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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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Barbosa RRB, Coelho PDF, Liberato FMG, Vidal PDR, Couto Olimpio de Carvalho RB, Melotti RDCNC, Donadio MVF. Sleep disorders are distinctively associated with exercise intolerance and sedentary behavior in children with cystic fibrosis. Sleep Med 2020; 74:145-151. [DOI: 10.1016/j.sleep.2020.07.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 07/01/2020] [Accepted: 07/12/2020] [Indexed: 10/23/2022]
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Abstract
This essay expounds on fundamental, quantitative elements of the exercise ventilation in children, which was the subject of the Tom Rowland Lecture given at the NASPEM 2018 Conference. Our knowledge about how much ventilation rises during aerobic exercise is reasonably solid; our understanding of its governance is a work in progress, but our grasp of dyspnea and ventilatory limitation in children (if it occurs) remains embryonic. This manuscript summarizes ventilatory mechanics during dynamic exercise, then proceeds to outline our current understanding of mechanisms of dyspnea, particularly during exercise (exertional dyspnea). Most research in this field has been done in adults, and the vast majority of these studies in patients with chronic obstructive pulmonary disease. To what extent conclusions drawn from this literature apply to children and adolescents-both healthy and those with cardiopulmonary disease-will be discussed. The few, recent, pertinent, pediatric studies will be reviewed in an attempt to provide an empirical basis for proposing a hypothetical model to study exertional dyspnea in youth. Just as somatic growth will have consequences for ventilatory and exercise capacity, so too will neural developmental plasticity and experience affect perception of dyspnea. Our path to understand how these evolving inputs and influences summate during a child's life will be Columbus' India.
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Abstract
PURPOSE The modified shuttle test (MST) is increasingly used in clinical practice to assess functional capacity in patients with cystic fibrosis (CF). The purpose of this study was to evaluate the physiological responses of the MST in adults with CF as compared with the gold standard cardiopulmonary exercise test (CPET). METHODS Participants performed an MST and a CPET on a cycle ergometer in random order. Oxygen (O2) uptake ((Equation is included in full-text article.)O2), carbon dioxide (CO2) retention (end-tidal PCO2; PETCO2), minute ventilation, heart rate, and peripheral O2 saturation (SpO2) were continuously monitored. Whole blood lactate, dyspnea, and leg discomfort were recorded immediately after both exercises. RESULTS Twenty patients with CF (aged 33 ± 8 years; forced expiratory volume in 1 second = 48% ± 17%) completed both tests. Peak values for (Equation is included in full-text article.)O2 (27 ± 7 vs 24 ± 6 mL/kg/min), heart rate (169 ± 19 vs 163 ± 16 bpm), end PETCO2 (42 ± 7 vs 39 ± 8 mm Hg), and O2 desaturation (end SpO2, 86% ± 7% vs 90% ± 6%) were significantly higher during the MST than during the CPET (all Ps < .05). Leg discomfort and whole blood lactate were significantly higher after the CPET (both Ps < .05). Thirty-five percent and 40% of patients showed significant O2 desaturation and CO2 retention, respectively, during the MST, which was not detected during the CPET. A strong relationship was found between MST peak (Equation is included in full-text article.)O2 and body weight walking distance product (r = 0.90; P < .01). CONCLUSIONS The MST may provide a strong indicator of exercise tolerance in adults with CF as indicated by high peak (Equation is included in full-text article.)O2 values. In clinical practice, body weight walking distance should be considered as the primary outcome. This test is also better than cycle ergometry CPET for detecting O2 desaturation and CO2 retention, further emphasizing its clinical interest.
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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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Improvement in exercise duration, lung function and well-being in G551D-cystic fibrosis patients: a double-blind, placebo-controlled, randomized, cross-over study with ivacaftor treatment. Clin Sci (Lond) 2017; 131:2037-2045. [PMID: 28611235 DOI: 10.1042/cs20170995] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2017] [Revised: 06/07/2017] [Accepted: 06/12/2017] [Indexed: 11/17/2022]
Abstract
G551D, a mutation of the cystic fibrosis transmembrane conductance regulator (CFTR) gene, results in impaired chloride channel function in cystic fibrosis (CF) with multiple end-organ manifestations. The effect of ivacaftor, a CFTR-potentiator, on exercise capacity in CF is unknown. Twenty G551D-CF patients were recruited to a single-centre, double-blind, placebo-controlled, 28-day crossover study of ivacaftor. Variables measured included percentage change from baseline (%Δ) of VO2max (maximal oxygen consumption, primary outcome) during cardiopulmonary exercise testing (CPET), relevant other CPET physiological variables, lung function, body mass index (BMI), sweat chloride and disease-specific health related quality of life (QOL) measures (CFQ-R and Alfred Wellness (AWEscore)). %ΔVO2max was unchanged compared with placebo as was %Δminute ventilation. However, %Δexercise time (mean 7.3, CI 0.5-14,1, P=0.0222) significantly increased as did %ΔFEV1 (11.7%, range 5.3-18.1, P<0·005) and %ΔBMI (1.2%, range 0.1-2.3, P=0·0393) whereas sweat chloride decreased (mean -43.4; range -55.5-18.1 mmol·l-1, P<0·005). Total and activity based domains in both CFQ-R and AWEscore also increased. A positive treatment effect on spirometry, BMI (increased), SCT (decreased) and total and activity based CF-specific QOL measures was expected. However, the lack of discernible improvement in VO2max and VE despite other positive changes including spirometric lung function and exercise time with a 28-day ivacaftor intervention suggests that ventilatory parameters are not the sole driver of change in exercise capacity in this study cohort. Investigation over a more prolonged period may delineate the potential interdependencies of the observed discordances over time. TRIAL REGISTRATION NUMBER ClinicalTrials.gov-NCT01937325.
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Quon BS, Wilkie SS, Molgat-Seon Y, Schaeffer MR, Ramsook AH, Wilcox PG, Guenette JA. Cardiorespiratory and sensory responses to exercise in adults with mild cystic fibrosis. J Appl Physiol (1985) 2015; 119:1289-96. [PMID: 26429870 DOI: 10.1152/japplphysiol.00692.2015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 09/28/2015] [Indexed: 12/31/2022] Open
Abstract
The purpose of this study was to evaluate cardiorespiratory fitness and reasons for exercise curtailment in a contemporary adult cystic fibrosis (CF) cohort with mild lung disease. Adults with mild CF (n = 19, forced expiratory volume in 1 s = 95 ± 17% predicted) were age-, sex-, ethnicity-, and body mass index-matched to healthy controls (n = 19) and underwent a detailed cardiopulmonary cycle exercise test. While CF subjects had a reduced peak oxygen uptake compared with controls, the values were normal when expressed as %predicted in 14/19 (74%) of subjects. Both groups demonstrated a normal cardiovascular limitation to exercise and stopped exercise primarily because of leg fatigue. Despite not being exercise-limited by respiratory factors, there was some evidence of ventilatory abnormalities as patients with mild CF had increased end-inspiratory lung volumes and reached an inflection/plateau in tidal volume relative to minute ventilation at lower exercise intensities compared with controls. Subjects with CF were not more likely to demonstrate expiratory flow limitation compared with controls and did not have evidence of dynamic hyperinflation during exercise. Despite increased end-inspiratory lung volumes and an earlier tidal volume inflection/plateau, CF subjects did not experience higher levels of dyspnea. In an exploratory analysis, a significant inverse correlation was observed between sweat chloride and peak work rate. Adult CF subjects with relatively well preserved spirometry have normal exercise performance relative to reference values and are primarily limited by nonrespiratory factors. However, ventilatory abnormalities were detected even in this mild CF cohort and should be evaluated in future therapeutic trials focused on disease-modifying therapies in mild CF.
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Affiliation(s)
- Bradley S Quon
- Division of Respiratory Medicine, Department of Medicine, Centre for Heart Lung Innovation, Providence Health Care Research Institute, St. Paul's Hospital
| | - Sabrina S Wilkie
- Centre for Heart Lung Innovation, Providence Health Care Research Institute, St. Paul's Hospital
| | - Yannick Molgat-Seon
- Centre for Heart Lung Innovation, Providence Health Care Research Institute, St. Paul's Hospital, School of Kinesiology, and
| | - Michele R Schaeffer
- Centre for Heart Lung Innovation, Providence Health Care Research Institute, St. Paul's Hospital, Department of Physical Therapy, University of British Columbia, Vancouver, British Columbia, Canada
| | - Andrew H Ramsook
- Centre for Heart Lung Innovation, Providence Health Care Research Institute, St. Paul's Hospital, Department of Physical Therapy, University of British Columbia, Vancouver, British Columbia, Canada
| | - Pearce G Wilcox
- Division of Respiratory Medicine, Department of Medicine, Centre for Heart Lung Innovation, Providence Health Care Research Institute, St. Paul's Hospital
| | - Jordan A Guenette
- Centre for Heart Lung Innovation, Providence Health Care Research Institute, St. Paul's Hospital, Department of Physical Therapy, University of British Columbia, Vancouver, British Columbia, Canada
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Bongers BC, Werkman MS, Takken T, Hulzebos EHJ. Ventilatory response to exercise in adolescents with cystic fibrosis and mild-to-moderate airway obstruction. SPRINGERPLUS 2014; 3:696. [PMID: 25512888 PMCID: PMC4254890 DOI: 10.1186/2193-1801-3-696] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 11/14/2014] [Indexed: 02/08/2023]
Abstract
Data regarding the ventilatory response to exercise in adolescents with mild-to-moderate cystic fibrosis (CF) are equivocal. This study aimed to describe the ventilatory response during a progressive cardiopulmonary exercise test (CPET) up to maximal exertion, as well as to assess the adequacy of the ventilatory response for carbon dioxide (CO2) exhalation. Twenty-two adolescents with CF (12 boys and 10 girls; mean ± SD age: 14.3 ± 1.3 years; FEV1: 78.6 ± 17.3% of predicted) performed a maximal CPET. For each patient, data of a sex- and age matched healthy control was included (12 boys and 10 girls; mean ± SD age: 14.3 ± 1.4 years). At different relative exercise intensities of 25%, 50%, 75%, and 100% of peak oxygen uptake (VO2peak), breathing pattern, estimated ventilatory dead space ventilation (VD/VT ratio), minute ventilation (VE) to CO2 production relationship (VE/VCO2-slope), partial end-tidal CO2 tension (PETCO2), and the VE to the work rate (VE/WR) ratio were examined. VO2peak was significantly reduced in CF patients (P = 0.01). We found no differences in breathing pattern between both groups, except for a significantly higher VE at rest and a trend towards a lower VE at peak exercise in patients with CF. Significantly higher values were found for the estimated VD/VT ratio throughout the CPET in CF patients (P < 0.01). VE/VCO2-slope and PETCO2 values differed not between the two groups throughout the CPET. VE/WR ratio values were significantly higher in CF during the entire range of the CPET (P < 0.01). This study found an exaggerated ventilatory response (high VE/WR ratio values), which was adequate for CO2 exhalation (normal VE/VCO2-slope and PETCO2 values) during progressive exercise up to maximal exhaustion in CF patients with mild-to-moderate airway obstruction.
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Affiliation(s)
- Bart C Bongers
- Department of Epidemiology, School for Public Health and Primary Care (CAPHRI), Maastricht University, Maastricht, The Netherlands ; Child Development & Exercise Center, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Maarten S Werkman
- Child Development & Exercise Center, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, The Netherlands ; De Kinderkliniek, Almere, The Netherlands
| | - Tim Takken
- Child Development & Exercise Center, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Erik H J Hulzebos
- Child Development & Exercise Center, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, The Netherlands
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Rand S, Prasad SA. Exercise as part of a cystic fibrosis therapeutic routine. Expert Rev Respir Med 2012; 6:341-51; quiz 352. [PMID: 22788948 DOI: 10.1586/ers.12.19] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The role of exercise in cystic fibrosis (CF) is well established, and over the last three decades it has become an important component in the management of all individuals with CF. The role of exercise as a prognostic indicator or therapeutic tool is an important area of research interest in CF care internationally. This article summarizes the currently available evidence regarding exercise capacity in CF, the potential effects of exercise on health outcomes in CF and the challenges faced when trying to incorporate exercise into a CF therapeutic routine, and highlights some methods to facilitate the incorporation of exercise into CF therapeutic routines.
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Affiliation(s)
- Sarah Rand
- Cystic Fibrosis Unit, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK.
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Salek MS, Jones S, Rezaie M, Davies C, Mills R, Ketchell RI. Do patient-reported outcomes have a role in the management of patients with cystic fibrosis? Front Pharmacol 2012; 3:38. [PMID: 22416231 PMCID: PMC3298894 DOI: 10.3389/fphar.2012.00038] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Accepted: 02/21/2012] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Health-related quality of life (HRQoL) is a rapidly growing area of expertise and the most commonly used patient-reported outcome (PRO). The impact of cystic fibrosis (CF) on HRQoL is liable to be great, making CF patients ideal candidates for the application of HRQoL instruments. The aims of this study were to assess the affect of CF on HRQoL, to ascertain the reliability and validity of the United Kingdom Sickness Impact Profile (UKSIP) and the Cystic Fibrosis Quality of Life Questionnaire (CFQoL) in the adult CF population, and to examine their role in the management of patients. METHODS Seventy participants were recruited from the All Wales Adult Cystic Fibrosis Centre at Llandough Hospital, UK. There were two stages to the study: self-report of the UKSIP and CFQoL; and completion of the same two questionnaires 7-10 days later. RESULTS The areas of HRQoL most impaired by CF were employment and concerns regarding the future. The UKSIP and CFQoL showed high internal consistency (rα = 0.89-0.93) and test-retest reliability (r(s) = 0.57-0.94, p < 0.005) in the CF population. Validity was variable with the UKSIP showing discrimination across socio-demographic factors, whilst the CFQoL showed increased sensitivity to clinical variables. Many parameters influenced patient-reported HRQoL, with the greatest correlations seen with the Borg score (p < 0.005). The use of a HRQoL instrument in CF annual reviews is recommended to provide holistic patient care. The results of this study underpin the value of HRQoL as a patient-reported outcome measure in the management of adult CF.
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Affiliation(s)
- M Sam Salek
- Centre for Socioeconomic Research, Cardiff University Cardiff, UK
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Reilly CC, Ward K, Jolley CJ, Frank LA, Elston C, Moxham J, Rafferty GF. Effect of endurance exercise on respiratory muscle function in patients with cystic fibrosis. Respir Physiol Neurobiol 2012; 180:316-22. [DOI: 10.1016/j.resp.2011.12.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Revised: 12/15/2011] [Accepted: 12/20/2011] [Indexed: 11/17/2022]
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Neuromuscular fatigue after maximal exercise in patients with cystic fibrosis. J Electromyogr Kinesiol 2011; 21:242-8. [DOI: 10.1016/j.jelekin.2010.10.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2010] [Revised: 10/21/2010] [Accepted: 10/21/2010] [Indexed: 11/20/2022] Open
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Wideman L, Baker CF, Brown PK, Consitt LA, Ambrosius WT, Schechter MS. Substrate utilization during and after exercise in mild cystic fibrosis. Med Sci Sports Exerc 2009; 41:270-8. [PMID: 19127200 DOI: 10.1249/mss.0b013e318188449b] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE To determine substrate utilization and energy expenditure during maximal and submaximal exercise and recovery in adolescents with cystic fibrosis (CF) and healthy age-matched controls (C). METHODS Ten clinically stable CF patients (four girls, six boys; age = 10-22 yr) were matched by body mass index, age, gender, and Tanner stage to healthy controls. Subjects completed VO(2peak) testing and submaximal exercise (20 min) on a cycle ergometer at a relative intensity of 50% VO2(peak) and at an absolute power output (PO). Metabolic parameters were assessed during exercise and recovery (20 min). RESULTS Similar respiratory quotient (RQ) values occurred in both groups during maximal exercise and recovery, despite differences in the maximal PO [CF = 114 (60-180) W and C = 171 (105-280) W, P = 0.006], the total work completed [CF = 27 (9.0-54.3) kJ and C = 55 (25.3-126.5) kJ, P = 0.008], or the VO(2peak) value attained [CF = 30.6 (8.5-45.2) mL kg(-1) min(-1) and C = 40.6 (29-64.5) mL kg(-1) min(-1), P = 0.027]. Submaximal exercise at the same absolute PO resulted in similar RQ values during exercise and recovery despite higher heart rates and average VO2 [CF = 18.8 (9.3-28.7) mL kg(-1) min(-1) and C = 15.2 (6.5-20.1) mL kg(-1)min(-1), P = 0.031] values in CF adolescents, and submaximal exercise at the same relative intensity also resulted in similar RQ values despite significantly greater average PO in the C group [CF = 38.7 (12.3-80) W and C = 67.8 (25.5-140) W, P = 0.039]. Excess postexercise oxygen consumption (EPOC) was greater in CF [2.79 (1.14-5.24) L O2] than C [1.46 (0.56-2.80) L O2] after submaximal exercise at a fixed PO (P = 0.036) but not after the relative exercise bout. CONCLUSIONS Habitual physical activity participation does not warrant adjustment of macronutrient intake ratios in adolescents with mild to moderate CF, but total caloric intake may need to be increased based on the level of EPOC and upon the intensity and the duration of the habitual activity.
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Affiliation(s)
- Laurie Wideman
- Department of Exercise and Sport Science, University of North Carolina at Greensboro, Greensboro, NC 27412, USA.
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Stevens D, Oades PJ, Armstrong N, Williams CA. Early oxygen uptake recovery following exercise testing in children with chronic chest diseases. Pediatr Pulmonol 2009; 44:480-8. [PMID: 19382220 DOI: 10.1002/ppul.21024] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The value of exercise testing as an objective measure of disease severity in patients with chronic chest diseases (CCD) is becoming increasingly recognized. The aim of this study was to investigate changes in oxygen uptake (VO2) during early recovery following maximal cardiopulmonary exercise testing (CPXT) in relation to functional capacity and markers of disease severity. Twenty-seven children with CCD (age 12.7 +/- 3.1 years; 17 female) [19 children with Cystic fibrosis (CF) (age 13.4 +/- 3.1 years; 10 female) and 8 with other stable non-CF chest diseases (NON-CF) (age 11.1 +/- 2.2 years; 7 female)] and 27 healthy controls (age 13.2 +/- 3.3 years; 17 female) underwent CPXT on a cycle ergometer. On-line respiratory gas analysis measured VO2 before and during CPXT to peak VO2) (VO2(peak)), and during the first 10 min of recovery. Early VO2 recovery was quantified by the time (sec) to reach 50% of the VO2 (peak) value. Early VO2 recovery was correlated against spirometry [forced expiratory volume in 1 sec (FEV(1)) and forced expiratory flow between 25% and 75% of the forced vital capacity (FEF(25-75))] and aerobic fitness (VO2)(peak)) as a measure of functional capacity. Disease severity was graded in the CF patients by the Shwachman score (SS). Compared to controls, children with CCD demonstrated a significantly reduced VO2(peak) (P = 0.011), FEV(1) (P < 0.001), FEF(25-75) (P < 0.001), and a significantly prolonged early (VO2) recovery (P = 0.024). In the CF patients the SS was significantly correlated with early VO2 recovery (r = -0.63, P = 0.004), FEV(1) (r = 0.72, P = 0.001), and FEF(25-75) (r = 0.57, P = 0.011). In the children with CCD, FEV(1), FEF(25-75), and BMI were not significantly correlated with VO2(peak) or early VO2 recovery. Lung function does not necessarily reflect aerobic fitness and the ability to recover from exercise in these patients. A significant relationship was found between VO2(peak) and early VO2 recovery (r = -0.39, P = 0.044) in the children with CCD, showing that a greater aerobic fitness corresponded with a faster recovery.
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Affiliation(s)
- D Stevens
- Children's Health and Exercise Research Centre, School of Sport and Health Sciences, University of Exeter, Exeter, Devon, UK
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Barry PJ, Waterhouse DF, Reilly CM, McKenna TJ, McKone EF, Gallagher CG. Androgens, Exercise Capacity, and Muscle Function in Cystic Fibrosis. Chest 2008; 134:1258-1264. [DOI: 10.1378/chest.08-1091] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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