João Paulo Heinzmann-Filho

Normal values for respiratory muscle strength in healthy preschoolers and school children.

AIM To generate reference values for respiratory muscle strength in healthy children aged three to twelve years. METHODS Participants were recruited from three schools and selected after a respiratory disease questionnaire analysis and written informed consent by parents or guardians. All participants included in the study had normal spirometry, height and weight were measured on the same day. Respiratory muscle strength was evaluated by a single examiner following the guidelines for pulmonary function tests. The association between MIP and MEP values with the potential predictive variables was analyzed using a multiple linear regression model. RESULTS A total of 171 participants were selected and distributed evenly by age. The age, height, weight and forced vital capacity showed moderate to strong correlations with both respiratory pressures. However, the regression model showed that height and weight were the best variables to predict MIP in both sexes, and age and weight to predict MEP. The power of prediction (R²) ranged from 46 to 58%. The intraclass correlation coefficient was used in a subgroup and demonstrated excellent reproducibility between tests. CONCLUSION The results of this study demonstrate that the behavior of respiratory muscle strength in healthy preschool and school children can be explained by age, height and weight.

Bone mineral density, pulmonary function, chronological age, and age at diagnosis in children and adolescents with cystic fibrosis

OBJECTIVE To assess bone mineral density in patients with cystic fibrosis (CF), and to correlate it with possible intervening variables. METHODS Children and adolescents diagnosed with CF, aged 6 to 18 years, followed at the outpatient clinic were included in the study. First, demographic data were collected and, subsequently, patients underwent a spirometric test. All patients answered the Cystic Fibrosis Quality of Life Questionnaire (CFQ) and underwent the six-minute walk test (6MWT) and bone densitometry (DXA). RESULTS A total of 25 CF patients were included, of which 56% were males. The mean age was 12.3±3.4 years; mean height was 149.2±14.4 cm; and mean weight was 44.4±13.9 kg. Most results on pulmonary function and bone mineral density (BMD) were within normal limits. The mean forced expiratory volume in one second (FEV) was 92.5±23.6 (% of predicted), mean forced vital capacity (FVC) was 104.4±21.3 (% of predicted), and1 mean BMD z-score was 0.1±1.0. BMD was moderately correlated with FEV (r = 0.43, p = 0.03) and FVC (r = 0.57, p = 0.003). Regarding chronological age and age at diagnosis, a moderate and inverse correlation was also found (r = -0.55, p = 0.004; r = -0.57, p = 0.003, respectively). However, no significant correlations were found with the data from CFQ, 6MWT, and body mass index. CONCLUSION Most patients had BMD within normal limits and presented a positive correlation with pulmonary function, as well as a negative correlation with chronological age and age at diagnosis.

Inspiratory Muscle Strength and Endurance in Children and Adolescents with Cystic Fibrosis

BACKGROUND: Pulmonary changes that occur in cystic fibrosis may influence inspiratory muscle strength and endurance. We evaluated inspiratory muscle strength and endurance in children and adolescents with cystic fibrosis in comparison with healthy subjects. METHODS: This is a cross-sectional observational study with subjects with cystic fibrosis and paired healthy individuals, age 6–18 y. Spirometry, impulse oscillometry, plethysmography, manovacuometry, and a protocol of inspiratory muscle endurance were performed. RESULTS: Subjects with cystic fibrosis (n = 34) had higher maximum percent-of-predicted inspiratory pressure (PImax) than healthy (n = 68) subjects (118.5 ± 25.8% vs 105.8 ± 18.0%) and no significant difference in endurance (60.9 ± 13.3% vs 65.3 ± 12.3%). When restricting the analysis to subjects without Pseudomonas aeruginosa colonization and with FEV1 > 80%, PImax values were significantly higher, and inspiratory muscle endurance was lower, in comparison with the control group. PImax correlated significantly with FVC (r = 0.44, P = .02) and FEV1 (r = 0.41, P = .02), whereas endurance correlated better with total airway resistance (r = 0.35, P = .045) and with central airway resistance (r = 0.48, P = .004). CONCLUSIONS: Children and adolescents with cystic fibrosis with no colonization by P. aeruginosa and normal lung function present increased inspiratory muscle strength and decreased endurance compared with healthy individuals, indicating that changes in the respiratory muscle function seem to be distinctly associated with pulmonary involvement. Strength was related to pulmonary function parameters, whereas endurance was associated with airway resistance.

Clinical characteristics of children and adolescents with severe therapy-resistant asthma in Brazil.

Abstract Objective: To describe the clinical characteristics, lung function, radiological findings, and the inflammatory cell profile in induced sputum in children and adolescents with severe therapy-resistant asthma (STRA) treated at a referral center in southern Brazil. Methods: We retrospectively analyzed children and adolescents (3-18 years of age) with uncontrolled STRA treated with high-dose inhaled corticosteroids and long-acting ß2 agonists. We prospectively collected data on disease control, lung function, skin test reactivity to allergens, the inflammatory cell profile in induced sputum, chest CT findings, and esophageal pH monitoring results. Results: We analyzed 21 patients (mean age, 9.2 ± 2.98 years). Of those, 18 (86%) were atopic. Most had uncontrolled asthma and near-normal baseline lung function. In 4 and 7, induced sputum was found to be eosinophilic and neutrophilic, respectively; the inflammatory cell profile in induced sputum having changed in 67% of those in whom induced sputum analysis was repeated. Of the 8 patients receiving treatment with omalizumab (an anti-IgE antibody), 7 (87.5%) showed significant improvement in quality of life, as well as significant reductions in the numbers of exacerbations and hospitalizations. Conclusions: Children with STRA present with near-normal lung function and a variable airway inflammatory pattern during clinical follow-up, showing a significant clinical response to omalizumab. In children, STRA differs from that seen in adults, further studies being required in order to gain a better understanding of the disease mechanisms.

Six-Minute Walk Test Results Predict Risk of Hospitalization for Youths with Cystic Fibrosis: A 5-Year Follow-Up Study

Objective To evaluate the association of 6‐minute walk test (6MWT) and other variables (anthropometry, chronic Pseudomonas aeroginosa colonization, pulmonary function, and respiratory muscle strength) with the risk of hospitalization for pulmonary exacerbation in children and adolescents with cystic fibrosis (CF). Study design Cohort study that included patients with CF aged 6‐18 years. All participants underwent spirometry, manovacuometry, and 6MWT during the 5‐year follow‐up. Anthropometric and clinical data were collected and the time to first hospitalization, total days of hospitalization, and antibiotic use during follow‐up was recorded. Results A total of 26 patients with CF, mean age 10.2 ± 2.8 years, were included. The group had mild impairment of lung function with a significant decline in forced expiratory volume in 1 second (P = .019) over the 5 years. Respiratory muscle strength and 6MWT proved to be preserved, although maximum inspiratory pressure increased (P < .001) and maximum expiratory pressure and 6‐minute walk distance (6MWD) remained stable. There were inverse associations of 6MWD in meters (r = −0.813, P < .001) and z score (r = −0.417, P = .015) with total days of hospitalization. Moreover, there was a reduction in the risk of a first hospitalization (Cox HR 0.32; P = .037) in patients with a greater 6MWD. Conclusions We found an association between the 6MWT and the risk of hospitalization in children and adolescents with CF. Furthermore, functional capacity apparently does not follow the expected decline in pulmonary function over time, whereas inspiratory muscle strength increases with disease progression.

Effects of obesity on lung volume and capacity in children and adolescents: a systematic review.

Abstract Objective: To assess the effects of obesity on lung volume and capacity in children and adolescents. Data source: This is a systematic review, carried out in Pubmed, Lilacs, Scielo and PEDro databases, using the following Keywords: Plethysmography; Whole Body OR Lung Volume Measurements OR Total Lung Capacity OR Functional Residual Capacity OR Residual Volume AND Obesity. Observational studies or clinical trials that assessed the effects of obesity on lung volume and capacity in children and adolescents (0-18 years) without any other associated disease; in English; Portuguese and Spanish languages were selected. Methodological quality was assessed by the Agency for Healthcare Research and Quality. Data synthesis: Of the 1,030 articles, only four were included in the review. The studies amounted to 548 participants, predominantly males, with sample size ranging from 45 to 327 individuals. 100% of the studies evaluated nutritional status through BMI (z-score) and 50.0% reported the data on abdominal circumference. All demonstrated that obesity causes negative effects on lung volume and capacity, causing a reduction mainly in functional residual capacity in 75.0% of the studies; in the expiratory reserve volume in 50.0% and in the residual volume in 25.0%. The methodological quality ranged from moderate to high, with 75.0% of the studies classified as having high methodological quality. Conclusions: Obesity causes deleterious effects on lung volume and capacity in children and adolescents, mainly by reducing functional residual capacity, expiratory reserve volume and residual volume.

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

Abstract 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.

Equações internacionais superestimam a força muscular ventilatória em crianças e adolescentes com fibrose cística

El objetivo de este estudio fue comparar los resultados de la normalizacion de los datos de fuerza muscular ventilatoria utilizando tres ecuaciones de referencia internacionales y una nacional en ninos y adolescentes con fibrosis quistica (FC). Estudio retrospectivo, en el cual fueron incluidos pacientes con FC, edad entre 8 y 12 anos y control ambulatorio regular. Fueron colectados datos demograficos y variables antropometricas. Todos los pacientes incluidos deberian haber realizado test de fuerza muscular ventilatoria y espirometria en los ultimos 12 meses. La normalizacion de los resultados fue realizada utilizando las variables predictoras requeridas en cada ecuacion estudiada. Los datos fueron comparados utilizando una ANOVA de una via. Fueron incluidos 24 pacientes, 62,5% masculinos, media de edad 10,5±1,53 anos, estatura 138,0±0,08 cm, masa corporal 34,6±9,07 kg, VEF1 93,29±29,02% y CVF 103,78±26,12%. Las presiones (cmH2O) inspiratoria (PIMAX) y expiratoria (PEMAX) maximas encontradas fueron 92,1±22,8 y 98,9±24,5, respectivamente. Despues de la normalizacion por las diferentes ecuaciones, se demostro que las internacionales tienden a sobreestimar los hallazgos para nuestra poblacion. La ecuacion nacional presento valores medios previstos significativamente (p 100%) en 91,6, 79,1, y 75,0% de los sujetos y la PEMAX en 66,6, 87,5 y 50%, mientras la ecuacion nacional estimaria apenas 50,0 y 37,5% de los individuos, respectivamente. La normalizacion de los resultados de fuerza muscular ventilatoria en ninos y adolescentes entre 8 y 12 anos con FC utilizando ecuaciones internacionales sobreestiman los valores de las presiones respiratorias maximas.

Impact of omalizumab in children from a middle-income country with severe therapy-resistant asthma: A real-life study

Severe asthma in children is a global health problem. Severe therapy‐resistant asthma (STRA) in children is a major clinical challenge due to persistent symptoms despite high doses of corticosteroids and results in high public health costs. Omalizumab (anti‐IgE monoclonal antibody) has been described as an effective add‐on therapy in these patients. The characteristics of children with STRA from low‐ and middle‐income countries have scarcely been reported, and no real‐life study has been published on the effects of omalizumab in this group of patients. The aim of our study is to report the first clinical real‐life experiences with omalizumab in Brazilian children with STRA.

Growth, lung function, and physical activity in schoolchildren who were very-low-birth-weight preterm infants

ABSTRACT Objective: To compare somatic growth, lung function, and level of physical activity in schoolchildren who had been very-low-birth-weight preterm infants (VLBWPIs) or normal-birth-weight full-term infants. Methods: We recruited two groups of schoolchildren between 8 and 11 years of age residing in the study catchment area: those who had been VLBWPIs (birth weight < 1,500 g); and those who had been normal-birth-weight full-term infants (controls, birth weight ≥ 2,500 g). Anthropometric and spirometric data were collected from the schoolchildren, who also completed a questionnaire regarding their physical activity. In addition, data regarding the perinatal and neonatal period were collected from the medical records of the VLBWPIs. Results: Of the 93 schoolchildren screened, 48 and 45 were in the VLBWPI and control groups, respectively. No significant differences were found between the groups regarding anthropometric characteristics, nutritional status, or pulmonary function. No associations were found between perinatal/neonatal variables and lung function parameters in the VLBWPI group. Although the difference was not significant, the level of physical activity was slightly higher in the VLBWPI group than in the control group. Conclusions: Among the schoolchildren evaluated here, neither growth nor lung function appear to have been affected by prematurity birth weight, or level of physical activity.