Cardiopulmonary exercise testing in children and adolescents with asthma who report symptoms of exercise-induced bronchoconstriction

Clinical recommendations for cardiopulmonary exercise testing in children with respiratory diseases

INTRODUCTION

Cardiopulmonary exercise testing (CPET) quantitates and qualitates the integrated physiological response of a person to incremental exercise and provides additional information compared to static lung function tests alone.

AREAS COVERED

This review covers rationale for the use of CPET parameters beyond the usual parameters like peak oxygen uptake and peak minute ventilation in children with respiratory disease.

EXPERT OPINION

CPET provides a wealth of data from rest, submaximal and maximal exercise and data during recovery from exercise. In this review, an interpretative approach is described for analyzing CPET data in children with respiratory disease.

Relationship between physical activity level and psychosocial and socioeconomic factors and issues in children and adolescents with asthma: a scoping review

BACKGROUND

Asthma is a heterogeneous chronic airway disease which may reduce capability for physical activity. In healthy peers, physical activity is influenced by psychosocial and socioeconomic factors. Knowledge about the role of these factors has not been mapped in children and adolescents with asthma.

OBJECTIVE

The main objective of this scoping review was to identify psychosocial and socioeconomic factors associated with physical activity level in children and adolescents with asthma in the literature. The specific objectives were to map the instruments used to measure these factors, report on the construction and validation of these instruments, map psychosocial and socioeconomic issues related to physical activity level reported in qualitative studies, and identify gaps in knowledge about the relationship between psychosocial and socioeconomic factors and physical activity level in children and adolescents with asthma.

INCLUSION CRITERIA TYPES OF PARTICIPANTS

Children and adolescents with asthma aged six to 18 years.

CONCEPT

Psychosocial and socioeconomic factors related to physical activity level and participation.

CONTEXT

All physical activity contexts.

TYPES OF SOURCES

Quantitative and qualitative primary studies in English, with no date limit.

SEARCH STRATEGY

The databases searched included nine major databases for health and sports science, and five databases for unpublished studies. After screening and identification of studies, the reference lists of all identified reports were searched, and forward citation searches were conducted using four databases.

EXTRACTION OF THE RESULTS

The following data were extracted: (a) relevant study characteristics and assessment of physical activity level, (b) instruments used to assess psychosocial and socioeconomic factors, (c) association between physical activity level and these factors, (d) construction and validation of instruments, and (e) psychosocial and socioeconomic issues related to physical activity participation.

PRESENTATION OF THE RESULTS

Twenty-one quantitative and 13 qualitative studies were included. In cross-sectional studies, enjoyment, physical self-concept, self-efficacy, attitudes and beliefs about physical activity and health, psychological distress, health-related quality of life, and social support were more often reported as being correlated with physical activity level. In three studies, the construct validity was assessed by factor analysis and construct reliability tests for the study population. Qualitative studies reported 10 issues related to physical activity participation, and capability and being like peers were most commonly reported. There was no direct evidence that qualitative research informed the development or adjustment of instruments in quantitative studies.

CONCLUSIONS

Seven psychosocial factors correlated with physical activity level; capability and being like peers were the most commonly reported issues. Reports of the construction and validation of instruments were sparse.

Reported Exercise-Related Respiratory Symptoms and Exercise-Induced Bronchoconstriction in Asthmatic Children

Background

Unlimited physical activity is one of the key issues of asthma control and management. We investigated how reliable reported exercise-related respiratory symptoms (ERRS) are in predicting exercise-induced bronchoconstriction (EIB) in asthmatic children.

Methods

In this prospective study, 179 asthmatic children aged 7 - 15 years were asked for specific questions on respiratory symptoms related to exercise and allocated into two groups according to whether they complained about symptoms. Group I (n = 134) consisted of children answering “yes” to one or more of the questions and group II (n = 45) consisted of children answering “no” to all of the questions.

Results

Sixty-four of 179 children showed a positive exercise challenge test (ECT). There was no difference in the frequency of a positive test between children in group I (n = 48) and group II (n = 12) (P = 0.47). The sensitivity of a positive report for ERRS to predict a positive ECT was only 37%, with a specificity of 0.72.

Conclusion

According to current guidelines, the report or lack of ERRS has direct consequences on treatment decisions. However, the history of ERRS did not predict EIB and one-third of asthmatic children without complaints of ERRS developed EIB during the ECT. This raises the question of the need for objective measures of bronchial hyperresponsiveness (BHR) in pediatric asthma management.

Perceived exercise limitation in asthma: The role of disease severity, overweight, and physical activity in children

BACKGROUND

Children with asthma may be less physically active than their healthy peers. We aimed to investigate whether perceived exercise limitation (EL) was associated with lung function or bronchial hyper-responsiveness (BHR), socioeconomic factors, prenatal smoking, overweight, allergic disease, asthma severity, or physical activity (PA).

METHODS

The 302 children with asthma from the 10-year examination of the Environment and Childhood Asthma birth cohort study underwent a clinical examination including perceived EL (structured interview of child and parent(s)), measure of overweight (body mass index by sex and age passing through 25 kg/m² or above at 18 years), exercise-induced bronchoconstriction (forced expiratory volume in one-second (FEV₁ ) pre- and post-exercise), methacholine bronchial challenge (severe BHR; provocative dose causing ≥20% decrease in FEV₁ ≤ 1 μmol), and asthma severity score (dose of controller medication and exacerbations last 12 months). Multivariate logistic regression analyses were conducted to assess associations with perceived EL.

RESULTS

In the final model explaining 30.1%, asthma severity score (OR: 1.49, (1.32, 1.67)) and overweight (OR: 2.35 (1.14, 4.82)) only were significantly associated with perceived EL. Excluding asthma severity and allergic disease, severe BHR (OR: 2.82 (1.38, 5.76)) or maximal reduction in FEV₁ post-exercise (OR: 1.48 (1.10, 1.98)) and overweight (OR: 2.15 (1.13, 4.08) and 2.53 (1.27, 5.03)) explained 9.7% and 8.4% of perceived EL, respectively.

CONCLUSIONS

Perceived EL in children with asthma was independently associated with asthma severity and overweight, the latter doubling the probability of perceived EL irrespectively of asthma severity, allergy status, socioeconomic factors, prenatal smoking, or PA.

Getting to grips with 'dysfunctional breathing'

Dysfunctional breathing (DB) is common, frequently unrecognised and responsible for a substantial burden of morbidity. Previously lack of clarity in the use of the term and the use of multiple terms to describe the same condition has hampered our understanding. DB can be defined as an alteration in the normal biomechanical patterns of breathing that result in intermittent or chronic symptoms. It can be subdivided into thoracic and extra thoracic forms. Thoracic DB is characterised by breathing patterns involving relatively inefficient, excessive upper chest wall activity with or without accessory muscle activity. This is frequently associated with increased residual volume, frequent sighing and an irregular pattern of respiratory effort. It may be accompanied by true hyperventilation in the minority of subjects. Extra thoracic forms include paradoxical vocal cord dysfunction and the increasingly recognised supra-glottic 'laryngomalacia' commonly seen in young sportsmen and women. While the two forms would appear to be two discreet entities they often share common factors in aetiology and respond to similar interventions. Hence both forms are considered in this review which aims to generate a more coherent approach to understanding, diagnosing and treating these conditions.

Physical deconditioning as a cause of breathlessness among obese adolescents with a diagnosis of asthma

BACKGROUND

Obese children frequently complain of breathlessness. Asthma and obesity can both contribute to the symptoms during exercise, and this symptom can contribute to a diagnosis of asthma in these children. Despite the high prevalence of obesity few studies have investigated the cardiopulmonary physiology of breathlessness in obese children with a diagnosis of asthma.

METHODS

In this case-control study, thirty adolescents between age 12 and 19 were studied with baseline spirometry and a cardiopulmonary exercise test. Ten adolescents were normal controls, ten had obesity without a diagnosis of asthma, and ten had obesity with a history of physician-diagnosed asthma.

RESULTS

Baseline characteristics including complete blood count and spirometry were comparable between obese adolescents with and without a diagnosis of asthma. During exercise, obese asthmatic and obese non-asthmatic adolescents had significantly reduced physical fitness compared to healthy controls as evidenced by decreased peak oxygen uptake after adjusting for actual body weight (21.7 ± 4.5 vs. 21.4 ± 5.4 vs. 35.3 ± 5.8 ml/kg/min, respectively). However, pulmonary capacity at the peak of exercise was comparable among all three groups as evidenced by similar pulmonary reserve.

CONCLUSION

In this study, breathlessness was primarily due to cardiopulmonary deconditioning in the majority of obese adolescents with or without a diagnosis of asthma.

Associations of obesity and asthma with functional exercise capacity in urban minority adolescents

PURPOSE

To examine the independent association of asthma and obesity and of their co-existence with functional exercise capacity among urban adolescents.

METHODS

One hundred eighteen Hispanic- and African-American adolescents including 33 obese asthmatics, 18 normal-weight asthmatics, 38 obese non-asthmatics, and 29 normal-weight non-asthmatics underwent anthropometric measures, 6-minute walk test (6MWT) as measure of functional exercise capacity and spirometry as measure of pulmonary function. The 6-minute walk distance (6MWD) was compared between the four study groups. The association of 6MWD with measures of lower airway obstruction, and measures of adiposity was assessed.

RESULTS

The 6MWD was lower among the obese groups with the least distance covered by the obese asthmatic group (P = 0.02). In the obese asthmatic group, there was a negative correlation between 6MWD and body mass index (BMI) (r = -0.35, P = 0.03), but no association was noted with percent-predicted forced expiratory volume in the 1st second (FEV(1) ; r = 0.07, P = 0.70). Conversely, the 6MWD correlated with FEV(1) among normal-weight asthmatics (r = 0.45, P = 0.04) and normal-weight non-asthmatics (r = 0.4, P = 0.03), but was not associated with BMI in either of the two groups. After adjusting for age, height, gender, and ethnicity, BMI was noted to be a significant predictor (β -2.76, 95% CI -4.77 to -0.76, P < 0.01) of the 6MWD among the obese while percent predicted FEV(1) (β 1.87, 95% CI 0.28-3.45, P = 0.02) was a significant predictor among the normal-weight participants.

CONCLUSIONS

Our findings suggest that among urban minority obese asthmatic adolescents, functional exercise capacity was associated with obesity, rather than pulmonary function.

Asthma severity, exacerbation risk, and controller treatment burden in underweight and obese children

OBJECTIVE

The relationship between weight status and asthma characteristics in children remains inadequately defined. Very little has been published on the risk of exacerbation, physician perception of severity, and the level controller treatment prescribed to underweight and obese children with asthma in a real-world setting.

METHODS

We assessed the diagnostic severity, pulmonary function, exacerbation prevalence, and controller treatment level in 10,559 new asthma patients seen at one of four pediatric asthma subspecialty clinics among three BMI groups. Participants were analyzed by body mass index (BMI)-percentile based on Centers for Disease Control & Prevention classification. Multivariable logistic regression models were used to assess the associations between BMI-percentile cohort group and asthma outcomes. RESULTS. Underweight asthmatics were rare (2.5%) relative to obese asthmatics but appeared to have the greatest impairment in forced vital capacity and had the greatest controller treatment burden. Obese asthmatic children made up 26.2% of our cohort and were more likely to have severe disease (odds ratio (OR) 1.40, 95% confidence interval (CI) 1.06-1.85) and airflow obstruction (OR 1.36, 95% CI 1.16-1.59) compared to normal weight asthmatics. Obese asthmatics were not at greater risk for exacerbation (OR 1.41, 95% CI 0.64-3.11) or high treatment burden (OR 1.03, 95% CI 0.83-1.28). CONCLUSIONS. Obesity is more common than underweight status among children with asthma. Both underweight and obese children with asthma have worse lung function and asthma-related outcomes compared to similar normal weight children, though the phenotypic characteristics of underweight and obese asthmatics differed considerably.

Exercise-Induced Lung Disease: Too Much of a Good Thing?

Exercise in children has important health benefits. However, in elite endurance athletes, there is an increased prevalence of exercise-induced bronchoconstriction and airway inflammation. Particularly at risk are those who practice in cold weather, ice rinks, swimming pools, and air pollution. The inflammation is caused by repetitive episodes of hyperventilation of cold, dry air, allergens, or toxins such as chlorine or air pollution. Children may be particularly at risk for lung injury under these conditions because of the immaturity and ongoing development of their lung. However, studies in pediatric athletes and exercising young children are sparse. Epithelial injury associated with hyperventilation of cold, dry air has not been described in children. However, exercise in the presence of air pollution and chlorine is associated with airway injury and the development of asthma in children; the effect appears to be modulated by both atopy and genetic polymorphisms. While management of exercise-induced bronchoconstriction and asthma is well established, there is little data to guide treatment or prevention of remodeling in athletes or inhalational lung injury in children. Studies underscore the need to maintain high levels of air quality. More investigations should be undertaken to better define the natural history, pathophysiology, and treatment of exercise-induced pulmonary inflammation in both elite athletes and exercising children.

Lifestyle and the Respiratory Health of Children

This article offers a review of the potential influences of personal lifestyle on respiratory health in children, looking at both healthy individuals and those with respiratory disorders. As with many aspects of health, regular physical activity, an appropriate diet, and avoidance of obesity and cigarette smoke all contribute to optimal development of the healthy child. An active lifestyle is associated with greater static and dynamic lung volumes, greater efficiency of the ventilatory process, and an optimization of breathing patterns. The risk of upper respiratory infections is also reduced in those maintaining a moderate level of physical activity. Maternal smoking during pregnancy, as well as active and passive smoking, all have an adverse influence on lung function in the child, the largest effects being on dynamic lung volumes. The risk of developing asthma seems reduced in children who maintain a normal body mass and are physically active. A program of graded physical activity is of therapeutic value in a number of established respiratory conditions, including asthma, cystic fibrosis, and ventilatory impairment from neuromuscular disorders. Exercise carries a slight risk of fatalities from asthma and anaphylactic reactions. In designing an optimal physical activity program, it is also important to guard against the hazards of deep oronasal breathing, including the precipitation of bronchospasm by the inhalation of cold, dry air and pollens; an increased exposure to atmospheric pollutants (reducing and oxidant smog, fine and ultra-fine particulates, and carbon monoxide); and possible long-term dangers from chlorine derivatives in the atmosphere of indoor swimming pools.

Imitators of exercise-induced bronchoconstriction

Exercise-induced bronchoconstriction (EIB) is described by transient narrowing of the airways after exercise. It occurs in approximately 10% of the general population, while athletes may show a higher prevalence, especially in cold weather and ice rink athletes. Diagnosis of EIB is often made on the basis of self-reported symptoms without objective lung function tests, however, the presence of EIB can not be accurately determined on the basis of symptoms and may be under-, over-, or misdiagnosed. The goal of this review is to describe other clinical entities that mimic asthma or EIB symptoms and can be confused with EIB.

Exercise testing in children with lung diseases

Exercise is an important aspect of health and development in children. By placing the pulmonary system under stress, exercise testing may reveal subtle dynamic abnormalities that are not apparent on conventional static pulmonary function tests. Furthermore, exercise testing assesses the functional impact of respiratory disease on children. Exercise testing has been used in children with a variety of respiratory diseases such as exercise induced bronchoconstriction, asthma, cystic fibrosis and bronchopulmonary dysplasia to assess the severity of disease as well as response to various interventions. Furthermore, there is good evidence that exercise testing is a useful tool to help determine prognosis in patients with cystic fibrosis. In addition to the clinical utility, exercise testing is also becoming an increasingly important outcome measure in research studies.

Asthma and obesity in children

PURPOSE OF REVIEW

Childhood asthma and obesity are significant public health problems. The prevalence of both disorders has increased considerably in the past decade. This review will highlight recent publications regarding the nature of the relationship between asthma and obesity and the clinical effects of obesity in children with asthma.

RECENT FINDINGS

Most prospective studies suggest that obesity increases the risk of subsequent asthma. Possible mechanisms for the relationship between asthma and obesity include airway inflammation, mechanical changes associated with obesity, changes in airway hyper-responsiveness, and changes in physical activity and diet. Most studies suggest that obesity increases the clinical severity of asthma and decreases quality of life in children with asthma. More research is required to further define and clarify the relationship between asthma and obesity in children.

SUMMARY

There are many questions and few answers regarding the relationship between asthma and obesity in children. Additional studies are needed to clarify the relationship between the two epidemics so that effective interventions can be developed to improve the health and lives of children with both asthma and obesity.