Exercise and asthma: an overview

The impact of exercise on gene regulation in association with complex trait genetics

Endurance exercise training is known to reduce risk for a range of complex diseases. However, the molecular basis of this effect has been challenging to study and largely restricted to analyses of either few or easily biopsied tissues. Extensive transcriptome data collected across 15 tissues during exercise training in rats as part of the Molecular Transducers of Physical Activity Consortium has provided a unique opportunity to clarify how exercise can affect tissue-specific gene expression and further suggest how exercise adaptation may impact complex disease-associated genes. To build this map, we integrate this multi-tissue atlas of gene expression changes with gene-disease targets, genetic regulation of expression, and trait relationship data in humans. Consensus from multiple approaches prioritizes specific tissues and genes where endurance exercise impacts disease-relevant gene expression. Specifically, we identify a total of 5523 trait-tissue-gene triplets to serve as a valuable starting point for future investigations [Exercise; Transcription; Human Phenotypic Variation].

Effect of exposure to disinfection by-products during swimming exercise on asthma-related immune responses

Swimming is a widely practiced exercise in modern society, where there is a heightened interest in health. The exceptional benefits of swimming are well-known, yet the issue of water quality management inevitably arises due to its nature as an aquatic exercise. Several studies reported that chlorine disinfectants commonly used in swimming pool water disinfection could degrade into toxic disinfection by-products (DBPs) and suggested that the DBPs might induce respiratory disorders, including asthma. Conversely, there were also reports that the DBPs had no significant effects on respiratory conditions. In this study, we investigated the influence of swimming exercise and DBPs on asthma. The decomposition products had little effect on the number of T cells in various immune organs. However, swimming exercise was found to increase the cell count in proportion to the exercise duration. Nevertheless, there were no significant changes in other immune cells and the secretion of asthma-related cytokines. These findings indicate that the effects of swimming pool DBPs on respiratory conditions during swimming exercise are either negligible or absent, and instead, the immunological benefits gained through consistent swimming exercise outweigh any potential drawbacks.

The Barriers to Shared Decision-making in Exercise Prescription for Children With Asthma: A Qualitative Study From Parents' Perspective

INTRODUCTION

The knowledge of barriers from the parental perspective is essential for facilitating shared decision-making in the field of pediatric asthma.

METHOD

Participants who were parents of children with a diagnosis of asthma were recruited, and in-depth, semistructured interviews were conducted. The interview transcripts were analyzed thematically using framework methods.

RESULTS

Seventeen participants undertook interviews. Three themes and nine subthemes emerged: (1) decision-making need level-limited understanding of decision-making knowledge, ambiguity regarding self-empowerment roles, and lack of family member support; (2) decision-making support level-insufficient ability to evaluate information, inefficient communication with health care professionals, and excessive use of professional terminology; and (3) decision-making outcome level-doubts about the final decision-making choices, time constraints on decision-making, and absence of mechanisms to track decisions made.

DISCUSSION

The findings would serve as crucial foundations for the development of decision-aid programs within the context of pediatric asthma.

Examining the Biopsychosocial Factors Related to Lifetime History of Concussion in Children and Youth

This study investigated the prevalence of lifetime concussions, related psychosocial problems, and post-concussion recovery rates in a clinical sample of children and youth. Participants were 24,186 children and youth (M = 11.9 years, SD = 3.5) who completed an interRAI Child and Youth Mental Health Assessment at mental health agencies across Ontario, Canada. In addition to the expected physiological correlates, results found concussions to be more prevalent in children and youth with attention deficit hyperactivity disorders, anxiety disorders, disruptive behaviour disorders, mood disorders, and those involved in self-harm, harm to others, destructive aggression, and internalizing and externalizing symptoms. The results of this study add to our understanding of children and youth's experiences with concussions. Clinical implications and recommendations are discussed to maximize the effectiveness of evidence-based interventions related to concussion recovery.

Respiratory oscillometry testing in relation to exercise in healthy and asthmatic Thoroughbreds

BACKGROUND

Racehorses may experience exercise-induced bronchodilation or bronchoconstriction, with potential differences between healthy and asthmatic individuals.

OBJECTIVES

To identify exercise-related lung function variations by oscillometry in racehorses, compare lung function between healthy and mild equine asthma (MEA) horses, assess oscillometry's potential as a predictor of racing fitness.

STUDY DESIGN

Prospective case-control clinical study.

METHODS

Fourteen Thoroughbred racehorses (5 healthy, 9 MEA) underwent a protocol including respiratory oscillometry at rest, exercise with fitness monitoring, oscillometry at 15 and 45 min post-exercise, and bronchoalveolar lavage fluid (BALf) cytology. Oscillometry parameters (resistance [Rrs] and reactance [Xrs]) were compared within and between healthy and MEA groups at different timepoints. Associations between Rrs and Xrs at rest and 15 min post-exercise and BALf cytology and fitness indices were evaluated.

RESULTS

MEA horses showed higher Rrs at 15 min post-exercise (0.6 ± 0.2 cmH2 O/L/s) than healthy horses (0.3 ± 0.1 cmH2 O/L/s) (p < 0.01). In healthy horses, Rrs decreased at 15 min post-exercise compared with resting values (0.5 ± 0.1 cmH2 O/L/s) (p = 0.04). In MEA horses, oscillometry parameters did not vary with time. Post-exercise Xrs inversely correlated with total haemosiderin score (p < 0.01, r2  = 0.51). Resting Rrs inversely correlated with speed at 200 bpm (p = 0.03, r2  = -0.61), and Xrs with maximum heart rate (HR) during exercise (p = 0.02, r2  = -0.62). Post-exercise Rrs inversely correlated with mean (p = 0.04, r2  = -0.60) and maximum speed (p = 0.04, r2  = -0.60), and HR variability (p < 0.01, r2  = -0.74).

MAIN LIMITATIONS

Small sample size, oscillometry repeatability not assessed, potential interference of upper airway obstructions, external variables influencing fitness indices.

CONCLUSIONS

Oscillometry identified lung function differences between healthy and MEA horses at 15 min post-exercise. Only healthy horses exhibited exercise-induced bronchodilation. Oscillometry showed potential in predicting subclinical airway obstruction.

Exercise-induced bronchoconstriction in elite athletes: a narrative review

Exercise-induced bronchoconstriction (EIB) is the most common chronic disease among elite athletes and when left untreated, can impact both respiratory health and sports performance. In recent years, there has been an increase in the awareness and detection of EIB in elite athletes. This narrative review aims to evaluate the risk, prevention, diagnosis, medication, and anti-doping policies of EIB in elite athletes, and to provide more references for athletes with EIB. The results showed that athletes of endurance, winter, and water sports generally have a higher prevalence of EIB than athletes of other sports. Adaptive warm-up before formal exercise and using heat exchange masks at low temperatures are effective ways for athletes to prevent EIB. For physicians, the exercise challenge test and eucapnic voluntary hyperpnea are the recommended diagnostic methods for EIB in athletes. The treatment of athletes with EIB is medication-based, such as inhaled corticosteroids and beta-2 agonists, but current anti-doping policies should be considered when used.

Effects of disinfection by-products in swimming pool environments on the immunological mechanisms of respiratory diseases

Swimming in pools is a popular and healthy recreational activity. However, potential adverse health effects from disinfection byproduct (DBP) exposure in pool water are concerning. This study evaluated how such DBP exposure affects the respiratory system. DBP exposure was simulated with an animal-specific pool environment model. Experimental animals were exposed to DBPs for a specified duration and frequency over 4 weeks. The wet and dry weights of murine lungs were measured, with no significant differences observed. There were no significant differences in interkeukin (IL)-2/4/10, and interferon-γ levels. However, IL-6 expression decreased in the experimental group. To investigate the effects of DBP exposure on immune cell response, various samples, such as bronchoalveolar lavage fluid, lymph nodes, spleen, and thymus, were collected for T-cell isolation and fluorescence-activated cell sorting. Asthma-related blood cell distribution was analyzed using a complete blood count test; no significant differences were found. Thus, DBP exposure through this model did not induce substantial lung tissue damage, major alterations in cytokine expression (besides IL-6), significant immune cell responses, or changes in asthma-associated blood cell distribution. However, considering earlier results, future studies should focus on specific types, intensity, and duration of exercise that could affect DBP exposure-related immune-inflammatory responses.

A Sociodemographic Analysis of the Impact of COVID-19-Related Schools' Closure on the Diet and Physical Activity of Children and Adolescents in Qatar

OBJECTIVES

To assess the impact of the COVID-19-related closure of government schools in Qatar on children and adolescents' dietary habits and physical activities and associated sociodemographic factors.

METHODS

An analytical cross-sectional study was conducted between June and August 2022 utilizing the national electronic health records system in Qatar to extract a sampling frame of students enrolled in governmental schools, specifically targeting students in 3rd to 9th grades, stratified by sex and developmental stage. A stratified sampling technique was employed to randomly select a proportionate number of students from each stratum, and data were collected through telephone interviews with the parents of selected students.

RESULTS

A total of 1546 interviews were completed by the end of the study. Of the included sample, 845 (54.7%) were between 8 and 11 years of age (middle childhood), while the rest were 12-15 years old (young teens and teenagers). Male to female ratio was almost 1:1. We found a significant decrease in the intake of vegetables, increases in the intake of soft drinks, fried food, fast food, and sweets, and a reduction in physical activity during schools' closure compared to before. Higher parental educational levels, maternal employment, and having a positive family history of obesity and/or overweight in first-degree relatives were significantly associated with adverse lifestyle changes during schools' closure.

CONCLUSION

The trends of lifestyle changes reported in this study during the periods of COVID-19-related schools' closure were found to be going in a health-compromising direction. These results underscore the importance of implementing targeted interventions to promote healthy lifestyles during such disruptions and emphasize the need to address lifestyle changes beyond emergencies and outbreaks to mitigate potential long-term health consequences, including the increased risk of non-communicable diseases.

Cardiopulmonary fitness in children with asthma versus healthy children

OBJECTIVES

To evaluate, with a cardiopulmonary exercise test (CPET), the cardiopulmonary fitness of children with asthma, in comparison to healthy controls, and to identify the clinical and CPET parameters associated with the maximum oxygen uptake (VO_2max) in childhood asthma.

DESIGN

This cross-sectional controlled study was carried out in CPET laboratories from two tertiary care paediatric centres. The predictors of VO_2max were determined using a multivariable analysis.

RESULTS

A total of 446 children (144 in the asthma group and 302 healthy subjects) underwent a complete CPET. Mean VO_2max was significantly lower in children with asthma than in controls (38.6±8.6 vs 43.5±7.5 mL/kg/min; absolute difference (abs. diff.) of -4.9 mL/kg/min; 95% CI of (-6.5 to -3.3) mL/kg/min; p<0.01) and represented 94%±9% and 107%±17% of predicted values, respectively (abs. diff. -13%; 95% CI (-17 to -9)%; p<0.01). The proportion of children with an impaired VO_2max was four times higher in the asthma group (24% vs 6%, p<0.01). Impaired ventilatory efficiency with increased VE/VCO₂ slope and low breathing reserve (BR) were more marked in the asthma group. The proportion of children with a decreased ventilatory anaerobic threshold (VAT), indicative of physical deconditioning, was three times higher in the asthma group (31% vs 11%, p<0.01). Impaired VO_2max was associated with female gender, high body mass index (BMI), FEV1, low VAT and high BR.

CONCLUSION

Cardiopulmonary fitness in children with asthma was moderately but significantly altered compared with healthy children. A decreased VO_2max was associated with female gender, high BMI and the pulmonary function.

TRIAL REGISTRATION NUMBER

NCT04650464.

Physical exercise in asthma adolescents: a concept review

Background: Asthma is a frequent pathological condition during childhood and adolescence. Young asthmatics demonstrate decreased aptitude for physical activity and a limited exercise capacity. Lower hospitalisation rates, reduced school absenteeism, fewer medical examinations, and limited use of bronchodilators have been documented in children and adolescents with bronchial asthma who engage in physical exercise regularly. Structured physical exercise protocols should be encouraged as they can work as a synergistic therapeutic option in addition to regular pharmacologic treatment. This article outlines the most suitable exercise training techniques for young patients with bronchial asthma and their effects on health status.

The effects of NLRP3 and MAVS gene polymorphisms on the risk of asthma: A case-control study

Genetic factors are important risk factors for asthma. Nucleotide-binding oligomerization domain-like receptor containing pyrin domain 3 (NLRP3) is closely associated with asthma. Mitochondrial antiviral signaling protein (MAVS) mediates the recruitment of NLRP3 to the mitochondria and activation of the NLRP3 inflammasome. The purpose of this study was to analyze the effects of NLRP3 and MAVS polymorphisms on the risk of asthma and the interactions between them. Children with asthma (n = 127) and healthy children (n = 100) were recruited between August, 2020 and July, 2021. Multiplex polymerase chain reaction and sequencing was used to analyze genotypes of single nucleotide polymorphisms. The multifactor dimensionality reduction statistical method was used to detect and model epistasis of gene-gene interactions. There were significant differences in the distribution of MVAS rs6515831 and NLRP3 rs10925023 genotypes between the asthma and healthy groups. Compared with rs6515831 TT genotype, the results showed that rs6515831CT genotype increased the risk of asthma (odds ratio: 2.243, 95% CI: 1.221-4.122, P = .009). Compared with rs10925023 GG genotype, the results showed that the risk of asthma in the population with rs10925023 TT genotype was lower (odd ratio: 0.643, 95% CI: 0.423-0.979, P = .039). In the genotype of the NLRP3 rs12048215 locus, the IgE level of asthma patients with genotype AG was lower than that of patients with genotype AA. The dendrogram model showed the strongest interaction between rs7272495 and rs10925023, which was expressed in a synergistic manner. Haplotype analysis revealed that rs10925023T/rs7272495G and rs10925023T/rs3272495A were statistically different in distribution between the two groups. The MAVS rs6515831 and NLRP3 rs10925023 polymorphisms were associated with the risk of asthma in children. There may be interactions between NLRP3 and MAVS polymorphisms in the risk of asthma.

Can physical exercise assist in controlling and reducing the severity of exercise-induced bronchospasm in children and adolescents? A systematic review

OBJECTIVE

The aim of this study was to analyze whether physical exercise can contribute to improving the control and severity of exercise-induced bronchospasm (EIB) in children and adolescents.

METHOD

This is a systematic review that used PubMed/Medline and Scopus databases as a search source, and using descriptors indexed to DeCS/Mesh. The articles were analyzed in three stages in the selection process. Methodological quality was assessed using the TESTEX scale.

RESULT AND DISCUSSION

A total of 5867 articles were filtered in the initial search; however, only eight of these were included after the eligibility criteria. All presented improvements in cardiorespiratory fitness. Only two followed the international EIB diagnostic guidelines. Of these, only one described a reduction in FEV1 and considered that this improvement may influence the EIB response in children and adolescent athletes with a non-asthmatic sample.

CONCLUSION

The studies analyzed in this review did not enable drawing a conclusion regarding the influence of physical exercise on EIB in asthmatics. The lack of clinical trials on EIB and physical exercise, as well as the difficulty in methodological standardization for EIB diagnosis evidence the lack of scientific knowledge in this area, serving as a stimulus for researchers to find more consolidated answers.

Cofactors, age at onset, allergic comorbidities and gender are different in patients sensitized to omega-5 gliadin and Pru p 3

Aim of this study is to clarify the impact of cofactors on allergic reactions in patients sensitized to LTP and ω-5-gliadin. We retrospectively examined the charts of our outpatients from January 2015 to July 2019 and identified 157 patients seen for urticaria/angioedema or anaphylaxis after a meal, in presence or absence of cofactors and sensitized to LTPs (Pru p 3 and/or Tri a 14) and/or ω-5-gliadin (Tri a 19). we compared LTPs-positive patients and those sensitized to Tri a 19 in order to assess the difference in cofactors involved and in frequency of clinical presentation. Our data show that exercise is the most frequent cofactor in FDEIAn and the involvement of exercise, alcohol and multiple cofactors was more frequently found in males than in females. We found that exercise, pollen counts peaks and multiple cofactors were more often related to anaphylaxis than mild reactions. Finally, we performed a comparison between patients LTPs+ and Tri a 19+ that showed in the latter group a lower frequency of allergic comorbidities, a higher median age at the onset of symptoms and frequency of alcohol exposure. Our data show that the search for possible cofactors involved in food allergy is essential not only for diagnostic purposes, but also for risk assessment strategies.

How to detect young athletes at risk of exercise-induced bronchoconstriction?

Exercise-induced bronchoconstriction (EIB) is a prevalent condition in elite athletes caused by transient airway narrowing during or after exercise. Young athletes nowadays start early to perform high level exercise, highlighting the need to screen for EIB in a younger population. The purpose of this review is to evaluate current evidence of pre-tests with high probability to predict a positive provocation test in young and adolescent athletes, aged 12-24 years and thus indicate whether a young athlete is at risk of having EIB. Up to now, there is no validated screening test available to increase the pre-test probability of a provocation test of EIB in young and adolescent athletes. We would recommend that a clinical guideline committee might consider the development of a flow chart to screen for EIB in adolescent athletes. It could be composed of a symptom-based questionnaire focusing on wheezing during exercise, atopic state, reversibility test (to exclude EIB with asthma) and completed with markers in blood/serum. However, more research is necessary.

An Overview on the Primary Factors That Contribute to Non-Allergic Asthma in Children

The prevalence of non-allergic asthma in childhood is low, peaking in late adulthood. It is triggered by factors other than allergens, like cold and dry air, respiratory infections, hormonal changes, smoke and air pollution. In the literature, there are few studies that describe non-allergic asthma in pediatric age. Even though it is a less common disorder in kids, it is crucial to identify the causes in order to keep asthma under control, particularly in patients not responding to conventional treatments. In this review, we discuss non-IgE-mediated forms of asthma, collecting the latest research on etiopathogenesis and treatment.

Exposure to Cigarette Smoke and Daily Physical Activity Associated with Asthma

Background: Asthmatic sufferers complain of sudden relapse when performing daily activities. exposure to cigarette smoke makes asthmatics where the longer the exposure is experienced by the patient, the more frequent asthma exacerbations are experienced. For people with asthma, avoiding excessive physical activity and exposure to cigarette smoke is very necessary to prevent recurrence of symptoms. So it is necessary to control the level of asthma, which is influenced by factors that trigger asthma recurrence.   Aim: The purpose of the study was to determine the relationship between daily physical activity and exposure to cigarette smoke on asthma recurrence in asthmatic patients   Methods: This type of research uses observational analytic using a cross sectional approach. Sampling in this study using purposive sampling obtained the number of respondents 358 with a vulnerable age of 18-45 years. This research was conducted for 6 months. The measuring instrument for exposure to cigarette smoke uses a questionnaire containing the categories of exposure to cigarette smoke less than 1 hour, exposure to cigarette smoke 1-4 hours and exposure to cigarette smoke more than 4 hours. Physical activity measurement tool using the International Physical Activity Questionnaire (IPAQ). Asthma recurrence was measured by using a questionnaire that refers to the Asthma Control Test (ACT). The research procedure was carried out by researchers by ensuring that respondents were in good health and signed the informed consent provided. Data analysis using Chi-Square test.   Result: The results of the Chi Square test with a significance value of = 0.05, p value = 0.000, which means p < then there is a relationship between daily physical activity and exposure to cigarette smoke on asthma recurrence in asthmatic patients.   Conclusions: There is a relationship between exposure to cigarette smoke and daily physical activity on asthma relapse in asthmatic patients. It is expected that asthmatics should avoid triggering factors for asthma relapse to achieve controlled asthma levels.    

A Meta Analysis of Physical Exercise on Improving Lung Function and Quality of Life Among Asthma Patients

Objective

This paper aims to perform a systematic assessment of the influence of physical exercise on asthma patients and discuss the intervention effects of different exercises on the lung function FEV1 (%pred) and quality of life among asthma patients so as to lay a scientific foundation for improving asthma symptoms.

Methods

Both Chinese and English databases were retrieved, including PubMed, Web of Science, Embase, The Cochrane Library, CBM, CNKI, Wan Fang Data, and VIP, whose retrieval period started from the founding date of each database to 1st, November 2021. Randomized controlled trials (RCT) studying the symptom indicators of asthma patients were collected. Those collected papers were screened according to the Inclusion Criteria and Exclusion Criteria. Then, methodological quality assessments were conducted on the included papers, and combined effect sizes were analyzed by using software ReMan 5.3.5.

Results

The meta analysis showed that physical exercise could significantly improve lung function FEV1 (%pred) and quality of life score. Trails containing breathing exercise are the main source of heterogeneity, and the subgroup of breathing exercise may have better performance than the subgroup of aerobic exercise in improving FEV1 (%pred).

Conclusion

Physical exercise can significantly improve the symptoms and quality of life of asthma patients. Except the breathing exercise that showed heterogeneity, the subgroup of aerobic exercise could improve the capacity of FEV1 (%pred) more effectively, which led to a significant difference in the influence of quality of life. However, with regard to the gymnastic exercise including breathing exercise, there are limited same intervention methods and insufficient same outcome indicators. Therefore, more precise and high-quality researches are needed to make deeper verification in the future.

Developing a Smartphone Application That Promotes Responsible Short-Acting Beta2-Agonist Use in People with Asthma: A Participatory Design

Around 339 million people worldwide have asthma, and 50% have uncontrolled asthma. One trait of uncontrolled asthma, often seen in primary care, is short-acting β2-agonist (SABA) overuse, defined as using SABA more than twice a week. SABA overuse can cause adverse health effects. An application could help patients gain more insight into their SABA use. Engaging stakeholders during the development is important to maximize the usability of and adherence to an application. This study describes the development process of an application that promotes responsible SABA use in people with asthma, using a participatory design. Different stakeholder groups were involved in two iterative development cycles. In the first cycle, four end-users evaluated the app’s prototype. During the second cycle, five end-users were interviewed about the usability of the new version. Resulting in an app that allows patients to register SABA use, asthma symptoms, and symptom triggers. A graph shows how these factors are related, and end-users can show the graph to their physician to facilitate communication. Medication use is compared to the medical guidelines or, when applicable, to the advice given by the users’ healthcare professionals. End-users found the app helpful. Research into the usability and effectiveness of the app in a bigger sample will follow.

Impact of Inhaled Corticosteroids on the Modulation of Respiratory Defensive Reflexes During Artificial Limb Exercise in Ovalbumin-Sensitized Rabbits

Introduction

Cough is a major lower airway defense mechanism that can be triggered by exercise in asthma patients. Studies on cough reflex in experimental animal models revealed a decrease of cough reflex sensitivity during exercise in healthy animals, but a lack of desensitization in ovalbumin-sensitized rabbits. The aim of our study is to evaluate the impact of inhaled corticosteroids on cough reflex during artificial limb exercise in an animal model of eosinophilic airway inflammation.

Materials and Methods

Sixteen adult ovalbumin-sensitized rabbits were randomly divided into two groups. The “OVA-Corticoid” group (n = 8) received inhaled corticosteroids (budesonide; 1 mg/day during 2 consecutive days) while the “OVA-Control” (n = 8) group was exposed to saline nebulization. The sensitivity of defensive reflexes induced by direct mechanical stimulation of the trachea was studied in anesthetized animals, at rest and during artificial limb exercise. Cell count was performed on bronchoalveolar lavage fluid and middle lobe tissue sections to assess the level of eosinophilic inflammation.

Results

All rabbits were significantly sensitized but there was no difference in eosinophilic inflammation on bronchoalveolar lavage or tissue sections between the two groups. Artificial limb exercise resulted in a significant (p = 0.002) increase in minute ventilation by 30% (+ 209 mL.min^–1, ± 102 mL/min^–1), with no difference between the two groups. 322 mechanical tracheal stimulations were performed, 131 during exercise (40.7%) and 191 at rest (59.3%). Cough reflex was the main response encountered (46.9%), with a significant increase in cough reflex threshold during artificial limb exercise in the “OVA-Corticoid” group (p = 0.039). Cough reflex threshold remained unchanged in the “OVA-Control” group (p = 0.109).

Conclusion

Inhaled corticosteroids are able to restore desensitization of the cough reflex during artificial limb exercise in an animal model of airway eosinophilic inflammation. Airway inflammation thus appears to be involved in the physiopathology of exercise-induced cough in this ovalbumin sensitized rabbit model. Inhaled anti-inflammatory treatments could have potential benefit for the management of exercise-induced cough in asthma patients.

Self-Reported Physical Activity and Asthma Risk in Children

BACKGROUND

Increased physical activity (PA) may protect against asthma but PA can trigger asthma symptoms.

OBJECTIVE

To investigate relationships between moderate-to-vigorous PA (MVPA) assessed during routine care visits and incident asthma.

METHODS

For this retrospective cohort, 542,486 children between 2 and 17 years from 2010 to 2017 were included who had an MVPA assessment (exercise vital sign) during routine care visits. The association of MVPA and asthma was analyzed using Cox proportional hazards regression models as a function of age, with MVPA and body mass index (BMI) being time-varying factors, adjusted for race and ethnicity, socioeconomic status, and air pollution.

RESULTS

The mean MVPA was 5.4 (standard deviation: 4.4) hours/week. Crude asthma incidence density rate (IDR) was highest in children with <1 hour/week of MVPA (IDR: 9.07, 95% confidence interval [CI]: 8.79, 9.36) and lowest in children engaging in 4 to 7 hours/week of MVPA (IDR: 6.55, 95% CI: 6.33, 6.77). In adjusted models, an increase in MVPA was associated with lower asthma risk in children reporting 0 hour/week of MVPA (hazard ratio: 0.981, 95% CI: 0.973, 0.990). In children with ≥8 hours/week of MVPA, an increase in MVPA was associated with higher asthma risk (1.005, 95% CI: 1.002, 1.009). There was no significant BMI by MVPA interaction.

CONCLUSION

Increasing MVPA in children with low activity levels is associated with lower asthma risk; children reporting high levels of activity may experience greater asthma risk as their activity levels increase further. Understanding the role of PA in the development of asthma and assessing MVPA during routine care visits in children may help to develop targeted interventions and guide asthma management.

Athlete Preparticipation Physical Evaluation

Preparticipation evaluations (PPE) are both a traditional and legal requirement by many governing bodies for sport. The ideal goal of the PPE is safe participation in sport for athletes. This article provides an overview of common PPE elements and current best practice recommendations. Descriptions of every possible examination are published elsewhere and are beyond the intent of this article. Additional considerations for transgender, masters athletes, and Special Olympians are also outside the scope of this review, but are well covered in The Preparticipation Physical Evaluation, fifth edition monograph.

Study of frequency and type of adverse analytical findings in the different disciplines of aquatics

We aimed to analyze the number and distribution of doping control tests in which a banned substance was reported (i.e., adverse analytical finding) in aquatics. The analysis was performed by using the data provided by the WADA Testing Figure Reports from 2015 to 2019. A total of 79,956 doping control tests were analyzed. Sprint swimming, middle-distance swimming and water polo were the disciplines with the highest number of doping control tests. However, there were no differences in the frequency of adverse findings among disciplines (overall, ∼0.56%, from 0.13 in artistic swimming to 0.76% in sprint swimming). Sprinters and long-distance swimmers presented a higher frequency of beta-2-agonists than the remaining aquatic disciplines (p < 0.05). These results indicate that the type of prohibited substances employed is strongly influenced by the intrinsic characteristics of each aquatic discipline.

Demographic, lifestyle and comorbid risk factors for all-cause mortality in a Danish cohort of middle-aged adults with incident asthma

OBJECTIVE

We aimed to identify factors associated with all-cause mortality in adults with incident asthma.

DESIGN AND SETTING

Cross-sectional cohort study, in the metropolitan areas of Copenhagen and Aarhus, Denmark.

PARTICIPANTS

Adults aged 50-64 years enrolled in the Danish Diet, Cancer, and Health cohort were followed up from baseline (1993-1997) in the National Patients Registry for first-time admissions for asthma and vital status. We defined incident asthma as at least one first-time hospital admission with asthma as the primary registered diagnosis between baseline and end of follow-up (2013) in participants without previously known asthma. Among the cohort comprising 57 053 individuals, we identified 785 adults (aged 50-64) with incident asthma, of whom 76 died during follow-up.

PRIMARY AND SECONDARY OUTCOME MEASURES

Baseline reported socioeconomic and lifestyle traits, and comorbidities associated with all-cause mortality.

RESULTS

Self-reported leisure-time physical activity was associated with a substantial reduction in risk with an HR of 0.53 (95% CI 0.33 to 0.85). Being male, single and having a diagnosis of hypertension or diabetes were associated with an increased risk of all-cause mortality with an HR of 1.83 (95% CI 1.14 to 2.38), 2.16 (95% CI 2.06 to 4.40), 2.47 (95% CI 1.54 to 3.95) and of 2.42 (95% CI 0.96 to 6.11), respectively.

CONCLUSIONS

This long-term study of adults with hospital contacts for incident asthma revealed that self-reported leisure-time physical activity is associated with an approximately 50% reduction in all-cause mortality. In contrast, both hypertension and diabetes were associated with a higher risk of mortality.

Incremental shuttle walk test: is it able to detect exercise-induced bronchospasm in young adult asthmatics?

OBJECTIVE

To determine the accuracy of incremental Shuttle Walking Test (ISWT) in detecting exercise-induced bronchospasm (EIB) in adults with asthma and to verify whether there is an association of the drop in FEV₁ between ISWT and cardiopulmonary exercise testing with constant-load CPET-CL.

METHODS

In this cross-sectional study 32 individuals with asthma performed two ISWTs, an incremental cardiopulmonary exercise test (CPET-I) and a constant-load cardiopulmonary exercise test (CPET-CL) with na interval of 48 h between tests. Spirometric measurements were obtained 5, 10, 15, 20 and 30 min after exercise; an FEV1 decline > 10% was considered EIB.

RESULTS

Fifteen individuals had EIB in both tests [χ2 = 9.41; κ = 0.46 p < 0.002 (95% CI: 0.201-0.708)], with moderate agreement. There was a significant correlation between the greatest variation in the drop in FEV₁ between the ISWT and the CPET-CL (r = 0.48; p < 0.01). There was a significant difference for ventilation maintenance time above 40% of Maximum Voluntary Ventilation between the groups of positive EIB (p = 0.001) and negative EIB (p = 0.001) and for ventilatory demand (positive EIB group) (p = 0.008) between ISWT vs CPET-CL. Moreover, assuming CPET-CL as the criterion test, ISWT presented a sensitivity of 62.5% and specificity was 100%.

CONCLUSION

ISWT showed moderate accuracy in detecting EIB in adults with asthma and was able to show similar metabolic and ventilatory demand presented in CPET-CL.

The Effect of High Flow Nasal Cannula Therapy in Exercised-Induced Asthma of Children

High flow nasal cannula (HFNC) therapy is a non-invasive oxygen delivery mode which is safe and well tolerated by adults and children with respiratory distress. HFNC is increasingly used in children with respiratory distress due to mucus retention, such as bronchiolitis and acute asthma. However, he effectiveness of this therapy in acute asthma has not been well researched. To evaluate HFNC for acute childhood asthma, we designed a randomized prospective crossover trial. In the trial, children aged 6–18 years, with a forced expiratory volume in one second (FEV1) lability of ≥30% during an exercise challenge test (ECT) are included. The time of fully recovered lung function within 10% of the baseline after peak fall of FEV1 is compared with and without HFNC therapy. A 50% reduction of recovery time during HFNC therapy compared to recovery time without HFNC is considered clinically relevant, with a power of 80% and a significance level of 5%. Secondly, the pressure used by the HFNC device to deliver the constant present flow is evaluated. A relationship between the measured pressure and the degree of recovery may reveal a working mechanism behind HFNC.

Management of Exercise-Induced Bronchoconstriction in Athletes

Exercise-induced bronchoconstriction (EIB) is a phenomenon observed in asthma but is also seen in healthy individuals and frequently in athletes. High prevalence rates are observed in athletes engaged in endurance sports, winter sports, and swimming. The pathophysiology of EIB is thought to be related to hyperventilation, cold air, and epithelial damage caused by chlorine and fine particles in inspired air. Several diagnostic procedures can be used; however, the diagnosis of EIB based on self-reported symptoms is not reliable and requires an objective examination. The hyperosmolar inhalation test and eucapnic voluntary hyperpnea test, which involve indirect stimulation of the airway, are useful for the diagnosis of EIB. A short-acting β-agonist is the first choice for prevention of EIB, and an inhaled corticosteroid is essential for patients with asthma. Furthermore, treatment should accommodate antidoping requirements in elite athletes. Tailoring of the therapeutic strategy to the individual case and the prognosis after cessation of athletic activity are issues that should be clarified in the future.

Management of Intermittent and Persistent Asthma in Adolescent and High School Athletes

Asthma is the most common chronic condition during childhood and adolescence, affecting an estimated 8% of children and youngsters below 18 years in the United States and the United Kingdom. In adolescent athletes, asthma-like symptoms may represent a common consequence of regular sport practice. Asthma in young athletes poses several challenges, including the ambiguity of definitions and diagnosis of asthma resulting from exercise-induced symptoms, the best pharmacological treatments, and the nonpharmacological options for the management of disease and the challenges inherent to this age group. At a time when the regular practice of sports is increasingly being recommended for a healthy living, the support network around the young athletes is crucial to reduce the impact of asthma on their physical and emotional well-being. In this review, we examine the main issues around the definitions and clinical differentiations of asthma in young sport athletes. We discuss best practice approaches to improve the adherence to the clinical management, including nonpharmacological strategies directed at the family and trainers of athlete adolescents.

Exercise-Induced Bronchoconstriction in Iraq and Afghanistan Veterans With Deployment-Related Exposures

INTRODUCTION

Acute exposure to high-levels of ambient fine particulate matter while exercising results in airway narrowing, but the long-term effects of repeated exposure on exercise-induced bronchoconstriction (EIB) are not well known. The goal of this preliminary study is to determine the rate of EIB among a sample of non-treatment seeking veterans deployed to Iraq and Afghanistan.

MATERIALS AND METHODS

Twenty-four veterans (median [interquartile range]: 35.0 [27.3, 45] years) without history of asthma volunteered for this study. Spirometry was assessed before and after a standardized exercise challenge. A positive EIB response was defined as an exercise-induced fall in forced expiatory volume in 1 second ≥10%. Secondary criteria (peak flow ≥10% or mid-expiratory flow ≥15%) were also considered as an estimate of probable EIB.

RESULTS

A positive EIB response was observed in 16.7% and probable EIB response was observed in 41.7% of our sample. Median deployment length to Iraq or Afghanistan was 13.0 [10.3, 17.5] months and the median time since deployment was 4.2 [2.7, 7.7] years. At the time of testing, veterans reported persistent cough (58.3%), wheeze (37.5%), and shortness of breath (37.5%). During deployment, veterans reported exposure to dust and sand (70.8%), smoke from burn pits (66.7%), vehicle exhaust (83.3%), and regional air pollution (26.0%) on most days or daily.

CONCLUSIONS

Approximately 17% of our sample of non-treatment seeking deployed Iraq and Afghanistan veterans demonstrated EIB, similar to the general population prevalence. However, persistent respiratory symptoms and alternative indices of probable EIB supports continued monitoring of this population.

Does Cold-Water Endurance Swimming Affect Pulmonary Function in Healthy Adults?

The acute effects of cold-water endurance swimming on the respiratory system have received little attention. We investigated pulmonary responses to cold-water endurance swimming in healthy recreational triathletes. Pulmonary function, alveolar diffusing capacity (DL_CO), fractional exhaled nitric oxide (FE_NO) and arterial oxygen saturation by pulse oximetry (SpO₂) were assessed in 19 healthy adults one hour before and 2.5 h after a cold-water (mean ± SD, 10 ± 0.9 °C) swim trial (62 ± 27 min). In addition, 12 out of the 19 participants measured pulmonary function, forced vital capacity (FVC) and forced expiratory volume in one second (FEV₁) 3, 10, 20 and 45 min post-swim by maximal expiratory flow volume loops and DL_CO by the single breath technique. FVC and FEV₁ were significantly reduced 3 min post-swim (p = 0.02) (p = 0.04), respectively, and five of 12 participants (42%) experienced exercise-induced bronchoconstriction (EIB), defined as a ≥ 10% drop in FEV₁. No significant changes were observed in pulmonary function 2.5 h post-swim. However, mean FE_NO and DL_CO were significantly reduced by 7.1% and 8.1% (p = 0.01) and (p < 0.001), respectively, 2.5 h post-swim, accompanied by a 2.5% drop (p < 0.001) in SpO₂. The absolute change in DL_CO correlated significantly with the absolute decline in core temperature (r = 0.52; p = 0.02). Conclusion: Cold-water endurance swimming may affect the lungs in healthy recreational triathletes lasting up to 2.5 h post-swim. Some individuals appear to be more susceptible to pulmonary impairments than others, although these mechanisms need to be studied further.

Exercise Related Respiratory Problems in the Young-Is It Exercise-Induced Bronchoconstriction or Laryngeal Obstruction?

Complaints of breathlessness during heavy exercise is common in children and adolescents, and represent expressions of a subjective feeling that may be difficult to verify and to link with specific diagnoses through objective tests. Exercise-induced asthma and exercise-induced laryngeal obstruction are two common medical causes of breathing difficulities in children and adolescents that can be challenging to distinguish between, based only on the complaints presented by patients. However, by applying a systematic clinical approach that includes rational use of tests, both conditions can usually be diagnosed reliably. In this invited mini-review, we suggest an approach we find feasible in our everyday clinical work.

Effect of age on exercise-induced bronchoconstriction in children and adolescents with asthma

OBJECTIVE

The relationship between exercise-induced bronchoconstriction (EIB) and exertional dyspnea in children and adolescents is yet to be fully established. This study examined whether indicators of fractional exhaled nitric oxide (FeNO), forced expiratory volume in 1 s (FEV₁) percent predicted at baseline, and dyspnea are useful for predicting children and adolescents with EIB.

METHODS

We enrolled 184 children and adolescents diagnosed with asthma (mean age 11.2 years); participants were divided into two groups according to age (12 years) and were subjected to a 6-min exercise challenge test. Lung function tests and modified Borg scale scores were used to examine perceptions of dyspnea at 0, 5 and 15 min after exercise.

RESULTS

Among children, the maximum percentage drop in FEV₁ after exercise correlated significantly with FeNO (adjusted β = 2.3, P < 0.001) and with the perception of dyspnea at 5 min after exercise (adjusted β = 1.9, P < 0.001). Among adolescents, the maximum percentage drop in FEV₁ correlated with FeNO (adjusted β = 2.7, P = 0.007) and with lung function (FEV₁, percent predicted; adjusted β = -0.28, P = 0.006). Children with EIB had significantly stronger dyspnea after exercise than did children without EIB. Adolescents even without EIB may experience more exertional dyspnea than children without EIB.

CONCLUSIONS

Overall, our findings indicated that EIB was associated with FeNO and exertional dyspnea in asthmatic children. By contrast, EIB was associated with FEV₁ percent predicted at baseline and FeNO but not with exertional dyspnea in asthmatic adolescents.

Anti-muscarinic drugs as preventive treatment of exercise-induced bronchoconstriction (EIB) in children and adults

Regular physical activity is strongly recommended to prevent chronic respiratory diseases, including asthma. On the other hand, vigorous physical training may trigger airway symptoms and bronchoconstriction. The transient airway narrowing occurring because of exercise is named exercise-induced bronchoconstriction (EIB). Despite management according to guidelines, a significant proportion of patients experiences uncontrolled EIB, which thus represents a relevant unmet medical need. In particular, although prevention and treatment of EIB are effectively based on the use of beta-2 bronchodilator drugs, high heterogeneity in individual responses has been reported. Furthermore, even though beta-2 adrenergic drugs remain the mainstay of EIB management, occurrence of tolerance and side effects, as well as doping concerns have been reported with their use. In regard to this, inhaled antimuscarinics could represent an alternative or additional effective and safe bronchodilator therapeutic option for achieving optimal EIB control and minimize adverse events. The present systematic review aims to collect and provide the most updated and evidence-based literature findings on the efficacy and safety of short- and long-acting inhaled anti-muscarinic drugs for the preventive treatment of EIB in both children and adults. Take-Home Message: Anti-muscarinic drugs are effective and safe in preventing EIB, despite response variability is reported. Further studies should focus on long-acting molecules, chronic administration and phenotype-driven effects.

Are adults with asthma less physically active? A systematic review and meta-analysis

OBJECTIVE

To systematically review the evidence on whether having current, ever asthma and asthma control is associated with levels of total, moderate and vigorous physical activity.

METHODS

We searched EMBASE, MEDLINE, and CINAHL databases, limiting searches to English language papers from inception until Oct 2019. We synthesized the evidence comparing levels of total, moderate and vigorous physical activity between adults with and without current asthma or ever asthma by random effects meta-analyses.

RESULTS

A total of 25 studies were included, with 18 of these included in meta-analyses. A meta-analysis of 4 case-control studies found that adults with current asthma were less active, with 942.12 steps fewer per day, than adults without current asthma (SMD = -0.39, 95%CI: -0.54, -0.24, I² = 0). Meta-analysis of four-high quality cross-sectional studies found that those with current or ever asthma were more likely to be inactive than those without asthma (binary OR _{current asthma} = 0.85, 95%CI: 0.82, 0.89, I² = 45.6%, and binary OR _{ever asthma} = 0.83, 0.75, 0.91, I² = 0, respectively). Meta-analysis, inclusive of all 10 cross-sectional studies with binary ORs, supported this finding. There was also some evidence that adults with current asthma and ever asthma (6 studies with categorical ORs) were less likely to exercise moderately and vigorously, but these meta-analyses were limited by high heterogeneity. No synthesis of the studies considering asthma control was possible.

CONCLUSION

Adults with current or ever asthma had lower levels of total, moderate and vigorous physical activity than those without asthma and may be missing out on the health benefits of being physically active. The association between asthma control and physical activity warrants further investigation.

Work Group Report: Perspectives in Diagnosis and Management of Exercise-Induced Bronchoconstriction in Athletes

Exercise-induced bronchoconstriction, otherwise known as exercise-induced bronchoconstriction with asthma or without asthma, is an acute airway narrowing that occurs as a result of exercise and can occur in patients with asthma. A panel of members from the American Academy of Allergy, Asthma & Immunology Sports, Exercise, & Fitness Committee reviewed the diagnosis and management of exercise-induced bronchoconstriction in athletes of all skill levels including recreational athletes, high school and college athletes, and professional athletes. A special emphasis was placed on the recommendations and regulations set forth by professional athletic organizations after a detailed review of their collective bargaining agreements, substance abuse policies, antidoping program manuals, and the World Anti-Doping Agency antidoping code. The recommendations in this review are based on currently available evidence in addition to providing guidance for athletes of all skill levels as well as their treating physicians to better understand which pharmaceutical and nonpharmaceutical management options are appropriate as well as which medications are permitted or prohibited, and the proper documentation required to remain compliant.

Motivation for physical activity in adolescents with asthma

OBJECTIVE

We explored motivation for physical activity (PA) and exercise in adolescents with asthma who entered and continued a 10-week play-based exercise intervention.

METHODS

Eighteen adolescents with asthma, aged 13-17 years, participated in a 10-week play- and interval-based indoor exercise intervention during winter and autumn months. Semi-structured focus group interviews were conducted in weeks 2 and 8, focusing on motivation for PA and exercise, as well as field observations of exercise sessions in weeks 2, 6, and 8. The first interview was analyzed separately from the second one and descriptive observational data were obtained using thematic analysis and self-determination theory as a framework.

RESULTS

In the first round of focus group interviews, participants (n = 18) described amotivation and motivation for PA within the following five themes: "teachers' lack of asthma knowledge", "embarrassment over asthma symptoms", "not being able to keep pace with peers", "seasonal challenges", and "mastering fun physical activities". Based on the second interview (n = 14) and descriptive observational data (n = 18), participants reported and revealed amotivation and motivation for PA within the following four themes: "understanding and relatedness", "social support", "competition", and "mastering fun activities".

CONCLUSION

We conclude that play-based exercises designed for groups of adolescents with asthma can support motivation for PA and exercise and reduce social and asthma-specific barriers.

Association Between Mouth Breathing and Asthma: a Systematic Review and Meta-analysis

PURPOSE OF REVIEW

This systematic review and meta-analysis evaluated the association between asthma and mouth breathing. We performed a systematic search in the PubMed, SCOPUS, Lilacs, Web of Science, Google Scholar and OpenThesis databases.

RECENT FINDINGS

Asthma is defined as a heterogeneous disease characterized by variable symptoms of wheezing, shortness of breath, chest oppression and/or cough, and limitation of expiratory airflow. Although several studies have examined the association between asthma and mouth breathing, there are no systematic reviews or meta-analyses that synthesize the available bodies of evidence. We used the odds ratio as a measure of the association between asthma and mouth breathing. Summary estimates were calculated using random-effects models, and the risk of bias was estimated using the Newcastle-Ottawa Scale for case-control studies and the National Institutes of Health tool for cross-sectional studies. Nine studies were included in the present systematic review. Data from 12,147 subjects were analyzed, of which 2083 were children and adolescents and 10,064 were adults. We found an association between mouth breathing and asthma in children and adolescents (OR 2.46, 95% CI 1.78-3.39) and in adults (OR 4.60, 95% CI 1.49-14.20). However, limitations were found in the methodological description of the included studies, as well as high heterogeneity among studies evaluating adult populations. This meta-analysis showed an association between mouth breathing and asthma in children, adolescents and adults, but the results should be interpreted with caution. Further studies with standardized criteria for the investigation of mouth breathing are needed.

Interchangeability between two breath-by-breath O2 uptake calculation algorithms in asthmatic and healthy volunteers

INTRODUCTION

The interchangeability analysis has been recently proposed to objectively assess whether a newly developed measurement tool can substitute the older ones; this analysis assumes that the measures yielded by the compared tools should differ less than a maximum acceptable value. We aimed to assess the interchangeability rate (IR) of the breath-by-breath O₂ uptake data calculated with the "Independent breath" (IND) and the "Expiration-only" (EXP) algorithms.

METHODS

Oxygen, carbon dioxide fractions, and ventilatory flow were recorded continuously over 26 min in 18 asthmatic and 20 well-matched healthy volunteers at rest, during cycling, and recovery; oxygen uptake (V'O₂) was calculated with the two algorithms under comparison. Coefficients of variation (CVs) of all the steady-state condition were modeled as a function of the average V'O₂ values and IR was calculated accordingly.

RESULTS

CVs were significantly greater in the asthmatic volunteers (F = 5.97, p < 0.05), being lower for IND compared to EXP (F > 7.04, p < 0.02). CVs decreased as a function of the reciprocal of the square root of the average V'O₂. The IR, calculated on the basis of this relationship, was not significantly different in the two groups of volunteers (F = 0.77, p = 0.385); taking as reference method the IND, or EXP algorithms, the IR values were significantly different (F = 58.6, p < 0.001), amounting to 97.4 ± 2.2% or to 98.2 ± 1.7%, respectively.

CONCLUSION

The relative noise of V'O₂ was greater in the asthmatic volunteers compared to the healthy ones and was lower for IND compared to EXP. The interchangeability analysis suggested that IND might be a better substitute for EXP than the opposite.

High incidence rate of asthma among elite endurance athletes: a prospective 4-year survey

Objective: The prevalence of asthma among elite endurance athletes is high, but less is known about the incidence of asthma among athletes. The aim of this study was to examine the incidence rate of physician-diagnosed asthma among elite endurance athletes.Method: An annual postal questionnaire was sent to an open prospective cohort of elite endurance athletes between 2011 and 2015. Athletes from Swedish National teams, students at universities with elite sport partnership, and pupils at Swedish National elite sport schools, competing in cross-country skiing, biathlon, ski orienteering, or orienteering were invited (n = 666). Incidence rate of physician-diagnosed asthma was calculated among those without asthma at baseline (n = 449). Risk factors for incident physician-diagnosed asthma were identified using a multivariate logistic regression analysis.Results: Response rate was 88.7% (n = 591) at baseline. The median age of participants was 17 (range 15-36) years at inclusion. The study population included 407 (69%) skiers and 184 (31%) orienteers. The prevalence of asthma at baseline was 23.9% (n = 141). Incidence rate (95% confidence interval [CI]) of physician-diagnosed asthma was 61.2 (45.7-80.3) per 1,000 person-years. Risk factors (odds ratio [OR (95% CI)]) for incident physician-diagnosed asthma were family history of asthma (1.97 [1.04-3.68]), being a skier (3.01 [1.42-7.21]), and wheezing without having a cold (4.15 [1.81-9.26]).Conclusion: The incidence rate of physician-diagnosed asthma is high among Swedish elite endurance athletes.

EFFECT OF PHYSICAL TRAINING ON EXERCISE-INDUCED BRONCHOSPASM IN YOUNG ASTHMATICS

ABSTRACT Introduction: Asthma is the most common chronic disease in childhood and its prevalence has increased in recent years. Although regular physical activity (PA) is considered to be beneficial for the health of asthmatics, especially children and adolescents, it can also be one of the elements that triggers asthma. This is known as exercise-induced bronchospasm (EIB), and is considered one of the factors that limits asthmatics’ participation in PA. Objective: This study aims to review the effects of physical conditioning on EIB in asthmatic children and adolescents. Methods: A systematic review was carried out on the Pubmed, Bireme and Web of Science databases, considering publications from 1998 to April 2019. Results: Eight articles were retrieved; five of the articles presented no significant difference in EIB parameters after physical training, and three demonstrated significant benefits in EIB. Conclusion: There is insufficient evidence that physical training helps reduce the frequency and severity of EIB in young asthmatics. There are still few studies that seek to show the effect of a physical training program on the improvement of EIB in children and adolescents. It is suggested that further randomized clinical trials be conducted, to investigate the effects of physical training on EIB parameters in children and adolescents. Level of Evidence II; Systematic review.

Physical activity and asthma development in childhood: Prospective birth cohort study

BACKGROUND

Sedentary behavior and decreased physical activity are possible risk factors for developing asthma. This longitudinal study investigates the association between physical activity and subsequent asthma. We hypothesize that children with decreased physical activity at early school age, have higher risk of developing asthma.

METHODS

One thousand eight hundred thirty-eight children from the KOALA Birth Cohort Study were analyzed. Children who were born prematurely or with congenital defects/diseases with possible influence on either physical activity or respiratory symptoms were excluded. Physical activity, sedentary behavior, and screen time were measured at age 4 to 5 years by questionnaire and accelerometry in a subgroup (n = 301). Primary outcome was asthma, assessed by repeated ISAAC questionnaires between age 6 and 10. Secondary outcome was lung function measured by spirometry in a subgroup (n = 485, accelerometry subgroup n = 62) (forced expiratory volume in 1 second [FEV1], forced vital capacity [FVC] and FEV1/FVC ratio) at age 6 to 7 years.

RESULTS

Reported physical activity was not associated with reported asthma nor lung function. Accelerometry data showed that daily being 1 hour less physically active was associated with a lower FEV1/FVC (z score β, -0.65; 95% confidence interval, -1.06 to -0.24).

CONCLUSIONS

Physical activity at early school age was not associated with reported asthma development later in life. However, lung function results showed that sedentary activity time was associated with lower FEV1/FVC later in childhood. As this is the first longitudinal study with objectively measured physical activity and lung function, and because the subgroup sample size was small, this result needs replication.

Assessing effects of personal behaviors and environmental exposure on asthma episodes: a diary-based approach

Background

Quantifying the effects of personal health behaviors and environmental exposure on asthma flare-ups is a challenge. Most studies have focused on monitoring the symptoms and drug usage for relieving symptoms. In this study, we emphasize the need to understand how personal and environmental conditions are related to the occurrence of asthma symptoms.

Methods

We designed an online health diary platform to collect personal health behaviors from children, their parents and other adults with any allergic diseases including asthma, allergic rhinitis, atopic dermatitis and allergic conjunctivitis. The participants used mobile devices or computers to record their daily health-related activities such as sleep, exercise, diet, perception of air quality and temperature, and asthma symptoms. The participants also recorded secondhand smoke exposure and the time of activities, which were combined with ambient air quality measurements for calculating personal air pollution exposure. A generalized linear mixed model was used to estimate the effects of the factors.

Results

During the study period (January 2017–June 2017, and October 2017–September 2018), 132 participants provided 25,016 diary entries, and 84 participants had experienced asthma symptoms in 1458 diary entries. The results showed some different risk factors for the minors and adults. For minors, high-intensity exercise, contact with persons with influenza-like illness (ILI) and the perception of hot temperature and bad indoor air quality were associated with the occurrence of asthma episodes. The identified risk factors for the adult participants included having dehumidifiers at home, exposure to secondhand smoke, having bad sleep quality, contact with persons with ILI, not eating fruit and seafood, perceiving cold temperature, bad quality of indoor and outdoor air, and exposure to high concentration of ozone.

Conclusions

The revealed personal risk factors and perceptions of air quality and temperature may provide guidance on behavioral change for people susceptible to asthma to help control acute onset and severe exacerbation of asthma flare-ups.

Effect of physical activity on asthma control in schoolchildren

OBJECTIVE

To investigate the effect of levels of physical activity on asthma control in children.

METHODS

A cross-sectional study, including public school students aged 8 to 12 years, of both sexes, with asthma, from a capital and a medium-sized cities in Southern Brazil. At home, the students answered the questionnaire on levels of physical activity and disease control.

RESULTS

A total of 482 schoolchildren with asthma participated in the study, with mean age of 10.9±2.2 years, and 253 (52%) were girls. Regarding disease control, 50% had controlled asthma, and 67% were considered sedentary. Schoolchildren with controlled asthma were more active than those with uncontrolled asthma (p=0.032). Active schoolchildren were more likely to have asthma controlled (OR=1.5; 95%CI: 1.04-2.25).

CONCLUSION

The results demonstrated an association between physical activity levels and asthma control. More active schoolchildren were more likely to have asthma controlled.

The Metabolic Requirements of Th2 Cell Differentiation

Upon activation, naïve CD4⁺ T cells differentiate into a number of specialized T helper (Th) cell subsets. Th2 cells are central players in immunity to helminths and are implicated in mediating the inflammatory pathology associated with allergies. The differentiation of Th2 cells is dependent on transcription factors such as GATA3 and STAT6, which prime Th2 cells for the secretion of interleukin- (IL-) 4, IL-5, and IL-13. Several lines of work now suggest that differentiating Th2 cells in the lymph node are potent IL-4 cytokine producers, but do not become competent IL-5- and IL-13-producing cells until after receiving cues from non-lymphoid tissue. It is evident that Th2 cells that enter tissues undergo considerable changes in chromatin architecture and gene expression, and that over this time, the metabolic requirements of these cells change considerably. Herein, we discuss the metabolic requirements of Th2 cells during their early and late differentiation, focusing on the impact of glucose and lipid metabolism, mTOR activation, the nuclear receptor PPAR-γ and several metabolites.

Exhaled nitric oxide as a marker of chlorine exposure in young asthmatic swimmers

BACKGROUND

Swimming is recommended for people with asthma. However, the inevitable exposure to chlorine and its disinfectant byproducts in indoor swimming pools could be responsible for bronchial inflammation and asthma development. Fractional exhaled nitric oxide (FeNO) is a noninvasive marker of airway inflammation that predicts asthma exacerbations.

OBJECTIVES

To evaluate pretraining and posttraining FeNO levels in young swimmers with asthma attending an indoor chlorinated pool compared with a set of healthy swimmers and to examine the potential risk of exposure to chlorine as a factor associated with bronchial inflammation.

METHODS

A total of 146 children (8-18 years old) constantly attending an indoor chlorinated swimming pool were enrolled. Spirometry and FeNO measurements were performed 30 minutes after their arrival at the pool and immediately after exercise. Pre-exercise and postexercise spirometric and FeNO levels were assessed in a random subgroup of 14 swimmers (10 with asthma and 4 without) who performed cardiopulmonary exercise testing.

RESULTS

Asthma was detected in 23 swimmers. In swimmers with asthma, preswimming FeNO values were significantly elevated compared with swimmers without asthma and their FeNO values measured before cardiopulmonary exercise testing. Postexercise FeNO values were significantly decreased by approximately one-third in healthy children and children with asthma in all sporting backgrounds. However, postswimming FeNO values remained significantly higher in swimmers with asthma compared with those without asthma. Forced expiratory volume in 1 second (FEV₁), forced vital capacity (FVC), and FEV₁/FVC ratio values showed no significant difference before and after 2 types of activity.

CONCLUSION

Elevated FeNO levels before and after swimming were recorded in swimmers with asthma not observed in a different exercise field. The presence of chlorine in the indoor swimming pool seems to explain this finding.

Cardiopulmonary exercise testing for identification of patients with hyperventilation syndrome

Introduction

Measurement of ventilatory efficiency, defined as minute ventilation per unit carbon dioxide production (V_E/VCO₂), by cardiopulmonary exercise testing (CPET) has been proposed as a screen for hyperventilation syndrome (HVS). However, increased V_E/VCO₂ may be associated with other disorders which need to be distinguished from HVS. A more specific marker of HVS by CPET would be clinically useful. We hypothesized ventilatory control during exercise is abnormal in patients with HVS.

Methods

Patients who underwent CPET from years 2015 through 2017 were retrospectively identified and formed the study group. HVS was defined as dyspnea with respiratory alkalosis (pH >7.45) at peak exercise with absence of acute or chronic respiratory, heart or psychiatric disease. Healthy patients were selected as controls. For comparison the Student t-test or Mann-Whitney U test were used. Data are summarized as mean ± SD or median (IQR); p<0.05 was considered significant.

Results

Twenty-nine patients with HVS were identified and 29 control subjects were selected. At rest, end-tidal carbon dioxide (P_ETCO₂) was 27 mmHg (25–30) for HVS patients vs. 30 mmHg (28–32); in controls (p = 0.05). At peak exercise P_ETCO₂ was also significantly lower (27 ± 4 mmHg vs. 35 ± 4 mmHg; p<0.01) and V_E/VCO₂ higher ((38 (35–43) vs. 31 (27–34); p<0.01)) in patients with HVS. In contrast to controls, there were minimal changes of P_ETCO₂ (0.50 ± 5.26 mmHg vs. 6.2 ± 4.6 mmHg; p<0.01) and V_E/VCO₂ ((0.17 (-4.24–6.02) vs. -6.6 (-11.4-(-2.8)); p<0.01)) during exercise in patients with HVS. The absence of V_E/VCO₂ and P_ETCO₂ change during exercise was specific for HVS (83% and 93%, respectively).

Conclusion

Absence of V_E/VCO₂ and P_ETCO₂ change during exercise may identify patients with HVS.

Asthma and youth soccer: an investigation into the level of asthma awareness and training among youth soccer coaches

Purpose

Asthma is the most common chronic disease among children. Exercise-induced bronchoconstriction which is common in asthmatic patients also occurs in individuals with no prior asthma diagnosis. Despite this and the fact that soccer is a high ventilation sport, there are no validated asthma management protocols in place for soccer coaches. This study aims to address 1) soccer coaches’ current knowledge on asthma, 2) whether there is a need for asthma-related training, and 3) any barriers to administration of such training.

Patients and methods

A total of 2,300 volunteer youth soccer coaches from the Edmonton Minor Soccer Association (EMSA) were invited to participate in completing a 22-question online survey. The survey was open for 1 month from June 8, 2018, to July 8, 2018.

Results

There was a response rate of 22% (513 of 2,300). Respondents were on average, inexperienced coaches, coached younger age groups, and approximately one-third of respondents had personal experience with asthma (either themselves or their child had asthma). 93% of respondents had not received any asthma-related training at any coaching level, whether it be from EMSA or the Alberta Soccer Association. Coaches had strong knowledge on how to treat asthma attacks, but mixed levels of knowledge on asthma attack prevention. Experienced coaches were better at identifying the number of players with asthma on their team and the number of asthma-related incidents they had encountered as coaches. Coaches demonstrated a receptive attitude toward receiving asthma-related training, with 91% of respondents saying training would be beneficial and 69% of respondents saying training should be mandatory.

Conclusion

The results of this study indicate that soccer coaches have limited knowledge regarding asthma management, acknowledge a need for asthma-related training, and are willing to participate in and could benefit from educational interventions as it pertains to their roles as coaches.

Heating-induced contraction in airways smooth muscle: A possible causative factor of exercise-induced bronchoconstriction

Asthmatic patients often suffer from bronchoconstriction or asthma following breathing hot air or exposure to exercise due to raises the core body temperature. However, the direct effect of heating airways has not been studied yet. The aim of this study is to investigate the effect of heating on tracheal and bronchiolar smooth muscles. Isolated ovine tracheal strips and bronchiolar segments preparations were suspended in organ baths containing Krebs' solution for isometric tension recording. Tissues responses were examined during decreasing and elevating baths temperature (20 °C, 40 °C-45 °C and 50 °C). Cooling or heating induced rapid and reproducible contractions proportional with decreasing or increasing temperature respectively in tracheal and bronchiolar preparations. On reset to 37 °C the tone returned rapidly to basal level. Changing the bath's temperature from 37 °C to 20 °C or to 40 °C and 45 °C for tracheal strips or to 45 °C and 50 °C for bronchiolar segments induced contractions in both preparations. Changing the temperature below or above the normal body temperature (37 °C), leads to airways contractions. Heating induced contractions in tracheal and bronchiolar smooth muscle proportional to the heating temperature. Therefore, breathing hot air or elevation of body core temperature due to exercise can be considered possible causative factor of heating- or exercise-induced bronchoconstriction.