Global prevalence of exercise-induced bronchoconstriction in childhood: A meta-analysis

Association of temperature and absolute humidity with incidence of exercise-induced bronchoconstriction in children

AIM

Exercise test outdoors is widely used to diagnose asthma in children, but it is unclear how much outdoor air factors affect the results.

METHODS

We analysed 321 outdoor exercise challenge tests with spirometry in children 6-16 years conducted due to suspicion of asthma or for assessing the effect of medication on asthma. We studied the association of FEV1 decrease and incidence of exercise-induced bronchoconstriction (EIB) with temperature, relative humidity (RH) and absolute humidity (AH).

RESULTS

Asthma was diagnosed in 57% of the subjects. AH ≥5 g/m3, but not RH or temperature, was associated with the EIB incidence (p = 0.035). In multivariable logistic regression, AH ≥5 g/m3 was negatively associated (OR = 0.51, 95% CI [0.28─0.92], p = 0.026) while obstruction before exercise (OR = 2.11, 95% CI [1.16─3.86], p = 0.015) and IgE-mediated sensitisation were positively associated with EIB (OR = 2.24, 95% CI [1.11─4.51], p = 0.025). AH (r = -0.12, p = 0.028) and temperature (r = -0.13, p = 0.023) correlated with decrease in FEV1. In multivariable linear regression, only AH was associated with FEV1 decrease (coefficient = -0.044, 95% CI [-0.085 to -0.004], p = 0.033).

CONCLUSION

AH of outdoor air associates with occurrence and severity of EIB in outdoor exercise tests in children. Care should be taken when interpreting negative outdoor exercise test results if AH of air is high.

Exercise-induced bronchoconstriction, allergy and sports in children

Exercise-induced bronchoconstriction (EIB) is characterized by the narrowing of airways during or after physical activity, leading to symptoms such as wheezing, coughing, and shortness of breath. Distinguishing between EIB and exercise-induced asthma (EIA) is essential, given their divergent therapeutic and prognostic considerations. EIB has been increasingly recognized as a significant concern in pediatric athletes. Moreover, studies indicate a noteworthy prevalence of EIB in children with atopic predispositions, unveiling a potential link between allergic sensitivities and exercise-induced respiratory symptoms, underpinned by an inflammatory reaction caused by mechanical, environmental, and genetic factors. Holistic management of EIB in children necessitates a correct diagnosis and a combination of pharmacological and non-pharmacological interventions. This review delves into the latest evidence concerning EIB in the pediatric population, exploring its associations with atopy and sports, and emphasizing the appropriate diagnostic and therapeutic approaches by highlighting various clinical scenarios.

GEMA 5.3. Spanish Guideline on the Management of Asthma

The Spanish Guideline on the Management of Asthma, better known by its acronym in Spanish GEMA, has been available for more than 20 years. Twenty-one scientific societies or related groups both from Spain and internationally have participated in the preparation and development of the updated edition of GEMA, which in fact has been currently positioned as the reference guide on asthma in the Spanish language worldwide. Its objective is to prevent and improve the clinical situation of people with asthma by increasing the knowledge of healthcare professionals involved in their care. Its purpose is to convert scientific evidence into simple and easy-to-follow practical recommendations. Therefore, it is not a monograph that brings together all the scientific knowledge about the disease, but rather a brief document with the essentials, designed to be applied quickly in routine clinical practice. The guidelines are necessarily multidisciplinary, developed to be useful and an indispensable tool for physicians of different specialties, as well as nurses and pharmacists. Probably the most outstanding aspects of the guide are the recommendations to: establish the diagnosis of asthma using a sequential algorithm based on objective diagnostic tests; the follow-up of patients, preferably based on the strategy of achieving and maintaining control of the disease; treatment according to the level of severity of asthma, using six steps from least to greatest need of pharmaceutical drugs, and the treatment algorithm for the indication of biologics in patients with severe uncontrolled asthma based on phenotypes. And now, in addition to that, there is a novelty for easy use and follow-up through a computer application based on the chatbot-type conversational artificial intelligence (ia-GEMA).

The effect of nose clip on exercise-induced bronchoconstriction in adolescents

BACKGROUND

Oral breathing is considered to increase hyper-responsiveness of the airways. Data on the need for nose clip (NC) during exercise challenge test (ECT) in children and adolescents is scarce. Ouraim was to evaluate the role of NC during ECT in children and adolescents.

METHODS

A prospective, cohort study; children referred for ECT were evaluated on two separate visits, with and without a NC. Demographic, clinical data and measurements of lung functions were recorded. Allergy and asthma control were evaluated by Total Nasal Symptoms Score (TNSS) and Asthma Control Test (ACT) questionnaires.

RESULTS

Sixty children and adolescents (mean age 16.7 ± 1.1 years, 38% Female,) performed ECT with NC and 48 (80%) completed visit 2 (ECT without NC), 8.7 ± 7.9 days after visit 1. Following exercise, 29/48 patients (60.4%) with NC had a decline of ≥12% in forced expiratory volume in the first second (FEV1 ) (positive ECT) compared to only 16/48 (33.3%) positive tests without NC (p = 0.0008). Test result was changed in 14 patients from positive ECT (with NC) to negative ECT (no NC) and in only one patient from negative to positive. The use of NC resulted in greater FEV1 decline (median 16.3% predicted, IQR 6.0-19.1% predicted vs. median 4.5% predicted, IQR 1.6-18.4% predicted, p = 0.0001), and better FEV1 increase after bronchodil at or inhalation compared to ECT without NC. Higher TNSS scores did not predict higher probability to positive ECT.

CONCLUSIONS

The use of NC during ECT increases detection rate of exercise induced bronchoconstriction during ECT in the pediatric population. These findings strengthen the recommendation of nasal blockage during ECT in children and adolescents.

Activation of epithelial and inflammatory pathways in adolescent elite athletes exposed to intense exercise and air pollution

RATIONALE

Participation in high-intensity exercise in early life might act as stressor to the airway barrier.

OBJECTIVES

To investigate the effect of intense exercise and associated exposure to air pollution on the airway barrier in adolescent elite athletes compared with healthy controls and to study exercise-induced bronchoconstriction (EIB) in this population.

METHODS

Early-career elite athletes attending 'Flemish-Elite-Sports-Schools' (12-18 years) of 4 different sport disciplines (n=90) and control subjects (n=25) were recruited. Presence of EIB was tested by the eucapnic voluntary hyperventilation (EVH) test. Markers at mRNA and protein level; RNA-sequencing; carbon load in airway macrophages were studied on induced sputum samples.

RESULTS

444 genes were differentially expressed in sputum from athletes compared with controls, which were related to inflammation and epithelial cell damage and sputum samples of athletes contained significantly more carbon loaded airway macrophages compared with controls (24%, 95% CI 20% to 36%, p<0.0004). Athletes had significantly higher substance P (13.3 pg/mL, 95% CI 2.0 to 19.2) and calprotectin (1237 ng/mL, 95% CI 531 to 2490) levels as well as IL-6, IL-8 and TNF-α mRNA levels compared with controls (p<0.05). The incidence of EIB in athletes was 9%. The maximal fall in forced expiratory volume in 1 s (%) after EVH test in athletes was significantly associated with prior PM10 and PM2.5 exposure.

CONCLUSION

Early-career elite athletes showed increased markers of air pollution exposure, epithelial damage and airway inflammation compared with controls. Acute exposure to increased air pollution PM10 levels was linked to increased airway hyper-reactivity.

TRIAL REGISTRATION NUMBER

NCT03587675.

Is there cardiac autonomic dysfunction in children and adolescents with exercise-induced bronchospasm?

BACKGROUND

The pulmonary impairment in patients with bronchoconstriction induced by eucapnic voluntary hyperpnea(EVH) goes beyond the respiratory system, also impairing autonomic nervous modulation. This study aimed to evaluate the behavior of cardiac autonomic modulation in young asthmatics with and without EIB after the EVH test.

RESEARCH DESIGN AND METHODS

A cross-sectional study design using 54 asthmatics(51.9% female), aged between 10 and 19 years, investigated with the EVH test. Forced expiratory volume in one second(FEV1) was measured at 5, 10, 15, and 30 min after EVH. Heart rate variability(HRV) measures of time were assessed pre and 30 min-post EVH. The diagnosis of Exercise-Induced bronchoconstriction with underlying clinical asthma(EIBA) was confirmed by a fall in FEV1 ≥10% compared to baseline.

RESULTS

Thirty(55.5%) asthmatics had EIBA. Subjects with EIBA have reduced mean of the R-R intervals in relation to baseline until 15 minutes after EVH. Individuals without EIBA had increased parasympathetic activity compared to baseline(rMSSD) from 5 min after EVH(p < 0.05). This parasympathetic activity increase in relation to baseline was seen in individuals with EIBA after 25 minutes (rMSSD = 49.9 ± 5.3 vs 63.5 ± 7.2, p < 0.05).

CONCLUSION

Young asthmatics with EIBA present a delay in the increase of the parasympathetic component after EVH when compared to asthmatics without EIBA.

Exercise-Induced Bronchoconstriction in Children: A Comparison between Athletes and Non-Athletes

Exercise-induced bronchoconstriction (EIB) is a dysfunction of the respiratory tract consisting of transient airflow obstruction. This study is a retrospective analysis of two prospective studies concerning EIB symptoms in two adolescent populations. Our study group included 400 non-athletes and 101 athletes. Due to the similarity of indoor exercise conditions, an analysis was performed on the basis of where training took place. The study aims to assess the EIB prevalence in the following groups of adolescent children: non-athletes and athletes. In "indoor" athletes, the EIB prevalence was 22.4%. Among non-athletes, EIB was diagnosed in 10.2% (p = 0.007). A history of asthma was found in 6.5% of non-athletes and 29.3% of indoor athletes (p < 0.001). The incidence of EIB without asthma was higher in indoor athletes (14.6%) than in non-athletes (9.9%). Athletes achieved higher mean values in forced expiratory volume in one second (FEV₁), forced vital capacity (FVC), peak expiratory flow (PEF), and maximum expiratory flow rate at 25% (MEF₂₅) parameters. In the group of non-athletes, higher results were observed in forced expiratory volume in one second % of vital capacity (FEV₁%VC), MEF₅₀, and MEF₇₅. The findings of the study present the complexity of the EIB diagnosis among children training in an indoor environment.

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.

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.

Impulse Oscillometry (IOS) for Detection of Exercise Induced Bronchoconstriction in Children with Asthma Ages 6-15 years

OBJECTIVES

To determine the discriminatory value of various impulse oscillometry (IOS) parameters, and to find the cutoff value of the appropriate parameter for identifying exercise-induced bronchoconstriction (EIB) in children with asthma.

METHODS

This cross-sectional study was conducted in India from October 2016 to March 2018 in children with asthma who were 6-15 years of age. One hundred and five children were enrolled and subjected to pre-exercise IOS and spirometry followed by free running treadmill test as an exercise challenge. All children could achieve minute ventilation >17.5-21 times of FEV₁ during the exercise challenge test. Then, IOS and spirometry were performed at 10 ± 2, 20 ± 2, and 30 ± 2 min post-exercise challenge. EIB was defined as reduction of FEV₁ ≥10% within 30 min of exercise. For purposes of analysis, the children were grouped into two categories: "EIB Present" or "EIB Absent".

RESULTS

The prevalence of EIB in our study was 20.95% (n = 22). ΔR5max percentage within 30 min post-exercise (AUC 0.74; 95% CI: 0.64, 0.84) had the best discriminating capacity among all IOS parameters for identifying EIB. A cutoff value of 14.1% increase in R5 within 30 min post-exercise was obtained for detection of EIB (sensitivity-95.45%, specificity-50.6%, PPV-33.87% and NPV-97.67%).

CONCLUSIONS

A percentage change in R5 with a cutoff value of 14.1% increase post-exercise had the best discriminatory capacity among all IOS parameters for detection of EIB in children with asthma. However, low positive predictive value (PPV) with high negative predictive value (NPV) made this cutoff value more apt to rule out EIB.

Comparison between impulse oscillometry parameters and spirometry for the diagnosis of exercise-induced bronchoconstriction in asthmatic children and adolescents

INTRODUCTION

Impulse oscillometry (IOS) parameters are obtained more easily and effortlessly in comparison to forced expiratory volume in the first second (FEV1).

OBJECTIVE

To compare IOS parameters to FEV1 in exercise-induced bronchoconstriction (EIB) diagnosis.

METHODS

Seventy-four (60.8% male; 39.2 female) young asthmatics aged between 7 and 17 years (mean 12.6 ± 2.8 years) were evaluated. EIB was defined as a reduction in FEV1 ≥ 10% compared with basal after standardized challenge by treadmill running (TR). IOS parameters and FEV1 were obtained at baseline and 5,15, and 30 min after TR. The area under the receiver operator characteristic curve (AUC) was calculated from the reduction in FEV1 ≥ 10% to evaluate the best psychometric characteristics of IOS parameters.

RESULTS

Twenty-four individuals (32.4%) were diagnosed with EIB. A moderate inverse correlation was found between the IOS and FEV1 variables immediately after the TR, with resistance at 5 Hz (R5Hz), resonant frequency (Fres), and reactance area (AX), (r = -0.64, r = -0.53 and r = -0.69, respectively, all with p < 0.05). An increase of 25 kPa/l/s in R5 Hz, of 19k Pa/l/s in AX and 21 Hz in Fres were found to best correlate with EIB diagnosis by FEV1 (sensitivity 67% and specificity 62%, sensitivity 84% and specificity 50%, and sensitivity 84% and specificity 60%, respectively).

CONCLUSION

IOS parameters have a significant inverse correlation with FEV1. This study presents cut-off points for EIB diagnosis for R5Hz, AX, and Fres, however, the findings in IOS parameters should be used and interpreted carefully if the goal is to replace spirometry.

Adolescent Athletes at Risk of Exercise-Induced Bronchoconstriction: A Result of Training or Pre-Existing Asthma?

Exercise may trigger bronchoconstriction, especially in a group of athletes in whom bronchospasm during exercise is reported to occur more frequently than in nonathletes. The aim of this study was to determine the prevalence and environmental risk factors contributing to exercise-induced bronchoconstriction (EIB) in adolescent athletes. A prospective study was conducted among a group of 101 adolescent athletes who underwent spirometry, exercise challenge, fractional exhaled nitric oxide (FeNO) measurements, and allergy assessment. The study group was divided into three subgroups of athletes based on the most common sports environments: swimmers, “indoor” athletes, and “outdoor” athletes. The clinical evaluation demonstrated a high frequency of EIB in the study group. Moreover, a large proportion of the athletes in whom EIB was observed reported no pre-existing symptoms suggestive of bronchospasm or asthma. Among patients without a previous diagnosis of asthma, clinical evaluation confirmed 22% with positive exercise challenges, compared with 77% of adolescents with negative test results. Moreover, among the athletes with a history of asthma, 39% had positive exercise challenges. Both EIB and asthma are common conditions that affect adolescent athletes. Physicians should pay particular attention to this group, as the symptoms can lead to under- and overdiagnosis.

Analysis of the association between exercise induced bronchospasm, cardiorespiratory fitness, and physical activity levels of adolescents

ABSTRACT This study aims to verify the association between exercise-induced bronchospasm (EIB), cardiorespiratory fitness, and physical activity levels in adolescents. To do so, we evaluated 202 healthy adolescents aged from 13 to 18 years, out of which 94 (46.5%) were females and 108 (53.5%) males. Participants performed a bronchial challenge test in a treadmill (Master Super ATL, Inbramed®) to evaluate bronchial hyper-responsiveness; a spirometric test (Microquark, Cosmed®) to evaluate lung function; answered the Baecke’s Questionnaire of Habitual Physical Activity; and performed the progressive aerobic cardiovascular endurance run test. Data were analyzed using Spearman’s correlation, chi-square test, and odds ratio. The significance level adopted was p<0.05. No statistically significant correlations were found between the decrease of the forced expiratory volume in the first second (FEV1), cardiorespiratory fitness, and physical activity levels. Likewise, the chi-squared test revealed no significant differences between classifications of cardiorespiratory fitness (low or adequate) and EIB (presence or absence) (χ2=0.155; p=0.694). Finally, odds ratio showed no increased chances of the presence of EIB in participants who presented low cardiorespiratory fitness (OR=1.130; CI: 0.616-2.073). We concluded that cardiorespiratory fitness and physical activity levels are not associated with the decrease of FEV1 and that there is no relation between the presence of EIB and the classification of cardiorespiratory fitness of adolescents.

Exercise Limitation in Children and Adolescents with Mild-to-Moderate Asthma

BACKGROUND

Children with uncontrolled asthma are less tolerant to exercise due to ventilatory limitation, exercise-induced bronchoconstriction (EIB), or physical deconditioning. The contribution of these factors in children with controlled mild-to-moderate asthma is unknown.

OBJECTIVE

To explore the underlying mechanisms of reduced exercise capacity in children with controlled mild-to-moderate asthma.

METHODS

This was a cross-sectional study of 45 children and adolescents (age 8-18 years) with controlled mild-to-moderate asthma (asthma control test score 21-25) and 61 age-matched healthy controls. All participants completed a physical activity questionnaire and performed spirometry and cardiopulmonary exercise testing (CPET; maximal incremental protocol). Spirometric indices and CPET parameters were compared between the two groups. The effect of EIB (FEV₁ decrease >10% post CPET), ventilatory limitation and physical deconditioning on maximum oxygen uptake (O₂peak), was assessed by multivariable linear regression.

RESULTS

62.2% of children with asthma and 29.5% of controls (P = 0.002) were categorized as inactive. Reduced exercise capacity (O₂peak <80%) was noted in 53.3% of asthmatics and 16.4% of controls (P < 0.001). EIB was documented in 11.1% of participants with asthma. Physical deconditioning was noted in 37.8% of children with asthma and in 14.8% of controls (P = 0.013). Physical deconditioning emerged as the only significant determinant of O₂peak, irrespective of asthma diagnosis, body mass index, ventilatory limitation and EIB.

CONCLUSION

Children with controlled mild-to-moderate asthma are less tolerant to strenuous exercise than their healthy peers. The decreased exercise capacity in this population should mainly be attributed to physical deconditioning, while the contribution of ventilatory limitation and EIB is rather small.

Demographics, Treatment Patterns, and Morbidity in Patients with Exercise-Induced Bronchoconstriction: An Administrative Claims Data Analysis

PURPOSE

Exercise-induced bronchoconstriction (EIB) is generally treated with short-acting β2-agonists (SABA) before exercising, to prevent symptoms. Real-world data on treatments and outcomes for patients with EIB alone (EIBalone), or with asthma (EIBasthma), in the USA are limited. This study compared demographics, treatment patterns, morbidity, and costs of treating EIB between these two groups of patients.

PATIENTS AND METHODS

Administrative claims from US IBM® MarketScan® Research databases were analyzed retrospectively. Patients aged ≥4 years filling a SABA claim between 1/1/2011 and 12/31/2016 were evaluated. Patients were indexed on a random SABA claim and required to have 12 months' continuous eligibility pre- and post-index, ≥1 maintenance medication and/or SABA fill post-index, and were designated EIBalone or EIBasthma according to diagnostic codes (EIB only or EIB plus asthma, respectively). Descriptive statistics were used.

RESULTS

In total, 13,480 patients had EIBalone and 14,862 had EIBasthma. Compared with EIBasthma, the EIBalone group was older (mean[SD] 20.4[13.6] vs 17.8[13.6] years), had more females (60.7% vs 54.7%), and filled fewer SABA claims (1.9[1.4] vs 2.5[2.2]) (all p<0.001). A smaller proportion of patients in the EIBalone than EIBasthma group had maintenance therapy claims (79.9% vs 90.6%, p<0.001). The EIBalone group also had a lower proportion of patients with oral or injectable corticosteroid claims (29.4% vs 32.0%) and asthma and/or EIB-related emergency department (1.0% vs 13.0%) or outpatient visits (65.1% vs 72.3%; all p<0.0001). Annual days' supply of oral corticosteroids was similar between groups (mean[SD] EIBalone: 20.7[30.8] vs EIBasthma: 19.8[28] days).

CONCLUSION

Individuals with EIBalone or EIBasthma demonstrate considerable morbidity. New treatment paradigms may be needed to optimize outcomes for both patient groups.

Reproducibility of eucapnic voluntary hyperpnoea for exercise-induced bronchoconstriction diagnosis in asthmatic children and adolescents

BACKGROUND

Respiratory symptoms after exercise are frequently reported by asthmatic patients, and exercise-induced bronchoconstriction (EIB) is a frequent cause, which requires objective testing for diagnosis. Eucapnic voluntary hyperpnea (EVH) is recommended as a surrogate stimulus for this purpose. Its short-term reproducibility is not yet established in children and young adolescents with asthma.

OBJECTIVE

To evaluate the short-term test-retest agreement and reproducibility of FEV₁ changes after EVH in this population.

METHODS

Asthmatic patients aged between 10 and 20 years underwent EVH for EIB diagnosis on two occasions 2-4 days apart at a specialized university clinic. FEV₁ was measured at 5, 15, and 30 min after EVH with a target ventilation rate 21 times the baseline FEV₁ . EIB was diagnosed as a decrease ≥10% in FEV₁ from baseline.

RESULTS

A total of 26 of 62 recruited individuals tested positive for EIB on both visits (positive group) and 17 on one visit only (divergent group), while 19 tested negative on both visits (negative group). The overall agreement was 72.5% (95%CI 61.6%, 83.6%), and Cohen's kappa coefficient was 0.452. Low bias (0.87%) and high intra-class correlation coefficient (0.854, 95%CI 0.758,0.912; p < .001) for FEV₁ response between test days were found, but with wide limits of agreement (±20.72%). There were no differences in pre-challenge FEV₁ or achieved ventilation rate between visits either between groups (p = .097 and p = .461) or within groups (p = .828 and p = .780). There were no safety issues.

CONCLUSIONS

More than one EVH test should be performed in children and young adolescents with asthma to exclude EIB and minimize misdiagnosis and mistreatment.

Impact of climate variability on exercise-induced bronchospasm in adolescents living in a semi-arid region

OBJECTIVE

To examine the impact of climate variability on the occurrence of exercise-induced bronchospasm in the rainy and dry seasons of a Brazilian semi-arid region.

METHODS

This sample comprised 82 adolescents aged 15 to 18 years, who were submitted to exercise-induced bronchospasm assessment on a treadmill and outdoors, during the rainy and the dry season. Anthropometric variables, sexual maturity and forced expiratory volume in the first second were analyzed. Air temperature and humidity, decline in forced expiratory volume in the first second (%) and frequency of bronchospasm were compared between seasons using the independent Student's t test, the Wilcoxon and McNemar tests, respectively. The level of significance was set at p<0.05.

RESULTS

The mean age was 15.65±0.82 years. Air temperature, air humidity and decline in forced expiratory volume in the first second (%) differed between seasons, with higher air temperature and humidity in the rainy season (29.6ºC±0.1 and 70.8%±0.6 versus 28.5ºC±0.2 and 48.5%±0.6; p<0.05). The decline in forced expiratory volume in the first second (%) was greater in the dry season (9.43%±9.97 versus 12.94%±15.65; p<0.05). The frequency of bronchospasm did not differ between seasons.

CONCLUSION

The dry season had a negative impact on forced expiratory volume in the first second in adolescents, with greater decrease detected during this period. Findings of this study suggested bronchospasm tends to be more severe under low humidity conditions.

Short- and long-term effects of fluticasone furate/vilaterol in exercising asthmatic adolescents: a randomized and open label trial

PURPOSE

Relvar® (Fluticasone furoate (FF)/Vilanterol (VI)) is a once-daily inhaler with bronchodilator effect lasting 24 hours. Our aim was to investigate the short- and long-term effects of FF/VI on exercise-induced asthma (EIA) in adolescents.

METHODS

Ninety-three adolescent asthmatics aged 12-18 years were referred for evaluation of EIA. Following a positive exercise challenge test (ECT), 22/44 were allocated to a single administration of salbutamol (400 μg) and 22/44 to FF/VI (92/22 μg) in a double-blind method. Thirty-five subjects were reassessed by repeat ECT 30-60 days of FF/VI.

RESULTS

Median FEV1 change post-ECT at baseline was -22.8% predicted (IQR -26.1 and -18.0) for salbutamol and -21.0 (IQR -30.7 and -16.8) for FF/VI. Following bronchodilator, FEV1 improved similarly in both groups. Repeat ECT following 30-60 days of FF/VI resulted in negative exercise challenge test in 33/35 subjects; the median decrease in FEV1 of these 35 subjects was 22.6% predicted (IQR 29-18) before, and 4.6% predicted (IQR 8.7-2.5) after 30-60 days of FF/VI treatment; p<0.0001).

CONCLUSIONS

FF/VI is effective in reversing EIA after 15 minutes in adolescents and in protecting EIA after 30-60 days in adolescents. Larger studies are needed to assess the effect of FF/VI on EIA.

Bronchial Provocation Testing for the Identification of Exercise-Induced Bronchoconstriction

Exercise-induced bronchoconstriction (EIB) occurs in patients with asthma, children, and otherwise healthy athletes. Poor diagnostic accuracy of respiratory symptoms during exercise requires objective assessment of EIB. The standardized tests currently available are based on the assumption that the provoking stimulus to EIB is dehydration of the airway surface fluid due to conditioning large volumes of inhaled air. "Indirect" bronchial provocation tests that use stimuli to cause endogenous release of bronchoconstricting mediators from airway inflammatory cells include dry air hyperpnea (eg, exercise and eucapnic voluntary hyperpnea) and osmotic aerosols (eg, inhaled mannitol). The airway response to different indirect tests is generally similar in patients with asthma and healthy athletes with EIB. Furthermore, the airway sensitivity to these tests is modified by the same pharmacotherapy used to treat asthma. In contrast, pharmacological agents such as methacholine, given by inhalation, act directly on smooth muscle to cause contraction. These "direct" tests have been used traditionally to identify airway hyperresponsiveness in clinical asthma but are less useful to diagnose EIB. The mechanistic differences between indirect and direct tests have helped to elucidate the events leading to airway narrowing in patients with asthma and elite athletes, while improving the clinical utility of these tests to diagnose and manage EIB.

Pulmonary function as a limiting factor of middle distance race performance

Exercise induced bronchoconstriction (EIB) is common and underdiagnosed phenomenon of yet largely unknown etiology. This study aimed to estimate prevalence of EIB in response to highly demanding skyscraper race and to test its association with race performance and hypothetical predisposing factors. Healthy participants (26 males, 8 females; 31.5 +/- 6.3 years) from mostly running-based amateur sports were measured for forced expiratory volume in first 1 s (FEV1) before and then repeatedly within 10 min after the completion of the 114 m skyscraper upstairs race. Allergy questionnaire (AQUA) data were collected and post-exercise blood lactate was measured. Over 40% of the participants developed >10% decrement in FEV1 shortly after all-out exercise. While EIB response was not associated with questionnaire-based atopic status, training background, gender, age, anthropometrics, pacing and exertion (estimated from the accumulated blood lactate values), participants exhibiting <10% decrement in FEV1 were faster, especially over the later stages of the race. In conclusion, nearly every other participant of the skyscraper race develops EIB not associated with training, demographic, anthropometric and atopic status, pacing and exertion (estimated from postexercise blood lactate), but the responders (FEV1 decrement >10%) were slower indicative of poorer fitness due to EIB developing during the exercise already.

Exercise Limitation in Children and Adolescents With Severe Refractory Asthma: A Lack of Asthma Control?

Background

Patients with severe refractory asthma (SRA), even when using high doses of multiple controller medications in a regular and appropriate way, can have persistent complaints of exercise limitation.

Methods

This was a cross-sectional study involving patients with SRA (treated with ≥ 800 μg of budesonide or equivalent, with ≥ 80% adherence, appropriate inhaler technique, and comorbidities treated), who presented no signs of a lack of asthma control other than exercise limitation. We also evaluated healthy controls, matched to the patients for sex, age, and body mass index. All participants underwent cardiopulmonary exercise testing (CPET) on a cycle ergometer, maximum exertion being defined as ≥ 85% of the predicted heart rate, with a respiratory exchange ratio ≥ 1.0 for children and ≥ 1.1 for adolescents. Physical deconditioning was defined as oxygen uptake (VO₂) < 80% of predicted at peak exercise, without cardiac impairment or ventilatory limitation. Exercise-induced bronchoconstriction (EIB) was defined as a forced expiratory volume in one second ≥ 10% lower than the baseline value at 5, 10, 20, and 30 minutes after CPET.

Results

We evaluated 20 patients with SRA and 19 controls. In the sample as a whole, the mean age was 12.9 ± 0.4 years. The CPET was considered maximal in all participants. In terms of the peak VO₂ (VO_{2 peak}), there was no significant difference between the patients and controls, (P = 0.10). Among the patients, we observed isolated EIB in 30%, isolated physical deconditioning in 25%, physical deconditioning accompanied by EIB in 25%, and exercise-induced symptoms not supported by the CPET data in 15%.

Conclusion and Clinical Relevance

Physical deconditioning, alone or accompanied by EIB, was the determining factor in reducing exercise tolerance in patients with SRA and was not therefore found to be associated with a lack of asthma control.

Prevalence of exercise-induced bronchoconstriction and laryngeal obstruction in adolescent athletes

OBJECTIVES

To study the prevalence of exercise-induced bronchoconstriction (EIB) and exercise-induced laryngeal obstruction (EILO) in adolescent athletes.

METHODS

All adolescents (n = 549) attending first year at a sports high school in 2016 and 2017, were invited to answer a questionnaire on respiratory symptoms. The 367 responding participants were divided into two groups based on whether they reported exercise-induced dyspnea (dyspnea group) or not (nondyspnea group). Randomly selected participants in each group were invited to undergo two standardized exercise tests, an EIB test and a continuous laryngoscopy exercise (CLE) test, to investigate EILO.

RESULTS

In total, 98 participants completed an EIB test, 75 of whom also completed a CLE test. Positive EIB tests: eight of 41 in the dyspnea group and 16 of 57 in the nondyspnea group. Positive CLE tests: 5 of 34 in the dyspnea group and three of 41 in the nondyspnea group. The estimated prevalence of EIB was 23.1% (95% confidence interval [CI]: 14.5-33.8) and of EILO 8.1% (95% CI: 2.5-18.5) in the whole study population. No differences in prevalence of EIB or EILO were found between the dyspnea and the nondyspnea groups.

CONCLUSION

EIB was highly prevalent in this cohort of adolescent athletes. EILO was less prevalent, but represents an important differential diagnosis to EIB. Self-reported exercise-induced dyspnea is a weak indicator for both EIB and EILO and standardized testing should be provided.

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.

Obesity is a risk factor for exercise-induced bronchospasm in asthmatic adolescents

INTRODUCTION

Exercise-induced bronchospasm (EIB) is common in young asthmatics and obesity is becoming an epidemic in this population. Both conditions can give rise to or worsen respiratory symptoms upon exercise and may interfere with recreational and sports activities.

OBJECTIVE

To investigate the association between obesity and the risk and severity of EIB in asthmatic children and adolescents.

METHODS

This study included data from asthmatic patients aged between 7 and 19 years undergoing treadmill running tests to evaluate EIB, defined as a reduction greater than or equal to 10% in forced expiratory volume in the first second (FEV₁ ) compared to baseline. Eutrophic, obese, and overweight individuals were categorized according to body mass index z-score (eutrophic, -0.5 < z ≤ 1; overweight, 1 < z < 2; and obese, z ≥ 2).

RESULTS

Of the 156 individuals studied (42% female), 58% were eutrophic, 22% overweight, and 19% obese. Seventy-three individuals (47%) presented with EIB, with higher risk among obese (OR, 2.86; 95% CI, 1.00-8.14; P = .05). Asthma severity was another independent risk factor for EIB (OR, 2.95; 95% CI, 1.36-6.42; P = .006). The number of patients in whom FEV₁ returned to baseline values (difference less than 10% from baseline) at the 13th minute after challenge was lower in obese individuals compared to eutrophic and overweight ones (P = .04). Baseline FEV₁ , gender, or age were not found to be risk factors for EIB in any of the groups.

CONCLUSION

Obese youngsters with asthma present a greater risk for EIB with slower recovery than their nonobese peers. Clinicians should be aware of this association, especially in those with more severe disease, for adequate recognition and treatment.

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.

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.

Exhaled TGF-β1 levels before and after an exercise challenge in asthmatic and healthy children, and during exacerbation

BACKGROUND

There is conflicting data regarding the role of transforming growth factor-β1 (TGF-β1) in the pathogenesis of airway hyper-reactivity and asthma exacerbation.

OBJECTIVE

To investigate the role of exhaled-TGF-β1 in exercise-induced bronchospasm (EIB) in asthmatic and nonasthmatic healthy children, and in asthma exacerbation and asthma control.

METHODS

The exhaled-TGF-β1 levels of 56 stable asthmatic children and 15 nonasthmatic healthy children were evaluated before and 30 min after an exercise challenge. The exhaled-TGF-β1 levels of 20 additional children with asthma exacerbation were evaluated.

RESULTS

While no significant difference in the exhaled-TGF-β1 levels was found at the baseline, exhaled-TGF-β1 levels after the exercise challenge were significantly higher in the non-EIB (n = 31) asthmatics when compared to the asthmatic children with EIB (n = 25) (p = 0.04). Although there was a statistically significant increase in the concentration of the exhaled-TGF-β1 after the exercise challenge in the non-EIB asthmatics (p = 0.008), the concentration of the TGF-β1 was not increased after the exercise challenge in EIB + asthmatics. The exhaled-TGF-β1 was significantly correlated with the ACT score (p = 0.01, r = 0.49) and the baseline FEV₁ level (p = 0.02, r = 0.35). The exhaled-TGF-β1 levels were significantly higher in the stable asthmatic children when compared to the nonasthmatic children (p < 0.0001). There was no significant difference in exhaled-TGF-β1 levels after the exercise challenge in the nonasthmatics. The exhaled-TGF-β1 levels were significantly lower in those children with asthma exacerbation when compared to the stable asthmatic children (p = 0.0003).

CONCLUSION

Our results suggest that TGF-β1 may play a role in suppressing airway reactivity and its deficiency is associated with asthma exacerbation.

Exercise-Induced Dyspnea in Children and Adolescents: Differential Diagnosis

Exercise-induced dyspnea in children and adolescents can occur for many reasons. Although asthma is the common cause, failure to prevent exercise-induced asthma by pretreatment with a bronchodilator, such as albuterol, indicates that other etiologies should be considered. Other causes of exercise-induced dyspnea include exercise-induced vocal cord dysfunction, exercise-induced laryngomalacia, exercise-induced hyperventilation, chest wall restrictive abnormalities, cardiac causes, and normal physiologic limitation. When exercise-induced dyspnea is not from asthma, cardiopulmonary exercise testing with reproduction of the patient's dyspnea is the means to identify the other causes. Cardiopulmonary exercise testing monitors oxygen use, carbon-dioxide production, end-tidal pCO₂ (partial pressure of carbon dioxide), and electrocardiogram. Additional components to testing are measurement of blood pH and pCO₂ when symptoms are reproduced, and selective flexible laryngoscopy when upper airway obstruction is observed to specifically identify vocal cord dysfunction or laryngomalacia. This approach is a highly effective means to identify exercise-induced dyspnea that is not caused by asthma. [Pediatr Ann. 2019;48(3):e121-e127.].