Guidance and standard operating procedures for functional exercise testing in cystic fibrosis

The Effects of Telerehabilitation Versus Home-based Exercise on Muscle Function, Physical Activity, and Sleep in Children with Cystic Fibrosis: A Randomized Controlled Trial

AIMS

To evaluate the effects of telerehabilitation (TG) compared with an unsupervised home exercise training program (HG) on muscle function, physical activity (PA), and sleep in children with cystic fibrosis (CF).

METHODS

Thirty children with CF (mean age = 10.2 ± 1.9 years) were randomly allocated to TG or HG. The exercise protocol was applied thrice a week for six weeks in the TG via Skype. The same exercises were sent in an exercise booklet to the HG, and phone contact was made once a week. Muscle function (one-minute sit-to-stand (1-min STS), sit-up, pushup, squat, and plank tests)), PA (Physical Activity Questionnaire for Older Children), and sleep (Epworth Sleepiness Scale (ESS) and Pediatric Sleep Questionnaire (PSQ)) were assessed before and after the 6-week study period.

RESULTS

The 1-min STS significantly improved in the TG compared with the HG (p ≤ .001, ηp2 = 0.474). The sit-up (p = .005, ηp2 = 0.247), pushup (p = .002, ηp2 = 0.180), squat (p = .002, ηp2 = 0.284), and plank (p < .001, ηp2 = 0.360) test scores were significantly improved in the TG compared to the HG. No significant changes between groups were seen for PA (p = .261, ηp2 = 0.045), ESS (p = .160, ηp2 = 0.069), or PSQ (p = .763, ηp2 = 0.003).

CONCLUSION

Children who received TG improved muscle function more than children who received an HG. The effectiveness of longer term TG programs should be investigated in children with CF.

Peripheral Muscle Function and Body Composition in People With Cystic Fibrosis on Elexacaftor/Tezacaftor/Ivacaftor: A Cross-Sectional Single-Centre Study

BACKGROUND

People with cystic fibrosis (pwCF) often have multifactorial peripheral muscle abnormalities attributed to, for example, malnutrition, steroid use, altered redox balance and, potentially, CF-specific intrinsic alterations. Malnutrition in CF now includes an increasing prevalence of overweight and obesity, particularly in those receiving CF transmembrane conductance regulator (CFTR) modulator therapy (CFTRm). We aimed to characterise peripheral muscle function and body composition in pwCF on Elexacaftor/Tezacaftor/Ivacaftor (ETI) CFTRm, compared to healthy controls.

METHODS

Fifteen pwCF on ETI, and 15 healthy age- and sex-matched controls (CON), underwent whole-body dual-energy X-ray absorptiometry scans, and a comprehensive evaluation of peripheral muscle function. Tests included quadriceps maximal isometric force measurement, an intermittent isometric quadriceps fatiguing protocol, handgrip strength dynamometry, squat jump height assessment, and 1-min sit-to-stand testing.

RESULTS

No significant differences in quadriceps maximal isometric force (CON: 181.60 ± 92.90 Nm vs. CF: 146.15 ± 52.48 Nm, p = 0.21, d = 0.47), handgrip strength (CON: 34 ± 15 kg vs. CF: 31 ± 11 kg, p = 0.62, d = 0.18), peripheral muscle endurance, fatigue, or power were observed between the groups. Moreover, no significant differences in whole-body, trunk or limb lean mass, fat-free mass, fat mass, or whole-body bone mineral density were evident.

CONCLUSION

Comparable peripheral muscle mass and function has been demonstrated in pwCF on ETI, albeit a group with good lung function. Research is needed to confirm these findings longitudinally in pwCF, including those with more severe lung disease, who are less physically active, and have less optimal nutrition and exercise support.

Physical activity promotion in French cystic fibrosis centers: capitalizing on experience

BACKGROUND

Physical activity (PA) provides physical and psychosocial benefits for people with cystic fibrosis (pwCF). However, practice levels remain below recommendations and strategies for promoting PA in specialist centers need to be better identified. The socio-ecological model of health emphasizes the central role of policies and environment in influencing individuals' health behaviors. This model provides a basis for understanding how health professionals perceive the promotion of PA in their centers.

OBJECTIVE

The aim of this study was to explore intervention components of PA promotion in specialized CF centers in France that are "experienced" in PA promotion, to identify elements that can be transferable to other centers.

METHODS

A descriptive qualitative study was conducted with 16 healthcare professionals and pwCF. Semi-structured interviews were conducted and analyzed using inductive and deductive methods classically used in psychology.

RESULTS

Five themes were extracted: the action and its context, the partnerships established around this action to promote physical activity, the evaluation of the action, its reproducibility, and the changes induced by COVID-19.

CONCLUSIONS

Some factors emerged as essential for promoting PA among pwCF, notably the dialogue between the health professionals and patients, the presence of adapted PA instructors, and the involvement of partners.

Effects of a Tailored Home-Based Exercise Program, "KidMove", on Children with Cystic Fibrosis: A Quasi-Experimental Study

Background/Objectives: Exercise for children with cystic fibrosis leads to well-known health benefits. However, maintaining regular activity is challenging due to the daily demands of academics, clinical care, and family tasks. Home-based exercise programs offer a more adaptable alternative, fitting into family schedules. This study evaluated the effectiveness of the "KidMove" program, a parent-supervised, tailored, home exercise regimen. Methods: A quasi-experimental study was conducted with an intervention group (IG) and a wait-list control group (CG). The "KidMove" program lasted 12 weeks and included 35 exercises targeting endurance, resistance, flexibility, and neuromotor training. The primary outcome, endurance, was measured with the Modified Shuttle Walking Test, while secondary outcomes included body composition, resistance, flexibility, postural control, respiratory function, and health-related quality of life. Data were collected at baseline and post-intervention. A per-protocol analysis was conducted with generalized estimating equations (GEEs). Results: Forty-six children aged 10 ± 4 years (6 to 18 years), mostly male (n = 24; 52.2%), participated. Significant improvements were observed in the Modified Shuttle Walking Test [Wald χ2 = 14.24, p < 0.001], postural control [Wald χ2 = 3.89, p = 0.048], knee flexibility [Wald χ2 = 5.58, p = 0.018], and emotional functioning [Wald χ2 = 9.34, p = 0.002] categories. Conclusions: The "KidMove" program offers a practical, family friendly alternative to center-based exercise by empowering parents to support their children's physical activity at home, endurance, flexibility, and emotional well-being, while reducing the logistical challenges.

Changes in exercise capacity in people with Cystic Fibrosis after one year of Elexacaftor/Tezacaftor/Ivacaftor treatment - A Danish prospective cohort

BACKGROUND

Cystic Fibrosis (CF) is an inherited multiorgan disease that causes lung damage and early death. People with CF (pwCF) experience diminished exercise capacity compared to the general population. This is due to an accelerated decline in lung function resulting from recurrent lung infections, declining lung function and nutritional challenges. Since 2020 the CFTR-modulator Elexacaftor/Tezacaftor/Ivacaftor (ETI) has been approved for pwCF aged 12 and above in Denmark. Initial experiences with the medication have shown promising results, including improved lung function and disease stability. To date a limited number of studies have evaluated the impact of CFTR-modulators on exercise capacity in pwCF.

OBJECTIVE

The study aims to assess the impact of one year of ETI treatment, without any further intervention, on exercise capacity measured through cardiopulmonary exercise test (CPET) in pwCF aged 12 years and above.

METHODS

A Danish prospective registry cohort study including pwCF from CF-Center Copenhagen, Copenhagen University Hospital and CF-Center Aarhus, Aarhus University Hospital. Participants underwent CPET before initiating ETI and at follow up one year later. Primary outcomes were VO₂ peak (ml/kg/min), secondary outcomes were VO2 peak (ml/min), VO2 peak (% pred), watt-max, HR-max and saturation at max. The difference between baseline and follow-up was assessed using a paired-sample t-test and regression analyses were applied to relevant outcomes.

RESULTS

We included 229 pwCF in the analyses. An increase in oxygen uptake, VO₂ peak (ml/kg/min) from baseline to follow-up was observed; 0.6, 95% CI [0.06; 1.09] p = 0.03. Moreover, significant increase was noted for all other CPET outcomes. Regression analysis showed that changes in FEV₁% pred and BMI could explain some of the differences, 0.05 ml/kg/min, 95% CI [0.01, 0.1] p = 0.02 and -0.5 ml/kg/min, 95% CI [-0.8, -0.2] p = 0.002 respectively.

CONCLUSION

Among Danish pwCF we found a significant, but not clinically relevant, increase in oxygen uptake, after one year of ETI treatment.

The 1-min sit-to-stand test induces a significant and reliable level of neuromuscular fatigability: insights from a mobile app analysis

PURPOSE

The performance metric associated with the execution of the 1-min sit-to-stand (1STS) typically relies on the number repetitions completed in 1 min. This parameter presents certain limitations (e.g., ceiling effect, motivational factors) which can impede its interpretation. Introducing additional parameters, such as neuromuscular fatigability level, could enhance the informative value of the 1STS and facilitate its interpretation. This study aimed to assess (i) whether the 1STS induces fatigability and (ii) the reliability of the fatigability level.

METHODS

Forty young, healthy, and active participants underwent the 1STS twice during the same session. Isolated sit-to-stand maneuvers were performed before, immediately, and 1 min after completing the 1STS. A mobile app was utilized to obtain time (STST), velocity (STSV), and muscle power (STSP) from these sit-to-stand maneuvers. The pre-post change in these parameters served as the fatigability marker. Reliability was assessed using the intra-class correlation coefficient (ICC) and the coefficient of variation (CV).

RESULTS

The mean number of repetitions during the 1STS was 63 ± 9. Significant decline in performance was observed for STST (13 ± 8%), STSV (-11.2 ± 6%), and STSP (-5.2 ± 3%), with more than 74% of participants exhibiting a decline beyond the minimal detectable change. Excellent between-session reliability (ICC ≥ 0.9; CV ≤ 5.3) was observed for the mobile app variables.

CONCLUSION

The 1STS induces significant levels of fatigability. The fatigability indicators derived from the mobile app demonstrated remarkable reliability. Utilizing this user-friendly interface for computing fatigability may empower professionals to acquire insightful complementary indicators from the 1STS.

Clinimetric properties of field exercise tests in cystic fibrosis: a systematic review

OBJECTIVES

Accurate measurement of exercise capacity is an important prognostic indicator for people with cystic fibrosis (pwCF); however, gold-standard, cardiopulmonary exercise tests are commonly unavailable. This review systematically describes the clinimetric properties of field exercise tests for pwCF.

METHODS

A systematic review was undertaken for studies reporting field exercise tests in pwCF. Four electronic databases were searched for studies published from 1990 to January 2024. Where available, clinimetric properties reported included reliability, validity, responsiveness and interpretability.

RESULTS

4041 studies were identified with 153 eligible for inclusion. 10 different field exercise tests were described, including six walk/run tests (incremental shuttle walk test (ISWT), modified shuttle test-15 levels (MST-15), MST-25 levels (MST-25), 20-m shuttle test, 6-min walk test (6MWT) and 12-min walk test (12MWT)), three step tests (3-min step test (3MST), incremental step test and Alfred step test (A-STEP)) and the 1-min sit-to-stand test (1STS). Reliability was found for the ISWT, MST-15, 6MWT, 1STS and 3MST (intraclass correlation coefficients >0.80). The ISWT, MST-15 and 6MWT were found to be valid (concurrent and discriminate). Responsiveness was supported for the 6MWT only. Four tests (MST-15, 6MWT, 3MST and 1STS) demonstrated ceiling effects.

CONCLUSION

This review supports the reliability, validity and responsiveness of the 6MWT in pwCF. The ISWT and MST-15 were found to be valid. The 1STS is reliable and feasible, but its utility is limited by ceiling effects. The 3MST, MST-25, 20-m shuttle test, incremental step test, A-STEP and 12MWT require further investigations of their clinimetric properties.

Lower physical activity levels in youth with Cystic Fibrosis compared to healthy controls: A multicentre comparative study

BACKGROUND

Regular physical activity (PA) offers significant health benefits on both short (i.e., emotional well-being) and long term (i.e., fewer hospitalizations) in Youth with Cystic Fibrosis (YwCF). Regardless, evidence on PA levels in YwCF compared to healthy controls (HC) is inconsistent. Additionally, PA is a multidimensional outcome influenced by several factors such as Quadriceps strength and functional performance. Therefore, we aimed to assess whether PA, Quadriceps strength and functional performance differ between YwCF and HC across different age groups (i.e., children and adolescents).

METHODS

YwCF aged 6-17 from two Belgian CF centres and age- and sex-matched HC were recruited. PA was measured with an ActiGraph GT3X + BT during 7 consecutive days. Isometric Quadriceps strength was assessed with a Hand Held Dynamometer and functional performance with a sit-to stand test (STS) and standing long jump (SLJ).

RESULTS

A total of 49 YwCF (44 % male; 11.3 ± 3.3 years) and 49 HC (48 % male; 11.9 ± 3.5 years) were included. On average days, YwCF performed 4 ± 6.4 min less light PA and 7.5 ± 6.7 min less moderate-to-vigorous PA compared to HC (p = 0.04; p = 0.01). The differences in moderate-to-vigorous PA seem more pronounced in children (6-11 years)(p = 0.04). Furthermore, YwCF had similar Quadriceps strength to HC but had lower scores on the STS and SLJ (p = 0.50, p = 0.08; p = 0.02).

CONCLUSIONS

This study shows lower PA levels and functional performance for YwCF, indicating that there is an urgent need for interventions promoting PA in YwCF. PA promotion will become increasingly important in the post modulator area to prevent health risks associated with low PA.

One year effect of tezacaftor and ivacaftor on functional exercise capacity and muscle strength in people with cystic fibrosis

BACKGROUND

The 1-min sit-to-stand test (1STST) is a practical tool to evaluate physical capacity. The aim of this study was to assess the impact of tezacaftor and ivacaftor on functional exercise capacity, muscle strength and symptoms in people with cystic fibrosis (PwCF).

METHODS

The assessments were performed during the first year of tezacaftor and ivacaftor using the 1STST, 6-min walk test (6MWT), MicroFET2 dynamometer®, CF Questionnaire-Revised (CFQ-R), Leicester Cough Questionnaire (LCQ). Forced expiratory volume in 1 s (FEV1), body mass index (BMI), pancreatic sufficiency status, genotype and microbiologic data were also collected.

RESULTS

Fifty-four PwCF participated to the study and took at least one dose of tezacaftor-ivacaftor. Mean age was 26y±10 (±SD), median BMI 20.9 kg/m2 (interquartile range) (19.4; 23.5) and mean FEV1 82 percent of predicted values (%PV) ± 21. Significant correlations were found at baseline between the 1STST and the 6MWT (r = 0.617, p < 0.0001), the quadriceps strength (r = 0.6556, p < 0.0001) and the FEV1 (r = 0.29, p = 0.03). After one year of treatment, the 1STST increased significantly in terms of number of repetitions (n) (median 50 versus 58.5, p < 0.0001), %PV (101.1 versus 115.2%PV, p = 0.0003) and n times weight in kg (2885 versus 3389nxkg, p < 0.0001). The 6MWT distance and quadriceps strength were not modified after treatment but during the 6MWT, oxygen desaturation decreased significantly. FEV1, BMI, CFQ-R, LCQ improved as previously demonstrated.

CONCLUSION

After one year of tezacaftor and ivacaftor, the 1STST improves, suggesting that the 1STST seems more responsive than the 6MWT and the MicroFET2 dynamometer® to assess the effects of CFTR modulators.

Does the modified shuttle test exhibit a ceiling effect in healthy and cystic fibrosis children and adolescents?

Introduction

The modified shuttle test-15 (MST-15) is a valid alternative for assessing exercise capacity when a cardiopulmonary exercise testing is not feasible. This study aims to describe the percentage of healthy and cystic fibrosis (CF) children and adolescents reaching the MST-15 ceiling. Additionally, it examines associations between MST-15 distance and demographic, anthropometric, and lung function data.

Methods

This retrospective cross-sectional study involved 286 healthy volunteers (11.5 ± 3.3 years) and 70 CF patients (11.9 ± 4.4 years). Data on age, gender, weight, height, body mass index, lung function, and MST-15 were collected. The ceiling effect was determined by the absolute and relative number of participants reaching the 15th level. Univariate linear regression and correlation analyses were conducted to explore associations with MST-15 distance.

Results

A ceiling effect for the MST-15 was found in 19 healthy participants (6.6%) and 1 CF patient (1.4%). The ceiling effect was correlated with age (r = 0.777 for healthy; r = 0.538 for CF), with no cases under 10 years and reaching 25% in healthy participants aged 17-19. Regression analysis showed significant associations between age and MST-15 distance in healthy participants (β = 53.6) and CF patients (β = 32.1). Additionally, sex was significantly associated with MST-15 distance in healthy participants (β = 107.0), and FEV1 with MST-15 distance in CF patients (β = 31.0).

Conclusions

The ceiling effect on the MST-15 is age-dependent, with no occurrences observed in children under 10 years and a gradual increase in incidence as participants age.

Standards for the care of people with cystic fibrosis; establishing and maintaining health

This is the second in a series of four papers updating the European Cystic Fibrosis Society (ECFS) standards for the care of people with CF. This paper focuses on establishing and maintaining health. The guidance is produced using an evidence-based framework and with wide stakeholder engagement, including people from the CF community. Authors provided a narrative description of their topic and statements, which were more directive. These statements were reviewed by a Delphi exercise, achieving good levels of agreement from a wide group for all statements. This guidance reinforces the importance of a multi-disciplinary CF team, but also describes developing models of care including virtual consultations. The framework for health is reinforced, including the need for a physically active lifestyle and the strict avoidance of all recreational inhalations, including e-cigarettes. Progress with cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapy is reviewed, including emerging adverse events and advice for dose reduction and interruption. This paper contains guidance that is pertinent to all people with CF regardless of age and eligibility for and access to modulator therapy.