Department of Epidemiology, University of Pittsburgh School of Public Health, Pittsburgh, Pennsylvania, USA.
Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.
J Gerontol A Biol Sci Med Sci. 2023 Aug 2;78(8):1392-1401. doi: 10.1093/gerona/glad037.
Cardiorespiratory fitness and perceived fatigability are interrelated components of physical capacity that may jointly influence movement within one's living environment (life-space mobility). We examined whether fitness and fatigability were associated with life-space mobility in community-dwelling older adults, and whether the association of fitness with life-space varied by the level of perceived fatigability.
Participants were from the Study of Muscle, Mobility and Aging (SOMMA) baseline cohort (N = 775, mean age 76.1 years). Life Space Assessment scores incorporated level, frequency, and assistance used (personal, devices) for life-space mobility. Fitness was measured as VO2peak from symptom-limited treadmill testing. Fatigability cut-points included: (i) Borg Rating of Perceived Exertion (RPE) ≥ 10 after a fixed-speed (1.5 mph) treadmill test, (ii) the Pittsburgh Fatigability Scale (PFS) Physical ≥ 15, and (iii) PFS Mental ≥ 13. The total count of cut-points was used as a composite fatigability measure (range: 0-3). Linear regressions were adjusted for demographic, lifestyle, and health confounders.
Better fitness was associated with greater life-space, but the association plateaued at higher fitness levels (VO2peak > 18). Life-space was significantly lower for individuals meeting ≥2 fatigability criteria (vs none), attributable mainly to more severe physical, but not mental, fatigability. In moderation analyses, the fitness-life-space association was significant only for those with RPE ≥ 10 but did not differ by PFS.
Fitness below a critically low threshold was associated with limited life-space mobility, suggesting that certain older individuals may need to operate close to their maximum aerobic capacity to traverse daily environments; these associations were driven by those with more severe physical fatigability.
心肺适能和感知疲劳性是身体能力的相互关联的组成部分，它们可能共同影响人们在生活环境中的活动（生活空间移动性）。我们研究了在社区居住的老年人中，适能和疲劳性是否与生活空间移动性相关，以及适能与生活空间的相关性是否因感知疲劳性的水平而异。
参与者来自肌肉、移动性和衰老研究（SOMMA）基线队列（N=775，平均年龄 76.1 岁）。生活空间评估评分纳入了生活空间移动性的水平、频率和使用的辅助工具（个人、设备）。适能通过症状限制跑步机测试测量为 VO2peak。疲劳性的切点包括：（i）在固定速度（1.5 英里/小时）跑步机测试后，Borg 感知用力等级（RPE）≥10，（ii）匹兹堡疲劳量表（PFS）身体≥15，和（iii）PFS 心理≥13。切点的总数用作复合疲劳性测量（范围：0-3）。线性回归调整了人口统计学、生活方式和健康混杂因素。
更好的适能与更大的生活空间相关，但这种关联在更高的适能水平上趋于平稳（VO2peak > 18）。对于符合≥2 项疲劳性标准（与无标准相比）的个体，生活空间明显较小，主要归因于更严重的身体疲劳性，而不是心理疲劳性。在适度分析中，只有 RPE≥10 的个体的适能与生活空间的关联具有统计学意义，但与 PFS 无关。
低于临界低阈值的适能与有限的生活空间移动性相关，这表明某些老年人可能需要接近其最大有氧能力来穿越日常环境；这些关联是由更严重的身体疲劳性驱动的。
