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dc.contributor.authorLatimer, Lorna
dc.contributor.authorPopat, Bhavesh
dc.contributor.authorHouchen-Wolloff, Linzy
dc.contributor.authorSteiner, Michael
dc.date.accessioned2022-05-23T10:21:24Z
dc.date.available2022-05-23T10:21:24Z
dc.date.issued2022-05-12
dc.identifier.citationLatimer, L. E., Constantin-Teodosiu, D., Popat, B., Constantin, D., Houchen-Wolloff, L., Bolton, C. E., Steiner, M. C., & Greenhaff, P. L. (2022). Whole-body and muscle responses to aerobic exercise training and withdrawal in ageing and COPD. The European respiratory journal, 59(5), 2101507.en_US
dc.identifier.other10.1183/13993003.01507-2021
dc.identifier.urihttp://hdl.handle.net/20.500.12904/15443
dc.description.abstractBackground: Chronic obstructive pulmonary disease (COPD) patients exhibit lower peak oxygen uptake (V'O2 peak), altered muscle metabolism and impaired exercise tolerance compared with age-matched controls. Whether these traits reflect muscle-level deconditioning (impacted by ventilatory constraints) and/or dysfunction in mitochondrial ATP production capacity is debated. By studying aerobic exercise training (AET) at a matched relative intensity and subsequent exercise withdrawal period we aimed to elucidate the whole-body and muscle mitochondrial responsiveness of healthy young (HY), healthy older (HO) and COPD volunteers to whole-body exercise. Methods: HY (n=10), HO (n=10) and COPD (n=20) volunteers were studied before and after 8 weeks of AET (65% V'O2 peak) and after 4 weeks of exercise withdrawal. V'O2 peak, muscle maximal mitochondrial ATP production rate (MAPR), mitochondrial content, mitochondrial DNA (mtDNA) copy number and abundance of 59 targeted fuel metabolism mRNAs were determined at all time-points. Results: Muscle MAPR (normalised for mitochondrial content) was not different for any substrate combination in HO, HY and COPD at baseline, but mtDNA copy number relative to a nuclear-encoded housekeeping gene (mean±sd) was greater in HY (804±67) than in HO (631±69; p=0.041). AET increased V'O2 peak in HO (17%; p=0.002) and HY (21%; p<0.001), but not COPD (p=0.603). Muscle MAPR for palmitate increased with training in HO (57%; p=0.041) and HY (56%; p=0.003), and decreased with exercise withdrawal in HO (-45%; p=0.036) and HY (-30%; p=0.016), but was unchanged in COPD (p=0.594). mtDNA copy number increased with AET in HY (66%; p=0.001), but not HO (p=0.081) or COPD (p=0.132). The observed changes in muscle mRNA abundance were similar in all groups after AET and exercise withdrawal. Conclusions: Intrinsic mitochondrial function was not impaired by ageing or COPD in the untrained state. Whole-body and muscle mitochondrial responses to AET were robust in HY, evident in HO, but deficient in COPD. All groups showed robust muscle mRNA responses. Higher relative exercise intensities during whole-body training may be needed to maximise whole-body and muscle mitochondrial adaptation in COPD.
dc.description.urihttps://erj.ersjournals.com/content/59/5/2101507.longen_US
dc.subjectExerciseen_US
dc.subjectExercise testen_US
dc.subjectOxygen consumptionen_US
dc.subjectAgingen_US
dc.subjectMusclesen_US
dc.subjectChronic obstructive pulmonary diseaseen_US
dc.titleWhole-body and muscle responses to aerobic exercise training and withdrawal in ageing and COPDen_US
dc.typeArticleen_US
rioxxterms.funderDefault funderen_US
rioxxterms.identifier.projectDefault projecten_US
rioxxterms.versionNAen_US
rioxxterms.typeJournal Article/Reviewen_US
refterms.panelUnspecifieden_US
html.description.abstractBackground: Chronic obstructive pulmonary disease (COPD) patients exhibit lower peak oxygen uptake (V'O2 peak), altered muscle metabolism and impaired exercise tolerance compared with age-matched controls. Whether these traits reflect muscle-level deconditioning (impacted by ventilatory constraints) and/or dysfunction in mitochondrial ATP production capacity is debated. By studying aerobic exercise training (AET) at a matched relative intensity and subsequent exercise withdrawal period we aimed to elucidate the whole-body and muscle mitochondrial responsiveness of healthy young (HY), healthy older (HO) and COPD volunteers to whole-body exercise. Methods: HY (n=10), HO (n=10) and COPD (n=20) volunteers were studied before and after 8 weeks of AET (65% V'O2 peak) and after 4 weeks of exercise withdrawal. V'O2 peak, muscle maximal mitochondrial ATP production rate (MAPR), mitochondrial content, mitochondrial DNA (mtDNA) copy number and abundance of 59 targeted fuel metabolism mRNAs were determined at all time-points. Results: Muscle MAPR (normalised for mitochondrial content) was not different for any substrate combination in HO, HY and COPD at baseline, but mtDNA copy number relative to a nuclear-encoded housekeeping gene (mean±sd) was greater in HY (804±67) than in HO (631±69; p=0.041). AET increased V'O2 peak in HO (17%; p=0.002) and HY (21%; p<0.001), but not COPD (p=0.603). Muscle MAPR for palmitate increased with training in HO (57%; p=0.041) and HY (56%; p=0.003), and decreased with exercise withdrawal in HO (-45%; p=0.036) and HY (-30%; p=0.016), but was unchanged in COPD (p=0.594). mtDNA copy number increased with AET in HY (66%; p=0.001), but not HO (p=0.081) or COPD (p=0.132). The observed changes in muscle mRNA abundance were similar in all groups after AET and exercise withdrawal. Conclusions: Intrinsic mitochondrial function was not impaired by ageing or COPD in the untrained state. Whole-body and muscle mitochondrial responses to AET were robust in HY, evident in HO, but deficient in COPD. All groups showed robust muscle mRNA responses. Higher relative exercise intensities during whole-body training may be needed to maximise whole-body and muscle mitochondrial adaptation in COPD.en_US
rioxxterms.funder.project94a427429a5bcfef7dd04c33360d80cden_US


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