1
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Cung S, Pyle L, Nadeau K, Dabelea D, Cree-Green M, Davis SM. In-vivo skeletal muscle mitochondrial function in Klinefelter syndrome. J Investig Med 2022; 70:104-107. [PMID: 34493629 PMCID: PMC8712372 DOI: 10.1136/jim-2021-001966] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/13/2021] [Indexed: 01/03/2023]
Abstract
Klinefelter syndrome (XXY) occurs in 1 in 600 males, resulting in testosterone deficiency and a high prevalence of insulin resistance. Testosterone deficiency in men is a known cause of insulin resistance, and mitochondrial dysfunction is hypothesized to mediate this relationship. The aim of this cross-sectional study was to evaluate muscle mitochondrial function in XXY compared with male controls. Twenty-seven boys with XXY (age 14.7±1.8 years) were compared with 87 controls (age 16.9±0.9). In-vivo calf muscle mitochondrial function was assessed via phosphorus magnetic resonance spectroscopy (31P-MRS) following 90 s of isometric 70% maximal exercise. Multiple linear regression was used to compare 31P-MRS outcomes (ADP and phosphocreatine (PCr) time constants, rate of oxidative phosphorylation (Oxphos), and Qmax or the maximal mitochondrial function relative to mitochondrial density) between groups after adjusting for age differences. There were no statistically significant differences in the mitochondrial outcomes of ADP, Oxphos, PCr, and Qmax between the groups. There were also no differences in a sensitivity analysis within the XXY group by testosterone treatment status. In this study, in-vivo postexercise skeletal muscle mitochondrial function does not appear to be impaired in adolescents with XXY compared with controls and is not significantly different by testosterone treatment status in XXY.
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Affiliation(s)
- Stephanie Cung
- University of Colorado School of Medicine; Aurora, CO USA
| | - Laura Pyle
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO USA.,Department of Biostatistics and Informatics, Colorado School of Public Health, Aurora, CO USA
| | - Kristin Nadeau
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO USA
| | - Dana Dabelea
- Department of Epidemiology, Colorado School of Public Health, Aurora, CO USA.,Lifecourse Epidemiology of Adiposity and Diabetes (LEAD) Center, Aurora, CO USA
| | - Melanie Cree-Green
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO USA
| | - Shanlee M. Davis
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO USA.,eXtraordinarY Kids Clinic and Research Program, Children’s Hospital Colorado, Aurora, CO USA
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2
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Gupta R, Karczewski KJ, Howrigan D, Neale BM, Mootha VK. Human genetic analyses of organelles highlight the nucleus in age-related trait heritability. eLife 2021; 10:68610. [PMID: 34467851 PMCID: PMC8476128 DOI: 10.7554/elife.68610] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Accepted: 08/30/2021] [Indexed: 12/15/2022] Open
Abstract
Most age-related human diseases are accompanied by a decline in cellular organelle integrity, including impaired lysosomal proteostasis and defective mitochondrial oxidative phosphorylation. An open question, however, is the degree to which inherited variation in or near genes encoding each organelle contributes to age-related disease pathogenesis. Here, we evaluate if genetic loci encoding organelle proteomes confer greater-than-expected age-related disease risk. As mitochondrial dysfunction is a 'hallmark' of aging, we begin by assessing nuclear and mitochondrial DNA loci near genes encoding the mitochondrial proteome and surprisingly observe a lack of enrichment across 24 age-related traits. Within nine other organelles, we find no enrichment with one exception: the nucleus, where enrichment emanates from nuclear transcription factors. In agreement, we find that genes encoding several organelles tend to be 'haplosufficient,' while we observe strong purifying selection against heterozygous protein-truncating variants impacting the nucleus. Our work identifies common variation near transcription factors as having outsize influence on age-related trait risk, motivating future efforts to determine if and how this inherited variation then contributes to observed age-related organelle deterioration.
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Affiliation(s)
- Rahul Gupta
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General Hospital, Boston, United States.,Broad Institute of MIT and Harvard, Cambridge, United States.,Analytic and Translational Genetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, United States
| | - Konrad J Karczewski
- Broad Institute of MIT and Harvard, Cambridge, United States.,Analytic and Translational Genetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, United States
| | - Daniel Howrigan
- Broad Institute of MIT and Harvard, Cambridge, United States.,Analytic and Translational Genetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, United States
| | - Benjamin M Neale
- Broad Institute of MIT and Harvard, Cambridge, United States.,Analytic and Translational Genetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, United States
| | - Vamsi K Mootha
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General Hospital, Boston, United States.,Broad Institute of MIT and Harvard, Cambridge, United States
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3
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Heskamp L, Lebbink F, van Uden MJ, Maas MC, Claassen JAHR, Froeling M, Kemp GJ, Boss A, Heerschap A. Post-exercise intramuscular O 2 supply is tightly coupled with a higher proximal-to-distal ATP synthesis rate in human tibialis anterior. J Physiol 2021; 599:1533-1550. [PMID: 33369737 PMCID: PMC7986184 DOI: 10.1113/jp280771] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 12/21/2020] [Indexed: 11/08/2022] Open
Abstract
Key points The post‐exercise recovery of phosphocreatine, a measure of the oxidative capacity of muscles, as assessed by 31P MR spectroscopy, shows a striking increase from distal to proximal along the human tibialis anterior muscle. To investigate why this muscle exhibits a greater oxidative capacity proximally, we tested whether the spatial variation in phosphocreatine recovery rate is related to oxygen supply, muscle fibre type or type of exercise. We revealed that oxygen supply also increases from distal to proximal along the tibialis anterior, and that it strongly correlated with phosphocreatine recovery. Carnosine level, a surrogate measure for muscle fibre type was not different between proximal and distal, and type of exercise did not affect the gradient in phosphocreatine recovery rate. Taken together, the findings of this study suggest that the post‐exercise spatial gradients in oxygen supply and phosphocreatine recovery are driven by a higher intrinsic mitochondrial oxidative capacity proximally.
Abstract Phosphorus magnetic resonance spectroscopy (31P MRS) of human tibialis anterior (TA) revealed a strong proximo‐distal gradient in the post‐exercise phosphocreatine (PCr) recovery rate constant (kPCr), a measure of muscle oxidative capacity. The aim of this study was to investigate whether this kPCr gradient is related to O2 supply, resting phosphorylation potential, muscle fibre type, or type of exercise. Fifteen male volunteers performed continuous isometric ankle dorsiflexion at 30% maximum force until exhaustion. At multiple locations along the TA, we measured the oxidative PCr resynthesis rate (VPCr = kPCr × PCr depletion) by 31P MRS, the oxyhaemoglobin recovery rate constant (kO2Hb) by near infrared spectroscopy, and muscle perfusion with MR intravoxel incoherent motion imaging. The kO2Hb, kPCr, VPCr and muscle perfusion depended on measurement location (P < 0.001, P < 0.001, P = 0.032 and P = 0.003, respectively), all being greater proximally. The kO2Hb and muscle perfusion correlated with kPCr (r = 0.956 and r = 0.852, respectively) and VPCr (r = 0.932 and r = 0.985, respectively), the latter reflecting metabolic O2 consumption. Resting phosphorylation potential (PCr/inorganic phosphate) was also higher proximally (P < 0.001). The surrogate for fibre type, carnosine content measured by 1H MRS, did not differ between distal and proximal TA (P = 0.884). Performing intermittent exercise to avoid exercise ischaemia, still led to larger kPCr proximally than distally (P = 0.013). In conclusion, the spatial kPCr gradient is strongly associated with the spatial variation in O2 supply. It cannot be explained by exercise‐induced ischaemia nor by fibre type. Our findings suggest it is driven by a higher proximal intrinsic mitochondrial oxidative capacity, apparently to support contractile performance of the TA. The post‐exercise recovery of phosphocreatine, a measure of the oxidative capacity of muscles, as assessed by 31P MR spectroscopy, shows a striking increase from distal to proximal along the human tibialis anterior muscle. To investigate why this muscle exhibits a greater oxidative capacity proximally, we tested whether the spatial variation in phosphocreatine recovery rate is related to oxygen supply, muscle fibre type or type of exercise. We revealed that oxygen supply also increases from distal to proximal along the tibialis anterior, and that it strongly correlated with phosphocreatine recovery. Carnosine level, a surrogate measure for muscle fibre type was not different between proximal and distal, and type of exercise did not affect the gradient in phosphocreatine recovery rate. Taken together, the findings of this study suggest that the post‐exercise spatial gradients in oxygen supply and phosphocreatine recovery are driven by a higher intrinsic mitochondrial oxidative capacity proximally.
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Affiliation(s)
- Linda Heskamp
- Department of Medical Imaging/Radiology, Radboud university medical center, Nijmegen, The Netherlands
| | - Franciska Lebbink
- Department of Medical Imaging/Radiology, Radboud university medical center, Nijmegen, The Netherlands
| | - Mark J van Uden
- Department of Medical Imaging/Radiology, Radboud university medical center, Nijmegen, The Netherlands
| | - Marnix C Maas
- Department of Medical Imaging/Radiology, Radboud university medical center, Nijmegen, The Netherlands
| | - Jurgen A H R Claassen
- Department of Geriatrics, Radboud university medical center, Nijmegen, The Netherlands
| | - Martijn Froeling
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Graham J Kemp
- Department of Musculoskeletal and Ageing Science, University of Liverpool, Liverpool, UK
| | - Andreas Boss
- Department of Medical Imaging/Radiology, Radboud university medical center, Nijmegen, The Netherlands
| | - Arend Heerschap
- Department of Medical Imaging/Radiology, Radboud university medical center, Nijmegen, The Netherlands
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4
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Krumpolec P, Klepochová R, Just I, Tušek Jelenc M, Frollo I, Ukropec J, Ukropcová B, Trattnig S, Krššák M, Valkovič L. Multinuclear MRS at 7T Uncovers Exercise Driven Differences in Skeletal Muscle Energy Metabolism Between Young and Seniors. Front Physiol 2020; 11:644. [PMID: 32695010 PMCID: PMC7336536 DOI: 10.3389/fphys.2020.00644] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 05/20/2020] [Indexed: 12/27/2022] Open
Abstract
Purpose: Aging is associated with changes in muscle energy metabolism. Proton (1H) and phosphorous (31P) magnetic resonance spectroscopy (MRS) has been successfully applied for non-invasive investigation of skeletal muscle metabolism. The aim of this study was to detect differences in adenosine triphosphate (ATP) production in the aging muscle by 31P-MRS and to identify potential changes associated with buffer capacity of muscle carnosine by 1H-MRS. Methods: Fifteen young and nineteen elderly volunteers were examined. 1H and 31P-MRS spectra were acquired at high field (7T). The investigation included carnosine quantification using 1H-MRS and resting and dynamic 31P-MRS, both including saturation transfer measurements of phosphocreatine (PCr), and inorganic phosphate (Pi)-to-ATP metabolic fluxes. Results: Elderly volunteers had higher time constant of PCr recovery (τPCr) in comparison to the young volunteers. Exercise was connected with significant decrease in PCr-to-ATP flux in both groups. Moreover, PCr-to-ATP flux was significantly higher in young compared to elderly both at rest and during exercise. Similarly, an increment of Pi-to-ATP flux with exercise was found in both groups but the intergroup difference was only observed during exercise. Elderly had lower muscle carnosine concentration and lower postexercise pH. A strong increase in phosphomonoester (PME) concentration was observed with exercise in elderly, and a faster Pi:PCr kinetics was found in young volunteers compared to elderly during the recovery period. Conclusion: Observations of a massive increment of PME concentration together with high Pi-to-ATP flux during exercise in seniors refer to decreased ability of the muscle to meet the metabolic requirements of exercise and thus a limited ability of seniors to effectively support the exercise load.
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Affiliation(s)
- Patrik Krumpolec
- High Field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria.,Biomedical Research Center, Institute of Experimental Endocrinology, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Radka Klepochová
- High Field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Ivica Just
- High Field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Marjeta Tušek Jelenc
- High Field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Ivan Frollo
- Department of Imaging Methods, Institute of Measurements Science, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Jozef Ukropec
- Biomedical Research Center, Institute of Experimental Endocrinology, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Barbara Ukropcová
- Biomedical Research Center, Institute of Experimental Endocrinology, Slovak Academy of Sciences, Bratislava, Slovakia.,Faculty of Medicine, Institute of Pathophysiology, Comenius University in Bratislava, Bratislava, Slovakia
| | - Siegfried Trattnig
- High Field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria.,Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria
| | - Martin Krššák
- High Field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria.,Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria.,Division of Endocrinology and Metabolism, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Ladislav Valkovič
- High Field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria.,Department of Imaging Methods, Institute of Measurements Science, Slovak Academy of Sciences, Bratislava, Slovakia.,Oxford Centre for Clinical Magnetic Resonance Research, RDM Cardiovascular Medicine, University of Oxford, Oxford, United Kingdom
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5
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Jones S, Tillin T, Williams S, Eastwood SV, Hughes AD, Chaturvedi N. Type 2 diabetes does not account for ethnic differences in exercise capacity or skeletal muscle function in older adults. Diabetologia 2020; 63:624-635. [PMID: 31820039 PMCID: PMC6997264 DOI: 10.1007/s00125-019-05055-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 10/29/2019] [Indexed: 01/14/2023]
Abstract
AIMS/HYPOTHESIS The aim of this study was to compare exercise capacity, strength and skeletal muscle perfusion during exercise, and oxidative capacity between South Asians, African Caribbeans and Europeans, and determine what effect ethnic differences in the prevalence of type 2 diabetes has on these functional outcomes. METHODS In total, 708 participants (aged [mean±SD] 73 ± 7 years, 56% male) were recruited from the Southall and Brent Revisited (SABRE) study, a UK population-based cohort comprised of Europeans (n = 311) and South Asian (n = 232) and African Caribbean (n = 165) migrants. Measurements of exercise capacity using a 6 min stepper test (6MST), including measurement of oxygen consumption ([Formula: see text]) and grip strength, were performed. Skeletal muscle was assessed using near infrared spectroscopy (NIRS); measures included changes in tissue saturation index (∆TSI%) with exercise and oxidative capacity (muscle oxygen consumption recovery, represented by a time constant [τ]). Analysis was by multiple linear regression. RESULTS When adjusted for age and sex, in South Asians and African Caribbeans, exercise capacity was reduced compared with Europeans ([Formula: see text] [ml min-1 kg-1]: β = -1.2 [95% CI -1.9, -0.4], p = 0.002, and β -1.7 [95% CI -2.5, -0.8], p < 0.001, respectively). South Asians had lower and African Caribbeans had higher strength compared with Europeans (strength [kPa]: β = -9 [95% CI -12, -6), p < 0.001, and β = 6 [95% CI 3, 9], p < 0.001, respectively). South Asians had greater decreases in TSI% and longer τ compared with Europeans (∆TSI% [%]: β = -0.9 [95% CI -1.7, -0.1), p = 0.024; τ [s]: β = 11 [95% CI 3, 18], p = 0.006). Ethnic differences in [Formula: see text] and grip strength remained despite adjustment for type 2 diabetes or HbA1c (and fat-free mass for grip strength). However, the differences between Europeans and South Asians were no longer statistically significant after adjustment for other possible mediators or confounders (including physical activity, waist-to-hip ratio, cardiovascular disease or hypertension, smoking, haemoglobin levels or β-blocker use). The difference in ∆TSI% between Europeans and South Asians was marginally attenuated after adjustment for type 2 diabetes or HbA1c and was also no longer statistically significant after adjusting for other confounders; however, τ remained significantly longer in South Asians vs Europeans despite adjustment for all confounders. CONCLUSIONS/INTERPRETATION Reduced exercise capacity in South Asians and African Caribbeans is unexplained by higher rates of type 2 diabetes. Poorer exercise tolerance in these populations, and impaired muscle function and perfusion in South Asians, may contribute to the higher morbidity burden of UK ethnic minority groups in older age.
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Affiliation(s)
- Siana Jones
- MRC Unit for Lifelong Health and Ageing at UCL, Department of Population Science and Experimental Medicine, Institute of Cardiovascular Science, University College London, Gower Street, London, WC1E 6BT, UK.
| | - Therese Tillin
- MRC Unit for Lifelong Health and Ageing at UCL, Department of Population Science and Experimental Medicine, Institute of Cardiovascular Science, University College London, Gower Street, London, WC1E 6BT, UK
| | - Suzanne Williams
- MRC Unit for Lifelong Health and Ageing at UCL, Department of Population Science and Experimental Medicine, Institute of Cardiovascular Science, University College London, Gower Street, London, WC1E 6BT, UK
| | - Sophie V Eastwood
- MRC Unit for Lifelong Health and Ageing at UCL, Department of Population Science and Experimental Medicine, Institute of Cardiovascular Science, University College London, Gower Street, London, WC1E 6BT, UK
| | - Alun D Hughes
- MRC Unit for Lifelong Health and Ageing at UCL, Department of Population Science and Experimental Medicine, Institute of Cardiovascular Science, University College London, Gower Street, London, WC1E 6BT, UK
| | - Nishi Chaturvedi
- MRC Unit for Lifelong Health and Ageing at UCL, Department of Population Science and Experimental Medicine, Institute of Cardiovascular Science, University College London, Gower Street, London, WC1E 6BT, UK
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6
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Drury B, Ratel S, Clark CC, Fernandes JF, Moran J, Behm DG. Eccentric Resistance Training in Youth: Perspectives for Long-Term Athletic Development. J Funct Morphol Kinesiol 2019; 4:E70. [PMID: 33467385 PMCID: PMC7739302 DOI: 10.3390/jfmk4040070] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Revised: 11/21/2019] [Accepted: 11/25/2019] [Indexed: 02/07/2023] Open
Abstract
The purpose of this narrative review is to discuss the role of eccentric resistance training in youth and how this training modality can be utilized within long-term physical development. Current literature on responses to eccentric exercise in youth has demonstrated that potential concerns, such as fatigue and muscle damage, compared to adults are not supported. Considering the importance of resistance training for youth athletes and the benefits of eccentric training in enhancing strength, power, speed, and resistance to injury, its inclusion throughout youth may be warranted. In this review we provide a brief overview of the physiological responses to exercise in youth with specific reference to the different responses to eccentric resistance training between children, adolescents, and adults. Thereafter, we discuss the importance of ensuring that force absorption qualities are trained throughout youth and how these may be influenced by growth and maturation. In particular, we propose practical methods on how eccentric resistance training methods can be implemented in youth via the inclusion of efficient landing mechanics, eccentric hamstrings strengthening and flywheel inertia training. This article proposes that the use of eccentric resistance training in youth should be considered a necessity to help develop both physical qualities that underpin sporting performance, as well as reducing injury risk. However, as with any other training modality implemented within youth, careful consideration should be given in accordance with an individual's maturity status, training history and technical competency as well as being underpinned by current long-term physical development guidelines.
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Affiliation(s)
- Benjamin Drury
- Department of Applied Sport Sciences, Hartpury University, Gloucestershire GL19 3BE, England, UK;
| | - Sébastien Ratel
- Laboratoire des Adaptations Métaboliques à l’Exercice en conditions Physiologiques et Pathologiques (AME2P, EA 3533), Université Clermont Auvergne, F-63000 Clermont-Ferrand, France;
| | - Cain C.T. Clark
- Faculty of Health and Life Sciences, Coventry University, Coventry CV1 5RW, England, UK;
| | - John F.T. Fernandes
- Department of Applied Sport Sciences, Hartpury University, Gloucestershire GL19 3BE, England, UK;
| | - Jason Moran
- School of Sport, Rehabilitation and Exercise Sciences, University of Essex, Colchester CO4 3WA, UK;
| | - David G Behm
- School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John’s Newfoundland and Labrador, A1C 5S7C, Canada;
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7
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Holloway GP, Holwerda AM, Miotto PM, Dirks ML, Verdijk LB, van Loon LJC. Age-Associated Impairments in Mitochondrial ADP Sensitivity Contribute to Redox Stress in Senescent Human Skeletal Muscle. Cell Rep 2019. [PMID: 29539414 DOI: 10.1016/j.celrep.2018.02.069] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
It remains unknown if mitochondrial bioenergetics are altered with aging in humans. We established an in vitro method to simultaneously determine mitochondrial respiration and H2O2 emission in skeletal muscle tissue across a range of biologically relevant ADP concentrations. Using this approach, we provide evidence that, although the capacity for mitochondrial H2O2 emission is not increased with aging, mitochondrial ADP sensitivity is impaired. This resulted in an increase in mitochondrial H2O2 and the fraction of electron leak to H2O2, in the presence of virtually all ADP concentrations examined. Moreover, although prolonged resistance training in older individuals increased muscle mass, strength, and maximal mitochondrial respiration, exercise training did not alter H2O2 emission rates in the presence of ADP, the fraction of electron leak to H2O2, or the redox state of the muscle. These data establish that a reduction in mitochondrial ADP sensitivity increases mitochondrial H2O2 emission and contributes to age-associated redox stress.
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Affiliation(s)
- Graham P Holloway
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada.
| | - Andrew M Holwerda
- NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre, 6200 Maastricht, the Netherlands
| | - Paula M Miotto
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Marlou L Dirks
- NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre, 6200 Maastricht, the Netherlands
| | - Lex B Verdijk
- NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre, 6200 Maastricht, the Netherlands
| | - Luc J C van Loon
- NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre, 6200 Maastricht, the Netherlands
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8
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Are Prepubertal Children Metabolically Comparable to Well-Trained Adult Endurance Athletes? Sports Med 2018; 47:1477-1485. [PMID: 28044282 DOI: 10.1007/s40279-016-0671-1] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
It is well acknowledged that prepubertal children have smaller body dimensions and a poorer mechanical (movement) efficiency, and thus a lower work capacity than adults. However, the scientific evidence indicates that prepubertal children have a greater net contribution of energy derived from aerobic metabolism in exercising muscle and reduced susceptibility to muscular fatigue, which makes them metabolically comparable to well-trained adult endurance athletes. For example, the relative energy contribution from oxidative and non-oxidative (i.e. anaerobic) sources during moderate-to-intense exercise, the work output for a given anaerobic energy contribution and the rate of acceleration of aerobic metabolic machinery in response to submaximal exercise are similar between prepubertal children and well-trained adult endurance athletes. Similar conclusions can be drawn on the basis of experimental data derived from intra-muscular measurements such as type I fibre percentage, succinate dehydrogenase enzyme activity, mitochondrial volume density, post-exercise phosphocreatine re-synthesis rate and muscle by-product clearance rates (i.e. H+ ions). On a more practical level, prepubertal children also experience similar decrements in peak power output as well-trained adult endurance athletes during repeated maximal exercise bouts. Therefore, prepubertal children have a comparable relative oxidative contribution to well-trained adult endurance athletes, but a decrease in this relative contribution occurs from childhood through to early adulthood. In a clinical context, this understanding may prove central to the development of exercise-based strategies for the prevention and treatment of many metabolic diseases related to mitochondrial oxidative dysfunction (e.g. in obese, insulin-resistant and diabetic patients), which are often accompanied by muscular deconditioning during adolescence and adulthood.
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9
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Boss A, Heskamp L, Breukels V, Bains LJ, van Uden MJ, Heerschap A. Oxidative capacity varies along the length of healthy human tibialis anterior. J Physiol 2018; 596:1467-1483. [PMID: 29455454 DOI: 10.1113/jp275009] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 02/12/2018] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS During exercise skeletal muscles use the energy buffer phosphocreatine. The post-exercise recovery of phosphocreatine is a measure of the oxidative capacity of muscles and is traditionally assessed by 31 P magnetic resonance spectroscopy of a large tissue region, assuming homogeneous energy metabolism. To test this assumption, we collected spatially resolved spectra along the length of human tibialis anterior using a home-built array of 31 P detection coils, and observed a striking gradient in the recovery rate of phosphocreatine, decreasing along the proximo-distal axis of the muscle. A similar gradient along this muscle was observed in signal changes recorded by 1 H muscle functional MRI. These findings identify intra-muscular variation in the physiology of muscles in action and highlight the importance of localized sampling for any methodology investigating oxidative metabolism of this, and potentially other muscles. ABSTRACT The rate of phosphocreatine (PCr) recovery (kPCr ) after exercise, characterizing muscle oxidative capacity, is traditionally assessed with unlocalized 31 P magnetic resonance spectroscopy (MRS) using a single surface coil. However, because of intramuscular variation in fibre type and oxygen supply, kPCr may be non-uniform within muscles. We tested this along the length of the tibialis anterior (TA) muscle in 10 male volunteers. For this purpose, we employed a 3T MR system with a 31 P/1 H volume transmit coil combined with a home-built 31 P phased-array receive probe, consisting of five coil elements covering the TA muscle length. Mono-exponential kPCr was determined for all coil elements after 40 s of submaximal isometric dorsiflexion (SUBMAX) and incremental exercise to exhaustion (EXH). In addition, muscle functional MRI (1 H mfMRI) was performed using the volume coil after another 40 s of SUBMAX. A strong gradient in kPCr was observed along the TA (P < 0.001), being two times higher proximally vs. distally during SUBMAX and EXH. Statistical analysis showed that this gradient cannot be explained by pH variations. A similar gradient was seen in the slope of the initial post-exercise 1 H mfMRI signal change, which was higher proximally than distally in both the TA and the extensor digitorum longus (P < 0.001) and strongly correlated with kPCr . The pronounced differences along the TA in functional oxidative capacity identify regional variation in the physiological demand of this muscle during everyday activities and have implications for the bio-energetic assessment of interventions to modify its performance and of neuromuscular disorders involving the TA.
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Affiliation(s)
- Andreas Boss
- Department of Radiology and Nuclear Medicine, Radboud university medical center, Nijmegen, The Netherlands
| | - Linda Heskamp
- Department of Radiology and Nuclear Medicine, Radboud university medical center, Nijmegen, The Netherlands
| | - Vincent Breukels
- Department of Radiology and Nuclear Medicine, Radboud university medical center, Nijmegen, The Netherlands
| | - Lauren J Bains
- Donders Centre for Cognitive Neuroimaging, Radboud University, Nijmegen, The Netherlands
| | - Mark J van Uden
- Department of Radiology and Nuclear Medicine, Radboud university medical center, Nijmegen, The Netherlands
| | - Arend Heerschap
- Department of Radiology and Nuclear Medicine, Radboud university medical center, Nijmegen, The Netherlands
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10
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Exercise-induced fatigue in young people: advances and future perspectives. Eur J Appl Physiol 2018; 118:899-910. [PMID: 29441401 DOI: 10.1007/s00421-018-3823-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 02/08/2018] [Indexed: 12/30/2022]
Abstract
PURPOSE In recent decades, the interest for exercise-induced fatigue in youth has substantially increased, and the effects of growth on the peripheral (muscular) and central (neural) mechanisms underpinning differences in neuromuscular fatigue between healthy children and adults have been described more extensively. The purpose of this review is to retrieve, report, and analyse the findings of studies comparing neuromuscular fatigue between children and adults. Objective measures of the evaluation of the physiological mechanisms are discussed. METHOD Major databases (PubMed, Ovid, Scopus and Web of Science) were systematically searched and limited to English language from inception to September 2017. RESULT Collectively, the analyzed studies indicate that children experience less muscular and potentially more neural fatigue than adults. However, there are still many unknown aspects of fatigue regarding neural (supraspinal and spinal) and peripheral mechanisms that should be more thoroughly examined in children. CONCLUSION Suitable methods, such as transcranial magnetic stimulation, transcranial electrical stimulation, functional magnetic resonance imaging, near-infrared spectroscopy, tendon vibration, H-reflex, and ultrasound are recommended in the research field of fatigue in youth. By designing studies that test the fatigue effects in movements that replicate daily activities, new knowledge will be acquired. The linkage and interaction between physiological, cognitive, and psychological aspects of human performance remain to be resolved in young people. This can only be successful if research is based on a foundation of basic research focused on the mechanisms of fatigue while measuring all three above aspects.
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Zane AC, Reiter DA, Shardell M, Cameron D, Simonsick EM, Fishbein KW, Studenski SA, Spencer RG, Ferrucci L. Muscle strength mediates the relationship between mitochondrial energetics and walking performance. Aging Cell 2017; 16:461-468. [PMID: 28181388 PMCID: PMC5418194 DOI: 10.1111/acel.12568] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/07/2016] [Indexed: 12/28/2022] Open
Abstract
Skeletal muscle mitochondrial oxidative capacity declines with age and negatively affects walking performance, but the mechanism for this association is not fully clear. We tested the hypothesis that impaired oxidative capacity affects muscle performance and, through this mechanism, has a negative effect on walking speed. Muscle mitochondrial oxidative capacity was measured by in vivo phosphorus magnetic resonance spectroscopy as the postexercise phosphocreatine resynthesis rate, kPCr, in 326 participants (154 men), aged 24–97 years (mean 71), in the Baltimore Longitudinal Study of Aging. Muscle strength and quality were determined by knee extension isokinetic strength, and the ratio of knee extension strength to thigh muscle cross‐sectional area derived from computed topography, respectively. Four walking tasks were evaluated: a usual pace over 6 m and for 150 s, and a rapid pace over 6 m and 400 m. In multivariate linear regression analyses, kPCr was associated with muscle strength (β = 0.140, P = 0.007) and muscle quality (β = 0.127, P = 0.022), independent of age, sex, height, and weight; muscle strength was also a significant independent correlate of walking speed (P < 0.02 for all tasks) and in a formal mediation analysis significantly attenuated the association between kPCr and three of four walking tasks (18–29% reduction in β for kPCr). This is the first demonstration in human adults that mitochondrial function affects muscle strength and that inefficiency in muscle bioenergetics partially accounts for differences in mobility through this mechanism.
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Affiliation(s)
- Ariel C. Zane
- Translational Gerontology Branch; National Institutes of Health; Baltimore MD USA
| | - David A. Reiter
- Laboratory of Clinical Investigation; Intramural Research Program, National Institute on Aging; National Institutes of Health; Baltimore MD USA
| | - Michelle Shardell
- Translational Gerontology Branch; National Institutes of Health; Baltimore MD USA
| | - Donnie Cameron
- Translational Gerontology Branch; National Institutes of Health; Baltimore MD USA
| | - Eleanor M. Simonsick
- Translational Gerontology Branch; National Institutes of Health; Baltimore MD USA
| | - Kenneth W. Fishbein
- Laboratory of Clinical Investigation; Intramural Research Program, National Institute on Aging; National Institutes of Health; Baltimore MD USA
| | | | - Richard G. Spencer
- Laboratory of Clinical Investigation; Intramural Research Program, National Institute on Aging; National Institutes of Health; Baltimore MD USA
| | - Luigi Ferrucci
- Translational Gerontology Branch; National Institutes of Health; Baltimore MD USA
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12
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Les enfants sont-ils métaboliquement nés endurants ? Sci Sports 2016. [DOI: 10.1016/j.scispo.2016.09.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Choi S, Reiter DA, Shardell M, Simonsick EM, Studenski S, Spencer RG, Fishbein KW, Ferrucci L. 31P Magnetic Resonance Spectroscopy Assessment of Muscle Bioenergetics as a Predictor of Gait Speed in the Baltimore Longitudinal Study of Aging. J Gerontol A Biol Sci Med Sci 2016; 71:1638-1645. [PMID: 27075894 DOI: 10.1093/gerona/glw059] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 03/06/2016] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Aerobic fitness and muscle bioenergetic capacity decline with age; whether such declines explain age-related slowing of walking speed is unclear. We hypothesized that muscle energetics and aerobic capacity are independent correlates of walking speed in simple and challenging performance tests and that they account for the observed age-related decline in walking speed in these same tests. METHODS Muscle bioenergetics was assessed as postexercise recovery rate of phosphocreatine (PCr), k PCr, using phosphorus magnetic resonance spectroscopy (31P-MRS) in 126 participants (53 men) of the Baltimore Longitudinal Study of Aging aged 26-91 years (mean = 72 years). Four walking tasks were administered-usual pace over 6 m and 150 seconds and fast pace over 6 m and 400 m. Separately, aerobic fitness was assessed as peak oxygen consumption (peak VO2) using a graded treadmill test. RESULTS All gait speeds, k PCr, and peak VO2 were lower with older age. Independent of age, sex, height, and weight, both k PCr and peak VO2 were positively and significantly associated with fast pace and long distance walking but only peak VO2 and not k PCr was significantly associated with usual gait speed over 6 m. Both k PCr and peak VO2 substantially attenuated the association between age and gait speed for all but the least stressful walking task of 6 m at usual pace. CONCLUSION Muscle bioenergetics assessed using 31P-MRS is highly correlated with walking speed and partially explains age-related poorer performance in fast and long walking tasks.
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Affiliation(s)
| | - David A Reiter
- Laboratory of Clinical Investigation, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, Maryland
| | | | | | | | - Richard G Spencer
- Laboratory of Clinical Investigation, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, Maryland
| | - Kenneth W Fishbein
- Laboratory of Clinical Investigation, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, Maryland
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Is There a Progressive Withdrawal of Physiological Protections against High-Intensity Exercise-Induced Fatigue during Puberty? Sports (Basel) 2015. [DOI: 10.3390/sports3040346] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Murray A, Cardinale M. Cold applications for recovery in adolescent athletes: a systematic review and meta analysis. EXTREME PHYSIOLOGY & MEDICINE 2015; 4:17. [PMID: 26464795 PMCID: PMC4603811 DOI: 10.1186/s13728-015-0035-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Accepted: 09/21/2015] [Indexed: 12/18/2022]
Abstract
Recovery and regeneration modalities have been developed empirically over the years to help and support training programmes aimed at maximizing athletic performance. Professional athletes undergo numerous training sessions, characterized by differing modalities of varying volumes and intensities, with the aim of physiological adaptation leading to improved performance. Scientific support to athletes focuses on improving the chances of a training programme producing the largest adaptive response. In competition it is mainly targeted at maximizing the chances of optimal performance and recovery when high performance levels are required repeatedly in quick succession (e.g. heats/finals). In recent years, a lot of emphasis has been put on recovery modalities. In particular, emphasis has been placed on the need to reduce the delayed onset of muscle soreness (DOMS) typically evident following training and competitive activities inducing a certain degree of muscle damage. One of the most used recovery modalities consists of cold-water immersion and/or ice/cold applications to muscles affected by DOMS. While the scientific literature has provided a rationale for such modalities to reduce pain in athletes and recreationally active adults, it is doubtful if this rationale is appropriate to aid training with adolescent athletes. In particular, since these methods have been suggested to potentially impair the muscle remodeling process leading to muscle hypertrophy. While this debate is still active in the literature, many coaches adopt such practices in youth populations, simply transferring what they see in elite sportspeople directly; without questioning the rationale, safety or effectiveness as well as the potential for such activity to reduce the adaptive potential of skeletal muscle remodeling in adolescent athletes. The aim of this review was to assess the current knowledge base on the use of ice/cold applications for recovery purposes in adolescent athletes in order to provide useful guidelines for sports scientists, medical practitioners, physiotherapists and coaches working with such populations as well as developing research questions for further research activities in this area. Based on the current evidence, it seems clear that evidence for acute benefits of such interventions are scarce and more work is needed to ascertain the physiological implications on a pre or peri-pubertal population.
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Affiliation(s)
- Andrew Murray
- />Department of Sports Science, Aspire Academy, Doha, Qatar
- />University of Edinburgh, Edinburgh, UK
| | - Marco Cardinale
- />Department of Sports Science, Aspire Academy, Doha, Qatar
- />Department of Computer Science and Institute of Sport Exercise and Health, University College London, London, UK
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Cree-Green M, Newcomer BR, Brown M, Hull A, West AD, Singel D, Reusch JEB, McFann K, Regensteiner JG, Nadeau KJ. Method for controlled mitochondrial perturbation during phosphorus MRS in children. Med Sci Sports Exerc 2015; 46:2030-6. [PMID: 24576856 DOI: 10.1249/mss.0000000000000316] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
UNLABELLED Insulin resistance is increasingly prevalent in children and may be related to muscle mitochondrial dysfunction, necessitating development of mitochondrial assessment techniques. Recent studies used phosphorus magnetic resonance spectroscopy (P-MRS), a noninvasive technique appealing for clinical research. P-MRS requires exercise at a precise percentage of maximum volitional contraction (MVC). MVC measurement in children, particularly in those with a disease, is problematic because of variability in perception of effort and motivation. We therefore developed a method to predict MVC using maximal calf muscle cross-sectional area (MCSA) to assure controlled and reproducible muscle metabolic perturbations. METHODS Data were collected from 66 sedentary 12- to 20-yr-old participants. Plantarflexion MVC was assessed using an MRI-compatible exercise treadle device. MCSA of the calf muscles were measured from magnetic resonance images. Data from the first 26 participants were used to model the relation between MVC and MCSA (predicted MVC = 24.763 + 0.0047 MCSA). This model was then applied to the subsequent 40 participants. RESULTS MVC versus model-predicted mean MVC was 43.9 ± 0.8 kg versus 44.2 ± 1.81 (P = 0.90). P-MRS results when predicted and MVC were similar showed expected changes during MVC-based exercise. In contrast, MVC was markedly lower than predicted in four participants and produced minimal metabolic perturbation. Upon repeat testing, these individuals could perform their predicted MVC with coaching, which produced expected metabolic perturbations. CONCLUSIONS Compared with using MVC testing alone, using magnetic resonance imaging to predict muscle strength allows for a more accurate and standardized P-MRS protocol during exercise in children. This method overcomes a major obstacle in assessing mitochondrial function in youths. These studies have importance as we seek to determine the role of mitochondrial function in youths with insulin resistance and diabetes and response to interventions.
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Affiliation(s)
- Melanie Cree-Green
- 1Division of Endocrinology, Department of Pediatrics, Children's Hospital Colorado, Anschutz Medical Campus, Aurora, CO; 2Center for Women's Health Research, University of Colorado Anschutz Medical Campus, Aurora, CO; 3Department of Clinical and Diagnostic Sciences, University of Alabama at Birmingham, Birmingham, AL; 4Department of Radiology, University of Colorado Anschutz Medical Campus, Aurora, CO; and 5Department of Internal Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
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Makimura H, Murphy CA, Feldpausch MN, Grinspoon SK. The effects of tesamorelin on phosphocreatine recovery in obese subjects with reduced GH. J Clin Endocrinol Metab 2014; 99:338-43. [PMID: 24178787 PMCID: PMC3879673 DOI: 10.1210/jc.2013-3436] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Few studies have assessed the relationship between GH and mitochondrial function. OBJECTIVE The objective of this study was to determine the effects of improving IGF-I using a GHRH analog, tesamorelin, on mitochondrial function assessed by phosphocreatine (PCr) recovery using (31)P magnetic resonance spectroscopy in obese adults with reduced GH. DESIGN A total of 39 obese men and women with reduced GH secretion as determined by GHRH-arginine stimulation tests underwent magnetic resonance spectroscopy as part of a 12-month, double-blind, randomized, placebo-controlled trial comparing tesamorelin vs placebo. PCr recovery after submaximal exercise was assessed at baseline and at 12 months. RESULTS At baseline, there were no differences in age, sex, race/ethnicity, and GH or PCr parameters between tesamorelin and placebo. After 12 months, tesamorelin treatment led to a significantly greater increase in IGF-I than did placebo treatment (change, 102.9±31.8 μg/L vs 22.8±8.9 μg/L, tesamorelin vs placebo; P=.02). We demonstrated a significant positive relationship between increases in IGF-I and improvements in PCr recovery represented as ViPCr (R=0.56; P=.01). The association between IGF-I and PCr recovery was even stronger among subjects treated with tesamorelin only (ViPCr: R=0.71; P=.03). This association remained significant after controlling for age, sex, race, ethnicity, and parameters of body composition and insulin sensitivity (all P<.05). CONCLUSIONS Increases in IGF-I from 12 months of treatment with tesamorelin were significantly associated with improvements in PCr recovery parameters in obese men and women with reduced GH secretion, suggestive of improvements in mitochondrial function.
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Affiliation(s)
- Hideo Makimura
- Program in Nutritional Metabolism and Neuroendocrine Unit (H.M., C.A.M., M.N.F., S.K.G.), Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
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Willcocks RJ, Fulford J, Armstrong N, Barker AR, Williams CA. Muscle metabolism during fatiguing isometric quadriceps exercise in adolescents and adults. Appl Physiol Nutr Metab 2013; 39:439-45. [PMID: 24669985 DOI: 10.1139/apnm-2013-0192] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Children and adolescents are less susceptible to muscle fatigue during repeated bouts of high-intensity exercise than adults, but the physiological basis for these differences is not clear. The purpose of the current investigation was to investigate the muscle metabolic responses, using 31-phosphorus magnetic resonance spectroscopy, during fatiguing isometric quadriceps exercise in 13 adolescents (7 females) and 14 adults (8 females). Participants completed 30 maximal voluntary contractions (6-s duration) separated by 6 s of rest. Fatigue was quantified as the relative decrease in force over the test. Fatigue was not significantly different with age (p = 0.20) or sex (p = 0.63). Metabolic perturbation (change in phosphocreatine, inorganic phosphate, and ADP concentrations) was significantly greater in adults compared with adolescents; no sex effects were present. Muscle pH did not differ with age or sex. Phosphocreatine recovery following exercise was not significantly different with age (p = 0.27) or sex (p = 0.97) but a significant interaction effect was present (p = 0.04). Recovery tended to be faster in boys than men but slower in girls than women, though no significant group differences were identified. The results of this study show that at a comparable level of muscle fatigue, the metabolic profile is profoundly different between adolescents and adults.
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Affiliation(s)
- Rebecca J Willcocks
- a Children's Health and Exercise Research Centre, Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, St. Luke's Campus, Magdalen Rd., Exeter EX1 2LU, UK
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Kappenstein J, Ferrauti A, Runkel B, Fernandez-Fernandez J, Müller K, Zange J. Changes in phosphocreatine concentration of skeletal muscle during high-intensity intermittent exercise in children and adults. Eur J Appl Physiol 2013; 113:2769-79. [PMID: 23995672 DOI: 10.1007/s00421-013-2712-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Accepted: 08/14/2013] [Indexed: 11/28/2022]
Abstract
PURPOSE The aim of the present study was to test the hypotheses that a greater oxidative capacity in children results in a lower phosphocreatine (PCr) depletion, a faster PCr resynthesis and a lower muscle acidification during high-intensity intermittent exercise compared to adults. METHODS Sixteen children (9.4 ± 0.5 years) and 16 adults (26.1 ± 0.3 years) completed a protocol consisting of a dynamic plantar flexion (10 bouts of 30-s exercise at 25 % of one repetition maximum separated by 20-s recovery), followed by 10 min of passive recovery. Changes of PCr, ATP, inorganic phosphate, and phosphomonoesters were measured by means of (31)Phosphorous-magnetic resonance spectroscopy during and post-exercise. RESULTS Average PCr (percentage of [PCr] at initial rest (%[PCr]i)) at the end of the exercise (adults 17 ± 12 %[PCr]i, children 38 ± 17 %[PCr]i, P < 0.01) and recovery periods (adults 37 ± 14 %[PCr]i, children 57 ± 17 %[PCr]i, P < 0.01) was significantly lower in adults compared to children, induced by a stronger PCr decrease during the first exercise interval (adults -73 ± 10 %[PCr]i, children -55 ± 15 %[PCr]i, P < 0.01). End-exercise pH was significantly higher in children compared to adults (children 6.90 + 0.20, -0.14; adults 6.67 + 0.23, -0.15, P < 0.05). CONCLUSIONS From our results we suggest relatively higher rates of oxidative ATP formation in children's muscle for covering the ATP demand of high-intensity intermittent exercise compared to adults, enabling children to begin each exercise interval with significantly higher PCr concentrations and leading to an overall lower muscle acidification.
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Affiliation(s)
- J Kappenstein
- Department of Training and Exercise Science, Faculty of Sport Science, Ruhr-University Bochum, Gesundheitscampus Nord Haus Nr. 10, 44780, Bochum, Germany,
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McCormack SE, Shaham O, McCarthy MA, Deik AA, Wang TJ, Gerszten RE, Clish CB, Mootha VK, Grinspoon SK, Fleischman A. Circulating branched-chain amino acid concentrations are associated with obesity and future insulin resistance in children and adolescents. Pediatr Obes 2013; 8:52-61. [PMID: 22961720 PMCID: PMC3519972 DOI: 10.1111/j.2047-6310.2012.00087.x] [Citation(s) in RCA: 308] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2012] [Revised: 06/01/2012] [Accepted: 06/29/2012] [Indexed: 12/24/2022]
Abstract
UNLABELLED What is already known about this subject Circulating concentrations of branched-chain amino acids (BCAAs) can affect carbohydrate metabolism in skeletal muscle, and therefore may alter insulin sensitivity. BCAAs are elevated in adults with diet-induced obesity, and are associated with their future risk of type 2 diabetes even after accounting for baseline clinical risk factors. What this study adds Increased concentrations of BCAAs are already present in young obese children and their metabolomic profiles are consistent with increased BCAA catabolism. Elevations in BCAAs in children are positively associated with insulin resistance measured 18 months later, independent of their initial body mass index. BACKGROUND Branched-chain amino acid (BCAA) concentrations are elevated in response to overnutrition, and can affect both insulin sensitivity and secretion. Alterations in their metabolism may therefore play a role in the early pathogenesis of type 2 diabetes in overweight children. OBJECTIVE To determine whether paediatric obesity is associated with elevations in fasting circulating concentrations of BCAAs (isoleucine, leucine and valine), and whether these elevations predict future insulin resistance. METHODS Sixty-nine healthy subjects, ages 8-18 years, were enrolled as a cross-sectional cohort. A subset of subjects who were pre- or early-pubertal, ages 8-13 years, were enrolled in a prospective longitudinal cohort for 18 months (n = 17 with complete data). RESULTS Elevations in the concentrations of BCAAs were significantly associated with body mass index (BMI) Z-score (Spearman's Rho 0.27, P = 0.03) in the cross-sectional cohort. In the subset of subjects that followed longitudinally, baseline BCAA concentrations were positively associated with homeostasis model assessment for insulin resistance measured 18 months later after controlling for baseline clinical factors including BMI Z-score, sex and pubertal stage (P = 0.046). CONCLUSIONS Elevations in the concentrations of circulating BCAAs are significantly associated with obesity in children and adolescents, and may independently predict future insulin resistance.
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Affiliation(s)
| | | | - M. A. McCarthy
- Program in Nutritional Metabolism and Neuroendocrine Unit; Massachusetts General Hospital and Harvard Medical School; Boston; Massachusetts; USA
| | - A. A. Deik
- Broad Institute of MIT and Harvard; Cambridge; Massachusetts; USA
| | | | | | - C. B. Clish
- Broad Institute of MIT and Harvard; Cambridge; Massachusetts; USA
| | | | - S. K. Grinspoon
- Program in Nutritional Metabolism and Neuroendocrine Unit; Massachusetts General Hospital and Harvard Medical School; Boston; Massachusetts; USA
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Ratel S, Martin V, Tonson A, Cozzone PJ, Bendahan D. Skeletal muscle mitochondrial function cannot be properly inferred from PCr resynthesis without taking pH changes into account. Magn Reson Imaging 2012; 30:1542-3. [PMID: 22898689 DOI: 10.1016/j.mri.2012.06.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2012] [Accepted: 06/21/2012] [Indexed: 10/28/2022]
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Can we simply infer mitochondrial function from PCr resynthesis after exercise in skeletal muscle? Pediatr Res 2012; 72:221. [PMID: 22832973 DOI: 10.1038/pr.2012.67] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Lima JGD, Nóbrega LHC, Nóbrega MLC, Santos Júnior ACD, Fernandes FDC, Mesquita DJTMD, Souza ABCD. [Influence of thyroid function in CPK serum levels]. ARQUIVOS BRASILEIROS DE ENDOCRINOLOGIA E METABOLOGIA 2012; 56:190-4. [PMID: 22666735 DOI: 10.1590/s0004-27302012000300007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2011] [Accepted: 03/05/2012] [Indexed: 11/21/2022]
Abstract
OBJECTIVE To determine serum CPK variation based on TSH e free T4 (FT4), and to assess serum CPK in pathological states of the thyroid (hyperthyroidism and hypothyroidism), in relation to the euthyroidism. MATERIAL AND METHODS We evaluated retrospectively 6,230 laboratory results of TSH and CPK from 2007 to 2011. From these, 3,369 had free T4 results. We evaluated the correlation between CPK and TSH and the pathological states of the thyroid. RESULTS The correlation between TSH and CPK was positive (r = 0.065), while that between CPK and FT4 was negative (r = -0.091, p < 0.05). From the total of results analyzed, 586 (9.4%) were measures of hyperthyroidism, with a median (range) of CPK of 98 U/L (27 to 1,113), and 556 (8.9%) were of hypothyroidism, with CPK of 114 U/L (25-4,182). CONCLUSION A positive correlation was found between serum CPK and TSH, and a negative correlation between CPK and FT4. CPK was lower in the group with hyperthyroidism, and greater in that with hypothyroidism.
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Affiliation(s)
- Josivan Gomes de Lima
- Hospital Universitário Onofre Lopes (HUOL), Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN, Brasil.
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McCormack SE, McCarthy MA, Farilla L, Hrovat MI, Systrom DM, Grinspoon SK, Fleischman A. Skeletal muscle mitochondrial function is associated with longitudinal growth velocity in children and adolescents. J Clin Endocrinol Metab 2011; 96:E1612-8. [PMID: 21832105 PMCID: PMC3200245 DOI: 10.1210/jc.2011-1218] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Periods of rapid growth require an increase in energy use and substrate formation. Mitochondrial function contributes to each of these and therefore may play a role in longitudinal growth. METHODS Twenty-nine children and adolescents of ages 8-15 yr were enrolled in a comprehensive longitudinal assessment of glucose homeostasis and mitochondrial function. Fasting laboratory studies and an estimate of mitochondrial function (as assessed by the time to recovery of phosphocreatine (PCr) concentration after submaximal quadriceps extension/flexion exercise using (31)P magnetic resonance spectroscopy) were obtained at baseline and annually for 2 yr. RESULTS Data were complete for 23 subjects. Subjects were 11.3 ± 1.9 (sd) yr old at the beginning of the study; 61% were male. Average annualized growth velocity at 1 yr for boys was 7.1 ± 1.5 cm/yr and for girls 6.5 ± 1.7 cm/yr. More rapid recovery of PCr concentration, suggestive of greater skeletal muscle oxidative phosphorylation capacity at baseline, was associated with faster growth velocity in the subsequent year (r(2) = 0.29; P = 0.008). In multivariate modeling, baseline mitochondrial function remained significantly and independently associated with growth (R(2) for model = 0.51; P = 0.05 for effect of phosphocreatine recovery time constant), controlling for age, gender, Tanner stage, body mass index Z-score, and height Z-score. CONCLUSIONS We report a novel association between time to recovery of PCr concentration after submaximal exercise and faster annual linear growth in healthy children. Future studies are needed to determine the physiological mechanisms and clinical consequences of this observation.
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Affiliation(s)
- Shana E McCormack
- Program in Nutritional Metabolism and Neuroendocrine Unit, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, LON 207, Boston, Massachusetts 02114, USA
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Makimura H, Stanley TL, Sun N, Hrovat MI, Systrom DM, Grinspoon SK. The association of growth hormone parameters with skeletal muscle phosphocreatine recovery in adult men. J Clin Endocrinol Metab 2011; 96:817-23. [PMID: 21177784 PMCID: PMC3047233 DOI: 10.1210/jc.2010-2264] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Previous studies have suggested a relationship between GH and mitochondrial function. However, little is known about the relationship of specific GH indices and in vivo measures of mitochondrial function in humans. OBJECTIVE The objective of this study was to determine the association between GH, IGF-I, and phosphocreatine (PCr) recovery, a measure of mitochondrial function, in otherwise healthy adults. DESIGN Thirty-seven healthy men and women were studied at a single university medical center. Subjects underwent GH stimulation testing with GH releasing hormone-arginine and measurement of IGF-I. Mitochondrial function was determined by PCr recovery after submaximal exercise by (31)Phosphorous magnetic resonance spectroscopy. Subjects underwent assessment of lean and fat mass with use of dual energy X-ray absorptiometry. RESULTS There were no differences in PCr recovery between men and women (men 20.7±1.5 vs. women 24.8±1.4 mM/min; P > 0.05). IGF-I (r = 0.33; P = 0.04) was associated with PCr recovery in all subjects. Among men, IGF-I (r = 0.69; P = 0.003), peak stimulated GH (r = 0.52; P = 0.04), and GH area under the curve (AUC) (r = 0.53; P = 0.04) were significantly associated with PCr recovery. However, neither IGF-I, peak stimulated GH, nor GH AUC (all P > 0.05) were associated with PCr recovery in women. After adjusting for age, race, and physical activity, IGF-I remained significantly associated with PCr recovery (β = 0.10; P = 0.02) among men. CONCLUSIONS IGF-I, peak stimulated GH, and GH AUC are associated with skeletal muscle PCr recovery in men.
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Affiliation(s)
- Hideo Makimura
- Program in Nutritional Metabolism and Neuroendocrine Unit, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, LON 211, Boston, Massachusetts 02114, USA.
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Makimura H, Stanley TL, Sun N, Connelly JM, Hemphill LC, Hrovat MI, Systrom DM, Grinspoon SK. Increased skeletal muscle phosphocreatine recovery after sub-maximal exercise is associated with increased carotid intima-media thickness. Atherosclerosis 2010; 215:214-7. [PMID: 21185022 DOI: 10.1016/j.atherosclerosis.2010.11.037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2010] [Accepted: 11/26/2010] [Indexed: 01/24/2023]
Abstract
BACKGROUND The association between skeletal muscle mitochondrial function and CVD risk in healthy subjects is unknown. METHODS Forty subjects were evaluated for CVD risk with lipid profile, oral glucose tolerance test and measurement of carotid intima-media thickness (cIMT). Skeletal muscle mitochondrial function was determined by phosphocreatine recovery after sub-maximal exercise with (31)Phosphorous-MRS and represented as τPCr. RESULTS τPCr was positively associated with age (r=+0.41; P=0.009) and cIMT (r=+0.50; P=0.001) on univariate analyses. In multivariate regression analysis controlling for age, the association between τPCr and cIMT remained significant (β=0.003; P=0.03). This association remained significant after controlling for traditional risk factors for CVD including age, gender, tobacco use, BMI, blood pressure, cholesterol and fasting glucose in a combined model (β=0.003; P=0.04; R(2)=0.53; P=0.008 for overall model). CONCLUSIONS These data suggest a novel association between skeletal muscle τPCr and increased cIMT, independent of age or traditional CVD risk factors.
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Affiliation(s)
- Hideo Makimura
- Program in Nutritional Metabolism and Neuroendocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.
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