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Associations between skeletal muscle energetics and accelerometry-based performance fatigability: Study of Muscle,
Yujia Susanna Qiao1, Adam J Santanasto1, Paul M Coen2
1Department of Epidemiology, School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
Aging Cell
|October 16, 2023
Summary
Skeletal muscle energetics, including maximal oxidative phosphorylation (max OXPHOS), maximal electron transfer system (max ETS), and maximal adenosine triphosphate production (ATPmax), are linked to performance fatigability in older adults. Lower muscle energetics correlate with increased fatigability, suggesting potential therapeutic targets.
Area of Science:
- Gerontology
- Skeletal Muscle Physiology
- Cellular Energetics
Background:
- Performance fatigability, characterized by insufficient energy for daily tasks, is a common issue in aging and can lead to mobility disability.
- Understanding the cellular mechanisms underlying fatigability is crucial for developing interventions to delay age-related functional decline.
- Skeletal muscle energetics are hypothesized to be a key factor contributing to performance fatigability.
Purpose of the Study:
- To investigate the association between skeletal muscle energetics and performance fatigability in older adults.
- To determine if measures of maximal oxidative phosphorylation (max OXPHOS), maximal electron transfer system (max ETS), and maximal adenosine triphosphate production (ATPmax) relate to fatigability.
Main Methods:
- Participants (N=795, age 70-94) from the Study of Muscle, Mobility and Aging underwent a 400-m walk to assess performance fatigability using the Pittsburgh Performance Fatigability Index (PPFI).
- Muscle biopsies were used to measure ex vivo max OXPHOS and max ETS via high-resolution respirometry.
- In vivo ATPmax was assessed using 31P magnetic resonance spectroscopy, with statistical analyses adjusting for relevant covariates.
Main Results:
- Lower levels of max OXPHOS, max ETS, and ATPmax were significantly associated with higher PPFI scores, indicating greater performance fatigability.
- Each one standard deviation decrease in max OXPHOS, max ETS, and ATPmax corresponded to a significant increase in PPFI score.
- The findings highlight a clear link between reduced skeletal muscle energy production capacity and increased fatigability in older individuals.
Conclusions:
- Impaired skeletal muscle energetics are associated with increased performance fatigability in older adults.
- Therapeutic strategies aimed at enhancing muscle energy production may offer a promising approach to mitigate fatigability.
- Such interventions could potentially reduce susceptibility to mobility disability in the aging population.
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