Physical fitness and quality of life in adolescents with asthma and fixed airflow obstruction.

Asthma is a disease characterized by reversible bronchoconstriction, but some subjects develop fixed airflow obstruction (FAO). Subjects with FAO present more asthma symptoms and may have increased sedentary behavior; however, the effect of FAO on aerobic fitness and physical activity levels (PAL) remains poorly understood. AIM: To compare adolescents with asthma and FAO and adolescents with asthma without FAO in terms of aerobic fitness, PAL, muscle strength, and health-related quality of life (HRQoL). METHODS: This cross-sectional study included adolescents with asthma, both sexes, and aged 12-18 years. They were divided into two groups: FAO and non-FAO groups. The adolescents were diagnosed with asthma according to the Global Initiative for Asthma guidelines and underwent optimal pharmacological treatment for at least 12 months. FAO was diagnosed when the forced expiratory volume in the first second/forced vital capacity ratio was below the lower limit of the normal range after optimal treatment. Aerobic fitness, PAL, peripheral and respiratory muscle strength, and HRQoL were evaluated. RESULTS: No significant differences were observed between FAO and non-FAO groups regarding the peak oxygen uptake (34.6 ± 8.5 vs. 36.0 ± 8.4 mLO2 /min/kg), sedentary time (578 ± 126 vs. 563 ± 90 min/day), upper limb muscle strength (29.1 ± 5.9 vs. 28.1 ± 5.7 kilograms of force [kgf]), lower limb muscle strength (42.8 ± 8.6 vs. 47.6 ± 9.6 kgf), or HRQoL (5.1 ± 1.3 vs. 4.7 ± 1.4 score; p > .05). However, the FAO group exhibited a higher maximal expiratory pressure than the non-FAO group (111.5 ± 15.5 vs. 101.5 ± 15.0 cmH2 O, respectively). CONCLUSION: Our results suggest that FAO does not impair aerobic fitness, PAL, peripheral muscle strength, or HRQoL in adolescents with asthma. Furthermore, adolescents with asthma were physically deconditioned.

Barriers to daily life physical activities for Brazilian children with asthma: a cross-sectional study.

BackgroundObjective: To identify barriers to daily life physical activities (DLPA) and to evaluate physical activity levels for children with asthma and without asthma.Method: This is a cross-sectional study that enrolled 130 children with asthma and 54 non-asthma, from 7 to 12 years old. All of the children in both groups used an accelerometer for 6 consecutive days to assess DLPA and completed a questionnaire to evaluate barriers to physical activity. Accelerometer was used to measure each child's total number of steps, as well as the number of steps and the time spent in moderate-to-vigorous physical activity (MVPA). The barrier questionnaire to DLPA included 11 questions, divided into three domains: personal, social and environmental.Results: The most commonly described barrier to DLPA in the asthma and non-asthma groups was an unsafe environment (23.6% vs 28.5%, respectively). The asthma group reported having asthma (19%) and lack of parental encouragement (17.3%) as being other important barriers to DLPA. It was also observed that the asthma and non-asthma groups presented similar values for the total number of steps (13,379 ± 3,837 vs 14,055 ± 3,914, respectively, p > 0.05), number of steps in MVPA (5,654 ± 1,988 vs. 6,025 ± 2,058, p > 0.05), and time spent in MVPA (46 ± 16 min vs. 50.8 ± 14.7 min, p > 0.05).Conclusions: An unsafe environment is the main barrier to physical activity for Brazilian children. Moreover, a lack of parental encouragement and having asthma were considered to be barriers to physical activity. And lastly, children have similar levels of physical activity whether they have asthma or do not have asthma.

Phenotypes of asthma in low-income children and adolescents: cluster analysis / Fenótipos de asma em crianças e adolescentes de baixa renda: análise de agrupamentos

ABSTRACT Objective: Studies characterizing asthma phenotypes have predominantly included adults or have involved children and adolescents in developed countries. Therefore, their applicability in other populations, such as those of developing countries, remains indeterminate. Our objective was to determine how low-income children and adolescents with asthma in Brazil are distributed across a cluster analysis. Methods: We included 306 children and adolescents (6-18 years of age) with a clinical diagnosis of asthma and under medical treatment for at least one year of follow-up. At enrollment, all the patients were clinically stable. For the cluster analysis, we selected 20 variables commonly measured in clinical practice and considered important in defining asthma phenotypes. Variables with high multicollinearity were excluded. A cluster analysis was applied using a twostep agglomerative test and log-likelihood distance measure. Results: Three clusters were defined for our population. Cluster 1 (n = 94) included subjects with normal pulmonary function, mild eosinophil inflammation, few exacerbations, later age at asthma onset, and mild atopy. Cluster 2 (n = 87) included those with normal pulmonary function, a moderate number of exacerbations, early age at asthma onset, more severe eosinophil inflammation, and moderate atopy. Cluster 3 (n = 108) included those with poor pulmonary function, frequent exacerbations, severe eosinophil inflammation, and severe atopy. Conclusions: Asthma was characterized by the presence of atopy, number of exacerbations, and lung function in low-income children and adolescents in Brazil. The many similarities with previous cluster analyses of phenotypes indicate that this approach shows good generalizability.

RESUMO Objetivo: Estudos que caracterizam fenótipos de asma predominantemente incluem adultos ou foram realizados em crianças e adolescentes de países desenvolvidos; portanto, sua aplicabilidade em outras populações, tais como as de países em desenvolvimento, permanece indeterminada. Nosso objetivo foi determinar como crianças e adolescentes asmáticas de baixa renda no Brasil são distribuídos através de uma análise de clusters. Métodos: Foram incluídos 306 crianças e adolescentes (6-18 anos de idade) com diagnóstico clínico de asma e sob tratamento médico por pelo menos um ano de acompanhamento. No momento da inclusão, todos os pacientes estavam clinicamente estáveis. Vinte variáveis comumente determinadas na prática clínica e consideradas importantes na definição dos fenótipos de asma foram selecionadas para a análise de clusters. As variáveis com alta multicolinearidade foram excluídas. Uma análise de clusters foi realizada utilizando-se um teste aglomerativo em duas etapas e log-likelihood distance measure. Resultados: Três clusters foram definidos para nossa população. O cluster 1 (n = 94) incluiu indivíduos com função pulmonar normal, inflamação eosinofílica leve, poucas exacerbações, início mais tardio da asma e atopia leve. O cluster 2 (n = 87) incluiu pacientes com função pulmonar normal, número moderado de exacerbações, início precoce da asma, inflamação eosinofílica mais grave e atopia moderada. O cluster 3 (n = 108) incluiu pacientes com função pulmonar ruim, exacerbações frequentes, inflamação eosinofílica e atopia graves. Conclusões: A asma foi caracterizada por presença de atopia, número de exacerbações e função pulmonar em crianças e adolescentes de baixa renda no Brasil. As muitas semelhanças entre esta e outras análises de clusters de fenótipos indicam que essa abordagem apresenta boa generalização.

Phenotypes of asthma in low-income children and adolescents: cluster analysis.

Objective: Studies characterizing asthma phenotypes have predominantly included adults or have involved children and adolescents in developed countries. Therefore, their applicability in other populations, such as those of developing countries, remains indeterminate. Our objective was to determine how low-income children and adolescents with asthma in Brazil are distributed across a cluster analysis. Methods: We included 306 children and adolescents (6-18 years of age) with a clinical diagnosis of asthma and under medical treatment for at least one year of follow-up. At enrollment, all the patients were clinically stable. For the cluster analysis, we selected 20 variables commonly measured in clinical practice and considered important in defining asthma phenotypes. Variables with high multicollinearity were excluded. A cluster analysis was applied using a twostep agglomerative test and log-likelihood distance measure. Results: Three clusters were defined for our population. Cluster 1 (n = 94) included subjects with normal pulmonary function, mild eosinophil inflammation, few exacerbations, later age at asthma onset, and mild atopy. Cluster 2 (n = 87) included those with normal pulmonary function, a moderate number of exacerbations, early age at asthma onset, more severe eosinophil inflammation, and moderate atopy. Cluster 3 (n = 108) included those with poor pulmonary function, frequent exacerbations, severe eosinophil inflammation, and severe atopy. Conclusions: Asthma was characterized by the presence of atopy, number of exacerbations, and lung function in low-income children and adolescents in Brazil. The many similarities with previous cluster analyses of phenotypes indicate that this approach shows good generalizability.

Objetivo: Estudos que caracterizam fenótipos de asma predominantemente incluem adultos ou foram realizados em crianças e adolescentes de países desenvolvidos; portanto, sua aplicabilidade em outras populações, tais como as de países em desenvolvimento, permanece indeterminada. Nosso objetivo foi determinar como crianças e adolescentes asmáticas de baixa renda no Brasil são distribuídos através de uma análise de clusters. Métodos: Foram incluídos 306 crianças e adolescentes (6-18 anos de idade) com diagnóstico clínico de asma e sob tratamento médico por pelo menos um ano de acompanhamento. No momento da inclusão, todos os pacientes estavam clinicamente estáveis. Vinte variáveis comumente determinadas na prática clínica e consideradas importantes na definição dos fenótipos de asma foram selecionadas para a análise de clusters. As variáveis com alta multicolinearidade foram excluídas. Uma análise de clusters foi realizada utilizando-se um teste aglomerativo em duas etapas e log-likelihood distance measure. Resultados: Três clusters foram definidos para nossa população. O cluster 1 (n = 94) incluiu indivíduos com função pulmonar normal, inflamação eosinofílica leve, poucas exacerbações, início mais tardio da asma e atopia leve. O cluster 2 (n = 87) incluiu pacientes com função pulmonar normal, número moderado de exacerbações, início precoce da asma, inflamação eosinofílica mais grave e atopia moderada. O cluster 3 (n = 108) incluiu pacientes com função pulmonar ruim, exacerbações frequentes, inflamação eosinofílica e atopia graves. Conclusões: A asma foi caracterizada por presença de atopia, número de exacerbações e função pulmonar em crianças e adolescentes de baixa renda no Brasil. As muitas semelhanças entre esta e outras análises de clusters de fenótipos indicam que essa abordagem apresenta boa generalização.

Daily physical activity in asthmatic children with distinct severities.

OBJECTIVE: The objective of this study was to evaluate daily physical activity (DPA) in asthmatic children with different levels of disease severity, but with good asthma control, relative to a control group. METHODS: This was a cross-sectional study in which a total of 121 children between the ages of 7 and 12 years old were evaluated; 72 were asthmatic children (32 mild, 24 moderate and 23 severe), and 42 children were not asthmatics. The asthmatic children studied had been in medical treatment for at least 6 months and experienced no change in symptoms during the 4 weeks prior to the study. The DPA was monitored over 6 days (4 weekdays and 2 weekend days). Motor activity was recorded with an accelerometer that measured the total number of steps (TNS), the number of steps in moderate physical activity (NS-MPA) and the duration, in minutes, of physical activity performed at moderate intensity. RESULTS: There were no differences among the TNS performed by children with mild, moderate or severe persistent asthma and the control group (14 410 ± 4379, 14 710 ± 4892, 13 838 ± 3341 and 12 968 ± 3682 steps, respectively). The NS-MPA was also similar among all of the groups (6589 ± 2065, 6605 ± 2324, 6223 ± 1689 and 5990 ± 1840 steps, respectively). Sedentary asthmatic children were overweight more often than asthmatic children who were physically active, although lung function was not different between these groups. CONCLUSION: Children with good asthma control, independent of disease severity, had DPA levels similar to children without asthma. However, more asthmatic children were overweight if sedentary as compared to physically active asthmatic children.