大摄氧量和最大氧化磷酸化，而非社会经济因素，减弱了400米步行速度的种族差异。总之，虽然行动能力种族差异的病因是多因素的，但我们的数据表明，肌肉线粒体呼吸和心肺适能可能导致自我认定为黑人的个体与白人相比步行速度较慢。
