The population of older adults is exponentially expanding. Alongside aging comes the onset of chronic disease, decline of functional capacity, and reduced quality of life. Thus, this population increase will stress the capacity and financial viability of health and long-term care systems. Developing pre-clinical models for age-related functional decline is imperative to advancing therapies that extend healthspan and prolong independence. Previously in a cross-sectional study, we established a powerful composite scoring system we termed CFAB (comprehensive functional assessment battery). CFAB measures physical function and exercise capacity using well-validated determinants to measure overall motor function, fore-limb strength, four-limb strength/endurance, aerobic capacity, and volitional exercise/activity rate. In the current work, we used CFAB to track cohorts of male and female C57BL/6 mice over the lifespan (measuring CFAB at 6, 12, 18, 24, and 28 months of age). Overall, we found statistically significantly declining function as the mice aged, with some differences between males and females in trajectory and slope. We also determined that body mass changes presented differently between sexes, and tracked body composition (fat percentage, using magnetic resonance imagery) in females. In a subset of mice, we tracked in vivo contractile physiology noting declines in plantar flexor maximum isometric torque. In summary, our data suggest that males and females declined at different rates. We confirmed the efficacy of CFAB to track longitudinal changes in exercise capacity and physical fitness in both males and females, further validating the system to track age-related functional decline.

中文翻译：

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雄性和雌性小鼠运动能力的纵向下降


老年人口呈指数级增长。随着衰老，慢性病的发作、功能能力的下降和生活质量的下降。因此，这种人口增长将给卫生和长期护理系统的能力和财务可行性带来压力。开发与年龄相关的功能衰退的临床前模型对于推进延长健康寿命和延长独立性的疗法至关重要。之前在一项横断面研究中，我们建立了一个强大的综合评分系统，我们称之为 CFAB（综合功能评估电池）。CFAB 使用经过充分验证的决定因素来测量整体运动功能、前肢力量、四肢力量/耐力、有氧能力和意志运动/活动率，从而测量身体机能和运动能力。在目前的工作中，我们使用 CFAB 来跟踪雄性和雌性 C57BL/6 小鼠在整个生命周期内的队列（测量 6、12、18、24 和 28 个月大时的 CFAB）。总体而言，我们发现随着小鼠年龄的增长，功能在统计学上显着下降，雄性和雌性在轨迹和斜率上存在一些差异。我们还确定体重变化在不同性别的呈现方式不同，并跟踪女性的身体成分（脂肪百分比，使用磁共振图像）。在小鼠的子集中，我们跟踪了体内收缩生理学，注意到跖屈肌最大等长扭矩下降。总之，我们的数据表明，男性和女性的下降速度不同。我们证实了 CFAB 跟踪男性和女性运动能力和身体健康纵向变化的有效性，进一步验证了该系统跟踪与年龄相关的功能下降的有效性。