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Lookup NU author(s): Dr Richard Dodds,
Dr Karen Davies,
Dr Antoneta Granic,
Dr Kieren Hollingsworth,
Professor Grainne Gorman,
Emeritus Professor Doug Turnbull,
Professor Avan Sayer
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
Introduction The loss of mitochondrial function and content have been implicated in sarcopenia although they have been little studied in the very old, the group in which sarcopenia is most common. In this pilot study, our aim was to determine if mitochondrial respiratory chain function and content are preserved among healthy 85-year-olds. Methods We recruited 19 participants (11 female) through their general practitioner and assessed their medical history, functional status and self-reported physical activity. We identified sarcopenia using grip strength, Timed Up-and-Go and bioimpedance analysis. We assessed mitochondrial respiratory chain function using phosphorous magnetic resonance spectroscopy, estimating t1/2 PCr, the recovery half-time of phosphocreatine in the calf muscles following a bout of aerobic exercise. We performed a biopsy of the vastus lateralis muscle and assessed mitochondrial respiratory chain content by measuring levels of subunits of complex I and IV of the respiratory chain, expressed as Z-scores relative to that in young controls. Results Participants had a median (IQR) of 2 (1,3) long-term conditions, reported regular aerobic physical activity, and one participant (5.3%) had sarcopenia. Sixteen participants completed the magnetic resonance protocol and the mean (SD) t1/2 PCr of 35.6 (11.3) seconds was in keeping with preserved mitochondrial function. Seven participants underwent muscle biopsy and the mean fibre Z-scores were -0.7 (0.7) and -0.2 (0.4) for complexes I and IV, respectively, suggesting preserved content of mitochondrial respiratory chain enzymes. Conclusion Muscle mitochondrial respiratory chain function and content are preserved in a sample of active, well-functioning 85-year-olds, among whom sarcopenia was uncommon. The results from this study will help inform future work examining the association between muscle mitochondrial deficiency and sarcopenia.
Author(s): Dodds RM, Davies K, Granic A, Hollingsworth KG, Warren C, Gorman G, Turnbull DM, Sayer AA
Publication type: Article
Publication status: Published
Journal: Experimental Gerontology
Print publication date: 01/11/2018
Online publication date: 25/09/2018
Acceptance date: 24/09/2018
Date deposited: 24/09/2018
ISSN (print): 0531-5565
ISSN (electronic): 1873-6815
Publisher: Elsevier Inc.
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