Determinants of exercise capacity in children and adolescents with severe therapy-resistant asthma.

OBJECTIVE: To evaluate the exercise capacity of children and adolescents with severe therapy resistant asthma (STRA) aiming to identify its main determinants. METHODS: Cross-sectional study including individuals aged 6-18 years with a diagnosis of STRA. Clinical (age and gender), anthropometric (weight, height and body mass index) and disease control data were collected. Lung function (spirometry), cardiopulmonary exercise testing (CPET) and exercise-induced bronchoconstriction (EIB) test were performed. RESULTS: Twenty-four patients aged 11.5 ± 2.6 years were included. The mean forced expiratory volume in one second (FEV1) was 91.3 ± 9.2%. EIB occurred in 54.2% of patients. In CPET, the peak oxygen uptake (VO2peak) was 34.1 ± 7.8 mL kg-1 min-1. A significant correlation between ventilatory reserve and FEV1 (r = 0.57; p = 0.003) was found. Similarly, there was a significant correlation between CPET and percent of FEV1 fall in the EIB test for both VE/VO2 (r = 0.47; p = 0.02) and VE/VCO2 (r = 0.46; p = 0.02). Patients with FEV1<80% had lower ventilatory reserve (p = 0.009). In addition, resting heart rate correlated with VO2peak (r=-0.40; p = 0.04), VE/VO2 (r = 0.46; p = 0.02) and VE/VCO2 (r = 0.48; p = 0.01). CONCLUSIONS: Exercise capacity is impaired in approximately 30% of children and adolescents with STRA. The results indicate that different aspects of aerobic fitness are influenced by distinct determinants, including lung function and EIB.

Diagnostic performance of the physical activity-related question of the GINA questionnaire to detect exercise-induced bronchoconstriction in asthma.

INTRODUCTION: The aim of the study was to evaluate the diagnostic performance of the item concerning physical activity of the Global Initiative for Asthma (GINA) asthma control questionnaire for detection of exercise-induced bronchoconstriction (EIB) in children and adolescents. MATERIAL AND METHODS: We divided participants (aged 6-18 years) with a diagnosis of asthma into two groups according to the GINA severity classification: mild/moderate asthma (MMA) and severe therapy-resistant asthma (STRA). We collected anthropometric, clinical and functional data (spirometry) and performed an EIB test. We used item 4 of the GINA questionnaire regarding exercise-induced symptoms to assess the diagnostic power of this instrument. RESULTS: We included 40 patients (17 with MMA and 23 with STRA) with a mean age of 11.3 years and a mean FEV1z-score of -0.33, of who 13 (32.5%) were classified as having uncontrolled asthma. Of the patients with uncontrolled asthma, 7 (53.8%) exhibited a decrease in the FEV1 after the EIB test. We found a higher frequency of EIB in participants with FEV1 z-score values of less than -1.0 compared to those with a z-score of -1.0 or greater (P = .05). There were no significant differences in the frequency of EIB based on disease severity and control. We also found no association of item 4 (GINA) with EIB. The area under the ROC curve demonstrated that the discriminative power of the GINA questionnaire for the detection of EIB is inadequate (P = .41), with sensitivity of 42.1% and specificity of 57.1%. CONCLUSIONS: The item concerning physical activity in the GINA questionnaire has insufficient diagnostic power to detect EIB in children and adolescents with asthma.

Continuous positive airway pressure acutely increases exercise duration in children with severe therapy-resistant asthma: a randomized crossover trial.

BACKGROUND: Lower exercise tolerance is an important component of asthma and the possible effects of non-invasive ventilation on exercise capacity in individuals with severe therapy-resistant asthma (STRA) are unknown. This study aimed to evaluate the immediate effect of continuous positive airway pressure (CPAP) on exercise tolerance in children with STRA. METHODS: We performed a controlled, randomized, crossover clinical trial including subjects aged 6 to 18 years old diagnosed with STRA. Clinical, anthropometric and lung function data were collected. The participants in the intervention group (IG) used CPAP (PEEP 10cmH2O and FiO2 0.21) for a period of 40 min. Subjects in the control group (CG) used CPAP with minimum PEEP at 1 cmH20 also for 40 min. Afterwards, subjects from both groups underwent cardiopulmonary exercise testing (CPET). After a 15-day washout period, on a subsequent visit, subjects participated in the opposite group to the initial one. RESULTS: Thirteen subjects with a mean age of 12.30 ± 1.7 years were included. The variables of peak expiratory flow (PEF) and forced expiratory volume in the first second (FEV1) before using CPAP and after performing CPET did not show significant differences. Regarding CPET results, there was no significant difference (P = 0.59) between groups at peak exercise for oxygen consumption-VO2 (CG: 33.4 ± 6.3 and IG: 34.5 ± 5.9, mL kg-1 min-1). However, the IG (12.4 ± 2.1) presented a total test time (min) significantly (P = 0.01) longer than the CG (11.5 ± 1.3). CONCLUSION: The results suggest that the use of CPAP before physical exercise increases exercise duration in children and adolescents with STRA.

Modified Shuttle Test Distance Correlates With Peak Oxygen Uptake in Children and Adolescents With Severe Therapy-Resistant Asthma.

INTRODUCTION: Several tests may be used to assess exercise intolerance in severe therapy-resistant asthma (STRA), including the gold standard cardiopulmonary exercise test (CPET) and the modified shuttle test (MST). OBJECTIVE: To correlate the distance achieved in the MST with peak oxygen uptake (VO2peak) and to compare the maximal heart rate (HRmax) obtained in both tests in children and adolescents with STRA. METHODS: This is a cross-sectional study, with 19 children and adolescents with STRA. Demographic, anthropometric, clinical data, and spirometric values were collected. CPET and the MST were performed in two consecutive visits. HRmax, pulse oxygen saturation, and dyspnea were compared between tests. The distance achieved in the MST was correlated with VO2peak. RESULTS: Nineteen patients with a mean age of 11.5 ± 2.5 years were included. The mean HRmax (bpm) achieved was 180.8 ± 12.10 for the MST and 187.6 ± 9.35 for CPET, whereas the mean HRmax as a percentage of predicted (HRmax%) was 90.7 ± 6.5 for the MST and 93.8 ± 4.5 for CPET. A difference of only 6 bpm was found for HRmax (p = 0.10) and of 3% for HRmax% (p = 0.06) between tests. A strong correlation was found between the MST (r = 0.79; p = 0.001) and VO2peak measured through CPET. However, there were no correlations between the MST and both body mass index (r = -0.14; p = 0.564) and forced expiratory volume in the first second - FEV1 (r = -0.02; p = 0.917). CONCLUSION: The results demonstrate that the MST distance strongly correlates with VO2peak, measured through CPET, and the main physiological variable responses were similar between both tests. Our results provide additional data for the use of the MST to assess exercise capacity in children and adolescents with STRA.

Efeitos de programas de exercício físico em pacientes com fibrose cística / Effects of physical exercise programs in patients with cystic fibrosis

Objetivos: Programas de exercício físico fazem parte do tratamento de pacientes com fibrose cística, entretanto há poucos ensaios clínicos controlados sobre os efeitos da atividade física nesses pacientes. O objetivo deste estudo foi avaliar, através de uma revisão da literatura, os efeitos de programas de exercício físico regular como parte do tratamento de pacientes com fibrose cística.Fonte de dados: A pesquisa foi realizada nas bases de dados Medline/PubMed, Lilacs e SciELO, selecionando ensaios clínicos controlados, publicados no período de 2002 a 2012, em inglês e português, utilizando os seguintes termos: cystic fibrosis/fibrose cística, exercise/exercício e physical activity/atividade física. Foram incluídos nesta revisão sete estudos que se enquadraram nos critérios de inclusão.Síntese dos dados: A maioria dos estudos selecionados avaliou o efeito do exercício aeróbico, três associaram o exercício ao treino de força muscular, e um trabalho comparou o treinamento aeróbico com o treinamento de força para os membros superiores. Dos sete artigos, cinco (71,4%) orientaram uma frequência semanal de três vezes por semana e três (42,8%) um tempo de realização da atividade física de 30 minutos.Conclusões: Em conjunto, a análise realizada demonstrou que a prática de exercício aeróbico e o treinamento da força muscular diminuem a queda progressiva da função pulmonar, aumentam a resistência ao exercício e melhoram a autoestima e a qualidade de vida dos pacientes com fibrose cística.

Aims: Exercise programs are part of the treatment of patients with cystic fibrosis, but there are few controlled trials on the effects of physical activity in these patients. The aim of this study was to evaluate, through a literature review, the effects of regular exercise programs as part of the treatment of patients with cystic fibrosis.Source of data: The survey was conducted in Medline/PubMed, Lilacs and SciELO databases, selecting controlled trials published between 2002 to 2012, in English or Portuguese, using the following terms: cystic fibrosis/fibrose cística, exercise/exercício e physical activity/atividade física. Seven studies that met the inclusion criteria were included in this review.Summary of findings: Most of the selected studies evaluated the effect of aerobic exercise; three associated exercise with muscular strength training, and one study compared aerobic training with strength training for the upper limbs. Of the seven articles, five (71.4%) recommended a frequency of three times a week and three (42.8%) recommended a time of 30 minutes of physical activity.Conclusions: Taken together, the analysis showed that the practice of aerobic exercise and muscle strength training decrease the progressive decline in lung function, increase exercise endurance and improve self-esteem and quality of life of patients with cystic fibrosis.