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Abbreviations BMI: Body mass index; BR: Breathing reserve; CF: Cystic Fibrosis; EELV: End-expiratory lung volume; FEV1: Forced expiratory volume in 1 s; FVC: Forced vital capacity; IC: Inspiratory capacity; PA: Physical activity; PET CO2 : Partial pressure of end-tidal CO 2 ; SpO 2 : Arterial oxygen saturation; TLC: Total lung capacity; V'E: Minute ventilation; V'E/V'CO 2 : Ventilatory equivalent for carbon dioxide; VO 2 : Oxygen uptake; V T : Tidal volume
Source publication
Background:
The aim of this study was to investigate the relationship between dynamic hyperinflation and daily physical activity (DPA) in adults with cystic fibrosis (CF).
Methods:
Thirty-four clinically stable CF were studied. All patients undertook incremental cardiopulmonary exercise testing (CPET). CPET-related measurements included: oxygen...
Contexts in source publication
Context 1
... − 1 (R = 0.52, p < 0.001). Interestingly, daily activity measures were related to the development of dynamic hyperinflation. We found a relationship between total energy expenditure and EELV peak (R = 0.56, p < 0.001) , EELV peak expressed as % of TLC (R = − 0.47, p = 0.001). Moreover, we found a positive relationship between total energy expenditure and change in EELV from rest to peak exercise (EELVΔ) (R = 0.57, p < 0.001, Fig. 1). A relationship was also found between activities requiring vigorous intensity and EELV peak (R = 0.59, p < 0.001) and EELVΔ (R = 0.46, p = 0.001). Among these significant contributors to DPA, the multivariate linear regression analysis identified V'O 2,peak and gender as independent predictor of DPA and ex- cluded the role of dynamic hyperinflation in predicting DPA levels (Table 4). Specifically, EELVΔ (l) and EELVΔ (% of TLC) were discarded as not significant predictors: EELVΔ (l) p values were 0.412, 0.513 and 0.719 for model 1, 2 and 3, respectively; EELVΔ (% of TLC) p values were 0.796, 0.581 and 0.691 for model 1, 2 and 3, re- spectively (Table ...Context 2
... is well known that the development of dynamic hyperinflation makes patients breathe at increased oper- ational lung volumes, resulting in a higher respiratory ef- fort and oxygen requirement of breathing [32]. Dynamic hyperinflation leaves less room for the expansion of tidal volume that comes with increasing minute ventilation. Several studies are available for COPD patients, which observed that dynamic hyperinflation is likely to lead to such mechanical constraints on tidal volume [26,33]. At some point, further increase in the effort to breathe does not result in an equal increase in tidal volume, known as neuromechanical dissociation [33]. This causes an in- crease in symptoms and impairments that patients ex- perience [33]. As consequence, in moderate-severe COPD patients, reduced DPA might be partially ex- plained by the development of dynamic hyperinflation during CPET [13]. Although extrapolation of data from COPD to CF is not appropriate, the COPD model is used to explain some physiological mechanisms during exercise mainly because the study of dynamic hyperinfla- tion and its clinical utility in CF is limited. Specifically, Definition of abbreviations: CF Cystic Fibrosis, V'O 2 oxygen uptake, HR heart rate, SpO 2 arterial oxygen saturation, V T tidal volume, V'E minute ventilation, BR breathing reserve, V'E/V'CO 2 ventilatory equivalent for carbon dioxide, PET CO2 partial pressure of end-tidal CO 2 , EELV end-expiratory lung volume, EELVΔ end-expiratory lung volume delta from rest to peak exercise, TLC total lung capacity Data recorded at peak exercise. Data are presented as mean ± SD, unless otherwise stated. p values are differences between the dynamic hyperinflation and non-dynamic hyperinflation groups the aspects of lung mechanics related to daily activity have not been studied in detail in patients with CF, who are younger and less likely to be smokers [34]. In our mild-to moderate CF who developed dynamic hyperinfla- tion during exercise, this neuromechanical dissociation did not happen, because their IC value at peak exercise was still large. We found that dynamic hyperinflation did not limit exercise tolerance on CPET in this CF group examined. The hyperinflated group reported symp- toms of muscle effort equal or in excess of dyspnea. Fig. 1 Relationship between total energy expenditure in daily living recorded by accelerometer and change in end-expiratory lung volume (EELV) in patients with cystic fibrosis (R = 0.57, p < 0.001). In this figure, the most hyperinflated CF patients, those with the highest EELV, also showed the highest physical activity parameter represented as total energy expenditure. Open circles = CF patients with dynamic hyperinflation, closed circles = CF patients without dynamic hyperinflation ...Similar publications
Background
Supplemental oxygen delivered with standard oxygen therapy (SOT) improves exercise capacity in patients with idiopathic pulmonary fibrosis (IPF). Although high-flow nasal cannula oxygen therapy (HFNC) improves oxygenation in other respiratory diseases, its impact on exercise performance has never been evaluated in IPF patients. We hypoth...
Citations
... When addressing DH, several studies [9,19] have shown that it is commonly seen in people with CF, but no association between DH and ventilatory limitation was demonstrated. Savi et al. [20] have also found DH to be prevalent in mild to moderate CF, and although their exercise tolerance was reduced, the daily physical activity was not impaired. ...
Background:
Lung function deterioration in cystic fibrosis (CF) is typically measured by a decline in the forced expiratory volume in one second (FEV1%), which is thought to be a late marker of lung disease. Dynamic hyperinflation (DH) is seen in obstructive lung diseases while exercising. Our aim was to assess whether DH could predict pulmonary deterioration in CF; a secondary measure was the peak VO2.
Methods:
A retrospective study was conducted of people with CF who performed cardiopulmonary exercise tests (CPETs) during 2012-2018. The tests were classified as those demonstrating DH non-DH. Demographic, genetic, and clinical data until 12.2022 were extracted from patient charts.
Results:
A total of 33 patients aged 10-61 years performed 41 valid CPETs with valid DH measurements; sixteen (39%) demonstrated DH. At the time of the CPETs, there was no difference in the FEV1% measurements between the DH and non-DH groups (median 83.5% vs. 87.6%, respectively; p = 0.174). The FEV1% trend over 4 years showed a decline in the DH group compared to the non-DH group (p = 0.009). A correlation was found between DH and the lung clearance index (LCI), as well as the FEV1% (r = 0.36 and p = 0.019 and r = -0.55 and p = 0.004, respectively). Intravenous (IV) antibiotic courses during the 4 years after the CPETs were significantly more frequent in the DH group (p = 0.046). The peak VO2 also correlated with the FEV1% and LCI (r = 0.36 and p = 0.02 and r = -0.46 and p = 0.014, respectively) as well as with the IV antibiotic courses (r = -0.46 and p = 0.014).
Conclusions:
In our cohort, the DH and peak VO2 were both associated with lung function deterioration and more frequent pulmonary exacerbations. DH may serve as a marker to predict pulmonary deterioration in people with CF.
jats:p>Cystic fibrosis (CF) is a life-shortening genetic disease, affecting multiple life domains including physical activity (PA). Although higher PA levels are associated with multiple health benefits, little insight exists on the PA level of people with CF (PwCF) compared to healthy peers. Evidence on the influencing factors ( i.e. correlates) of PA in this clinical population is scarce, but essential to fully understand their PA behaviour. Therefore, the present review aims to provide an overview of the PA level of PwCF compared to healthy peers, and the correlates of PA in PwCF. A systematic search of three databases resulted in 46 included studies. Analysis of 16 studies showed that the CF population is equally active compared to healthy peers, but there is a trend towards less high-intensity PA in youths with CF. Furthermore, PA is positively associated with quality of life, lung function, (maximal) exercise capacity, bone mineral density and quadriceps force. Also, PA was lower on weekdays compared to weekend days and lower when experiencing pulmonary exacerbations. More high-quality research is required in PwCF, particularly longitudinal studies that further explore the correlates of PA, with PA investigated as a primary outcome and measured objectively.</jats:p
La mucoviscidose est la maladie génétique la plus fréquente des populations caucasiennes. Chez les personnes atteintes, la protéine CFTR est anormale et les sécrétions acheminées vers l’extérieur ou un organe creux, ne contiennent pas assez d’eau. Peu fluides, elles s’épaississent et sont difficilement évacuées, dégradant le fonctionnement des organes concernés (pancréas, poumons, foie et voies biliaires, glandes sudoripares, glandes sexuelles). A ce jour, il n’existe pas de traitement curatif de la mucoviscidose et les soins s’organisent selon le traitement symptomatologique de la maladie, nécessitant une prise en charge multidisciplinaire où la réhabilitation à l’exercice et les activités physiques ont une place croissante.Dans cette pathologie, le travail des muscles respiratoire est augmenté du fait des anomalies bronchiques auxquelles ils font face quotidiennement, pouvant engendrer une fatigabilité accrue voire une dysfonction. Dans les premiers temps de la maladie, la force des muscles respiratoires est inchangée voire augmentée et, lorsqu’un déclin est identifié, l’ensemble des paramètres cliniques le sont aussi.Dans ce sens, la force des muscles respiratoires ne semble pas être un marqueur physiologique suffisamment sensible aux changements discrets et ne permet pas de détecter de façon précoce le déclin de la fonction musculaire respiratoire. De plus, évaluée de façon ponctuelle, elle ne permet pas de caractériser la fatigabilité des muscles respiratoires.Les caractéristiques de force et d’endurance des muscles respiratoires étant susceptibles d’évoluer distinctement, il paraît intéressant d’examiner si l’endurance ne serait pas un marqueur plus sensible que la force pour détecter précocement le déclin de la fonction respiratoire de ces patients ainsi que de leur statut fonctionnel. A ce jour, il n’existe pas d’évaluation standard de l’endurance des muscles respiratoires et les quelques travaux ayant dans lesquels cette caractéristique a été étudiée présentent beaucoup d’hétérogénéité.Dans ce contexte, nos objectifs de recherche sont d’étudier les caractéristiques cliniques et les mécanismes de la tolérance à l’effort des patients atteints de mucoviscidose sous l’angle de la fonction musculaire respiratoire et, plus particulièrement, de l’endurance musculaire respiratoire.Dans ce travail, nous avons tout d’abord étudié et comparé la reproductibilité de deux méthodes d’évaluation distinctes de l’endurance des muscles respiratoires à partir d’un groupe de sujets en bonne santé. Nous avons ensuite caractérisé l’ensemble de la fonction musculaire respiratoire de patients atteints de mucoviscidose afin d’établir et comparer les significations cliniques de l’endurance et de la force des muscles respiratoires avec la fonction pulmonaire, la tolérance à l’exercice, la force périphérique et la qualité de vie des patients. Enfin nous avons étudié les effets d’un entraînement spécifique des muscles respiratoires.Nous avons montré que l’endurance des muscles respiratoires des patients atteints de mucoviscidose pouvait être diminuée indépendamment de la force des muscles respiratoires. Nous soulignons aussi que l’endurance des muscles respiratoire est un indicateur pertinent pour caractériser la tolérance à l’effort global de ces patients. Cependant, le choix du test retenu pour mesurer l’endurance est déterminant afin de pouvoir détecter les changements potentiels de la fonction musculaire respiratoire au cours de la mucoviscidose. Par ailleurs nous avons montré qu’un entraînement spécifique des muscles respiratoires améliorait la force des muscles respiratoires, sans pouvoir conclure sur d’autres effets significatifs sur le plan de la fonction pulmonaire, de la tolérance à l’exercice et de la qualité de vie des patients.
Rationale:
Despite being a hallmark and an independent prognostic factor in several cardiopulmonary diseases, ventilatory efficiency - i.e. minute ventilation/carbon dioxide output relationship (V'E/V'CO2) has never been systematically explored in cystic fibrosis (CF).
Objective:
To provide a comprehensive frame of reference regarding measures of ventilatory efficiency in CF adults with normal to moderately impaired lung function and to confirm the hypothesis that V'E/V'CO2 is a sensitive marker of early lung disease.
Methods:
CF patients were divided into 3 groups according to their spirometry: normal (G1), mild impairment (G2) and moderate impairment (G3) in lung function. All participants underwent incremental cardiopulmonary exercise testing on a cycle-ergometer. Lowest V'E/V'CO2 ratio (nadir) and the slope and the intercept of the linear region of the V'E/V'CO2 relationship were contrasted in a two-center retrospective analysis involving 72 CF patients and 36 healthy controls (HC).
Results:
Compared to HC, CF patients had significantly higher V'E/V'CO2 nadir, slope and intercept (p<0.001, p<0.001 and p=0.049, respectively). Subgroup analysis revealed significant differences in nadir (p=0.001) and slope (p=0.012) values even between HC and G1. Dynamic hyperinflation related negatively with slope (p=0.045) and positively with intercept (p=0.001), whilst no impact on nadir was observed.
Conclusions:
Ventilatory inefficiency is a clear feature of adults with CF, even among patients with normal spirometry. V'E/V'CO2 nadir seems to be the most reliable metric to describe ventilatory efficiency in CF adults. Further prospective studies are needed to clarify whether V'E/V'CO2 could represent an useful marker in the evaluation of early lung disease in CF.
