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Dorobantu DM, Wadey CA, Berryman B, Amir NH, Forsythe L, Stuart AG, Pieles GE, Williams CA. A new protocol for a single-stage combined cardiopulmonary and echocardiography exercise test: a pilot study. EUROPEAN HEART JOURNAL. IMAGING METHODS AND PRACTICE 2024; 2:qyae021. [PMID: 39045209 PMCID: PMC11195695 DOI: 10.1093/ehjimp/qyae021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Accepted: 03/11/2024] [Indexed: 07/25/2024]
Abstract
Aims The value of cardiopulmonary exercise testing (CPET) and exercise stress echocardiography (ESE) in managing cardiac disease is well known, but no standard CPET-ESE protocol is currently recommended. This pilot study aims to compare feasibility and cardiac function responses between a new high-intensity single-stage combined test (CPET-hiESE) and a standard maximal ESE (smESE). Methods and results After screening and maximal CPET, all volunteers (n = 21) underwent three ESE modalities: (i) based on the gas exchange threshold (hiESE-GET, 40% of peak-GET, 6 min), (ii) based on heart rate (HR) (hiESE-HR, 80% of peak HR, 6 min), and (iii) smESE (85% of predicted peak HR for age, 3 min). Speckle tracking echocardiography (STE) and tissue Doppler imaging (TDI) were measured at each step. There was superior image quality and data completeness for the right ventricle strain for both hiESE modalities compared with smESE (71.4 and 76.2 vs. 42.9%, P = 0.07). Left ventricular STE data completeness was similar for all three conditions. Despite systematically higher HR, work rate and levels of exertion in the smESE compared with hiESE, STE and TDI parameters were not systematically different. Concordance correlation coefficients ranged from 0.56 to 0.88, lowest for strain rate parameters and mean difference from -0.34 to 1.53, highest for TDI measurements. Conclusion The novel CPET-hiESE protocol allowed for better data completeness, at lower levels of exertion compared with smESE, without systematically different cardiac reserve measurements in healthy participants. This single-stage protocol can be individualized to clinical populations, which would provide practical advantages to standard testing.
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Affiliation(s)
- Dan M Dorobantu
- Children’s Health and Exercise Research Centre (CHERC), Public Health and Sports Sciences, Faculty of Life and Health Sciences, University of Exeter Medical School, St Luke’s Campus, Heavitree Road, Exeter EX1 2LU, UK
- Population and Translational Health Sciences, University of Bristol, Bristol, Beacon House, Queens Rd, BS8 1QU, UK
| | - Curtis A Wadey
- Children’s Health and Exercise Research Centre (CHERC), Public Health and Sports Sciences, Faculty of Life and Health Sciences, University of Exeter Medical School, St Luke’s Campus, Heavitree Road, Exeter EX1 2LU, UK
| | - Ben Berryman
- Children’s Health and Exercise Research Centre (CHERC), Public Health and Sports Sciences, Faculty of Life and Health Sciences, University of Exeter Medical School, St Luke’s Campus, Heavitree Road, Exeter EX1 2LU, UK
| | - Nurul H Amir
- Population and Translational Health Sciences, University of Bristol, Bristol, Beacon House, Queens Rd, BS8 1QU, UK
- Faculty of Sport Science and Recreation, Universiti Teknologi MARA, Perlis Branch, Arau Campus, Uitm Arau, 02600 Arau, Malaysia
| | - Lynsey Forsythe
- Congenital Heart Unit, Bristol Royal Hospital for Children and Heart Institute, Upper Maudlin St, BS2 8BJ, Bristol, UK
| | - A Graham Stuart
- Congenital Heart Unit, Bristol Royal Hospital for Children and Heart Institute, Upper Maudlin St, BS2 8BJ, Bristol, UK
| | - Guido E Pieles
- Sports Cardiology and Screening Department, ASPETAR Qatar Orthopaedic and Sports Medicine Hospital, Sports City Street, Inside Aspire Zone, Al Buwairda St, Doha, Qatar
- Institute of Sport Exercise and Health, University College London, 170 Tottenham Ct Rd, W1T 7HA, London, UK
| | - Craig A Williams
- Children’s Health and Exercise Research Centre (CHERC), Public Health and Sports Sciences, Faculty of Life and Health Sciences, University of Exeter Medical School, St Luke’s Campus, Heavitree Road, Exeter EX1 2LU, UK
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2
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Tomlinson OW, Barker AR, Fulford J, Wilson P, Shelley J, Oades PJ, Williams CA. Skeletal muscle contributions to reduced fitness in cystic fibrosis youth. Front Pediatr 2023; 11:1211547. [PMID: 37388288 PMCID: PMC10300555 DOI: 10.3389/fped.2023.1211547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 06/02/2023] [Indexed: 07/01/2023] Open
Abstract
Background Increased maximal oxygen uptake (V̇O2max) is beneficial in children with cystic fibrosis (CF) but remains lower compared to healthy peers. Intrinsic metabolic deficiencies within skeletal muscle (muscle "quality") and skeletal muscle size (muscle "quantity") are both proposed as potential causes for the lower V̇O2max, although exact mechanisms remain unknown. This study utilises gold-standard methodologies to control for the residual effects of muscle size from V̇O2max to address this "quality" vs. "quantity" debate. Methods Fourteen children (7 CF vs. 7 age- and sex-matched controls) were recruited. Parameters of muscle size - muscle cross-sectional area (mCSA) and thigh muscle volume (TMV) were derived from magnetic resonance imaging, and V̇O2max obtained via cardiopulmonary exercise testing. Allometric scaling removed residual effects of muscle size, and independent samples t-tests and effect sizes (ES) identified differences between groups in V̇O2max, once mCSA and TMV were controlled for. Results V̇O2max was shown to be lower in the CF group, relative to controls, with large ES being identified when allometrically scaled to mCSA (ES = 1.76) and TMV (ES = 0.92). Reduced peak work rate was also identified in the CF group when allometrically controlled for mCSA (ES = 1.18) and TMV (ES = 0.45). Conclusions A lower V̇O2max was still observed in children with CF after allometrically scaling for muscle size, suggesting reduced muscle "quality" in CF (as muscle "quantity" is fully controlled for). This observation likely reflects intrinsic metabolic defects within CF skeletal muscle.
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Affiliation(s)
- Owen William Tomlinson
- Children’s Health and Exercise Research Centre, Public Health and Sports Sciences, University of Exeter Medical School, University of Exeter, Exeter, United Kingdom
- Royal Devon University Healthcare NHS Foundation Trust, Exeter, United Kingdom
- Biomedical and Clinical Science, University of Exeter Medical School, University of Exeter, Exeter, United Kingdom
| | - Alan Robert Barker
- Children’s Health and Exercise Research Centre, Public Health and Sports Sciences, University of Exeter Medical School, University of Exeter, Exeter, United Kingdom
| | - Jonathan Fulford
- Biomedical and Clinical Science, University of Exeter Medical School, University of Exeter, Exeter, United Kingdom
| | - Paul Wilson
- Children’s Health and Exercise Research Centre, Public Health and Sports Sciences, University of Exeter Medical School, University of Exeter, Exeter, United Kingdom
| | - James Shelley
- Royal Devon University Healthcare NHS Foundation Trust, Exeter, United Kingdom
| | - Patrick John Oades
- Royal Devon University Healthcare NHS Foundation Trust, Exeter, United Kingdom
| | - Craig Anthony Williams
- Children’s Health and Exercise Research Centre, Public Health and Sports Sciences, University of Exeter Medical School, University of Exeter, Exeter, United Kingdom
- Royal Devon University Healthcare NHS Foundation Trust, Exeter, United Kingdom
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3
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Caterini JE, Ratjen F, Barker AR, Williams CA, Rendall K, Schneiderman JE, Wells GD. Exercise intolerance in cystic fibrosis-the role of CFTR modulator therapies. J Cyst Fibros 2021; 21:282-292. [PMID: 34955387 DOI: 10.1016/j.jcf.2021.11.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 10/18/2021] [Accepted: 11/20/2021] [Indexed: 12/11/2022]
Abstract
Exercise intolerance is common in people with CF (pwCF), but not universal among all individuals. While associated with disease prognosis, exercise intolerance is not simply a reflection of the degree of lung disease. In people with severe CF, respiratory limitations may contribute more significantly to impaired exercise capacity than in those with mild-moderate CF. At all levels of disease severity, there are peripheral factors e.g., abnormal macro- and micro-vascular function that impair blood flow and reduce oxygen extraction, and mitochondrial defects that diminish metabolic efficiency. We discuss advances in understanding the central and peripheral mechanisms underlying exercise intolerance in pwCF. Exploring both the central and peripheral factors that contribute to exercise intolerance in CF can help inform the development of new therapeutic targets, as well as help define prognostic criteria.
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Affiliation(s)
- Jessica E Caterini
- Translational Medicine Program, SickKids Research Institute, Toronto, ON M5G 0A4, Canada; Queen's Medical School, Kingston, ON K7L 3N6, Canada
| | - Felix Ratjen
- Translational Medicine Program, SickKids Research Institute, Toronto, ON M5G 0A4, Canada; Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, ON M5G 1X8, Canada; Division of Respiratory Medicine, The Hospital for Sick Children, University of Toronto, Toronto, ON M5G 1X8, Canada
| | - Alan R Barker
- Children's Health and Exercise Research Centre, Sport and Health Sciences, University of Exeter, Exeter EX1 2LU, UK
| | - Craig A Williams
- Children's Health and Exercise Research Centre, Sport and Health Sciences, University of Exeter, Exeter EX1 2LU, UK
| | - Kate Rendall
- Translational Medicine Program, SickKids Research Institute, Toronto, ON M5G 0A4, Canada
| | - Jane E Schneiderman
- Division of Respiratory Medicine, The Hospital for Sick Children, University of Toronto, Toronto, ON M5G 1X8, Canada; Faculty of Kinesiology & Physical Education, University of Toronto, Toronto, ON M5S 1A1, Canada
| | - Greg D Wells
- Translational Medicine Program, SickKids Research Institute, Toronto, ON M5G 0A4, Canada.
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Rodriguez-Miguelez P, Seigler N, Ishii H, Crandall R, McKie KT, Forseen C, Harris RA. Exercise Intolerance in Cystic Fibrosis: Importance of Skeletal Muscle. Med Sci Sports Exerc 2021; 53:684-693. [PMID: 33105385 PMCID: PMC7969358 DOI: 10.1249/mss.0000000000002521] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
PURPOSE Exercise intolerance, evaluated by O2 consumption, predicts mortality in cystic fibrosis (CF). People with CF exhibit skeletal muscle dysfunctions that may contribute to an imbalance between O2 delivery and utilization. Sildenafil, a phosphodiesterase type 5 inhibitor, increases blood flow and improves O2 consumption, although the exact mechanisms in CF have yet to be elucidated. Thus, we hypothesized that exercise intolerance in CF is limited primarily by an impaired skeletal muscle O2 utilization, and sildenafil improves exercise tolerance in CF by addressing this mismatch between O2 demand and extraction. METHODS Fifteen individuals with mild to moderate CF and 18 healthy controls completed an incremental exercise test and measurements of gaseous exchange, chronotropic response, hemodynamics, and O2 extraction and utilization. People with CF also completed a 4-wk treatment with sildenafil with a subsequent follow-up evaluation after treatment. RESULTS Skeletal muscle O2 extraction and utilization during exercise were reduced in people with CF when compared with controls. Exercise capacity in our CF population was minimally limited by hemodynamic or chronotopic responses, whereas peripheral O2 extraction was more closely associated with exercise capacity. The study also demonstrated that 4 wk of sildenafil improved skeletal muscle O2 utilization during exercise to similar values observed in healthy individuals. CONCLUSIONS Individuals with mild to moderate CF exhibit exercise intolerance secondary to a reduction in O2 utilization by the exercising skeletal muscle. The present study demonstrated that 4 wk of sildenafil treatment improves the capacity of the skeletal muscle to use O2 more efficiently during exercise. Findings from the present study highlight the importance of targeting skeletal muscle O2 utilization to improve exercise tolerance in CF.
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Affiliation(s)
- Paula Rodriguez-Miguelez
- Department of Kinesiology and Health Sciences, Virginia Commonwealth University, Richmond, VA
- Georgia Prevention Institute, Augusta University, Augusta GA
| | - Nichole Seigler
- Georgia Prevention Institute, Augusta University, Augusta GA
| | - Haruki Ishii
- Georgia Prevention Institute, Augusta University, Augusta GA
| | - Reva Crandall
- Georgia Prevention Institute, Augusta University, Augusta GA
| | | | - Caralee Forseen
- Pulmonary and Critical Care Medicine, Augusta University, Augusta GA
| | - Ryan A. Harris
- Georgia Prevention Institute, Augusta University, Augusta GA
- Sport and Exercise Science Research Institute, University of Ulster, Jordanstown, United Kingdom
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Combret Y, Medrinal C, Prieur G, Robledo Quesada A, Gillot T, Gravier FE, Bonnevie T, Lamia B, Le Roux P, Reychler G. Oxygen uptake kinetics during treadmill walking in adolescents with clinically stable cystic fibrosis. Physiother Theory Pract 2021; 38:1389-1397. [PMID: 33390080 DOI: 10.1080/09593985.2020.1868029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Background: Oxygen uptake (V̇O2) kinetics have been shown to be slowed in adolescents with cystic fibrosis (CF) during heavy-intensity cycling and maximal exercise testing.Objectives: This study investigated V̇O2 kinetics in adolescents with CF compared to control adolescents (CON) during a treadmill-walking exercise.Methods: Eight adolescents with CF and mild-to-moderate pulmonary obstruction (5 girls; 13.1 ± 2.5 years; FEV1 67.8 ± 21.4%) and 18 CON adolescents (10 girls; 13.8 ± 1.8 years) were recruited. Pulmonary gas exchange and ventilation were measured during a single transition of 10 min of treadmill walking and a 5 min seated recovery period. Participant's walking speed was determined during a one-minute self-paced walking task along a 50-m corridor. A six-parameter, non-linear regression model was used to describe the changes in V̇O2 function during the treadmill walking and recovery, with monoexponential curve fitting used to describe the mean response time (MRT1) at the onset of exercise, and the half-life (T1/2V̇O2) at the offset of exercise. V̇O2 baseline and amplitude, minute ventilation and respiratory equivalents were recorded.Results: V̇O2 kinetics were slower in CF group compared to CON group during the treadmill walking with a greater MRT1 (32 ± 14 s vs 21 ± 16 s; p = .04, effect size = 0.75). The T1/2V̇O2 was prolonged during recovery in CF group compared to CON group (86 ± 24 s vs 56 ± 22 s; p = .04, effect size = 1.31). The mean VE/V̇CO2 during exercise was the only parameter significantly greater in CF group compared to CON group (32.9 ± 2.3 vs 29.0 ± 2.4; p < .01, effect size = 1.66). Conclusion: V̇O2 kinetics were found to be slowed in adolescents with CF during treadmill walking.
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Affiliation(s)
- Yann Combret
- Physiotherapy Department, Le Havre Hospital, Montivilliers, France.,Institut De Recherche Et d'Expérimentation Clinique (IREC), Pôle De Pneumologie, ORL and Dermatologie, Université Catholique De Louvain, Brussels, Belgium
| | - Clément Medrinal
- Physiotherapy Department, Le Havre Hospital, Montivilliers, France.,Erphan, Paris-Saclay University, UVSQ, Versailles, France.,Saint Michel School of Physiotherapy, Paris, France
| | - Guillaume Prieur
- Physiotherapy Department, Le Havre Hospital, Montivilliers, France.,Institut De Recherche Et d'Expérimentation Clinique (IREC), Pôle De Pneumologie, ORL and Dermatologie, Université Catholique De Louvain, Brussels, Belgium.,UPRES EA3830 - GRHV, Normandie University, UNIROUEN, Institute for Research and Innovation in Biomedicine (IRIB), Rouen, France
| | | | - Timothée Gillot
- Cetaps, EA3832, Rouen University, Mont Saint Aignan, France.,School of Physiotherapy, Rouen University Hospital, Rouen, France
| | - Francis-Edouard Gravier
- UPRES EA3830 - GRHV, Normandie University, UNIROUEN, Institute for Research and Innovation in Biomedicine (IRIB), Rouen, France.,ADIR Association, Rouen University Hospital, Bois-Guillaume, France
| | - Tristan Bonnevie
- UPRES EA3830 - GRHV, Normandie University, UNIROUEN, Institute for Research and Innovation in Biomedicine (IRIB), Rouen, France.,ADIR Association, Rouen University Hospital, Bois-Guillaume, France
| | - Bouchra Lamia
- UPRES EA3830 - GRHV, Normandie University, UNIROUEN, Institute for Research and Innovation in Biomedicine (IRIB), Rouen, France.,Pulmonology Department, Le Havre Hospital, Montivilliers, France.,Intensive Care Unit, Respiratory Department, Rouen University Hospital, Rouen, France
| | - Pascal Le Roux
- Pediatric Department, Le Havre Hospital, Montivilliers, France
| | - Grégory Reychler
- Institut De Recherche Et d'Expérimentation Clinique (IREC), Pôle De Pneumologie, ORL and Dermatologie, Université Catholique De Louvain, Brussels, Belgium.,Department of Physical Medicine and Rehabilitation, Saint-Luc University Clinics, Brussels, Belgium
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6
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McNarry MA, Winn CON, Davies GA, Eddolls WTB, Mackintosh KA. Effect of High-Intensity Training and Asthma on the V˙O2 Kinetics of Adolescents. Med Sci Sports Exerc 2020; 52:1322-1329. [PMID: 31972630 DOI: 10.1249/mss.0000000000002270] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE High-intensity interval training (HIIT) represents a potent stimulus to the dynamic oxygen uptake (V˙O2) response in adults, but whether the same is evident in youth is unknown. HIIT has also been suggested to place a lower demand on the respiratory system, decreasing the likelihood of exacerbation in those with respiratory conditions, such as asthma. METHODS Sixty-nine adolescents (13.6 ± 0.9 yr; 36 asthma) took part, 35 of which (17 asthma) participated in a 30-min HIIT intervention three times a week for 6 months. Each participant completed an incremental ramp test to volitional exhaustion and three heavy-intensity constant work rate tests to determine the dynamic V˙O2, heart rate, and deoxyhemoglobin response at baseline, midintervention, postintervention and at a 3-month follow-up. RESULTS There was no influence of asthma at baseline or in response to the intervention. Participants in the intervention group demonstrated a faster V˙O2 time constant (τp) after intervention (intervention: 29.2 ± 5.7 s vs control: 34.2 ± 6.5 s; P = 0.003), with these differences maintained at follow-up (intervention: 32.5 ± 5.5 s vs control: 37.3 ± 8.7 s; P = 0.008). The intervention was associated with a speeding of the concentration of deoxyhemoglobin τ (pre: 20.1 ± 4.7 s vs post: 18.2 ± 4.1 s; P = 0.05) compared with a slowing over the same time period in the control participants (pre: 17.9 ± 4.9 s vs post: 20.1 ± 4.6 s; P = 0.012). Heart rate kinetics were not altered (pre: 46.5 ± 12.2 s vs post: 47.7 ± 11.1 s; P = 0.98). CONCLUSION These findings highlight the potential utility of school-based HIIT as a strategy to enhance the V˙O2 kinetics of youth, regardless of the presence of asthma.
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Affiliation(s)
- Melitta A McNarry
- Applied Sports Technology, Exercise and Medicine (A-STEM) Research Centre, College of Engineering, Bay Campus, Swansea University, Swansea, UNITED KINGDOM
| | | | - Gwyneth A Davies
- Swansea University Medical School, Singleton Campus, Swansea University, Swansea, UNITED KINGDOM
| | - William T B Eddolls
- Applied Sports Technology, Exercise and Medicine (A-STEM) Research Centre, College of Engineering, Bay Campus, Swansea University, Swansea, UNITED KINGDOM
| | - Kelly A Mackintosh
- Applied Sports Technology, Exercise and Medicine (A-STEM) Research Centre, College of Engineering, Bay Campus, Swansea University, Swansea, UNITED KINGDOM
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Saynor ZL, Gruet M, Rodriguez-Miguelez P, Harris RA. Oxygen transport and utilisation during exercise in cystic fibrosis: contributors to exercise intolerance. Exp Physiol 2020; 105:1979-1983. [PMID: 33119143 DOI: 10.1113/ep088106] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 10/21/2020] [Indexed: 01/04/2023]
Abstract
NEW FINDINGS What is the topic of this review? This review highlights the central and peripheral mechanisms that alter oxygen transport and utilisation and thereby contribute to exercise limitation in people with cystic fibrosis, considering also viable therapeutic targets for intervention. What advances does it highlight? Although traditionally considered a respiratory condition, pathological intramuscular and cardiovascular changes in people with cystic fibrosis appear to be key determinants of exercise intolerance up until the later stages of respiratory disease. Even young, habitually active patients with normal lung function experience multisystemic abnormalities, which play a role in exercise intolerance. ABSTRACT Cystic fibrosis (CF) is a complex condition, commonly associated with exercise limitation. The mechanisms responsible for this in CF are of interest, given that lower aerobic fitness is associated with an increased risk of being hospitalised with pulmonary exacerbation, a poorer quality of life and a poorer prognosis. Pathophysiological changes in lung function are considered central to CF, and may contribute to exercise limitation. However, it is now clear that the pathogenesis of exercise limitation in this population is multifactorial, with alterations in cardiovascular, muscle and pulmonary function contributing. Whilst some of these changes are attributable to respiratory disease per se, the CF transmembrane conductance regulator protein is also found in skeletal muscle and the vascular endothelium and can directly alter central and localised oxygen delivery, as well as the ability to effectively extract and utilise oxygen at the myocyte level. Since intense exercise poses considerable challenges to arterial oxygen content and/or blood flow and its supply to the working skeletal muscle, evaluating the exercise physiology of people with CF has helped us understand the mechanisms underlying exercise intolerance. Through several investigations over recent years, we have collectively demonstrated that people with CF exhibit reduced skeletal muscle oxygen extraction and utilisation during exercise, with a lesser contribution from haemodynamic or chronotropic mechanisms. Taken together, our findings highlight the importance of targeting mechanisms of skeletal muscle oxygen utilisation in CF to improve exercise tolerance and we offer potential therapeutic interventional strategies.
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Affiliation(s)
- Zoe L Saynor
- School of Sport, Health and Exercise Science, Faculty of Science and Health, University of Portsmouth, Portsmouth, UK
| | - Mathieu Gruet
- Laboratory of the Impact of Physical Activity on Health (IAPS), Toulon University, Toulon, France
| | - Paula Rodriguez-Miguelez
- Department of Kinesiology and Health Sciences, College of Humanities and Sciences, Virginia Commonwealth University, Richmond, VA, USA
| | - Ryan A Harris
- Georgia Prevention Institute, Department of Medicine, Augusta University, Augusta, GA, USA
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Coelho CC, Aquino EDS, Diniz ALR, Santos MDS, Oliveira LCD, Poeiras PTC, Pereira DAG. Tissue oxygenation in peripheral muscles and functional capacity in cystic fibrosis: a cross-sectional study. Exp Physiol 2020; 105:1571-1578. [PMID: 32770583 DOI: 10.1113/ep088764] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 08/06/2020] [Indexed: 12/21/2022]
Abstract
NEW FINDINGS What is the central question of this study? How do peripheral muscle tissue oxygenation and physical conditioning levels of children and adolescents with cystic fibrosis compare to demographically matched controls? What is the main finding and its importance? Children and adolescents with cystic fibrosis consumed more oxygen, more quickly and exhibited slower recovery, demonstrating that there may have been deficiencies in oxygen supply related to both oxygen uptake and oxygen transport. ABSTRACT Cystic fibrosis affects skeletal muscle performance and functional capacity. However, it is currently unclear how peripheral muscle behaviour is affected, especially in children and adolescents. To examine this, we compared tissue oxygenation of children and adolescents with cystic fibrosis against healthy volunteers. We also evaluated the functional capacity of participants via the modified shuttle test (MST) and assessed for associations between performance and near-infrared spectroscopy. A total of 124 participants enrolled. Participants were divided into either the cystic fibrosis group (CFG) or the healthy group (HG). Statistical comparisons between groups were evaluated with the Mann-Whitney U test and associations with functional capacity were evaluated using Spearman's correlation coefficient. CFG volunteers scored lower on the MST compared to the HG. They walked shorter distances (P = 0.001) with less efficiency because they performed the tests with a less efficient walking economy (P = 0.001) and a greater deoxyhaemoglobin concentration (P = 0.001). Further, they experienced reduced tissue oxygen saturation (P = 0.037) faster than the HG. As a result, they presented lower respiratory (P = 0.001) and lower heart (P = 0.001) rate values at the end of the MST, with a longer post-test heart rate recovery time (P = 0.005). There was a significant association between deoxygenation time and functional capacity. The CFG consumed more oxygen, more quickly, with a slower recovery, reflecting impairments in the dynamics of muscle oxygen extraction. The results suggest differences in functional capacity and haemodynamic recovery in children and adolescents with cystic fibrosis.
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Affiliation(s)
- Cristiane Cenachi Coelho
- Hospital Infantil João Paulo II - FHEMIG, Brazil.,Program in Rehabilitation Sciences, Universidade Federal de Minas Gerais, Brazil
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9
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Reuveny R, DiMenna FJ, Gunaratnam C, Arad AD, McElvaney GN, Susta D, Peled M, Moyna NM. High-intensity interval training accelerates oxygen uptake kinetics and improves exercise tolerance for individuals with cystic fibrosis. BMC Sports Sci Med Rehabil 2020; 12:9. [PMID: 32308986 PMCID: PMC7153226 DOI: 10.1186/s13102-020-0159-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 01/14/2020] [Indexed: 12/31/2022]
Abstract
Background Exercise training provides benefits for individuals with cystic fibrosis; however, the optimal program is unclear. High-intensity interval training is safe and effective for improving ‘functional capacity’ in these individuals with peak rate of O2 uptake typically referenced. The ability to adjust submaximal rate of oxygen uptake (V̇O2 kinetics) might be more important for everyday function because maximal efforts are usually not undertaken. Moreover, the ability of high-intensity training to accelerate V̇O2 kinetics for individuals with cystic fibrosis could be enhanced with O2 supplementation during training. Methods Nine individuals with cystic fibrosis completed incremental cycling to limit of tolerance followed by 8 weeks of high-intensity interval cycling (2 sessions per week x ~ 45 min per session) either with (n = 5; O2+) or without (AMB) oxygen supplementation (100%). Each session involved work intervals at 70% of peak work rate followed by 60 s of recovery at 35%. For progression, duration of work intervals was increased according to participant tolerance. Results Both groups experienced a significant increase in work-interval duration over the course of the intervention (O2+, 1736 ± 141 v. 700 ± 154 s; AMB, 1463 ± 598 v. 953 ± 253 s; P = 0.000); however, the increase experienced by O2+ was greater (P = 0.027). During low-intensity constant-work-rate cycling, the V̇O2 mean response time was shortened post compared to pre training (O2+, 34 ± 11 v. 44 ± 9 s; AMB, 39 ± 14 v. 45 ± 17 s; P = 0.000) while during high-intensity constant-work-rate cycling, time to exhaustion was increased (O2+, 1628 ± 163 v. 705 ± 133 s; AMB, 1073 ± 633 v. 690 ± 348 s; P = 0.002) and blood [lactate] response was decreased (O2+, 4.5 ± 0.9 v. 6.3 ± 1.4 mmol. L− 1; AMB, 4.5 ± 0.6 v. 5.2 ± 1.4 mmol. L− 1; P = 0.003). These positive adaptations were similar regardless of gas inspiration during training. Conclusion Eight weeks of high-intensity interval training for patients with cystic fibrosis accelerated V̇O2 kinetics and increased time to exhaustion. This provides some evidence that these patients may benefit from this type of exercise. Trial registration This study was retrospectively registered in the ISRTCN registry on 22/06/2019 (#ISRCTN13864650).
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Affiliation(s)
- Ronen Reuveny
- 1Centre for Preventive Medicine, School of Health and Human Performance, Dublin City University, Dublin, Ireland.,2Pulmonary Institute, Sheba Medical Center, Tel-HaShomer, Ramat Gan, affiliated with Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Fred J DiMenna
- 3Department of Medicine, Division of Endocrinology, Diabetes and Bone Disease, Mt. Sinai St. Luke's Hospital, New York, USA.,4Department of Biobehavioral Sciences, Teachers College, Columbia University, 525 W. 120th Street, New York, N.Y 10027 USA
| | - Cedric Gunaratnam
- Department of Medicine, Respiratory Research Division, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin 9, Ireland
| | - Avigdor D Arad
- 3Department of Medicine, Division of Endocrinology, Diabetes and Bone Disease, Mt. Sinai St. Luke's Hospital, New York, USA.,4Department of Biobehavioral Sciences, Teachers College, Columbia University, 525 W. 120th Street, New York, N.Y 10027 USA
| | - Gerry N McElvaney
- Department of Medicine, Respiratory Research Division, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin 9, Ireland
| | - Davide Susta
- 1Centre for Preventive Medicine, School of Health and Human Performance, Dublin City University, Dublin, Ireland
| | - Michael Peled
- 2Pulmonary Institute, Sheba Medical Center, Tel-HaShomer, Ramat Gan, affiliated with Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Niall M Moyna
- 1Centre for Preventive Medicine, School of Health and Human Performance, Dublin City University, Dublin, Ireland
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Lomax M, Mayger B, Saynor ZL, Vine C, Massey HC. Practical Considerations for Assessing Pulmonary Gas Exchange and Ventilation During Flume Swimming Using the MetaSwim Metabolic Cart. J Strength Cond Res 2019; 33:1941-1953. [PMID: 30113916 DOI: 10.1519/jsc.0000000000002801] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Lomax, M, Mayger, B, Saynor, ZL, Vine, C, and Massey, HC. Practical considerations for assessing pulmonary gas exchange and ventilation during flume swimming using the MetaSwim metabolic cart. J Strength Cond Res 33(7): 1941-1953, 2019-The MetaSwim (MS) metabolic cart can assess pulmonary gas exchange and ventilation in aquatic environments. The aims of this study were: (a) to determine the agreement between minute ventilation (VE), pulmonary oxygen uptake (VO2), and carbon dioxide output (VCO2) using the MS and Douglas bag (DB) methods during flume swimming; and (b) to assess the repeatability of these and other MS-derived parameters. Sixteen trained swimmers completed a combined incremental and supramaximal verification cardiopulmonary swimming test to determine maximal VO2, 2 progressive intensity swimming tests during which MS and DB measurements were made (agreement protocol), and 3-4 constant-velocity submaximal swimming tests during which only the MS was used (repeatability protocol). Agreement was determined using limits of agreement (LoA), bias, random error, and 95% confidence intervals with systematic bias assessed using paired samples t-tests. Within-trial and between-trial repeatability were determined using the coefficient of variation (CV) and the repeatability coefficient (CR). Where data were heteroscedastic, LoA and CR were log-transformed, antilogged, and displayed as ratios. MetaSwim underestimated peak VO2 and VCO2 (≤0.39 L·min) and VE (9.08 L·min), whereas submaximal values varied between 2 and 5% for CV and ±1.09-1.22 for ratio CR. The test-retest CV during constant-velocity swimming for VE, tidal volume, breathing frequency, VO2, VCO2, and end-tidal pressures of O2 and CO2 was <9% (ratio CR of ±1.09-1.34). Thus, the MS and DB cannot be used interchangeably. Whether the MS is suitable for evaluating ventilatory and pulmonary responses in swimming will depend on the size of effect required.
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Affiliation(s)
- Mitch Lomax
- Department of Sport and Exercise Science, University of Portsmouth, Portsmouth, Hampshire, United Kingdom
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11
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Shei RJ, Mackintosh KA, Peabody Lever JE, McNarry MA, Krick S. Exercise Physiology Across the Lifespan in Cystic Fibrosis. Front Physiol 2019; 10:1382. [PMID: 31780953 PMCID: PMC6856653 DOI: 10.3389/fphys.2019.01382] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 10/21/2019] [Indexed: 01/19/2023] Open
Abstract
Cystic fibrosis (CF), a severe life-limiting disease, is associated with multi-organ pathologies that contribute to a reduced exercise capacity. At present, the impact of, and interaction between, disease progression and other age-related physiological changes in CF on exercise capacity from child- to adult-hood is poorly understood. Indeed, the influences of disease progression and aging are inherently linked, leading to increasingly complex interactions. Thus, when interpreting age-related differences in exercise tolerance and devising exercise-based therapies for those with CF, it is critical to consider age-specific factors. Specifically, changes in lung function, chronic airway colonization by increasingly pathogenic and drug-resistant bacteria, the frequency and severity of pulmonary exacerbations, endocrine comorbidities, nutrition-related factors, and CFTR (cystic fibrosis transmembrane conductance regulator protein) modulator therapy, duration, and age of onset are important to consider. Accounting for how these factors ultimately influence the ability to exercise is central to understanding exercise impairments in individuals with CF, especially as the expected lifespan with CF continues to increase with advancements in therapies. Further studies are required that account for these factors and the changing landscape of CF in order to better understand how the evolution of CF disease impacts exercise (in)tolerance across the lifespan and thereby identify appropriate intervention targets and strategies.
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Affiliation(s)
- Ren-Jay Shei
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, The University of Alabama at Birmingham, Birmingham, AL, United States
- Gregory Fleming James Cystic Fibrosis Research Center, The University of Alabama at Birmingham, Birmingham, AL, United States
| | - Kelly A. Mackintosh
- Applied Sports, Technology, Exercise and Medicine Research Centre, College of Engineering, Swansea University, Swansea, United Kingdom
| | - Jacelyn E. Peabody Lever
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, The University of Alabama at Birmingham, Birmingham, AL, United States
- Gregory Fleming James Cystic Fibrosis Research Center, The University of Alabama at Birmingham, Birmingham, AL, United States
- Medical Scientist Training Program, The University of Alabama at Birmingham, Birmingham, AL, United States
| | - Melitta A. McNarry
- Applied Sports, Technology, Exercise and Medicine Research Centre, College of Engineering, Swansea University, Swansea, United Kingdom
| | - Stefanie Krick
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, The University of Alabama at Birmingham, Birmingham, AL, United States
- Gregory Fleming James Cystic Fibrosis Research Center, The University of Alabama at Birmingham, Birmingham, AL, United States
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12
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Lai N, Kummitha C, Drumm M, Hoppel C. Alterations of skeletal muscle bioenergetics in a mouse with F508del mutation leading to a cystic fibrosis-like condition. Am J Physiol Endocrinol Metab 2019; 317:E327-E336. [PMID: 31211618 PMCID: PMC6732463 DOI: 10.1152/ajpendo.00064.2019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
High energy expenditure is reported in cystic fibrosis (CF) animal models and patients. Alterations in skeletal muscle oxidative capacity, fuel utilization, and the creatine kinase-phosphocreatine system suggest mitochondrial dysfunction. Studies were performed on congenic C57BL/6J and F508del (Cftrtm1kth) mice. Indirect calorimetry was used to measure gas exchange to evaluate aerobic capacity during treadmill exercise. The bioenergetic function of skeletal muscle subsarcolemmal (SSM) and interfibrillar mitochondria (IFM) was evaluated using an integrated approach combining measurement of the rate of oxidative phosphorylation by polarography and of electron transport chain activities by spectrophotometry. CF mice have reduced maximal aerobic capacity. In SSM of these mice, oxidative phosphorylation was impaired in the presence of complex I, II, III, and IV substrates except when glutamate was used as substrate. This impairment appeared to be caused by a defect in complex V activity, whereas the oxidative system of the electron transport chain was unchanged. In IFM, oxidative phosphorylation and electron transport chain activities were preserved, whereas complex V activity was reduced, in CF. Furthermore, creatine kinase activity was reduced in both SSM and IFM of CF skeletal muscle. The decreased complex V activity in SSM resulted in reduced oxidative phosphorylation, which could explain the reduced skeletal muscle response to exercise in CF mice. The decrease in mitochondrial creatine kinase activity also contributed to this poor exercise response.
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Affiliation(s)
- Nicola Lai
- Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, Virginia
- Biomedical Engineering Institute, Old Dominion University, Norfolk, Virginia
- Department of Biomedical Engineering, School of Engineering, Case Western Reserve University, Cleveland, Ohio
| | - Chinna Kummitha
- Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, Virginia
- Biomedical Engineering Institute, Old Dominion University, Norfolk, Virginia
- Department of Biomedical Engineering, School of Engineering, Case Western Reserve University, Cleveland, Ohio
| | - Mitchell Drumm
- Department of Genetics, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Charles Hoppel
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, Ohio
- Center for Mitochondrial Disease, School of Medicine, Case Western Reserve University, Cleveland, Ohio
- Department of Medicine, School of Medicine, Case Western Reserve University, Cleveland, Ohio
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13
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Abstract
Pulmonary oxygen uptake ( V˙O2 ) kinetics, which describes the aerobic response to near instantaneous changes in metabolic demand, provides a valuable insight into the control and coordination of oxidative phosphorylation during exercise. Despite their applicability to the highly sporadic habitual physical activity and exercise patterns of children, relatively little is known regarding the influence of internal and external stimuli on the dynamic V˙O2 response. Although insufficient evidence is available during moderate-intensity exercise, an age-related slowing of the phase 2 time constant (τ) and augmentation of the V˙O2 slow component appears to manifest during heavy-intensity exercise, which may be related to changes in the muscle phosphate controllers of oxidative phosphorylation, muscle oxygen delivery and utilization, and/or muscle fiber type recruitment patterns. Similar to findings in adults, aerobic training is associated with a faster phase 2 τ and smaller V˙O2 slow component in youth, independent of age or maturity, indicative of an enhanced oxidative metabolism. However, a lack of longitudinal or intervention-based training studies limits our ability to attribute these changes to training per se. Further, methodologically rigorous studies are required to fully resolve the interaction(s) between age, sex, biological maturity, and external stimuli, such as exercise training and exercise intensity and the dynamic V˙O2 response at the onset and offset of exercise.
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14
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Van Iterson EH, Baker SE, Wheatley CM, Morgan WJ, Olson TP, Snyder EM. Exercise Stroke Volume in Adult Cystic Fibrosis: A Comparison of Acetylene Pulmonary Uptake and Oxygen Pulse. CLINICAL MEDICINE INSIGHTS-CIRCULATORY RESPIRATORY AND PULMONARY MEDICINE 2018; 12:1179548418790564. [PMID: 30083061 PMCID: PMC6073827 DOI: 10.1177/1179548418790564] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 06/28/2018] [Indexed: 12/19/2022]
Abstract
Cardiac hemodynamic assessment during cardiopulmonary exercise testing (CPET) is proposed to play an important role in the clinical evaluation of individuals with cystic fibrosis (CF). Cardiac catheterization is not practical for routine clinical CPET. Use of oxygen pulse (O2pulse) as a noninvasive estimate of stroke volume (SV) has not been validated in CF. This study tested the hypothesis that peak exercise O2pulse is a valid estimate of SV in CF. Measurements of SV via the acetylene rebreathe technique were acquired at baseline and peak exercise in 17 mild-to-moderate severity adult CF and 25 age-matched healthy adults. We calculated O2pulse=V.O2HR. Baseline relationships between SV and O2pulse were significant in CF (r = .80) and controls (r = .40), persisting to peak exercise in CF (r = .63) and controls (r = .73). The standard error of estimate for O2pulse-predicted SV with respect to measured SV was similar at baseline (14.1 vs 20.1 mL) and peak exercise (18.2 vs 13.9 mL) for CF and controls, respectively. These data suggest that peak exercise O2pulse is a valid estimate of SV in CF. The ability to noninvasively estimate SV via O2pulse during routine clinical CPET can be used to improve test interpretation and advance our understanding of the impact cardiac dysfunction has on exercise intolerance in CF.
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Affiliation(s)
| | - Sarah E Baker
- College of Pharmacy, The University of Arizona, Tucson, AZ, USA.,Department of Anesthesiology, Mayo Clinic, Rochester, MN, USA
| | - Courtney M Wheatley
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN, USA.,College of Pharmacy, The University of Arizona, Tucson, AZ, USA
| | - Wayne J Morgan
- Department of Pediatrics, The University of Arizona, Tucson, AZ, USA
| | - Thomas P Olson
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN, USA
| | - Eric M Snyder
- College of Pharmacy, The University of Arizona, Tucson, AZ, USA.,School of Kinesiology, University of Minnesota, Minneapolis, MN, USA
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15
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Tomlinson OW, Barker AR, Chubbock LV, Stevens D, Saynor ZL, Oades PJ, Williams CA. Analysis of oxygen uptake efficiency parameters in young people with cystic fibrosis. Eur J Appl Physiol 2018; 118:2055-2063. [PMID: 30003381 PMCID: PMC6153633 DOI: 10.1007/s00421-018-3926-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 06/25/2018] [Indexed: 12/18/2022]
Abstract
PURPOSE This study characterised oxygen uptake efficiency (OUE) in children with mild-to-moderate cystic fibrosis (CF). Specifically, it investigated (1) the utility of OUE parameters as potential submaximal surrogates of peak oxygen uptake ([Formula: see text]), and (2) the relationship between OUE and disease severity. METHODS Cardiopulmonary exercise test (CPET) data were collated from 72 children [36 CF, 36 age- and sex-matched controls (CON)], with OUE assessed as its highest 90-s average (plateau; OUEP), the gas exchange threshold (OUEGET) and respiratory compensation point (OUERCP). Pearson's correlation coefficients, independent t tests and factorial ANOVAs assessed differences between groups and the use of OUE measures as surrogates for [Formula: see text]. RESULTS A significant (p < 0.05) reduction in allometrically scaled [Formula: see text] and all OUE parameters was found in CF. Significant (p < 0.05) correlations between measurements of OUE and allometrically scaled [Formula: see text], were observed in CF (r = 0.49-0.52) and CON (r = 0.46-0.52). Furthermore, measures of OUE were significantly (p < 0.05) correlated with pulmonary function (FEV1%predicted) in CF (r = 0.38-0.46), but not CON (r = -0.20-0.14). OUEP was able to differentiate between different aerobic fitness tertiles in CON but not CF. CONCLUSIONS OUE parameters were reduced in CF, but were not a suitable surrogate for [Formula: see text]. Clinical teams should, where possible, continue to utilise maximal CPET parameters to measure aerobic fitness in children and adolescents with CF. Future research should assess the prognostic utility of OUEP as it does appear sensitive to disease status and severity.
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Affiliation(s)
- Owen W Tomlinson
- Children's Health and Exercise Research Centre, Sport and Health Science, College of Life and Environmental Sciences, University of Exeter, St Luke's Campus, Heavitree Road, Exeter, EX1 2LU, UK
- Royal Devon and Exeter NHS Foundation Trust Hospital, Barrack Road, Exeter, EX2 5DW, UK
| | - Alan R Barker
- Children's Health and Exercise Research Centre, Sport and Health Science, College of Life and Environmental Sciences, University of Exeter, St Luke's Campus, Heavitree Road, Exeter, EX1 2LU, UK
| | - Lucy V Chubbock
- Children's Health and Exercise Research Centre, Sport and Health Science, College of Life and Environmental Sciences, University of Exeter, St Luke's Campus, Heavitree Road, Exeter, EX1 2LU, UK
| | - Daniel Stevens
- Division of Respirology, Department of Pediatrics, Faculty of Medicine and School of Health and Human Performance, Faculty of Health Professions, Dalhousie University, Stairs House, 6230 South St., PO BOX 15000, Halifax, NS B3H 4R2, Canada
| | - Zoe L Saynor
- Department of Sport and Exercise Science, Faculty of Science, University of Portsmouth, Spinnaker Building, Cambridge Road, Portsmouth, PO1 2ER, UK
- Paediatric and Adult Respiratory Departments, University Hospital Southampton, Tremona Road, Southampton, SO16 6YD, UK
| | - Patrick J Oades
- Royal Devon and Exeter NHS Foundation Trust Hospital, Barrack Road, Exeter, EX2 5DW, UK
| | - Craig A Williams
- Children's Health and Exercise Research Centre, Sport and Health Science, College of Life and Environmental Sciences, University of Exeter, St Luke's Campus, Heavitree Road, Exeter, EX1 2LU, UK.
- Royal Devon and Exeter NHS Foundation Trust Hospital, Barrack Road, Exeter, EX2 5DW, UK.
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16
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Williams CA, Tomlinson OW, Chubbock LV, Stevens D, Saynor ZL, Oades PJ, Barker AR. The oxygen uptake efficiency slope is not a valid surrogate of aerobic fitness in cystic fibrosis. Pediatr Pulmonol 2018; 53:36-42. [PMID: 29064163 DOI: 10.1002/ppul.23896] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 09/21/2017] [Indexed: 11/10/2022]
Abstract
BACKGROUND Maximal cardiopulmonary exercise testing is recommended on an annual basis for children with cystic fibrosis (CF), due to clinically useful prognostic information provided by maximal oxygen uptake (V̇O2max ). However, not all patients are able, or willing, to reach V̇O2max , and therefore submaximal alternatives are required. This study explored the validity of the oxygen uptake efficiency slope (OUES) as a submaximal measure of V̇O2max in children and adolescents with CF. METHODS Data were collated from 72 cardiopulmonary exercise tests (36 CF, 36 controls), with OUES determined relative to maximal and submaximal parameters of exercise intensity, time, and individual metabolic thresholds. Pearson's correlation coefficients, independent t-tests, and factorial ANOVAs were used to determine validity. RESULTS Significant (P < 0.05) correlations with V̇O2max were observed for most expressions of OUES, but were consistently weaker in CF (r = 0.30-0.47) when compared to CON (r = 0.58-0.89). Mean differences for all OUES parameters between groups were not significant (P > 0.05). When split by V̇O2max tertiles, minimal significant differences were found between, and within, groups for OUES, indicating poor discrimination of V̇O2max . CONCLUSIONS The OUES is not a valid (sub) maximal measure of V̇O2max in children and adolescents with mild-to-moderate CF. Clinicians should continue to use maximal markers (ie, V̇O2max ) of exercise capacity.
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Affiliation(s)
- Craig A Williams
- Children's Health and Exercise Research Center, Sport and Health Science, University of Exeter, Exeter, United Kingdom.,Pediatric Department, Royal Devon and Exeter NHS Foundation Trust Hospital, Exeter, United Kingdom
| | - Owen W Tomlinson
- Children's Health and Exercise Research Center, Sport and Health Science, University of Exeter, Exeter, United Kingdom.,Pediatric Department, Royal Devon and Exeter NHS Foundation Trust Hospital, Exeter, United Kingdom
| | - Lucy V Chubbock
- Children's Health and Exercise Research Center, Sport and Health Science, University of Exeter, Exeter, United Kingdom
| | - Daniel Stevens
- Department of Pediatrics, Division of Respirology, Faculty of Medicine and School of Health and Human Performance, Faculty of Health Professions, Dalhousie University, Halifax, Canada
| | - Zoe L Saynor
- Department of Sport and Exercise Science, Faculty of Science, University of Portsmouth, Portsmouth, United Kingdom
| | - Patrick J Oades
- Pediatric Department, Royal Devon and Exeter NHS Foundation Trust Hospital, Exeter, United Kingdom
| | - Alan R Barker
- Children's Health and Exercise Research Center, Sport and Health Science, University of Exeter, Exeter, United Kingdom
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17
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Peripheral muscle abnormalities in cystic fibrosis: Etiology, clinical implications and response to therapeutic interventions. J Cyst Fibros 2017; 16:538-552. [DOI: 10.1016/j.jcf.2017.02.007] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 02/10/2017] [Accepted: 02/12/2017] [Indexed: 12/14/2022]
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