Skeletal Muscle Mitochondrial Function and Fatigability in Older Adults

Adam J. Santanasto, Nancy W. Glynn, Sharon A. Jubrias, Kevin E. Conley, Robert M. Boudreau, Francesca Amati, Dawn C. Mackey, Eleanor M. Simonsick, Elsa S. Strotmeyer, Paul M. Coen, Bret H. Goodpaster, Anne B. Newman

Research output: Contribution to journalArticlepeer-review

Abstract

Background. Fatigability increases while the capacity for mitochondrial energy production tends to decrease significantly with age. Thus, diminished mitochondrial function may contribute to higher levels of fatigability in older adults. Methods. The relationship between fatigability and skeletal muscle mitochondrial function was examined in 30 participants aged 78.5 ± 5.0 years (47% female, 93% white), with a body mass index of 25.9 ± 2.7 kg/m2 and usual gait-speed of 1.2 ± 0.2 m/s. Fatigability was defined using rating of perceived exertion (6-20 point Borg scale) after a 5-minute treadmill walk at 0.72 m/s. Phosphocreatine recovery in the quadriceps was measured using 31P magnetic resonance spectroscopy and images of the quadriceps were captured to calculate quadriceps volume. ATPmax (mM ATP/s) and oxidative capacity of the quadriceps (ATPmax·Quadriceps volume) were calculated. Peak aerobic capacity (VO2peak) was measured using a modified Balke protocol. Results. ATPmax·Quadriceps volume was associated with VO2peak and was 162.61mM ATP·mL/s lower (p = .03) in those with high (rating of perceived exertion ≥10) versus low (rating of perceived exertion ≤9) fatigability. Participants with high fatigability required a significantly higher proportion of VO2peak to walk at 0.72 m/s compared with those with low fatigability (58.7 ± 19.4% vs 44.9 ± 13.2%, p < .05). After adjustment for age and sex, higher ATPmax was associated with lower odds of having high fatigability (odds ratio: 0.34, 95% CI: 0.11-1.01, p = .05). Conclusions. Lower capacity for oxidative phosphorylation in the quadriceps, perhaps by contributing to lower VO2peak, is associated with higher fatigability in older adults.

Original languageEnglish (US)
Pages (from-to)1379-1385
Number of pages7
JournalJournals of Gerontology - Series A Biological Sciences and Medical Sciences
Volume70
Issue number11
DOIs
StatePublished - Nov 2015
Externally publishedYes

Keywords

  • Aerobic capacity
  • Fatigability
  • Mitochondrial function
  • Skeletal muscle

ASJC Scopus subject areas

  • Aging
  • Geriatrics and Gerontology

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