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.

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.

Inspiratory muscle function in asthmatic and healthy subjects: influence of age, nutrition and physical activity.

OBJECTIVE: To compare inspiratory muscle function (strength and endurance) between asthmatics and healthy controls, and the influence of age, nutritional status and physical activity on them. METHODS: This is a cross-sectional study. Asthmatic and healthy subjects, aged 6 to 18 years old, recruited from two public schools in Southern Brazil were included in the study. Asthmatic subjects were selected using the criteria presented by the International Study on Asthma and Allergies in Children and control subjects based on the absence of respiratory symptoms. Anthropometric data was measured, body mass index calculated and subjects classified as normal weight, overweight or obese. Physical activity levels, maximum inspiratory pressure (MIP) and inspiratory muscle endurance (IME) were also evaluated. RESULTS: A total of 314 participants were included, separated into control group (181) and asthmatics (133), with a total mean age of 11 years. When both groups were compared, there were no significant differences in both MIP and IME. However, when groups were analyzed subdivided in children and adolescents, IME was significantly reduced (p = 0.003) in asthmatic adolescents. Indeed, when groups were also stratified considering the nutritional status, IME showed a reduction in asthmatic adolescents with overweight (p = 0.042) and obesity (p = 0.041) when compared to healthy controls. No effects of physical activity levels between groups were found. CONCLUSIONS: Results demonstrate a reduction in the IME in asthmatic adolescents with overweight and obesity, indicating an association between asthma, nutritional status and respiratory muscle function.

Impact of COVID-19 social distancing recommendations on pulmonary function, nutritional status, and morbidity in patients with cystic fibrosis.

OBJECTIVE: To evaluate the impact of COVID-19 social distancing recommendations on nutritional status, pulmonary function, and morbidity in patients with cystic fibrosis (CF). METHODS: A retrospective cohort study including patients older than six years with a diagnosis of CF was performed. Demographic and clinical data, anthropometric measurements, pulmonary function, days of antibiotic use, and length of hospital stay were recorded. Variables were recorded at three time points relative to the baseline for implementation of social distancing measures: T-1 (14 months before implementation), T0 (baseline), and T1 (14 months after implementation). Delta (Δ) was calculated for each period: Δ1 (pre-pandemic T0-T-1) and Δ2 (pandemic T1-T0). RESULTS: The study included 25 patients, with a mean age of 11.7±4.3 years. The mean forced expiratory volume in the first second (FEV1) was 85.6±23.6%, and body mass index (BMI) was 17.5±3.0 kg/m2. When comparing the two periods (Δ1 and Δ2), there was a significant increase in the FEV1/forced vital capacity (FVC) ratio (p=0.013) and in the forced expiratory flow between 25 and 75% of vital capacity (FEF25-75%) (p=0.037) in the pandemic period. There was also a significant reduction (p=0.005) in the use of antibiotics in the pandemic period compared with the pre-pandemic period. The Δ1 and Δ2 values did not differ significantly for BMI, FEV1, or length of hospital stay. CONCLUSIONS: COVID-19 social distancing recommendations had a positive impact (decrease) on morbidity (use of antibiotics) and small airway obstruction (FEF25-75%) in patients with CF.

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.

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.

EFFECTS OF PHYSICAL EXERCISE DURING HOSPITALIZATION IN CHILDREN AND ADOLESCENTS WITH CANCER: A SYSTEMATIC REVIEW.

OBJECTIVE: To identify the effects of exercise programs during hospitalization on children and adolescents with cancer. DATA SOURCE: This is a systematic review, carried out in PubMed/ Medical Literature Analysis and Retrieval System Online (MEDLINE), Latin American and Caribbean Health Sciences Literature (LILACS), Scientific Electronic Library Online (SciELO), Latin American and Caribbean Center on Health Sciences Information (BIREME), and Physiotherapy Evidence Database (PEDro). We selected studies that included children and adolescents diagnosed with cancer (solid or hematologic) and submitted to exercise protocols during hospitalization. Studies involving patients with other pathologies or with a medical contraindication for exercise were excluded. We used the following search strategy: Neoplasm OR Leukemia OR Cancer OR Tumor OR Medical Oncology AND Hospitalization OR Inpatient Care Units OR Intrahospital AND Exercise. The methodological quality of the studies was analyzed by the PEDro scale. DATA SYNTHESIS: Among the 626 articles found, only 9 fulfilled the inclusion criteria, obtaining a regular methodological quality. The samples had 172 participants, aged 4 to 18 years. Only 6 studies presented both intervention group and control group. The intervention group received strength, aerobic, and muscle stretching exercises, and games, among others. The control group received the standard treatment. The studies varied regarding time, frequency, intensity, and type of exercise. Most studies showed an increase in muscle strength (4/5), followed by an improvement in physical fitness (2/3) and functional capacity (2/4). No adverse events were reported during the interventions. The methodological quality was considered regular. CONCLUSIONS: The findings suggest that. during hospitalization of children and adolescents with cancer, exercise improves muscle strength, physical fitness, and functionality.

EFFECTS OF HAMMOCK POSITIONING ON CLINICAL PARAMETERS IN PRETERM INFANTS ADMITTED TO A NEONATAL INTENSIVE CARE UNIT: A SYSTEMATIC REVIEW.

OBJECTIVE: To review the effects of the hammock positioning on clinical parameters of preterm newborn infants (PTNB) admitted to the Neonatal Intensive Care Unit (NICU). DATA SOURCES: This was a systematic review performed by searching the Pubmed, Lilacs, SciELO and PEDro databases. Intervention studies in English, Portuguese and Spanish that evaluated the effects of hammock positioning on clinical parameters of PTNB admitted to the NICU were selected. Three search strategies were used: 1) hammock positioning OR patient positioning AND intensive care units AND infant, newborn; 2) hammock positioning OR patient positioning AND intensive care units; 3) hammock positioning OR patient positioning AND intensive care units, neonatal. There was no restriction on the year of publication of the articles. Methodological quality was assessed by the PEDro scale. DATA SYNTHESIS: Among 597 articles, only six were included and 139 neonates with gestational ages between 26 and 37 weeks and an average gestational weight <2240g were analyzed. Four studies included patients without any associated pathology and most of them placed the PTNB supine in hammock positioning. The duration of the intervention ranged from 15 to 180 minutes and most applied it at just one moment. There was an improvement in heart rate (HR), respiratory rate (RR) and pain (3/4 studies), as well as gains in peripheral oxygen saturation (SpO2) (2/4 studies). Only one study reported worsening of SpO2 with the intervention. The methodological quality of the studies was classified as low. CONCLUSIONS: Although this review suggests improvement with hammock positioning in HR, RR and pain in PTNB, the low methodological quality makes the results inconsistent.

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.

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.

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.

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.

Peak Oxygen Uptake and Mortality in Cystic Fibrosis: Systematic Review and Meta-Analysis.

BACKGROUND: Aerobic fitness, as measured by peak oxygen uptake (V̇O2 peak), correlates with survival in children and adults with cystic fibrosis (CF). We sought to evaluate the effects of V̇O2 peak on mortality rates in subjects with CF. METHODS: An online search in PubMed, Embase, LILACS, and SciELO databases was conducted, and cohort studies that assessed mortality rates after oxygen absorption measurements during a maximal exercise test were included. Data were extracted independently by 2 reviewers. The quality analysis of the selected articles was performed using the Newcastle-Ottawa scale. The main outcome evaluated was the mortality of subjects with CF. Whenever possible, and if appropriate, a random effect meta-analysis was performed. RESULTS: Six cohort studies were included in this systematic review including 551 subjects. Five studies were classified with high methodological quality. Two analyses were carried out to evaluate the influence of V̇O2 peak on mortality. Total difference standardized mean between V̇O2 peak averages in the survival or non-survival groups was -0.606 (95% CI = -0.993 to -0.219, P = .002). In addition, subjects with a lower V̇O2 peak had a significantly higher mortality risk (relative risk 4.896, 95% CI = 1.086 to 22.072, P = .039) in an 8-y follow-up period. CONCLUSION: Low levels of peak oxygen uptake are associated with an increase of 4.9 in the risk of mortality in subjects with CF. This indicates that V̇O2 could be an important follow-up variable to measure, in addition to FEV1.

Impact of COVID-19 social distancing recommendations on pulmonary function, nutritional status, and morbidity in patients with cystic fibrosis / Impacto das recomendações de distanciamento social por COVID-19 sobre a função pulmonar, estado nutricional e morbidade em pacientes com fibrose cística

ABSTRACT Objective: To evaluate the impact of COVID-19 social distancing recommendations on nutritional status, pulmonary function, and morbidity in patients with cystic fibrosis (CF). Methods: A retrospective cohort study including patients older than six years with a diagnosis of CF was performed. Demographic and clinical data, anthropometric measurements, pulmonary function, days of antibiotic use, and length of hospital stay were recorded. Variables were recorded at three time points relative to the baseline for implementation of social distancing measures: T-1 (14 months before implementation), T0 (baseline), and T1 (14 months after implementation). Delta (Δ) was calculated for each period: Δ1 (pre-pandemic T0-T-1) and Δ2 (pandemic T1-T0). Results: The study included 25 patients, with a mean age of 11.7±4.3 years. The mean forced expiratory volume in the first second (FEV1) was 85.6±23.6%, and body mass index (BMI) was 17.5±3.0 kg/m2. When comparing the two periods (Δ1 and Δ2), there was a significant increase in the FEV1/forced vital capacity (FVC) ratio (p=0.013) and in the forced expiratory flow between 25 and 75% of vital capacity (FEF25-75%) (p=0.037) in the pandemic period. There was also a significant reduction (p=0.005) in the use of antibiotics in the pandemic period compared with the pre-pandemic period. The Δ1 and Δ2 values did not differ significantly for BMI, FEV1, or length of hospital stay. Conclusions: COVID-19 social distancing recommendations had a positive impact (decrease) on morbidity (use of antibiotics) and small airway obstruction (FEF25-75%) in patients with CF.

RESUMO Objetivo: Avaliar o impacto das recomendações de medidas de distanciamento social por COVID-19 sobre estado nutricional, função pulmonar e morbidade em pacientes com fibrose cística (FC). Métodos: Estudo de coorte, retrospectivo, que incluiu pacientes com diagnóstico de FC e idade superior a seis anos. Foram registrados os dados demográficos, antropométricos, clínicos, de função pulmonar e o total de dias de uso de antibiótico e de hospitalizações. As variáveis foram registradas em três momentos relativos ao início das recomendações de distanciamento social: T-1 (14 meses antes), T0 (início das recomendações) e T1 (14 meses depois). Foram calculados deltas (Δ) para cada um dos períodos: Δ1 (pré-pandemia T0-T-1) e Δ2 (pandemia T1-T0). Resultados: Vinte e cinco pacientes, com média de idade de 11,7±4,3 anos, sendo 76% homozigotos para Δf508 e 28% colonizados por Pseudomonas aeruginosa, foram incluídos. A média do volume expiratório forçado no primeiro segundo (VEF1) foi de 85,6±23,6 (% do previsto) e o índice de massa corporal (IMC) foi de 17,5±3,0 kg/m2. Ao compararmos os períodos (Δ1 e Δ2), houve aumento significativo do VEF1/CVF (p=0,013) e do FEF25-75% (p=0,037) no período das recomendações de distanciamento. Também se observou redução significativa (p=0,005) do uso de antibióticos no período da pandemia em comparação ao período anterior a ela. Não houve diferenças significativas nos deltas para o IMC, VEF1 e dias de hospitalização. Conclusões: As recomendações de distanciamento social por COVID-19 tiveram impacto positivo (redução) sobre a morbidade (uso de antibióticos) e a obstrução de vias aéreas de menor calibre (FEF25-75%) em pacientes com FC.

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 Assessment by the Modified Shuttle Walk Test and its Correlation with Biochemical Parameters in Obese Children and Adolescents.

OBJECTIVES: To evaluate exercise capacity of obese children and adolescents compared with normal-weight individuals and to investigate possible correlations with blood biochemical parameters. METHODS: In this study, children and adolescents between 6 and 18 y were included and divided into control (eutrophic) and obese groups according to body mass index (BMI). Data were collected regarding demographic, anthropometric, waist circumference and exercise capacity through the Modified Shuttle Walk Test (MSWT). In the obese group, biochemical parameters in the blood (total cholesterol, HDL, LDL, triglycerides and glucose) were evaluated, and a physical activity questionnaire was applied. RESULTS: Seventy seven participants were included; 27 in the control group and 50 obese. There was no significant difference between the two groups regarding sample characteristics, except for body weight, BMI and waist circumference. Most obese children presented results of biochemical tests within the desirable limit, though none were considered active. There was a significant exercise capacity reduction (p < 0.001) in the obese group compared to control subjects. Positive correlations were identified for the MSWT with age and height, and a negative correlation with BMI. However, there were no correlations with the biochemical parameters analyzed. CONCLUSIONS: Obese children and adolescents have reduced exercise capacity when compared to normal individuals. The MSWT performance seems to have a negative association with BMI, but is not correlated with blood biochemical parameters.

THE USE OF ULTRASONOGRAPHY TO EVALUATE MUSCLE THICKNESS AND SUBCUTANEOUS FAT IN CHILDREN AND ADOLESCENTS WITH CYSTIC FIBROSIS. / USO DA ULTRASSONOGRAFIA PARA AVALIAR A ESPESSURA MUSCULAR E A GORDURA SUBCUTÂNEA EM CRIANÇAS E ADOLESCENTES COM FIBROSE CÍSTICA.

OBJECTIVE: To compare muscle thickness and subcutaneous fat in cystic fibrosis (CF) patients and healthy controls using ultrasonography (US), and to correlate US findings with nutritional, clinical and functional variables. METHODS: Patients aged 6 to 18 years old with a diagnosis of CF and healthy controls were included. Participants underwent anthropometric measurements, an ultrasonographic evaluation of muscle thickness and subcutaneous fat in the triceps, quadriceps, and gastrocnemius regions, and skinfold thickness measurements. Body fat percentage was estimated using skinfold measurement. Subjects with CF also underwent a pulmonary function assessment using spirometry. RESULTS: We studied 39 CF patients and 45 controls. Alower body mass index was observed in CF patients (p=0.011). Body composition and muscle thickness were similar between the groups. Only calf (p=0.023) circumference and femur diameter (p<0.001) were lower in CF patients. Although there were no significant between-group differences in the comparison of US measurements of subcutaneous fat, CF patients exhibited decreased skinfold thickness in the triceps (p=0.031) and quadriceps (p=0.019). Moreover, there were weak and moderate correlations of US quadricep thickness with forced vital capacity (FVC) and lean mass, respectively. Moderate correlations of the triceps, quadriceps and gastrocnemius between US subcutaneous fat and skinfold measurements were found. CONCLUSIONS: Patients with CF presented a reduction in subcutaneous fat content. Muscle thickness correlated with FVC and nutritional parameters. In addition, US findings correlated positively with skinfold measurements.

OBJETIVO: Comparar a espessura muscular e a gordura subcutânea entre pacientes com fibrose cística (FC) e controles saudáveis e correlacionar os achados ultrassonográficos com variáveis nutricionais, clínicas e de função pulmonar. MÉTODOS: Foram incluídos sujeitos (6 a 18 anos) com o diagnóstico de FC e indivíduos saudáveis. Foram realizadas medidas antropométricas, avaliação ultrassonográfica da espessura muscular e da gordura subcutânea do tríceps, quadríceps e da região do gastrocnêmio, além da quantificação das pregas cutâneas. O percentual de gordura corporal foi estimado pelas pregas cutâneas. Osindivíduos com FC também tiveram a função pulmonar avaliada por espirometria. RESULTADOS: Foram incluídos 39 pacientes com FC e 45 controles. Ossujeitos com FC apresentaram do índice de massa corporal menor (p=0,011). Acomposição corporal e a espessura muscular foram similares entre os grupos. Apenas a circunferência da panturrilha (p=0,023) e o diâmetro do fêmur (p<0,001) foram menores nos pacientes com FC. Embora sem diferença na comparação dos achados ultrassonográficos da gordura subcutânea, os pacientes com FC apresentaram redução das dobras cutâneas do tríceps (p=0,0031) e do quadríceps (p=0,019). Além disso, observaram-se correlações fracas e moderadas da espessura do quadríceps pelo ultrassom com a capacidade vital forçada (CVF) e massa magra, respectivamente. Também houve correlações moderadas das pregas cutâneas do tríceps, quadríceps e gastrocnêmio com a gordura subcutânea avaliada pela ultrassonografia. CONCLUSÕES: Pacientes com FC apresentaram menor espessura da gordura subcutânea. A espessura muscular se correlacionou com a CVF e os parâmetros nutricionais, e a ultrassonografia apresentou correlação positiva com as pregas cutâneas.

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.

Reference Values for Inspiratory Muscle Endurance in Healthy Children and Adolescents.

AIMS: To generate reference values for two inspiratory muscle endurance (IME) protocols in healthy children and adolescents. MATERIALS AND METHODS: This is an observational, cross-sectional study, in healthy children and adolescents from 4 to 18 years of age. Weight, height, maximal inspiratory pressure (MIP) and IME were measured using two protocols. A fixed load of 30% of MIP with a 10% increment every 2 minutes was used in the incremental threshold loading protocol. As for the maximal loading protocol, a fixed load of 70% of MIP was used and the time limit (Tlim) achieved until fatigue was measured. RESULTS: A total of 462 participants were included, 281 corresponding to the incremental loading protocol and 181 to maximal loading. There were moderate and positive correlations between IME and age, MIP, weight and height in the incremental threshold loading. However, the regression model demonstrated that MIP and age were the best variables to predict the IME. Otherwise, weak and positive correlations with age, weight and height were found in the maximal loading. Only age and height influenced endurance in the regression model. The predictive power (r2) of the incremental threshold loading protocol was 0.65, while the maximal loading was 0.15. The reproducibility measured by the intraclass correlation coefficient (ICC) was higher in the incremental loading (0.96) compared to the maximal loading test (0.69). CONCLUSION: IME in healthy children and adolescents can be explained by age, height and MIP. The incremental threshold loading protocol showed more reliable results and should be the model of choice to evaluate IME in the pediatric age group.

Asthma and Obesity in Children Are Independently Associated with Airway Dysanapsis.

BACKGROUND: An increase in the prevalence of overweight and asthma has been observed. Both conditions affect negatively lung function in adults and children. The aim of this study was to analyze the effect of overweight and asthma on lung function in children. METHODS: We designed a case-control study of healthy and asthmatic subjects nested within an epidemiological asthma prevalence study in children between 8 and 16 years of age. The effect of asthma and overweight on lung function was assessed by impulse oscillometry and spirometry obtained at baseline and 10-15 min after salbutamol. RESULTS: 188 children were recruited, 114 (61%) were asthmatics and 72 (38%) were overweight or obese. Children with asthma and overweight had a higher FVC (+1.16 z scores, p < 0.001) and higher FEV1 (+0.79 z scores, p = 0.004) and lower FEV1/FVC (-0.54 z scores, p = 0.008) when compared to healthy controls. Compared to normal weight asthmatics, the overweight had higher FVC (+0.78 z scores, p = 0.005) and lower FEV1/FVC (-0.50 z scores, p = 0.007). In the multivariate analysis, overweight was associated with an increase of 0.71 and 0.44 z scores in FVC and FEV1, respectively, and a reduction in FEV1/FVC by 0.40 z scores (p < 0.01 for all). Overweight had no effect on maximal flows and airway resistance at baseline, and this was not modified by inhalation of a bronchodilator. Asthma was also associated with higher post-BD FVC (0.45 z scores, p = 0.012) and FEV1 (0.35 z scores, p = 0.034) but not with FEV1/FVC and FEF25-75%. Two-way analysis of variance did not detect any interaction between asthma and overweight on lung function variables before or after bronchodilator. CONCLUSION: Our results suggest that asthma and overweight are independently associated with airway dysanaptic growth in children which can be further scrutinized using impulse oscillometry. Overweight contributed more to the reduction in FEV1/FVC than asthma in children without increasing airway resistance. Spirometry specificity and sensitivity for obstructive diseases may be reduced in populations with high prevalence of overweight. Adding impedance oscillometry to spirometry improves our understanding of the ventilatory abnormalities in overweight children.