Exercise In Cystic Fibrosis Research Articles

Perception and Participation in Sport and Exercise in Cystic Fibrosis: The Impact of CFTR Modulators

People with cystic fibrosis (pwCF) have barriers to physical activity including exercise intolerance and fatigue. The advent of small molecule cystic fibrosis transmembrane conductance regulator (CFTR) modulators have shown great clinical improvements in pwCF; however, the effect of CFTR modulators on exercise perception and participation is unknown. The purpose of this study was to investigate whether the administration of CFTR modulators changed the perception and participation in sport and exercise in pwCF. A survey-based, retrospective cohort study was conducted including individuals aged 18 and above. Eighty-three participants were recruited with a mean age of 30.0 ± 10.5 years. The majority (82%) of participants were taking CFTR modulators. Participants in the modulator group rated enjoyment of exercise and importance of exercise higher than the non-modulator group and were more likely to exercise as a means to socialize. Participants in the modulator group reported lack of time as the most frequent barrier to sport and exercise whereas fatigue was most reported in the non-modulator group. Twenty-eight percent of the modulator group participated in team/structured sports, whereas no participant engaged in team and structured sports in the non-modulator group. Adults with CF who used CFTR modulators rated exercise more favorably and engaged in more team sport activities compared to pwCF who did not use CFTR modulators. The most frequent barrier to exercise in pwCF who used modulators might no longer be CF-related. More research is needed to confirm whether CFTR modulator administration resulted in increased overall physical activity.

Oxygen transport and utilisation during exercise in cystic fibrosis: contributors to exercise intolerance.

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. 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.

EPS1.06 Ventilatory limitations to exercise in cystic fibrosis are dependent on lung function and equation selection

ePS1.06 Ventilatory limitations to exercise in cystic fibrosis are dependent on lung function and equation selection

WS16.5 Expansion of a leading cystic fibrosis exercise programme: collaborative partnership between the UK’s largest healthcare charity and 12 UK cystic fibrosis centres

WS16.5 Expansion of a leading cystic fibrosis exercise programme: collaborative partnership between the UK’s largest healthcare charity and 12 UK cystic fibrosis centres

Physical Activity Level and Perception of Exercise in Cystic Fibrosis

More patients with cystic fibrosis (CF) are living longer, and lifestyle-related behavior is becoming increasingly important for improving morbidity and mortality. Declining levels of exercise leads to low cardiorespiratory fitness, which is a strong, independent predictor of mortality in patients with CF. As a result, exercise training has become a commonly accepted form of treatment for patients with CF. The purpose of this study was to determine physical activity levels and perception of exercise in adult patients with CF. Adult patients from an in-patient CF unit were recruited to participate. A structured interview and self-report questionnaires were used to collect information on levels of physical activity and exercise perception including preferences, readiness, and barriers. Forty-six adult patients with CF consented to participate in the interview and completed self-report questionnaires. Subjects self-reported that the majority (84%) of their time was spent performing physical activity at a moderate level, with mean ± SD of 11.8 ± 12.2 h per week of moderate physical activity. Vigorous physical activity was described as hard and very hard physical activity, with a mean ± SD of 1.8 ± 4.6 h (13%) and 0.4 ± 1.6 h (3%), respectively. Most of the adult subjects with CF preferred walking, and 65% of them felt that exercise was very important. Lack of energy, lack of good health, lack of self-discipline, and lack of time were noted as the most frequent barriers to exercise. In this study, adult subjects with CF self-reported performing an adequate amount of moderate physical activity, although only a small proportion of time was spent at a vigorous level of physical activity. Clinicians providing rehabilitation have an opportunity to improve adherence to prescribed exercise by understanding the impact that physiological and psychological factors have on patients with CF. Further, motivating patients with CF to engage in more vigorous physical activity may provide a stimulus that improves clinical outcomes and potentially survival.

Variable agreement between wearable heart rate monitors during exercise in cystic fibrosis.

In people with cystic fibrosis (CF), greater cardiorespiratory fitness is associated with improved survival and quality of life. Wearable activity monitors are a popular method of monitoring exercise, with measures of heart rate used to indicate exercise intensity. We assessed the agreement of heart rate recordings obtained using the Fitbit Charge HR™, Polar® H7 heart rate sensor and Masimo SET® Rad-5v pulse oximeter with the three-lead ECG during continuous and interval exercise.Adults with CF completed two exercise sessions, of 15-min duration per session, on a cycle ergometer while wearing the previously mentioned monitors. Firstly, participants cycled at 30% of estimated peak workload (Wpeak). Secondly, participants cycled at 1-min intervals at 60% of Wpeak interspersed with 2 min of unloaded cycling. Heart rate readings on all devices were recorded at minute intervals and their agreement was analysed using the Bland–Altman method.The Polar® H7 heart rate sensor had the best agreement with three-lead ECG, with a bias of 0±1 bpm during both continuous and interval exercise. The Masimo SET® Rad-5v pulse oximeter had good agreement, with a bias of 1±7 bpm and 1±5 bpm during continuous and interval exercise, respectively. The Fitbit Charge HR™ demonstrated less agreement, with a bias of 9±17 bpm and 5±13 bpm during continuous and interval exercise, respectively.The Fitbit Charge HR™ is not recommended for assessing heart rate during exercise in adults with CF. Findings support the use of the Polar® H7 for accurate heart rate monitoring.

Exercise Stroke Volume in Adult Cystic Fibrosis: A Comparison of Acetylene Pulmonary Uptake and Oxygen Pulse.

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 . 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.

Blood flow regulation and oxidative stress during submaximal cycling exercise in patients with cystic fibrosis

BackgroundThe impact of blood flow regulation and oxidative stress during exercise in cystic fibrosis (CF) has yet to be investigated. MethodsA maximal graded exercise test was conducted to determine exercise capacity (VO2 peak) and peak workload in 14 pediatric patients with mild CF (age 14±3y, FEV1 93±16 % predicted) and 14 demographically-matched controls. On a separate visit, participants performed submaximal cycling up to 60% of peak workload where brachial artery blood velocity was determined using Doppler ultrasound. Retrograde and antegrade components were further analyzed as indices of blood flow regulation. ResultsThe cumulative AUC for retrograde velocity was lower in patients versus controls (1770±554 vs. 3440±522cm, P=0.038). In addition, an exaggerated oxidative stress response during exercise occurred in patients only (P=0.004). ConclusionThese data suggest that patients with mild CF exhibit impaired blood flow regulation and an exaggerated oxidative stress response to submaximal exercise.

Exercise for all cystic fibrosis patients: is the evidence strengthening?

Regular physical activity and exercise have become important components of cystic fibrosis care. This review summarizes the recent evidence in favour of regular exercise in cystic fibrosis that has accumulated over the past years. Several recently published small randomized-controlled trials and observational studies have added to our knowledge on positive effects of exercise training on pulmonary function and aerobic fitness in cystic fibrosis. Relevant outcomes, such as body posture, health-related quality of life and rate of hospitalization, are increasingly studied. Findings from these studies suggest that exercise might also be beneficial for these outcomes. So far, many important questions such as the best way of integrating exercise in cystic fibrosis care and the determination of the optimal strategies for training and motivation remain mostly unanswered. Over the past years, evidence for the beneficial effects of regular exercise on lung health and aerobic exercise capacity is strengthening. Despite the fact that most of the knowledge is based on small studies, the observed effects are encouraging and there is no reason why exercise should not be implemented in all patients' care.

Influence of Circulating Catecholamines on Cardiovascular Function at Rest and During Exercise in Cystic Fibrosis

Mutations in the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) lead to altered ion regulation, resulting in CF. CFTR also plays an important role in cardiac function. We have shown that β‐agonist inhalation results in increased cardiac output (Q), stroke volume (SV), and decreased systemic vascular resistance (SVR) in healthy humans, suggesting stimulation of the β‐adrenergic receptors via inhalation. We have also shown that this cardiovascular (CV) response is attenuated in CF, which could be due to receptor desensitization or inhibited drug delivery to the blood stream due to mucus build‐up. This study sought to determine the effects of epinephrine (EPI) and norepinephrine (NE) on CV function in CF. 11 CF patients and 27 controls completed a cycle ergometery test with measures of Q, SV, SVR, and HR along with EPI and NE. CF patients had lower Q corrected for NE at 50% and peak exercise (rest: Q/NE= 0.012 ±0.002 vs 0.017 ±0.002; 50%: Q/NE= 0.026 ±0.004 vs 0.045 ±0.004; peak: Q/NE= 0.03 ±0.004 vs 0.05 ±0.005, CF vs healthy, p<0.05) and lower SV corrected for NE at rest, 50%, and peak (rest: SV/NE= 0.12 ±0.03 vs 0.22 ±0.02; 50%: SV/NE= 0.17 ±0.04 vs 0.32 ±0.03; peak: SV/NE= 0.18 ±0.04 vs 0.35 ±0.03, CF vs healthy, p<0.05), no difference in SVR when corrected for EPI (rest: SVR/EPI= 53 ±13 vs 33 ±4; 50%: SVR/EPI= 28 ±7 vs 15 ±2; peak: SVR/EPI= 22 ±5 vs 15 ±3; in CF vs healthy). These results suggest that CF patients have lower cardiac function relative to circulating NE, no difference in SVR relative to EPI, indicating impairment in cardiac function, likely as a result from a loss of CFTR function.

A Novel Protocol to Detect Impaired Ventilatory Response to Brief Exercise in Cystic Fibrosis

A Novel Protocol to Detect Impaired Ventilatory Response to Brief Exercise in Cystic Fibrosis

WS9.2 Patient- and physiotherapist-reported adherence to airway clearance therapy, inhalational therapy and exercise in cystic fibrosis

WS9.1 Effectiveness of airway clearance techniques when patients choose their airway clearance technique M.P. McIlwaine1, J.L. Agnew2, N. Alarie3, L.C. Lands4, G.F. Davidson1, F. Ratjen5. 1BC Children’s Hospital, Cystic Fibrosis Clinic, Vancouver, Canada; 2The Hospital for Sick Children, Respiratory Medicine, Toronto, Canada; 3The Montreal Children’s Hospital, Cystic Fibrosis Clinic, Montreal, Canada; 4The Montreal Children’s Hospital, Division of Pediatric Respiratory Medicine, Montreal, Canada; 5The Hospital for Sick Children, Department of Respiratory Medicine, Toronto, Canada

211 What physiotherapy is being carried out for infants with cystic fibrosis (CF) in the UK since the introduction of newborn screening? Results from a national physiotherapy survey conducted by the Cystic Fibrosis Trust

Introduction: The importance of physical fitness in CF has been increasingly recognised in recent years. A survey was carried out investigating issues relating to physiotherapy exercise for people with Cystic Fibrosis (CF) in the UK. Objectives: To identify types of physiotherapy and exercise being practiced by individuals, to look at attitudes towards exercise. Method 6119 questionnaires were sent out to adults and parents of children with CF and to physiotherapists working in all 50 UK Specialist paediatric and adult CF centres in the UK. Results: The overall response rate was 23% (parents 32%, adults 17%) and from the centre questionnaire 34%. 95% of children are reported to exercise on a regular basis, and 76% of adults with 22% exercising to a high level. Only 3% of adults avoid exercise altogether. Children and adults report a wide variety of different types of exercise. The main benefits as perceived by both adults and children are that exercise is good for them, it helps keep their chest clear and that they enjoy it. More children (84%) enjoy exercise than adults (55%.) Nearly a quarter of children and adults do exercise instead of physiotherapy but more often, exercise is in addition to physiotherapy. Conclusion: Separate health surveys of the general population carried out different parts of the UK show a variety of activity levels, but overall the majority of children are not active enough according to the DoH guidelines for physical activity (2011). This is an increasing problem as people get older. It appears that people with CF exercise just as much if not more than the non CF population. Adults do not enjoy or partake in as much exercise as children.

Infection, inflammation and exercise in cystic fibrosis

Regular exercise is positively associated with health. It has also been suggested to exert anti-inflammatory effects. In healthy subjects, a single exercise session results in immune cell activation, which is characterized by production of immune modulatory peptides (e.g. IL-6, IL-8), a leukocytosis and enhanced immune cell functions. Upon cessation of exercise, immune activation is followed by a tolerizing phase, characterized by a reduced responsiveness of immune cells. Regular exercise of moderate intensity and duration has been shown to exert anti-inflammatory effects and is associated with a reduced disease incidence and viral infection susceptibility. Specific exercise programs may therefore be used to modify the course of chronic inflammatory and infectious diseases such as cystic fibrosis (CF).Patients with CF suffer from severe and chronic pulmonary infections and inflammation, leading to obstructive and restrictive pulmonary disease, exercise intolerance and muscle cachexia. Inflammation is characterized by a hyper-inflammatory phenotype. Patients are encouraged to engage in exercise programs to maintain physical fitness, quality of life, pulmonary function and health.In this review, we present an overview of available literature describing the association between regular exercise, inflammation and infection susceptibility and discuss the implications of these observations for prevention and treatment of inflammation and infection susceptibility in patients with CF.

Exercise as part of a cystic fibrosis therapeutic routine

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.

WS16.5 Airway clearance therapy and exercise in cystic fibrosis: patients’ perceptions versus participation

Objectives: Airway clearance therapy (ACT) and exercise are important components in the physiotherapy management of Cystic Fibrosis (CF). There is limited evidence observing the relationship between perception of the importance of these adjuncts and compliance with recommended targets in the paediatric CF population. The objective of this study was to establish patients’/parents’ perceptions of the importance of ACT and exercise in the management of CF and their compliance with both and to compare the results with recommended standards. Methods: This study was carried out by the physiotherapist in a paediatric CF centre. Patients were invited to participate by means of a postal questionnaire regarding their perception of the importance of ACT and exercise and their participation in both. Parents of younger patients completed the questionnaire themselves. Results: Eighty-five questionnaires were posted and 42 were returned for analysis (57% male, 43% female). Ninety-five percent of respondants (n = 41) reported doing ACT and 95% reported doing regular exercise. While 92% felt that physiotherapy was important in daily life only 83% (n = 35) reported doing ACT on five or more days per week. Sixty two percent strongly agreed that exercise was valuable to them, whereas 50% strongly agreed that ACT was valuable. Although 93% (n = 39) of participants felt that physiotherapy (ACT and exercise) was important in daily life, only 40% (n = 17) reported achieving their recommended daily targets. Conclusion: Our study demonstrates that while exercise and ACT were perceived to be equally important in the management of CF, patients were more likely to participate in exercise than ACT.

MRI‐based screening for metabolic insufficiency of leg muscle during aerobic exercise in Cystic Fibrosis

There is evidence for mitochondrial dysfunction in various tissues in Cystic Fibrosis (CF) including muscle. Among others, a slow rate of high‐energy phosphate resynthesis following exercise involving single limb muscle activity was found in human CF using in vivo 31P magnetic resonance spectroscopy (MRS). This raises the question whether this outcome would be ameliorated versus exacerbated if instead an exercise regime is used that puts a significant cardiopulmonary load on the body as in running or bicycling. This is of interest because exercise therapy is commonly prescribed in CF. To investigate this matter, ten pediatric CF patients (age 12–16 years) and healthy peers performed two ramp exercise tests to volitional exhaustion using a bicycle ergometer fit for use inside a MR scanner. Endurance, VO2max and heart rate were determined in the exercise laboratory. Quadriceps muscle energy‐and acid/base balance during exercise and recovery were measured on a separate day using MR imaging‐based 31P MRS. This study brings together for the first time this powerful biomedical imaging platform and whole body exercise testing in the clinical setting of human CF.

Determinants of dyspnea and alveolar hypoventilation during exercise in cystic fibrosis: Impact of inspiratory muscle endurance

Dyspnea is one of the main complaints of patients with cystic fibrosis (CF). Lung function at rest is not sufficient to explain dyspnea during exercise. Because inspiratory muscles are faced with an increased workload in advanced CF, we studied the impact of their strength and endurance on dyspnea and alveolar hypoventilation during exercise. Methods Eighteen stable CF patients performed a maximal exercise test on a cycloergometer. Level of exercise dyspnea was recorded by a Borg scale at exhaustion. Blood gases were analysed at rest and at maximal peak exercise. Inspiratory muscle endurance (IME), expressed as a percentage of maximal inspiratory pressure (PImax), was measured according to an incremental threshold loading technique (Martyn). Results Four men and fourteen women were included with a mean age of 32 years (20–67). Mean FEV 1 was 44% predicted (21–82%). Mean PImax was 78% predicted (24–148%). No significant correlation was found between dyspnea and age, body mass index, pulmonary function at rest, blood gases, inspiratory muscle strength (PImax) or exercise capacity. Dyspnea was correlated with IME (r = − 0.72, p = 0.0029) and plethysmographic airway resistance (r = 0.64, p = 0.009). When patients were grouped according to degree of exercise dyspnea, half expressed a dyspnea more than “severe” (above level 5 on Borg scale) and half reported a lower dyspnea (Borg score ≤ 5). Significant differences were observed between these two groups in inspiratory muscle endurance (46.8 versus 76.4% of PImax; p < 0.001), PaCO2 at rest (40.3 versus 36.2 mmHg; p = 0.03) and PaCO2 at peak exercise (47.7 versus 40.6 mmHg; p = 0.04). Conclusion Exertional dyspnea may be significantly influenced by inspiratory muscle function and alveolar hypoventilation in CF patients. Inspiratory muscle endurance could be of importance to analyse the impact of pulmonary rehabilitation in this specific disease.

Breathlessness during exercise in cystic fibrosis

Breathlessness during exercise in cystic fibrosis

Evaluation of the SenseWear activity monitor during exercise in cystic fibrosis and in health

Determine the SenseWear Pro3 Armband (SWA) accuracy for estimating energy expenditure (EE) and step count during treadmill walking in cystic fibrosis (CF) compared to healthy adults. SWA estimation of EE would be less accurate for CF, than for healthy subjects, due to interference with the SWA skin sensors caused by the high salt concentration in the sweat of CF subjects. 17 CF (mean age 26 yr; FEV1 54% predicted) and 17 age-matched control subjects walked slightly faster than their comfortable pace on a treadmill for 20 min, whilst simultaneously wearing the SWA and breathing through an open-circuit indirect calorimetry (IC) system. Subjects' steps were manually counted. Combined EE data from all subjects showed no significant difference in EE measured by IC (6.0+/-3.4 kcal min(-1)) compared to the SWA estimate (6.3+/-2.5 kcal min(-1)), however the SWA significantly overestimated EE at low exercise intensities and underestimated EE at high exercise intensities. Correlations between EE values, estimated by the SWA and measured by IC, were greater than 0.85 (p<0.001) for both the CF and control group. Standard multiple regression showed that diagnosis of CF independently predicted less than 0.1% of the difference between the IC measure of EE and the SWA estimate. The SWA recorded slightly but significantly fewer steps (113+/-12 steps min(-1)) than the manual count (119+/-9 steps min(-1)). Diagnosis of CF had no significant negative impact on the accuracy of the SWA estimate of EE. The SWA provided a reasonably accurate estimate of EE and step count during treadmill walking.