Relationship of anabolic hormones with motor unit characteristics in quadriceps muscle in healthy and frail ageing men

Swiecicka, Agnieszka; Piasecki, Mathew; Stashuk, Daniel; Jones, David; Wu, Frederick; McPhee, Jamie; Rutter, Martin K.

Abstract

Context
Anabolic hormones are important factors in maintaining muscle mass for ageing men, but their role in overall motor unit structure and function is unclear.

Objective
To determine associations of anabolic and reproductive hormone levels with motor unit characteristics in quadriceps muscle in older healthy and frail men.

Design
Observational cohort study of community dwelling men.

Participants
Healthy and frail men > 65 years old.

Intervention
None.

Outcome measure
Quantitative assessments of electromyography-derived motor unit potential size (MUP) and compound muscle action potential size (CMAP) of vastus lateralis muscle.

Results
We studied 98 men (mean±SD: age 73±6 years; BMI 25.7±4.0 kg/m2; diabetes 11%) of whom 45% were prefrail and 18% frail. After adjusting for age, BMI and prevalent diabetes, higher total and free testosterone levels were significantly related to larger CMAP (total testosterone: β (95% CI): 0.3 (0.08, 0.53); free testosterone: 0.34 (0.13, 0.56)). Exploratory analysis showed the relationship between free testosterone and CMAP was stronger in frail rather than robust men. In univariate analyses, estradiol was associated with CMAP size (0.37 (0.16, 0.57)); and vitamin D was associated with MUP size (0.22 (0.01, 0.43)) but these relationships were no longer significant after adjusting for potential confounders.

Conclusion
Our data highlight the associations between androgen levels and the electrophysiological characteristics of older men, particularly in the frail. Clinical trials involving administration of androgens will help to elucidate the potential benefits of intervention on neuromuscular function and/or frailty status.

Citation

Swiecicka, A., Piasecki, M., Stashuk, D., Jones, D., Wu, F., McPhee, J., & Rutter, M. K. (2020). Relationship of anabolic hormones with motor unit characteristics in quadriceps muscle in healthy and frail ageing men. Journal of Clinical Endocrinology and Metabolism, 105(7), https://doi.org/10.1210/clinem/dgaa100

• Journal Article Type: Article
• Acceptance Date: Feb 28, 2020
• Online Publication Date: Mar 5, 2020
• Publication Date: 2020-07
• Deposit Date: Mar 9, 2020
• Publicly Available Date: Mar 6, 2021
• Journal: Journal of Clinical Endocrinology & Metabolism
• Print ISSN: 0021-972X
• Electronic ISSN: 1945-7197
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 105
• Issue: 7
• DOI: https://doi.org/10.1210/clinem/dgaa100
• Keywords: Anabolic hormones, electromyography, frailty, motor unit, muscle, testosterone
• Public URL: https://nottingham-repository.worktribe.com/output/4114330
• Publisher URL: https://academic.oup.com/jcem/advance-article/doi/10.1210/clinem/dgaa100/5781153
• Additional Information: This is a pre-copyedited, author-produced version of an article accepted for publication in Journal of Clinical Endocrinology & Metabolismfollowing peer review. The version of record Agnieszka Swiecicka, Mathew Piasecki, Daniel Stashuk, David Jones, Frederick Wu, Jamie McPhee, Martin K Rutter, Relationship of anabolic hormones with motor unit characteristics in quadriceps muscle in healthy and frail ageing men, The Journal of Clinical Endocrinology & Metabolismis available online at: https://doi.org/10.1210/clinem/dgaa100