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.

The modified shuttle test as a predictor of risk for hospitalization in youths with cystic fibrosis: A two-year follow-up study

BACKGROUND: Patients with cystic fibrosis (CF) present exercise intolerance and episodes of pulmonary exacerbations. This study aimed to evaluate the association of the distance covered on the modified shuttle test (MST), as well as other clinical variables (anthropometry, chronic colonization by Pseudomonas aeruginosa, lung function), with the risk of hospitalization for pulmonary exacerbation. METHODS: Cohort study including CF patients older than 6 years, from two specialized CF centers. All patients underwent a MST and a lung function test at the time of inclusion. Demographic, anthropometric and clinical data were collected. Free time until the first hospitalization, total days of hospitalization and use of antibiotics during the two years of follow-up were recorded. RESULTS: Sixty-seven patients with a mean (SD) age of 12.4 (5.2) years and forced expiratory volume in the first second (FEV1) of 78.7% (22.4) were included. The mean distance covered (m) in the MST was 775.6 (255.7) (73.4 ± 19.5% of predicted). The distance achieved (MST) was considered as the main independent variable to predict the risk of hospitalization (Cox HR 0.97, p = 0.029). Patients who walked a distance of less than 80% of predicted in the MST showed an increase of 3.9 (95%CI 1.0-15.3) in the relative risk for hospitalization and significantly higher total number of days of hospitalization (p = 0.022). CONCLUSION: There is an association between the distance covered in the MST and the risk of hospitalization in youths with CF. Patients with reduced exercise capacity presented a 3.9 times increase in the relative risk for hospitalization due to pulmonary exacerbation.

Peripheral muscle strength is associated with aerobic fitness and use of antibiotics in patients with cystic fibrosis.

AIMS: Individuals with cystic fibrosis (CF) may develop muscle abnormalities, although little is known on its clinical and functional impact. This study aimed to evaluate the association of peripheral muscle strength with aerobic fitness, habitual physical activity, lung function and the use of antibiotics (ATB) in patients with CF. METHODS: A cross-sectional study where individuals aged ≥6 years underwent peripheral muscle strength evaluation (biceps, quadriceps and hamstrings) and performed a cardiopulmonary exercise test. Demographic, anthropometric, genetic, lung function and total days of ATB use within 1 year of tests were also collected. RESULTS: Correlation was found for biceps (r = .45; P = .002) strength with the peak oxygen consumption (VO2 peak). Muscle strength (biceps and quadriceps) also correlated with the ventilatory equivalent for oxygen consumption (VE /VO2 ) at anaerobic threshold (AT) and with the ventilatory equivalent for carbon dioxide production (VE /VCO2 ) both at AT and peak exercise. Negative correlations were found for quadriceps (r = -.39) and hamstrings (r = -.42) with the total days of ATB use in the following year. Patients needing to use ATB presented lower biceps strength (P = .05) and individuals with VO2 peak lower than 37 mL·kg-1 ·min-1 presented lower muscle strength for both biceps (P = .01) and quadriceps (P = .02). CONCLUSIONS: The results have shown that peripheral muscle strength is associated with aerobic fitness and the use of antibiotics in patients with CF.

Effect of an interdisciplinary intervention with motivational approach on exercise capacity in obese adolescents: a randomized controlled clinical trial.

Objective To evaluate the effect of an interdisciplinary intervention with a motivational approach on exercise capacity and usual physical activity levels in overweight and obese adolescents. Methods This is a randomized, controlled clinical trial with single blinding of subjects. Adolescents aged 15 to 18 years with overweight and obesity (body mass index ≥ 85 percentile) were included. The adolescents were randomized into two groups: interdisciplinary intervention or control - traditional approach aiming at lifestyle modifications. The initial evaluations were carried out, including the cardiopulmonary exercise test and the physical activity level measurement by using the International Physical Activity Questionnaire and a pedometer. The evaluations were performed in two moments: time zero (time of inclusion in the study) and after 3 months (end of intervention). There were 12 sessions with weekly meetings. Results A total of 37 participants were included, 19 in the Intervention Group. There were no significant differences in the baseline demographic, anthropometric and physical activity characteristics between groups, with mean age of 17.3±1.0 years in the Control Group, and 16.8±0.9 years in the Intervention Group (p=0.14). The motivational intervention did not cause significant differences (p>0.05) in the comparison of the variables of exercise capacity and usual physical activity (questionnaire and pedometer) between groups. Conclusion The intervention with a motivational approach did not alter exercise capacity and levels of usual physical activity in overweight and obese adolescents. Clinical Trial Registry: NCT02455973 and REBEC: RBR-234nb5.

Determinants of Exercise Capacity Assessed With the Modified Shuttle Test in Individuals With Cystic Fibrosis.

BACKGROUND: Patients with cystic fibrosis develop decreased exercise capacity. However, the main factors responsible for this decline are still unclear. Thus, the objective of this study was to evaluate the factors influencing exercise capacity assessed with the modified shuttle test (MST) in individuals with cystic fibrosis. METHODS: A cross-sectional study was carried out in subjects with a diagnosis of cystic fibrosis who were 6-26 y old and were regularly monitored at 2 cystic fibrosis reference centers in Brazil. Individuals who were unable to perform the tests or who exhibited hemodynamic instability and exacerbation of respiratory symptoms were excluded. Anthropometric, clinical, and genotype data were collected. In addition, lung function and exercise capacity were evaluated with the MST. RESULTS: 73 subjects (mean age 12.2 ± 4.9 y and FEV1 76.8 ± 23.3%) were included. The mean distance achieved in the MST was 765 ± 258 m (71.6% of predicted). The distance achieved on the MST correlated significantly with age (r = 0.49, P < .001), body mass index (r = 0.41, P < .001), resting heart rate (r = -0.51, P < .001), and FEV1 (r = 0.24, P = .042). Subjects with FEV1 > 67% of predicted (P = .02) and those with resting heart rate < 100 beats/min (P = .01) had a greater exercise capacity. Resting heart rate, age, and FEV1 (%) were found as significant variables to explain the distance achieved on the MST (R2 = 0.48, standard error = 191.0 m). CONCLUSIONS: The main determinants of exercise capacity assessed with the MST in individuals with cystic fibrosis were resting heart rate, age, and lung function.

Evaluation of the exercise intensity generated by active video gaming in patients with cystic fibrosis and healthy individuals.

BACKGROUND: Adherence of patients with cystic fibrosis (CF) to exercise is challenging. Here we compared the physiological responses during the use of interactive video games (VG) with the cardiopulmonary exercise test (CPET) in healthy and CF subjects. METHODS: Cross-sectional study including CF and healthy (CON) subjects older than 6 years. Individuals were evaluated in two visits. At visit one, anthropometric measures, spirometry and CPET were performed. In the second visit, a physical activity questionnaire was applied and gas analyses performed during the use (10 min) of both Nintendo Wii (Wii Fit Plus: (1) Obstacle Course, (2) Rhythm Boxing and (3) Free Run) and Xbox One (Just Dance 2015: (1) Love Me Again, (2) Summer and (3) Happy). RESULTS: Twenty-five CON and 30 CF patients were included. The mean FEV1 (%) was significantly lower in the CF group compared to CON. There were no differences between groups at peak exercise (CPET) for heart rate (HR), oxygen consumption (VO2) and minute ventilation (VE). In the CON group, games 2 and 3 (Xbox) and game 3 (Nintendo) increased HR to values similar to the anaerobic threshold (AT), while for the CF group this occurred for games 2 (Xbox) and 3 (Nintendo). As for VO2 and VE, both groups obtained similar responses as compared to AT values in games 2 (Xbox) and 3 (Nintendo). CONCLUSION: The use of VG generated a cardiorespiratory response similar to AT levels found during CPET, indicating that it may be an alternative for exercise training of CF individuals.

Respiratory physical therapy techniques recommended for patients with cystic fibrosis treated in specialized centers.

BACKGROUND: Respiratory therapy is a part of the treatment of patients with cystic fibrosis (CF). However, there is no information about the main factors influencing the recommendation of the use of different techniques or devices by physical therapists from different specialized centers. OBJECTIVE: To determine the respiratory therapy techniques recommended for the treatment of patients with CF seen in specialized treatment centers in Brazil. METHODS: This is a descriptive study including a sample of Brazilian CF specialized treatment centers. Data on demographics, spirometric variables, and recommended respiratory therapy treatment techniques were collected. RESULTS: Twelve specialized treatment centers with a total of 974 patients were included (13.5±11.3 years old and FEV1 (%) 75.7±27.9). The most recommended techniques were huffing (61.1% of patients), high frequency oral oscillation (HFOO) (52.0%), and positive expiratory pressure (PEP) (45.3%). Most often, recommendation was to perform treatment once (54.8% of patients) or twice (34%) a day. There was great variability in the recommendation among the different states. When data were separated by age, there was a predominance of performing conventional and manual techniques in infants and preschool children. There were no significant variations according to pulmonary function. Based on the literature, techniques based on volume, huffing, and PEP were most prevalently performed in international centers. CONCLUSION: The most recommended treatment techniques for patients with CF in Brazil are huffing, HFOO, and PEP, followed by volume-based techniques. There were geographical variations in the preferred treatment techniques, as well as based on patient age, but not based on the level of pulmonary function.

Effect of an interdisciplinary intervention with motivational approach on exercise capacity in obese adolescents: a randomized controlled clinical trial / Efeito de intervenção interdisciplinar com abordagem motivacional na capacidade de exercício em adolescentes obesos: ensaio clínico controlado randomizado

ABSTRACT Objective To evaluate the effect of an interdisciplinary intervention with a motivational approach on exercise capacity and usual physical activity levels in overweight and obese adolescents. Methods This is a randomized, controlled clinical trial with single blinding of subjects. Adolescents aged 15 to 18 years with overweight and obesity (body mass index ≥ 85 percentile) were included. The adolescents were randomized into two groups: interdisciplinary intervention or control − traditional approach aiming at lifestyle modifications. The initial evaluations were carried out, including the cardiopulmonary exercise test and the physical activity level measurement by using the International Physical Activity Questionnaire and a pedometer. The evaluations were performed in two moments: time zero (time of inclusion in the study) and after 3 months (end of intervention). There were 12 sessions with weekly meetings. Results A total of 37 participants were included, 19 in the Intervention Group. There were no significant differences in the baseline demographic, anthropometric and physical activity characteristics between groups, with mean age of 17.3±1.0 years in the Control Group, and 16.8±0.9 years in the Intervention Group (p=0.14). The motivational intervention did not cause significant differences (p>0.05) in the comparison of the variables of exercise capacity and usual physical activity (questionnaire and pedometer) between groups. Conclusion The intervention with a motivational approach did not alter exercise capacity and levels of usual physical activity in overweight and obese adolescents. Clinical Trial Registry: NCT02455973 and REBEC: RBR-234nb5.

RESUMO Objetivo Avaliar o efeito de uma intervenção interdisciplinar com abordagem motivacional na capacidade de exercício e no nível de atividade física habitual em adolescentes com sobrepeso e obesidade. Métodos Trata-se de ensaio clínico controlado, randomizado, com cegamento único dos indivíduos. Foram incluídos adolescentes com idade entre 15 e 18 anos, com sobrepeso e obesidade (índice de massa corporal ≥ percentil 85). Os adolescentes foram randomizados em dois grupos: intervenção interdisciplinar motivacional ou controle − abordagem tradicional, visando à modificação do estilo de vida. Foram realizadas as avaliações iniciais incluindo o teste de exercício cardiopulmonar e a aferição do nível de atividade física por meio do International Physical Activity Questionnaire e do pedômetro. As avaliações foram realizadas em dois momentos, no tempo zero (inclusão no estudo) e após 3 meses (término da intervenção). Foram realizadas 12 sessões com encontros semanais. Resultados Foram incluídos 37 participantes, sendo 19 no Grupo Intervenção. Não houve diferenças significativas nos dados basais de características demográficas, antropométricas e de atividade física entre os grupos, e a média de idade foi de 17,3±1,0 anos no Grupo Controle e 16,8±0,9 anos no Intervenção (p=0,14). A intervenção motivacional não provocou diferenças significativas (p>0,05) na comparação das variáveis de capacidade de exercício e atividade física habitual (questionário e pedômetro) entre os grupos. Conclusão A intervenção com abordagem motivacional não alterou a capacidade de exercício e os níveis de atividade física habitual em adolescentes com sobrepeso e obesidade. Clinical Trial Registry: NCT02455973 and REBEC: RBR-234nb5.

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.

Exercise capacity in children and adolescents with post-infectious bronchiolitis obliterans: a systematic review / Capacidade de exercício em crianças e adolescentes com bronquiolite obliterante pós-infecciosa: uma revisão sistemática

ABSTRACT Objective: To evaluate exercise capacity in children and adolescents with post-infectious bronchiolitis obliterans. Data source: This is a systematic review based on data from PubMed, Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS), Scientific Electronic Library Online (SciELO), and Physiotherapy Evidence Database (PEDro). We used the following search strategy: "Exercise capacity OR Exercise Test OR Physical fitness OR Functional capacity OR Six-minute walk test OR Shuttle walk test OR Cardiopulmonary exercise test AND Bronchiolitis obliterans." We selected studies that evaluated exercise capacity through maximal/submaximal testing in children and adolescents with post-infectious bronchiolitis obliterans, and no other associated disease. We searched articles in English, Portuguese, and Spanish, without restrictions regarding the period of publication. The methodological quality was assessed by the Agency for Healthcare Research and Quality (AHRQ) protocol. Data synthesis: Out of the 81 articles found, only 4 were included in this review. The studies totaled 135 participants (121 with post-infectious bronchiolitis obliterans and 14 healthy), with sample sizes between 14 and 58 subjects. All patients underwent spirometry to evaluate pulmonary function, indicating an obstructive ventilatory pattern. Among them, 3/4 had their physical performance assessed by the six-minute walk test and 2/4 by the cardiopulmonary exercise testing. These test results were compared to those of a control group (1/4) and presented as percentage of predicted and/or in meters (3/4). Lastly, 3/4 of the studies showed reduced exercise capacity in this population. The studies included were classified as having high methodological quality. Conclusions: Findings of the study demonstrate that children and adolescents with post-infectious bronchiolitis obliterans have reduced exercise capacity.

RESUMO Objetivo: Avaliar a capacidade de exercício em crianças e adolescentes com bronquiolite obliterante pós-infeciosa. Fonte de dados: Trata-se de uma revisão sistemática por meio das bases de dados PubMed, Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS), Scientific Electronic Library Online (SciELO) e Physiotherapy Evidence Database (PEDro). Utilizou-se a seguinte estratégia de busca: "Exercise capacity OR Exercise Test OR Physical fitness OR Functional capacity OR Six minute walk test OR Shuttle walk test OR Cardiopulmonary exercise test AND Bronchiolitis obliterans". Foram selecionados estudos que avaliaram a capacidade de exercício por meio de testes máximos/submáximos em crianças e adolescentes com bronquiolite obliterante pós-infeciosa, sem qualquer outra doença associada. Buscaram-se artigos nos idiomas inglês, português e espanhol e sem restrições quanto ao período de publicação. A qualidade metodológica foi avaliada pelo protocolo da Agency for Health Care Research and Quality (AHRQ). Síntese dos dados: De um total de 81 artigos, apenas 4 foram incluídos nesta revisão. Os estudos totalizaram 135 participantes (121 com bronquiolite obliterante pós-infeciosa e 14 saudáveis), com tamanho amostral entre 14 e 58 sujeitos. Todos avaliaram a função pulmonar por meio da espirometria, observando um padrão ventilatório obstrutivo. Desses, 3/4 avaliaram o desempenho físico pelo teste de caminhada de seis minutos e 2/4 pelo teste de exercício cardiopulmonar. Os resultados desses testes foram comparados a um grupo controle (1/4), bem como apresentados em percentual do previsto e/ou em metros (3/4). Por fim, 3/4 dos estudos demostraram que a capacidade de exercício se encontra reduzida nessa população. Os estudos incluídos foram classificados com alta qualidade metodológica. Conclusões: Os achados do estudo demonstram que crianças e adolescentes com bronquiolite obliterante pós-infeciosa apresentam redução da capacidade de exercício.

EXERCISE CAPACITY IN CHILDREN AND ADOLESCENTS WITH POST-INFECTIOUS BRONCHIOLITIS OBLITERANS: A SYSTEMATIC REVIEW.

OBJECTIVE: To evaluate exercise capacity in children and adolescents with post-infectious bronchiolitis obliterans. DATA SOURCE: This is a systematic review based on data from PubMed, Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS), Scientific Electronic Library Online (SciELO), and Physiotherapy Evidence Database (PEDro). We used the following search strategy: "Exercise capacity OR Exercise Test OR Physical fitness OR Functional capacity OR Six-minute walk test OR Shuttle walk test OR Cardiopulmonary exercise test AND Bronchiolitis obliterans." We selected studies that evaluated exercise capacity through maximal/submaximal testing in children and adolescents with post-infectious bronchiolitis obliterans, and no other associated disease. We searched articles in English, Portuguese, and Spanish, without restrictions regarding the period of publication. The methodological quality was assessed by the Agency for Healthcare Research and Quality (AHRQ) protocol. DATA SYNTHESIS: Out of the 81 articles found, only 4 were included in this review. The studies totaled 135 participants (121 with post-infectious bronchiolitis obliterans and 14 healthy), with sample sizes between 14 and 58 subjects. All patients underwent spirometry to evaluate pulmonary function, indicating an obstructive ventilatory pattern. Among them, 3/4 had their physical performance assessed by the six-minute walk test and 2/4 by the cardiopulmonary exercise testing. These test results were compared to those of a control group (1/4) and presented as percentage of predicted and/or in meters (3/4). Lastly, 3/4 of the studies showed reduced exercise capacity in this population. The studies included were classified as having high methodological quality. CONCLUSIONS: Findings of the study demonstrate that children and adolescents with post-infectious bronchiolitis obliterans have reduced exercise capacity.

Prenatal stress induces long-lasting effects in lung glucocorticoid receptor gene expression in a sex-dependent manner / O estresse pré-natal induz efeitos de longo prazo na expressão gênica de receptores de glicocorticoides no pulmão de uma maneira dependente do sexo

AIM: Stressful events during pregnancy may influence respiratory system development, resulting in long-term effects in the offspring. However, little is known on its long-lasting effects upon the expression of important genes in the lungs. Thus, we aimed to evaluate the effect of two different prenatal stress paradigms on lung glucocorticoid receptor (GR) expression in adulthood. METHODS: Pregnant BALB/c mice were divided into 3 groups: control (CON), prenatal stress from the second week of pregnancy (PNS1) and prenatal stress on the last week of pregnancy (PNS2). In both groups (PNS1 and PNS2), restraint stress was used. When adults, male and female offspring were submitted to 30 min of restraint stress. Lung gene expression of GR was evaluated. RESULTS: There was a significant increase in GR expression in males (PNS1), under basal conditions. Restraint stress during adulthood significantly reduced GR expression in PNS1 and PNS2 males as compared to controls. No significant differences were found for females. CONCLUSION: Results indicate that prenatal stress from the second week of gestation modulates adult male mice GR expression in the lungs. Thus, fetal exposure to maternal stress from the second week of gestation seems to modulate mechanisms responsible for pulmonary development in a sex-dependent manner.

OBJETIVO: Eventos estressores durante a gestação podem influenciar o desenvolvimento do sistema respiratório, resultando em efeitos a longo prazo na prole. No entanto, pouco se sabe sobre seus efeitos duradouros sobre a expressão de genes importantes nos pulmões. Assim, nosso objetivo foi avaliar o efeito de dois diferentes modelos de estresse pré-natal na expressão pulmonar do receptor de glicocorticoide (GR) na vida adulta. MÉTODOS: Camundongos BALB/c prenhes foram divididas em 3 grupos: controle (CON), estresse pré-natal a partir da segunda semana de gestação (PNS1) e estresse pré-natal durante a última semana de gestação (PNS2). Nos dois grupos (PNS1 e PNS2), o estresse por contenção foi utilizado. Quando adultas, as proles machos e fêmeas foram submetidas ao estresse por contenção durante 30 min. A expressão do gene GR no pulmão foi avaliada. RESULTADOS: Houve um aumento significativo na expressão de GR em machos (PNS1) sob condições basais. O estresse na vida adulta reduziu significativamente a expressão de GR em machos PNS1 e PNS2 em comparação aos controles. Não foram encontradas diferenças significativas em fêmeas. CONCLUSÃO: Os resultados indicam que o estresse pré-natal a partir da segunda semana de gestação modula a expressão do GR nos pulmões de camundongos machos adultos. Assim, a exposição fetal ao estresse materno a partir da segunda semana de gestação parece modular os mecanismos responsáveis pelo desenvolvimento pulmonar de uma maneira dependente do sexo.

MAXIMUM HEART RATE MEASURED VERSUS ESTIMATED BY DIFFERENT EQUATIONS DURING THE CARDIOPULMONARY EXERCISE TEST IN OBESE ADOLESCENTS. / FREQUÊNCIA CARDÍACA MÁXIMA MEDIDA VERSUS ESTIMADA POR DIFERENTES EQUAÇÕES DURANTE O TESTE DE EXERCÍCIO CARDIOPULMONAR EM ADOLESCENTES OBESOS.

OBJECTIVE: To compare the values of measured maximum heart rate (HRmax) and maximum heart rate estimated by different equations during the cardiopulmonary exercise test (CPET) in obese adolescents. METHODS: This is a cross-sectional study. Adolescents aged between 15 and 18 years old, with obesity (BMI Z-score>2.0) were included. Demographic and anthropometric data were collected, followed by CPET, recording HRmax. The highest heart rate reached at peak exercise was considered as HRmax. The comparison between measured and estimated HRmax values was performed using four previous equations. Descriptive statistics and the ANOVA test (Bonferroni post-test) were used. RESULTS: Fifty-nine obese adolescents were included, 44% of them male. The mean age was 16.8±1.2 years old and the BMI (Z-score) was 3.0±0.7. At peak exercise, the mean HRmax (bpm) was 190.0±9.2, the respiratory coefficient was 1.2±0.1, and the VO2max (mL/kg/min) was 26.9±4.5. When comparing the measured values of HRmax with those estimated by the different formulas, the equations "220-age", "208-0.7 x age" and "207-0.7 x age" were shown to overestimate (p<0.001) the measured HRmax results in obese adolescents. Only the "200-0.48 x age" equation presented similar results (p=0.103) with the values measured in the CPET. CONCLUSIONS: The findings of the present study demonstrate that the equation "200-0.48 x age" seems to be more adequate to estimate HRmax in obese adolescents.

OBJETIVO: Comparar os valores de frequência cardíaca máxima (FCmáx) medidos e estimados por diferentes equações durante o teste de exercício cardiopulmonar (TECP) em adolescentes obesos. MÉTODOS: Trata-se de um estudo transversal. Foram incluídos adolescentes, de idades entre 15 e 18 anos, com obesidade (escore-Z do índice de massa corpórea - IMC>2,0). Coletaram-se dados demográficos e antropométricos, seguidos da realização do TECP, pela qual foi registrada a FCmáx. O valor mais elevado de frequência cardíaca (FC) atingida no pico do exercício foi considerado como a FCmáx. A comparação entre os valores de FCmáx medidos e os estimados pelas equações foi realizada empregando-se quatro equações prévias. Utilizaram-se a estatística descritiva e o teste de ANOVA (pós-teste de Bonferroni). RESULTADOS: Foram incluídos 59 adolescentes obesos, sendo 44% do sexo masculino. A média de idade foi de 16,8±1,2 anos e a do IMC (escore-Z), de 3,0±0,7. No pico do exercício, a média de FCmáx (batimentos por minuto - bpm) foi de 190,0±9,2, o coeficiente de troca respiratória de 1,2±0,1 e o consumo máximo de oxigênio - VO2máx (mL/kg/min) - de 26,9±4,5. Ao comparar-se os valores medidos de FCmáx com os estimados pelas diferentes fórmulas, demonstrou-se que as equações "220-idade", "208-0,7 x idade" e a "207-0,7 x idade" superestimam (p<0,001) os resultados medidos de FCmáx em adolescentes obesos. Apenas a equação "200-0,48 x idade" apresentou resultados similares (p=0,103) com os valores mensurados no TECP. CONCLUSÕES: Os achados do presente estudo demonstram que a equação "200-0,48 x idade" parece ser mais adequada para estimar a FCmáx em adolescentes obesos.

Frequência cardíaca máxima medida versus estimada por diferentes equações durante o teste de exercício cardiopulmonar em adolescentes obesos / Maximum heart rate measured versus estimated by different equations during the cardiopulmonary exercise test in obese adolescents

RESUMO Objetivo: Comparar os valores de frequência cardíaca máxima (FCmáx) medidos e estimados por diferentes equações durante o teste de exercício cardiopulmonar (TECP) em adolescentes obesos. Métodos: Trata-se de um estudo transversal. Foram incluídos adolescentes, de idades entre 15 e 18 anos, com obesidade (escore-Z do índice de massa corpórea - IMC>2,0). Coletaram-se dados demográficos e antropométricos, seguidos da realização do TECP, pela qual foi registrada a FCmáx. O valor mais elevado de frequência cardíaca (FC) atingida no pico do exercício foi considerado como a FCmáx. A comparação entre os valores de FCmáx medidos e os estimados pelas equações foi realizada empregando-se quatro equações prévias. Utilizaram-se a estatística descritiva e o teste de ANOVA (pós-teste de Bonferroni). Resultados: Foram incluídos 59 adolescentes obesos, sendo 44% do sexo masculino. A média de idade foi de 16,8±1,2 anos e a do IMC (escore-Z), de 3,0±0,7. No pico do exercício, a média de FCmáx (batimentos por minuto - bpm) foi de 190,0±9,2, o coeficiente de troca respiratória de 1,2±0,1 e o consumo máximo de oxigênio - VO2máx (mL/kg/min) - de 26,9±4,5. Ao comparar-se os valores medidos de FCmáx com os estimados pelas diferentes fórmulas, demonstrou-se que as equações "220-idade", "208-0,7 x idade" e a "207-0,7 x idade" superestimam (p<0,001) os resultados medidos de FCmáx em adolescentes obesos. Apenas a equação "200-0,48 x idade" apresentou resultados similares (p=0,103) com os valores mensurados no TECP. Conclusões: Os achados do presente estudo demonstram que a equação "200-0,48 x idade" parece ser mais adequada para estimar a FCmáx em adolescentes obesos.

ABSTRACT Objective: To compare the values of measured maximum heart rate (HRmax) and maximum heart rate estimated by different equations during the cardiopulmonary exercise test (CPET) in obese adolescents. Methods: This is a cross-sectional study. Adolescents aged between 15 and 18 years old, with obesity (BMI Z-score>2.0) were included. Demographic and anthropometric data were collected, followed by CPET, recording HRmax. The highest heart rate reached at peak exercise was considered as HRmax. The comparison between measured and estimated HRmax values was performed using four previous equations. Descriptive statistics and the ANOVA test (Bonferroni post-test) were used. Results: Fifty-nine obese adolescents were included, 44% of them male. The mean age was 16.8±1.2 years old and the BMI (Z-score) was 3.0±0.7. At peak exercise, the mean HRmax (bpm) was 190.0±9.2, the respiratory coefficient was 1.2±0.1, and the VO2max (mL/kg/min) was 26.9±4.5. When comparing the measured values of HRmax with those estimated by the different formulas, the equations "220-age", "208-0.7 x age" and "207-0.7 x age" were shown to overestimate (p<0.001) the measured HRmax results in obese adolescents. Only the "200-0.48 x age" equation presented similar results (p=0.103) with the values measured in the CPET. Conclusions: The findings of the present study demonstrate that the equation "200-0.48 x age" seems to be more adequate to estimate HRmax in obese adolescents.

Protective effect of early prenatal stress on the induction of asthma in adult mice: Sex-specific differences.

Adversities faced during the prenatal period can be related to the onset of diseases in adulthood. However, little is known about the effects on the respiratory system. This study aimed to evaluate the effects of prenatal stress in two different time-points during pregnancy on pulmonary function and on the inflammatory profile of mice exposed to an asthma model. Male and female BALB/c mice were divided into 3 groups: control (CON), prenatal stress from the second week of pregnancy (PNS1) and prenatal stress on the last week of pregnancy (PNS2). Both PNS1 and PNS2 pregnant females were submitted to restraint stress. As adults, fear/anxiety behaviors were assessed, and animals were subjected to an asthma model induced by ovalbumin. Pulmonary function, inflammatory parameters in bronchoalveolar lavage (BAL) and histology were evaluated. There was a significant decrease in the number of entries and time spent in the central quadrant on the open field test for the PNS1 animals. Females (PNS1) showed improved pulmonary function (airway resistance, tissue damping and pulmonary elastance), significant increase in the percentage of neutrophils and lymphocytes and a decrease in eosinophils when compared to controls. There was a significant decrease in inflammatory cytokines in BAL of both males (IL-5 and IL-13) and females (IL-4, IL-5 and IL-13) from PNS1 and PNS2 when compared to the CON group. Prenatal stress starting from the beginning of pregnancy reduces the impact of asthma development in adult female mice, showing an improved pulmonary function and a lower inflammatory response in the lungs.