Six minute walk test versus incremental shuttle walk test in cystic fibrosis

Exercise performance in children and adolescents with cystic fibrosis with and without abnormal glucose tolerance: a single center cross-sectional study

BACKGROUND

Abnormal glucose tolerance (AGT) in cystic fibrosis (CF) affects lung function and clinical parameters, including aerobic fitness. However, its effects on physical activity level (PAL), anaerobic power (AP), and muscle strength (MS) in children and adolescents are unknown.

PURPOSE

To investigate aerobic fitness, PAL, AP, and MS in pediatric patients with mild-to-moderate CF and AGT.

METHODS

The study included children and adolescents with CF aged 10-18 years. Participants underwent a pulmonary function test, quadriceps, and handgrip MS measurement, vertical jump test to assess AP, and six-minute walk test (6MWT) to assess aerobic fitness. Bouchard's Three-Day Physical Activity record was used to determine PAL.

RESULTS

Height z-score (p = .006), 6MWT (p = .024), handgrip (p = .028), quadriceps MS (p = .044), and AP (p = .036) were significantly lower in AGT (n = 21) than normal glucose tolerance (NGT) (n = 19). In the AGT group, glycosylated hemoglobin (HbA1c) was significantly associated with forced expiratory volume in one second (FEV1) (p = .046). 6MWT distance (6MWD) was associated with height (p = .008), FEV1 (p = .001), forced vital capacity (FVC) (p = .001), forced expiratory flow from 25% to 75% (FEF25-75%) (p = .030), handgrip MS (p = .012), and PAL (p = .034). After adjusting for height and FEV1, the groups had similar 6MWD, MS, and AP (p > .05); also, insulin was associated with MS and AP but not with 6MWT or quadriceps MS.

CONCLUSION

Measures of aerobic fitness, MS, and AP are lower in AGT, but after adjusting for height and FEV1, aerobic fitness, MS, and AP do not show substantial differences. Insulin sensitivity and resistance are associated with MS and AP.

Comparison of the modified shuttle walk test in children with cystic fibrosis and healthy controls

OBJECTIVE

To evaluate and compare performance in the modified shuttle walk test (MSWT) with cardiorespiratory parameters and respiratory muscle strength in children with cystic fibrosis (CF) and healthy controls.

METHODS

A cross-sectional study with children divided into the CF group (CFG) and healthy control group (HCG). Two MSWTs were performed and the data from the test with the longest distance walked and its cardiorespiratory parameters (blood pressure, respiratory rate, heart rate (HR), oxygen saturation, and dyspnea sensation) were considered, the last three every 4 levels. Respiratory muscle strength was evaluated using a manometer. The Wilcoxon test was used to compare the parameters before and after the MSWT, and the Mann-Whitney and independent t-tests were applied to compare the data between the groups. The distance walked and its association with the variation in cardiorespiratory parameters and respiratory muscle strength were analyzed by Spearman's correlation.

RESULTS

Sixty-two children (31 in each group) participated, with an average age of 10.2 (2.1) years. Children with CF had poorer performance in the average distance walked (CFG 716.7 (274.3)) when compared to the HCG (948.0 (202.8)). Both groups exhibited an increase in all the cardiorespiratory parameters at the end of the test, but the CFG displayed less variation in some parameters. Children with CF presented a positive correlation between distance walked and respiratory muscle strength, HR variation, and systolic blood pressure.

CONCLUSIONS

There was no difference in respiratory muscle strength between the groups. In the CFG, the greater the respiratory muscle strength, the better the performance in the MSWT. The CFG exhibited less variation in cardiorespiratory parameters than the HCG.

Exercise and Airway Clearance Techniques in Cystic Fibrosis

Exercise and airway clearance techniques (ACTs) have been a cornerstone of treatment for people with cystic fibrosis (pwCF) for many decades. Exercise may confer both respiratory and nonrespiratory benefits for pwCF, with greater exercise capacity associated with improved survival. A wide variety of exercise interventions for pwCF have been investigated. ACTs may assist in reducing respiratory symptoms for pwCF and are currently recommended to be performed daily, with the types of ACTs used varying globally. While recommended components of care, both exercise and ACTs are time-intensive and maintaining adherence to the recommendations over the longer term can be challenging. It has been proposed that with advances in the therapeutic options for pwCF, a rationalization of the therapeutic regimen may be possible. We summarize the current evidence for the use of exercise and ACTs by pwCF, discuss the implications of the introduction of cystic fibrosis transmembrane conductance regulator modulators on both exercise and ACTs, and highlight areas for further research.

Which field test should be used to compare the functional exercise capacities of patients with type 2 diabetes mellitus with and without diabetic peripheral neuropathy? Cross-sectional study

BACKGROUND

The 6-minute step test (6MST) has begun to be used as a simple and effective alternative for assessing functional exercise capacity. There is no study using 6MSTs to evaluate the exercise capacities of patients with type 2 diabetes mellitus (DM) with and without diabetic peripheral neuropathy (DPN).

OBJECTIVE

To compare the cardiorespiratory responses of the 6-minute walk test (MWT) and the 6MST exercise tests and to analyze the usability of the 6MST in Type 2 DM patients with and without neuropathy.

METHODS

32 non-neuropathic Type 2 DM, 32 neuropathic Type 2 DM patients, and 30 healthy volunteers were included in this cross-sectional study. Functional exercise capacity was evaluated with the 6MWT and the 6MST. The 30-second sit-stand test (30s STS) was used to evaluate general lower extremity muscle strength and function.

RESULTS

There was a significant difference in the results of 6MWT (m), 6MST (number of steps), and 30s STS of the three groups (p<0.05). The 6MST results of patients with neuropathic Type 2 DM were significantly lower than those of non-neuropathic diabetics and those who were healthy (number of steps; 114.07±25.57 vs. 133.48±33.57 vs. 160.35±28.52, respectively) (p=0.001). The change in cardiorespiratory response in systolic blood pressure, heart rate, perceived dyspnea, and leg fatigue severity was significantly higher at 6MST than 6MWT in the three groups (p<0.05). 6MST was correlated with 6MWT (r=0.679, p=0.001), and 30s STS (r=0.589, p=0.001) in patients with Type 2 DM.

CONCLUSIONS

Cardiorespiratory responses increased more in 6MST compared to 6MWT. In patients with Type 2DM, 6MWT and 6MST were moderately correlated with each other. 6MST is an effective and safe assessment method that may better reveal the differences in functional exercise capacity between neuropathic and non-neuropathic individuals in clinics.

Reliability and validity of the incremental shuttle walk test in patients with fully ambulatory multiple sclerosis

BACKGROUND

Functional exercise capacity evaluation is crucial to monitor treatment effects and disease progression in people with multiple sclerosis (pwMS). Compared to other tests, the incremental shuttle walking test (ISWT), which more accurately reflects cardiovascular responses, may be more useful for assessing exercise capacity. The aim of the study is to investigate the reliability and validity of the ISWT.

METHODS

Thirty-six pwMS with an Expanded Disability Status Scale (EDSS) score<4.5 between the ages of 25 and 65 were included in the study. The subjects underwent practice (ISWT-p) before undergoing the test-retest protocol in order to rule out the ISWT learning effect (ISWT-1 - ISWT-2). ISWT-1 and ISWT-2 were administered with a 3-7 day interval for test-retest reliability. Six-minutes walking test (6MWT) were applied for concurrent validity. The EDSS, pulmonary function tests, Fatigue Impact Scale (FIS), respiratory muscle strength [maximum inspiratory and expiratory pressure (MIP-MEP)] measurements were made for convergent validity.

RESULTS

ISWT was found to have excellent test-retest reliability with an ICC value of 0.97. The area under the curve value was 0.904 indicating that ISWT has a good performance for predicting disease severity. The moderate correlation between ISWT and 6MWT (rho: 0.68, p<0,001) proved concurrent validity. It was also moderately correlated with EDSS, MEP (rho: -0.58 and 0.47 respectively), weakly correlated with MIP and FIS (rho:0.37 and -0.36, respectively) while not correlated with pulmonary function tests.

CONCLUSION

The ISWT had excellent test-retest reliability, acceptable criterion and construct validity in ambulatory MS patients.

"Just Move It . . . Move It": A Multidisciplinary Motivational Approach to Improve Physical Activity in Children With Cystic Fibrosis

Regular physical activity (PA) is essential in cystic fibrosis (CF). This study assessed the impact of a motivational interviewing (MI)-based project titled "Just move it . . . move it," aimed at improving the PA of pediatric CF patients. At baseline and month 6, body mass index, spirometric values, and duration of extracurricular sport activities were collected. Concurrently, the maximum oxygen uptake (VO2max) was estimated. MI was performed during each visit. Overall, 19 CF children were included. Ten patients (52.7%) increased their regular PA (mean 1.9 hours/week) between both visits (PA+ group), while 9 did not (PA- group). No significant differences in functional and nutritional values were observed between the groups, while extracurricular sport time significantly increased in the PA+ group. "Just move it . . . move it" seems to be an efficient approach, as it was able to motivate several CF patients to initiate or increase their PA, yet without improving functional parameters.

Investigation of dynamic hyperinflation and its relationship with exercise capacity in children with bronchiectasis

BACKGROUND AND AIM

Dynamic hyperinflation (DH) is a major contributor to exercise intolerance in patients with obstructive lung diseases. However, it has not been investigated in children with bronchiectasis (BE). We aimed to investigate dynamic ventilatory responses and their influence on functional exercise capacity in children with BE.

METHODS

Forty children with BE (mean forced expiratory volume in 1 s [FEV₁ ] = 78 ± 19%pred) were included. Six-minute walk test (6MWT) was conducted using Spiropalm 6MWT® for evaluating dynamic ventilatory responses including inspiratory capacity (IC), minute ventilation (VE), breathing reserve (BR) and respiratory rate (RR). A decrease of ≥100 ml in IC during exertion was defined as DH. Also, spirometry was performed, and peripheral muscle strength were measured.

RESULTS

Twenty patients (50%) developed DH, and four patients (10%) were ventilatory limited (BR < %30) during 6MWT. There was a 176 [100-590] ml decrease in IC after exertion in patients with DH. DH did not correlate to clinical or functional indicators of the disease, except for an increase in RR (∆RR) during exertion. High ∆RR was associated with presence of DH (r_pb = 0.390; p < 0.05). Clinical features, peripheral muscle strength, and Spiropalm 6MWT metrics including 6MWT distance did not differ between patients with and without DH. Univariate analysis revealed FVC% (R = 0.340), VE_peak (R = 0.565), quadriceps strength (R = 0.698) and handgrip strength (R = 0.711) were the only predictors of 6MWT distance (p < 0.05).

CONCLUSION

Although DH is common in children with BE, the severity of DH is rather low and may not seem to affect functional exercise capacity. However, peripheral muscle strength was a major contributor to functional exercise capacity.

Is the modified shuttle test a maximal effort test in children and adolescents with asthma?

PURPOSE

Whether the modified shuttle test (MST) achieves maximal effort in children and adolescents with asthma is unclear. The aim was to compare the physiological responses of MST to the cardiopulmonary exercise test (CPET) in pediatric patients with asthma, to observe its convergent validity.

PATIENTS AND METHODS

A cross-sectional study with volunteers with asthma (6-17 years of age) under regular treatment. The MST is an external-paced test, and the participants were allowed to walk/run. CPET was performed on a cycle ergometer to compare with MST. Gas exchange (VO₂ , VCO₂ , and VE) and heart rate (HR) were the outcomes and were continuously assessed in both tests.

RESULTS

Forty-seven volunteers were included, normal lung function expiratory forced volume at 1st second/forced vital capacity (FEV₁ /FVC) 88.6 (7.7). VO_2peak was higher at MST (2.0 ± 0.6 L/min) compared to CPET (1.6 ± 0.5 L/min), p < 0.001. Similar results was observed to VE at MST (50 ± 16 L/min) versus VE at CPET (40 ± 13 L/min), and to VCO₂ at MST (2.1 ± 0.8 L/min) versus VCO₂ at CPET (1.7 ± 0.6 L/min), p < 0.001. HR was also higher at MST (94 ± 6%pred) versus CPET (87 ± 8%pred), p = 0.002. VO_2peak in MST correlated to the CPET (r = 0.78, p < 0.001). The ICC of VO_2peak between tests was 0.73 (0.06-0.89), p < 0.001, and VO_2peak Bland-Altman analysis showed a bias of 0.46 L/min.

CONCLUSION

The MST showed a maximal physiologic response in children and adolescents with asthma. It is a valid test and can be used as an alternative to evaluating exercise capacity.

Quality of life and exercise tolerance tools in children/adolescents with cystic fibrosis: Systematic review

INTRODUCTION

This systematic review aims to analyze the validity and reliability of available tools to assess health-related quality of life (HRQoL) and exercise tolerance in children and adolescents with cystic fibrosis (CF).

MATERIALS AND METHODS

A review of observational studies studying the validity and reliability of the tools was conducted. The COSMIN (COnsesus-based Standards for the selection of health Measurements INstruments) guide was followed to analyze the quality of these tools.

RESULTS

A total of 18 studies were selected. Of the eight HRQoL tools, five generic and three specific, analyzed in 14 studies, the Cystic Fibrosis Questionnaire-Revised (CFQ-R) presents the best properties. Of the four tools analyzed to assess exercise tolerance, cycle ergometry and the modified shuttle test are the most valid and reliable.

CONCLUSIONS

The CFQ-R, cycloergometry and the modified shuttle test have the best properties for the assessment of children with CF, but more studies are needed.

Clinical use of the modified shuttle test in children with cystic fibrosis: Is one test sufficient?

OBJECTIVE

To evaluate the reproducibility of the modified shuttle test (MST) and to determine whether the test needs to be performed more than once to assess the exercise capacity of children and adolescents with cystic fibrosis (CF).

METHODS

This was a longitudinal study including patients diagnosed with CF aged more than 6 years. The participants were followed for a period of 9 months and were evaluated at three different time points (visits 1, 2, and 3). Spirometric, anthropometric, clinical, and genetic data were collected, and two MSTs were performed at each visit.

RESULTS

Forty-eight clinically stable volunteers with a mean age of 10.1 ± 2.7 years were initially included. The reproducibility of the test was evaluated using the distance achieved (DA) as the main variable. There were no significant differences in the DA (visit 1, p = .23; visit 2, p = .24; visit 3, p = .85), baseline heart rate (HR) (visit 1, p = .35; visit 2, p = .20; visit 3, p = .98), and peak HR (visit 1, p = .16; visit 2, p = .94; visit 3, p = .23) between the tests performed at each visit. The test-retest reliability demonstrated a high intraclass correlation coefficient at all visits (visit 1, 2, and 3: 0.83, 0.90, and 0.80, respectively) and the variation in HR was the main factor associated with the DA in the MST over time.

CONCLUSION

The MST was found to be a reproducible and reliable test. The data presented here support the use of a single MST to evaluate and monitor exercise capacity of patients with CF during clinic visits.

Capacidade de exercício e nível de atividade física diária de crianças e adolescentes com fibrose cística: associação com estado nutricional, função pulmonar, hospitalização e uso de antibióticos

RESUMO O objetivo deste trabalho é avaliar a capacidade de exercício e nível de atividade física diária de crianças e adolescentes com fibrose cística e associar com estado nutricional, função pulmonar, tempo de hospitalização e uso de antibióticos. Trata-se de estudo transversal em indivíduos com fibrose cística entre 6 e 18 anos, registrando-se informações sobre perfil clínico, histórico de hospitalizações e uso de antibióticos. Os participantes foram submetidos à espirometria, bioimpedância, avaliação da capacidade de exercício com teste de Shuttle modificado (MST), o nível da atividade física foi medido por meio do questionário internacional de atividade física (IPAQ) e usando acelerômetro por 5 dias. Participaram 30 indivíduos com idade de 11,2 ± 3,6 anos e volume expirado forçado (VEF1) de 68,0 ± 24,8%. A mediana da distância percorrida no MST foi de 820 metros (66,3%) e demonstrou associação com a função pulmonar (r = 0,78), estado nutricional (r = 0,38), tempo de hospitalização (r = -0,42) e uso de antibióticos (r = -0,46). De acordo com o questionário, 20 pacientes (64,6%) foram classificados como sedentários, o acelerômetro revelou que os indivíduos passam 354,2 minutos em atividades sedentárias e apenas 14,9 minutos em atividades moderadas a vigorosas por dia. Quanto maior a porcentagem de tempo em atividade física moderada a vigorosa, maior o índice de massa corpórea (IMC) e menor o tempo de hospitalização. Assim, a capacidade de exercício e nível de atividade física em crianças e adolescentes com fibrose cística apresentou-se reduzida e associada com menores valores de IMC e aumento do tempo de hospitalização.

Força muscular respiratória e qualidade de vida em crianças e adolescentes com fibrose cística

RESUMO A fibrose cística (FC) é uma doença genética multissistêmica caracterizada por obstrução crônica que, associada a outras alterações pulmonares, pode comprometer a força muscular respiratória (FMR) e, em consequência, interferir no desempenho de atividades típicas da infância, alterando a qualidade de vida (QV) dessa população. O objetivo do estudo foi avaliar a relação entre FMR e QV de crianças e adolesceantes com FC. Trata-se de um estudo transversal, que incluiu pacientes com idades entre 6 e 14 anos, provenientes de um centro de referência no Brasil. Realizou-se avaliação antropométrica e da FMR, esta utilizando as pressões inspiratória (PImáx) e expiratória máximas (PEmáx) por meio da manovacuômetria digital (Globalmed® MVD300). Aplicou-se o Cystic Fibrosis Questionnaire (QFC), questionário específico para a avaliar a QV nessa doença, nas versões para crianças (QFC-C) e para os pais ou responsáveis (QFC-R). A gravidade da doença foi classificada segundo o escore de Schwachman Doeurshuk (ESD). Dados sobre a colonização de bactérias e o genótipo da doença foram consultados por meio da análise dos prontuários. Analisou-se os dados por meio do software SPSS version 20.0 for Windows. Após o teste Shapiro-Wilk, aplicou-se o teste de correlação de Pearson ou Spearman. Em toda a análise foi adotado nível de significância de 5%. Participaram do estudo 28 crianças (15 meninos) com média de idade de 10,10±1,79 anos, as quais apresentaram FMR próxima ao predito e pontuações do QFC indicando boa QV. O ESD relacionou-se negativamente com domínio digestivo (p=0,03; rho=-0,400). A PEmáx apresentou correlação negativa com domínio corpo do QFC-R (p=0,002; rho=-0,426) e com domínio tratamento do QFC-C (p=0,01; rho=-0,453). A PImáx apresentou correlação positiva com os domínios físico (p=0,03; rho=0,410), emocional (p=≤0,001; rho=0,573) e tratamento (p=≤0,01; rho=-0,605) do QFC-C. A PImáx também mostrou correlação positiva com o domínio respiratório (p=0,01; rho=0,572) do QFC-R. Em conclusão, identificou-se associação entre domínios da QV e FMR, bem como com o ESD e aspectos nutricionais. Essa amostra apresentou valores de FMR acima do esperado e boa QV.

Exercise Parameters Predict Technique Survival in Patients on Peritoneal Dialysis

OBJECTIVE

The incremental shuttle walking test (ISWT) is an important marker of aerobic capacity in patients on peritoneal dialysis (PD). This study aimed to evaluate its predictive value for PD-related outcomes.

METHODS

This single-center cohort study recruited outpatients on maintenance PD from our hospital between March 2017 and March 2018. Exercise capacity was assessed using measurement of ISWT and handgrip and quadriceps strength. Patients were divided into 2 groups according to the median of exercise capacity and prospectively followed up until cessation of PD, death, or the study end (October 2019). The primary end point of this study was technique survival rate, and secondary outcomes were rates of peritonitis-free survival and PD-related hospitalization-free survival.

RESULTS

Among the 50 participants, age and PD vintage were [median (IQR)] 62.5 (58.3-70) and 3.5 (1.3-6.5) years, respectively. At the end of the study, 3 of the 28 participants (11%) in the long-ISWT group and 13 of the 22 participants (59%) in the short-ISWT group were transferred to hemodialysis. The short-ISWT group showed lower technique survival rate (p < 0.001), peritonitis-free survival rate (p = 0.01), and PD-related hospitalization-free survival rate (p < 0.01) than the long-ISWT group, whereas those survival rates did not differ when participants were divided by handgrip or quadriceps strength. Multivariate analysis revealed lower ISWT to be independently associated with technique failure (p = 0.002).

CONCLUSION

The ISWT is an important predictor of technique survival for patients on PD. Monitoring and enhancing ISWT as a marker of aerobic capacity might improve PD-related outcomes.

FUNCTIONAL PERFORMANCE IN THE MODIFIED SHUTTLE TEST IN CHILDREN AND ADOLESCENTS WITH CYSTIC FIBROSIS

Objective:

To evaluate factors associated with the performance of children and adolescents with cystic fibrosis (CF) in the Modified Shuttle Test (MST) and compare it with healthy children and adolescents.

Methods:

This is a cross-sectional study, with children and adolescents divided into two groups: cystic fibrosis (CFG) and control (CG). Variables evaluated in the MST: walking distance, test level, heart rate variation (∆Hr), post-test mean arterial pressure (MAP Pt) and peripheral oxygen saturation variation (∆SPO₂). Statistical analysis included Mann Whitney and Spearman coefficient tests, being significant p<0.05.

Results:

Sixty individuals aged 6-16 years old were evaluated. Anthropometric data was similar between groups. Differences between groups were shown for: baseline heart rate (BHr), peak heart rate (PHr), ∆Hr, recovery heart rate (RHr), post-test respiratory rate (PtBr), saturation variables, peripheral oxygen level (SpO₂B) and level test. The ∆Hr and MAP Pt had a moderate positive correlation with distance and level test for both groups (respectively: r=0.6 / p<0.001; r=0.6 / p<0.001). In CFG, the level test had a significant association (r=0.4 - p=0.02) with %FEV₁.

Conclusions:

Children with cystic fibrosis presented functional limitation in the Modified Shuttle Test, which was influenced by lung function.

Exercise testing for children with cystic fibrosis: A systematic review

BACKGROUND

Exercise testing is routinely used to measure exercise capacity in children with cystic fibrosis (CF). Various tests are available, however the psychometric properties of these measures have not been systematically reviewed for this population.

METHOD

A systematic search of electronic databases (PubMed, Web of Science, Medline, CINHAL, Cochrane, and PEDro) was performed to identify papers that: (a) reported original psychometric data, (b) examined a measure of exercise capacity, (c) examined children with CF aged eight to 18 years; and (d) were published in English after 1950. The level of psychometric evidence was evaluated using the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) checklist.

RESULTS

Searches identified 1025 papers. Forty-six papers were included, covering 15 tests: incremental cardiopulmonary exercise test using a cycle ergometer (CPET(cycle)) or treadmill (CPET(treadmill)), 6 minute walk test (6MWT), modified shuttle test (MST), 3-minute step test (3MST), 2 minute walk test (2MWT), Bratteby walk test, intermittent sprint test, speed ramp test, incremental step test, forward-backwards jump test (FBJT), astride jump test (AJT), motor quotient test, Munich fitness test, and Glittre ADL test.

CONCLUSION

There is a plethora of exercise tests available with varying psychometric robustness. The CPET, 6MWT, and MST have fair to good psychometric properties, but each with their clinical advantages and limitations. Thus, a Selection Guide was developed to assist clinicians and researchers in selecting the most appropriate exercise test for various situations.

Three-axis accelerometer system for comparison of gait parameters in children with cystic fibrosis and healthy peers

BACKGROUND

Cystic Fibrosis (CF), affecting functional exercise capacity generally measured by submaximal exercise test such as 6min walk test, is a progressive, autosomal recessive and metabolic disorder. Three-axis accelerometers, which are used during gait, are an easy way to assess gait parameters in patients and healthy individuals. Gait parameters were significantly associated with clinical outcomes of COPD. However, the association between gait parameters and clinical outcomes in children with CF is unclear.

RESEARCH QUESTION

Do clinical outcomes in CF have an important role in determining gait parameters?.

METHODS

Twenty-one CF and 21 healthy subjects participated in this case-control study. Body composition was evaluated using Tanita-BC 418. Respiratory and knee extension muscle strengths were assessed. Functional exercise capacity was evaluated using the 6-min walk test (6MWT). Spatiotemporal gait parameters were evaluated using a validated wireless inertial sensing device (G-Sensor, BTS Bioengineering S.p.A., Italy) during the 6MWT and 7-meter gait test.

RESULTS

MIP, the distance of 6MWT, and stride length were significantly lower in the CF group compare to healthy children (p<0.05). Gait speed and functional exercise capacity, cadence and functional exercise capacity, quadriceps muscle strength, FEV1, fat-free mass were found to be correlated in CF patients (p<0.05).

SIGNIFICANCE

The aerobic capacity and gait parameters were affected in CF patients with mild disease severity in our study. Clinical outcomes were associated with gait parameters in CF patients. This is the first study to use the 3-axis accelerometer to evaluate functional exercise capacity and gait parameters of CF and healthy children. A three-axis accelerometer can be used to assess functional exercise capacity and gait parameters in CF patients at the clinics.

Exercise-based cardiac rehabilitation for postcoronary artery bypass grafting and its effect on hemodynamic responses and functional capacity evaluated using the Incremental Shuttle Walking Test: A retrospective pilot analysis

BACKGROUND

Coronary artery bypass grafting (CABG) is a common surgical procedure for the restoration of blood flow into stenotic or blocked coronary arteries. Cardiac rehabilitation has been implemented to some extent worldwide for the management of postoperative CABG. However, studies about the effect of exercise training on hemodynamic responses of the heart using the Incremental Shuttle Walking (ISWT) test are limited in Saudi Arabia.

OBJECTIVES

To investigate the effect of exercise-based cardiac rehabilitation (Phase 3, hospital-based) on some hemodynamic responses including blood pressure, heart rate (HR) and heart rate recovery (HRR), and rate pressure product (RPP) using ISWT on post-CABG patients.

METHODS

Fifteen CABG (51.4 ± 6.4 years, 14 male, 1 female) patients without altering their medication were enrolled in a hospital-based cardiac rehabilitation program (Phase 3) between 2011 and 2012 for supervised individual exercise training sessions (three times per week for 8 weeks; 60-minute session at a moderate intensity). Patients performed two tests (ISWT1 and ISWT2) and one before exercise training program and one after, during which resting systolic blood pressure (SBP) and diastolic blood pressure (DBP), post-ISWT SBP and DBP, resting HR, peak HR, HRR (which was defined as the absolute change from peak HR to 1-minute post peak HR), and RPP at rest and at the end of the ISWT were measured. Exercise training sessions included both aerobic and resistance exercises, which were preceded by a cooling down period and followed by a recovery period.

RESULTS

Paired t-test showed a significant reduction in both resting SBP (p = 0.04) and DBP (p = 0.03), and a significant increase in post-ISWT2 SBP (p = 0.004), peak HR (p = 0.003), HRR (p = 0.03), and RPP at maximum (p = 0.002) after 8 weeks of supervised exercise training. In addition, there was a significant increase in the speed and distance achieved on ISWT2 (p < 0.001) after the training program.

CONCLUSION

Supervised exercise training (cardiac rehabilitation) for 8 weeks was effective in improving hemodynamic responses and functional exercise capacity in CABG patients. Cardiac rehabilitation should be implemented more frequently and health-care providers should be aware of its importance. Further research is needed in this area to confirm these findings in the region.

Patients with asthma have reduced functional capacity and sedentary behavior

OBJECTIVE

The modified shuttle test is a field test that avoids the ceiling effect, and there are no reports of a multidimensional assessment concerning physical activity in asthmatic patients. Thus, the aim was to evaluate functional capacity by MST, additionally to perform a multidimensional assessment as physical activity in daily life, muscle strength, and cytokine levels in children and adolescents with asthma, and to correlate these variables.

METHOD

This cross-sectional study included volunteers aged between 6 and 18 years who were divided into two groups: asthma group (n=43) that received regular treatment and control group (n=24). Functional capacity was evaluated by distance walked during the MST; physical activity in daily life was evaluated using an accelerometer by the number of steps. Quadriceps femoris strength was evaluated by load cell.

RESULTS

Distance walked was lower for the asthma group (790m [222m]) when compared with the control group (950m [240m]; p=0.007); however, the number of steps was similar between the two groups (asthma group: 7743 [3075]; control group: 7181 [3040]; p=0.41), and both groups were classified as sedentary behavior. There was no difference in muscle strength. Tumor necrosis factor-α differed, but interleukin levels were similar between groups. Quadriceps strength was correlated to distance walked (r=0.62; p<0.001) and tumor necrosis factor-α to the number of steps taken (r=-0.54, p=0.005).

CONCLUSION

Children and adolescents undergoing regular asthma treatment showed reduced functional capacity and sedentary behavior. The lower the quadriceps strength, the shorter the distance walked; the higher the tumor necrosis factor-α levels, the lower their daily physical activity levels.

Exercise and Cystic Fibrosis

Cystic fibrosis (CF) is an autosomal recessive, inherited congenital disease caused by the mutation of the family autosomal CF gene, with cumulative exocrine secretion characterized by inflammation, tracheal remodeling, and mucus accumulation. With the development of modern medical technology, CF patients are living longer lives and receiving more and more treatments, including traditional drugs, physical therapy, and gene therapy. Exercise is widely used to prevent and treat metabolic diseases such as cardiovascular diseases, obesity, diabetes, and metabolic syndrome. Regular exercise is beneficial to aerobic capacity and lung health. Exercise therapy has been of great interest since people realized that CF can be affected by exercise. Exercise alone can be used as an ACT (airway clearance technique), which promotes the removal of mucosal cilia. Exercise therapy is more easily accepted by any society, which helps to normalize the lives of CF patients, rather than placing a psychological burden on them. In this chapter, we will review the latest research progress about exercise in CF.

Força muscular respiratória e desempenho no Modified Shuttle Walk Test em escolares com fibrose cística

RESUMO O Modified Shuttle Walk Test (MSWT) é um teste de exercício potencialmente máximo que, associado à avaliação da força muscular respiratória (FMR), reflete a condição respiratória e a capacidade de exercício de escolares com fibrose cística (FC). O objetivo desta pesquisa foi investigar a relação entre FMR e distância percorrida (DP) no MSWT realizado por escolares com FC e comparar os dados obtidos com valores preditos na literatura. Trata-se de um estudo observacional transversal que incluiu escolares com FC. Realizou-se avaliação antropométrica, espirometria e FMR, utilizando as pressões inspiratória máxima (PImáx) e expiratória máxima (PEmáx) por meio da manovacuometria. Dois MSWT foram realizados, com intervalo de 30 minutos entre eles. Verificou-se a distribuição dos dados pelo teste de Shapiro-Wilk e aplicou-se teste t pareado para comparação entre valores das avaliações e predito, bem como para comparação entre gêneros. Aplicou-se teste de Pearson para correlação entre PImáx e PEmáx e DP no MSWT. Aceitou-se significância de 5%. Participaram 28 crianças (9,9±1,9 anos) destas, 57,14% apresentaram PImáx abaixo do predito (15 crianças) e 53,57% da PEmáx (16 crianças). A média da DP foi 730,4±266,1m, abaixo do predito na literatura. Não houve relação entre DP e FMR. Identificou-se correlação moderada entre valores de PImáx e PEmáx (r=0,58 e p=0,01). Não houve relação entre FMR e desempenho no MSWT nos escolares com FC estudados. A FMR, bem como o DP no MSWT, apresentou-se abaixo do predito na literatura.

Pediatric Glittre ADL-test in cystic fibrosis: Physiological parameters and respiratory mechanics

Background: To evaluate the functional capacity in children and adolescents with cystic fibrosis (CF) through the pediatric Glittre ADL-test (TGlittre-P) and its implications for respiratory mechanics, physiological parameters and clinical markers. Methods: Impulse oscillometry system (IOS) parameters, vital signs (heart rate, respiratory rate and blood pressure), perception of dyspnea and peripheral oxygen saturation (SpO₂) were assessed before and immediately after the TGlittre-P. Test performance was correlated with age, quality of life, disease severity, nutrition, spirometry and IOS parameters. Results: Twenty-six patients were included thirteen boys, mean age of 9.54 ± 1.94 and FEV₁ of 71.45%±22.67%. The mean time to complete the test was 2.94 min, similar to that predicted for healthy children. There was a correlation of time with age, as well as with some IOS parameters. Disease severity, spirometric parameters, nutritional aspects and quality of life (QoL) were correlated with performance in the TGlittre-P. Immediate increase of vital signs and decline in SpO₂ were observed after the test, without an impact on IOS parameters. Conclusion: Patients with CF showed similar performance and changes of vital signs at the TGlittre-P compared to reference values for healthy children. There were no immediate changes in parameters for the assessed respiratory mechanics. Also, there was no correlation of time to complete the TGLittre-P test with respiratory mechanics, physiological parameters and clinical markers.

Validation of the Incremental Shuttle Walk Test as a Clinical End Point in Bronchiectasis

BACKGROUND

A validated clinical end point is needed to assess response to therapies in bronchiectasis.

OBJECTIVES

The goal of this study was to assess the reliability, validity, and responsiveness of the incremental shuttle walk test (ISWT) as a clinical end point in bronchiectasis.

METHODS

In clinically stable patients (n = 30), the ISWT was performed twice, 6 months apart. Correlation between the St. George's Respiratory Questionnaire (SGRQ) and the ISWT (n = 94) was performed. The 1-year gentamicin study was reanalyzed to assess the area under the curve (percent change of ISWT with a ≥ 4 unit improvement in total SGRQ). ISWT was performed prior to and following 14 days of antibiotics for an exacerbation (94 oral courses and 30 IV courses, n = 124) and reanalysis of the 1-year gentamicin study (n = 57).

RESULTS

The ISWT did not significantly change over 6 months while clinically stable. The ISWT correlated inversely with the SGRQ (rs = -0.60; P < .0001), Bronchiectasis Severity Index score (rs = -0.44; P < .0001), and sedentary time (rs = -0.48; P = .0007) but correlated with physical activity (rs = 0.42; P = .004). The area under the curve for percent change in ISWT with ≥ 4 unit improvement in SGRQ was 0.79 (95% CI, 0.66-0.91; P = .001). A threshold of 5% improvement in the ISWT had a 92% sensitivity but 50% specificity, and from the responsiveness studies would capture 73% of all patients.

CONCLUSIONS

This study confirmed the ISWT to be reliable, valid, and responsive to change in patients with bronchiectasis. The authors propose that a minimum clinically important difference of 5% improvement in the ISWT would be a useful objective end point to assess therapies in bronchiectasis.

Validation of the Modified Shuttle Test to Predict Peak Oxygen Uptake in Youth Asthma Patients Under Regular Treatment

Background: Oxygen uptake (VO₂) evaluations by cardiopulmonary exercise test is expensive and time-consuming. Estimating VO₂ based on a field test would be an alternative.

Objective: To develop and validate an equation to predict VO_2peak based on the modified shuttle test (MST).

Methods: Cross sectional study, with 97 children and adolescents with asthma. Participants were divided in two groups: the equation group (EG), to construct the equation model of VO_2peak, and the cross-validation group (VG). Each subject performed the MST twice using a portable gas analyzer. The peak VO_2peak during MST was used in the equation model. The patients’ height, weight, gender, and distance walked (DW) during MST were tested as independent variables.

Results: The final model [-0.457 + (gender × 0.139) + (weight × 0.025) + (DW × 0.002)] explained 87% of VO_2peak variation. The VO_2peak predicted was similar to VO_2peak measured by gas analyzer (1.9 ± 0.5 L/min and 2.0 ± 0.5 L/min, respectively) (p = 0.67), and presented significant ICC 0.91 (IC95% 0.77 to 0.96); p < 0.001. The Bland–Altman analysis showed low bias (-0.15 L/min) and limits of agreement (-0.65 to 0.35 L/min). There was no difference in DW between EG (760 ± 209 m) and VG (731 ± 180 m), p = 0.51.

Conclusion: The developed equation adequately predicts VO_2peak in pediatric patients with asthma.

Correlation between parameters of volumetric capnography and spirometry during a submaximal exercise protocol on a treadmill in patients with cystic fibrosis and healthy controls

INTRODUCTION

Spirometry is the most frequently used test to evaluate the progression of lung damage in cystic fibrosis (CF). However, there has been low sensitivity in detecting early lung changes. In this context, our objective was to identify the correlation between parameters of volumetric capnography (VCap) and spirometric parameters during a submaximal treadmill exercise test.

METHODS

A cross-sectional and controlled study which included 64 patients with CF (CFG) and 64 healthy control subjects (CG) was performed. The CFG was from a university hospital and the CG from local schools. All participants underwent spirometry and VCap before, during and after the submaximal treadmill exercise test. The main variable analyzed by VCap was the slope of phase 3 (slope 3), which indicates the [exhaled carbon dioxide] at the end of expiration, and expresses the heterogeneity of gas emptying in pulmonary periphery. The correlation analysis between spirometry and VCap was conducted using the Spearman correlation test, considering α=0.05.

RESULTS

The indices analyzed by VCap showed correlation with parameters of VCap. Slope 3 showed an inverse correlation with forced expiratory volume in the first second of forced vital capacity (FEV₁) in both groups and at all moments of the submaximal treadmill exercise test. Forced vital capacity (FVC) and FEV₁/FVC ratio showed an inverse correlation with slope 3 only for CFG. Values of slope 3 corrected by the spontaneous tidal volume (VT) and end-tidal carbon dioxide tension (PetCO₂) showed results similar to slope 3 analyzed separately.

CONCLUSION

Parameters of VCap such as slope 3, slope 3/VT and slope 3/PetCO₂ correlated with sensitive variables of spirometry such as FEV₁, FVC and FEV₁/FVC ratio. For the evaluated variables, there was consistency in the correlation between the two tests, which may indicate the impact of CF on pulmonary physiology.

Supervised physical exercise improves clinical, anthropometric and biochemical parameters in adult cystic fibrosis patients: A 2-year evaluation

OBJECTIVE

Cystic fibrosis (CF) is the most common inherited, life limiting condition among Caucasians. No healing therapy is currently available for patients with CF. The aim of the study was to define clinical, anthropometric and biochemical effects of regular, supervised physical exercise in a large cohort of patients with CF.

MATERIALS AND METHODS

Fifty-nine adult patients with CF that performed regularly supervised physical exercise in the last 3 years in comparison to 59 sex and age matched sedentary patients with CF were included in the study.

RESULTS

Physical exercise had significantly beneficial effects on: (a) FEV1% decline; (b) anthropometric parameters (lower number of cases with altered BMI, waist and arm circumferences); (c) lipid and glucose metabolism; (d) vitamin D serum levels. Of course, some of this improvement may be because of the better adherence to therapy typical of patients with CF that perform physical activity.

CONCLUSIONS

Such clinical and metabolic effects make supervised physical activity one of the hubs in managing patients with CF.