Sex Differences in Muscle Decline in Older Adults
Author Information
Author(s): Y. Guo, Eleanor J. Jones, Thomas F. Smart, Abdulmajeed Altheyab, Nishadi Gamage, Daniel W. Stashuk, Jessica Piasecki, Bethan E. Phillips, Philip J. Atherton, Mathew Piasecki
Primary Institution: Centre of Metabolism, Ageing & Physiology (COMAP), University of Nottingham
Hypothesis
Females would have lower functional performance than males and markers of more extensive motor unit remodelling and physical deterioration than males.
Conclusion
Older females display higher motor unit firing rates at normalized contraction intensities compared to older males, but functional deterioration progresses similarly from early to late elderly stages of ageing.
Supporting Evidence
- Females had higher motor unit firing rates than males.
- Both sexes showed decreased neuromuscular function from early to late elderly.
- Females had smaller muscle size and lower strength compared to males.
Takeaway
Older women can use their muscles faster than older men, but they still struggle more with strength and balance as they age.
Methodology
Intramuscular electromyography signals were collected from 50 healthy older adults during standardized submaximal contractions to quantify motor unit characteristics.
Limitations
The study did not measure circulating levels of sex hormones or other biomarkers related to neural plasticity, and findings cannot be extrapolated to higher threshold motor units.
Participant Demographics
26 healthy older males (age range: 61−83 years) and 24 healthy older females (age range: 60−79 years).
Statistical Information
P-Value
0.025
Confidence Interval
95% CI: −7.24 to −4.74
Statistical Significance
p<0.05
Digital Object Identifier (DOI)
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