Physical activity and exercise-induced bronchoconstriction in Greek schoolchildren

Exercise-Induced Bronchoconstriction in Children: State of the Art from Diagnosis to Treatment

Exercise-induced bronchoconstriction (EIB) is a common clinical entity in people with asthma. EIB is characterized by postexercise airway obstruction that results in symptoms such as coughing, dyspnea, wheezing, chest tightness, and increased fatigue. The underlying mechanism of EIB is not completely understood. "Osmotic theory" and "thermal or vascular theory" have been proposed. Initial assessment must include a specific work-up to exclude alternative diagnoses like exercise-induced laryngeal obstruction (EILO), cardiac disease, or physical deconditioning. Detailed medical history and clinical examination must be followed by basal spirometry and exercise challenge test. The standardized treadmill running (TR) test, a controlled and standardized method to assess bronchial response to exercise, is the most adopted exercise challenge test for children aged at least 8 years. In the TR test, the goal is to reach the target heart rate in a short period and maintain it for at least 6 min. The test is then followed by spirometry at specific time points (5, 10, 15, and 30 min after exercise). In addition, bronchoprovocation tests like dry air hyperpnea (exercise and eucapnic voluntary hyperpnea) or osmotic aerosols (inhaled mannitol) can be considered when the diagnosis is uncertain. Treatment options include both pharmacological and behavioral approaches. Considering medications, the use of short-acting beta-agonists (SABA) just before exercise is the commonest option strategy, but daily inhaled corticosteroids (ICS) can also be considered, especially when EIB is not controlled with SABA only or when the patients practice physical activity very often. Among the behavioral approaches, warm-up before exercise, breathing through the nose or face mask, and avoiding polluted environments are all recommended strategies to reduce EIB risk. This review summarizes the latest evidence published over the last 10 years on the pathogenesis, diagnosis using spirometry and indirect bronchoprovocation tests, and treatment strategies, including SABA and ICS, of EIB. A specific focus has been placed on EIB management in young athletes, since this condition can not only prevent them from practicing regular physical activity but also competitive sports.

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.

School-Age Obese Asthmatic Children have Distinct Lung Function Measures From Lean Asthmatics and Obese Children

Background: The lung functions of children with obese asthma seem to be distinct from those of obese children or lean asthmatics.Aim: To measure baseline lung function, exercise-induced bronchoconstriction (EIB), and bronchial hyperreactivity (BHR) in school-age obese asthmatics (OA group) and to compare the data with obese children (O group), lean asthmatics (A group), and healthy controls (H group).Methods: One hundred seventy school-age children were enrolled in this prospective cross-sectional study. Baseline fractionated exhaled nitric oxide (FeNO), and baseline, post-exercise (post-E), and post-bronchodilation (post-BD) impulse oscillometry (IOS) and spirometry tests were performed. EIB and BHR were evaluated based on the difference (Δ) in post-E - baseline, and post-BD - baseline values.Results: The mean FeNO level was higher in the OA group than in the other groups (p = 0.002). Baseline zR5 and R5-20 were higher (p = 0.013 and p = 0.044), but zFEF25-75 was lower (p < 0.01), in the OA group. ΔPost-E - baseline zFEV1 was lower in the A group (p = 0.003) but was higher in the OA group (p = 0.014) than the other groups. ΔPost-BD - baseline zFEV1 was lower in the H group compared to the other three groups (p = 0.004), but no significant difference was observed among the O, A, and OA groups (p > 0.05).Conclusion: A higher airway inflammation (high FeNO), peripheral airway resistance (high zR5 and zR5-20) and a lower peripheral airway flow (low FEF25-75) were observed at baseline measurement in school-age obese asthmatics compared to lean asthmatics and obese children. Obese asthmatics had no EIB but exhibited a similar BHR to that of asthmatics.

Levels of physical activity in children and adolescents with asthma: A systematic review and meta-analysis

BACKGROUND

In children and adolescents with asthma, the disease may reduce the perceived capability to participate in physical activity (PA) contributing to an increase in the sedentary lifestyle. The literature is unclear as to whether children and adolescents with asthma differ their PA levels from their healthy peers.

OBJECTIVE

Our objective was to describe the different methods and instruments used to measure PA and to compare the PA levels of children and adolescents with asthma with those of their healthy peers.

STUDY DESIGN

We conducted a systematic review of five databases. We included studies that compared the PA measured by objective and subjective instruments in children and adolescents with asthma versus controls. Two independent reviewers analyzed the studies, extracted the data, and assessed the quality of evidence.

RESULTS

Of the 5966 reports returned by the initial search, 28 articles reporting on 3184 patients were included in the data synthesis. A forest plot showed that both groups had similar values of moderate to vigorous PA (MVPA; mean difference, -0.05 h/day; 95% confidence interval [CI], -0.11-0.01; p = .13), sedentary time (mean difference 0.00 h/day; 95% CI, -0.22-0.23 h/day; p = .99) and steps/day (mean difference 354 steps/day; 95% CI, -563-1270 steps/day; p = .45).

CONCLUSION

Children and adolescents with asthma have similar MVPA, steps/day, and sedentary time compared to the controls. The main instruments used were questionnaires and accelerometers.

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.

Does exercise-induced bronchoconstriction affect physical activity patterns in asthmatic children?

Exercise-induced bronchoconstriction (EIB) is a sign of uncontrolled childhood asthma and classically occurs after exercise. Recent research shows that EIB frequently starts during exercise, called breakthrough-EIB (BT-EIB). It is unknown whether this more severe type of EIB forces children to adapt their physical activity (PA) pattern in daily life. Therefore, this pilot study aims to investigate daily life PA (amount, intensity, duration, and distribution) in children with BT-EIB, 'classic' EIB, and without EIB. A Fitbit Zip activity tracker was used for one week to objectively measure daily life PA at one-minute intervals. Thirty asthmatic children participated. Children with BT-EIB were less physically active compared to children without EIB (respectively 7994 and 11,444 steps/day, p = .02). Children with BT-EIB showed less moderate-to-vigorous PA compared to the children without (respectively 117 and 170 minutes/day, p = .02). Children with EIB (both BT and classic) had significant shorter bouts of activity and a less stretched distribution of bout lengths compared to the non-EIB group (all p < .05). These results emphasize a marked association between EIB severity and PA patterns in daily life, stressing the need for a thorough clinical evaluation of exercise-induced symptoms in childhood asthma.

Prevalence of asthma symptoms and association with obesity, sedentary lifestyle and sociodemographic factors: data from the Hellenic National Action Plan for the assessment, prevention and treatment of childhood obesity (MIS301205)

Objectives: To evaluate the prevalence of asthma symptoms in a representative sample of Greek schoolchildren and to evaluate its association with overweight/obesity as well as other socioeconomic, demographic, and lifestyle factors. Methods: This is a cross-sectional study conducted from 10/2012 to 12/2013 on a pre-selected, representative elementary school cohort. Parents completed standardized questionnaires evaluating among others socioeconomic and sedentary activity habits. Students were measured with high sensitivity methods. Socioeconomic status (SES) index (range: 0-13) was calculated on years of parental education, rented versus owned residence, size of residence evaluated as meters squared per person (m²/person), and number of vehicles. Asthma was defined according to the approved Greek version of the International Study on Allergies and Asthma in Childhood (ISAAC) criteria. Results: The prevalence of any asthma symptoms was documented in 31% of population. The odds of presenting any asthma symptoms decreased with increase in age (odds ratio: 0.96, 95% CI: 0.94-0.98) and increased with overweight (odds ratio: 1.13, 95% CI: 1.03-1.25), obesity (odds ratio: 1.27, 95% CI: 1.11-1.46) and sedentary lifestyle. Conclusion: This is the first representative survey of prevalence of asthma symptoms in children and adolescents in Greece indicating its continuous increase. A strong association between presence of asthma symptoms and obesity and sedentary activities was documented irrespectively of socioeconomic and regional factors. The findings stress the importance of public health policies toward obesity prevention and enhancement of physical activities in pediatric populations.

Exercise-induced bronchoconstriction: prevalence, pathophysiology, patient impact, diagnosis and management

Exercise-induced bronchoconstriction (EIB) can occur in individuals with and without asthma, and is prevalent among athletes of all levels. In patients with asthma, symptoms of EIB significantly increase the proportion reporting feelings of fearfulness, frustration, isolation, depression and embarrassment compared with those without symptoms. EIB can also prevent patients with asthma from participating in exercise and negatively impact their quality of life. Diagnosis of EIB is based on symptoms and spirometry or bronchial provocation tests; owing to low awareness of EIB and lack of simple, standardised diagnostic methods, under-diagnosis and mis-diagnosis of EIB are common. To improve the rates of diagnosis of EIB in primary care, validated and widely accepted symptom-based questionnaires are needed that can accurately replicate the current diagnostic standards (forced expiratory volume in 1 s reductions observed following exercise or bronchoprovocation challenge) in patients with and without asthma. In patients without asthma, EIB can be managed by various non-pharmacological methods and the use of pre-exercise short-acting β2-agonists (SABAs). In patients with asthma, EIB is often associated with poor asthma control but can also occur in individuals who have good control when not exercising. Inhaled corticosteroids are recommended when asthma control is suboptimal; however, pre-exercise SABAs are also widely used and are recommended as the first-line therapy. This review describes the burden, key features, diagnosis and current treatment approaches for EIB in patients with and without asthma and serves as a call to action for family physicians to be aware of EIB and consider it as a potential diagnosis.

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

BACKGROUND

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

OBJECTIVE

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

INCLUSION CRITERIA TYPES OF PARTICIPANTS

Children and adolescents with asthma aged six to 18 years.

CONCEPT

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

CONTEXT

All physical activity contexts.

TYPES OF SOURCES

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

SEARCH STRATEGY

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

EXTRACTION OF THE RESULTS

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

PRESENTATION OF THE RESULTS

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

CONCLUSIONS

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

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

AIM

This systematic review and meta-analysis aimed to estimate the global prevalence of exercise-induced bronchoconstriction (EIB) in children and adolescents.

METHOD

We searched PubMed, Google Scholar, and the Virtual Health Library-BIREME from inception to December 23, 2017. We selected observational studies that reported the prevalence of EIB (diagnosed by exercise challenge test) in children and adolescents aged 5-18 years. We conducted random-effects meta-analyses to estimate the pooled prevalence of EIB and 95% CI.

RESULTS

We included 66 studies (55 696 participants, 5670 cases of EIB) in the review, of which 33 in general population of children and adolescents, 10 in child and adolescent athletes and 23 in children and adolescents with asthma. The global mean prevalence of EIB in the general population of children and adolescents was 9% (IC95%: 8-10%), with a higher rate (12%) in Asia-Pacific and America. The mean prevalence of EIB was 15% (95% CI: 9-21%) in child and adolescent athletes, and 46% (95% CI: 39-53%) in children and adolescents with asthma. We estimated that, globally, around 16.5 million (95% CI: 15-18 million) children and adolescents up to 18 years of age may have EIB.

CONCLUSION

EIB in childhood should be considered as a global public health problem that needs more attention. The substantial heterogeneity between studies highlights the need for evidence-based guidelines for diagnosis of EIB in this age group.

Respiratory muscle strength and pulmonary function in children with rhinitis and asthma after a six-minute walk test

OBJECTIVE

Rhinitis and asthma decrease quality of life. Few studies have assessed the performance of children with asthma or rhinitis under submaximal exercise. We evaluated maximal respiratory pressures, spirometric parameters, and ability to sustain submaximal exercise in these children before and after the 6-minute walk test (6MWT), compared to healthy children.

METHODS

This cross-sectional, analytical study included 89 children aged 6-12 years in outpatient follow-up: 27 healthy (H), 31 with rhinitis (R), and 31 with mild asthma under control (A). Pulmonary function parameters and maximal respiratory pressures were measured before and 5, 10, and 30 minutes after the 6MWT. Wilcoxon test was used to compare numerical numerical variables between two groups and analysis of variance or Kruskal-Wallis test for comparison among three groups.

RESULTS

Total distance traveled in the 6MWT was similar among the three groups. Compared to pre-test values, VEF1 (Forced Expiratory Volume in 1 second), VEF0.75 (Forced Expiratory Volume in 0.75 second), and FEF25-75 (Forced Expiratory Flow 25-75% of the Forced Vital Capacity - CVF - curve) decreased significantly after the 6MWT in group A, and VEF0.75, FEF25-75, and VEF1/CVF decreased significantly in group R. Groups A and R had lower Maximum Inspiratory Pressure values than group H before and after the 6MWT at all time points assessed.

CONCLUSIONS

The findings suggest that children with rhinitis and mild asthma present with alterations in respiratory muscle strength and pulmonary function not associated with clinical complaints, reinforcing the concept of the united airways.

An obesity-preventive lifestyle score is negatively associated with pediatric asthma

PURPOSE

Lifestyle (diet and physical activity) may increase asthma risk, but evidence in this area is lacking. The aims of the present study were to calculate an obesity-preventive lifestyle score comprising of eating and physical activity behaviors and investigate the overall effect of lifestyle on asthma in children.

METHODS

A cross-sectional case-control study was carried out in 514 children (217 asthma cases and 297 healthy controls). Data were collected on medical history, anthropometry, dietary intake, and physical activity. We constructed an overweight/obesity-preventive score (OPLS) using study-specific quartile rankings for nine target lifestyle behaviors that were either favorable or unfavorable in preventing obesity (i.e., screen time was an unfavorable lifestyle behavior). The score was developed using the recommendations of the Expert Committee of American Academy of Pediatrics. Score values ranged from 0-18 points; the higher the score, the more protective against high body weight.

RESULTS

The OPLS was negatively associated with obesity indices (BMI, waist circumference, and hip circumference), (p < 0.05). Control children had a higher score when compared to asthma cases (9.3 ± 2.7 vs. 8.6 ± 2.9, p = 0.007). A high OPLS was protective against physician-diagnosed asthma (OR 0.92; 95% CI 0.86-0.98, p = 0.014), adjusted for several confounders. The OPLS was no longer protective after adjustment for BMI.

CONCLUSION

Higher adherence to an obesity-preventive lifestyle score-consistent with several behaviors for the prevention of childhood overweight/obesity-is negatively associated with obesity indices and lowers the odds for asthma in children. Lifestyle behaviors that contribute to a higher body weight may contribute to the obesity-asthma link. These findings are hypothesis-generating and warrant further investigation in prospective intervention studies.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A systematic review of the relationship between asthma, overweight, and the effects of physical activity in youth

PURPOSE

The association of asthma and overweight in youth is well studied. However, the temporal relationship between asthma and overweight, the strength of their association, and mediating factors involved in this relationship remain unclear. This review investigates the relationship between asthma and overweight in youth, while examining the role of physical activity as a mediator.

METHODS

A systematic review of literature was conducted using PubMed and Medline databases. Studies conducted among youth aged 0-18 years, published in English between 2000-2014 were included. The Strengthening the Reporting of Observational Studies in Epidemiology guidelines were consulted to evaluate quality of selected citations.

RESULTS

A comprehensive search yielded 143 studies in PubMed and 133 studies in Medline databases. Of these, 75 studies met the eligibility criteria. The review found varying hypotheses regarding the temporal relationship between asthma and overweight in youth; existing evidence supports the mediation of this association by decreased expenditure of energy due to reduced physical activity. Negative self-perception or parental perception of exercise ability due to asthma symptoms secondary to physical exertion was identified as a determinant of physical activity in asthmatic youth.

CONCLUSIONS

Physical activity likely mediates the relationship between asthma and overweight in youth. Temporality of this relationship remains unclear.

The relationship between exercise induced bronchial obstruction and health related quality of life in female and male adolescents from a general population

Background

Previous studies have observed that exercise-induced bronchoconstriction (EIB) is more common and more strongly related to exercise related breathing problems in female adolescents than male adolescents. However, few studies have investigated the association between EIB and health related quality of life (HRQoL) from a gender perspective. The aim of this study was to examine the association between EIB and HRQoL and physical activity level in female and male adolescents with and without EIB.

Methods

From a population based study on exercise-induced breathing problems among adolescents (13–15 years, n = 3838) a cross sectional study with prospective data collection was carried out in a random subsample of 140 adolescents. The subjects in the sample were tested for EIB with a standardised exercise test, of which 49 adolescents were tested positive. HRQoL was assessed with the Pediatric Quality of Life Inventory (PedsQL) and the adolescents’ physical activity levels were measured objectively with accelerometer.

Results

The female subjects with EIB reported a lower HRQoL, both in total score (p = 0.03) and physical functioning score (p = 0.009) and had a lower baseline FEV₁ compared to females without EIB (88 vs. 94 % predicted, p = 0.001). No differences were found in HRQoL or baseline lung function between males with or without EIB. There were no differences in minutes of moderate to vigorous physical activity per day between females or males with and without EIB.

Conclusion

In a general population, the female adolescents with EIB had lower HRQoL and poorer baseline lung function compared to counterparts without EIB. These differences were not observed in males. EIB does not appear to affect the level of daily physical activity neither in females nor males.

School environmental factors are predictive for exercise-induced symptoms in children

BACKGROUND

Environmental factors in schools have a significant effect on the exercise-induced bronchoconstriction and symptoms in a general paediatric population.

OBJECTIVES

To determine the environmental factors such as atmospheric conditions and the presence of allergens in gymnasiums, that could be predictive of the presence of exercise-induced symptoms/bronchospasm in children during physical education (PE).

METHODS

1370 schoolchildren were enrolled. Children attended 45 min PE lesson with similar exercise intensity. Pulmonary function tests were performed before and after PE lesson. Air temperature, humidity and pressure, samples of dust for allergen exposure in the gymnasiums were taken. Children who reported symptoms induced during PE lesson were invited to the clinic for ETC (exercise treadmill challenge) and atopy measurement.

RESULTS

1033 participants were included into the analysis. Sixty seven(6.5%) children reported dyspnea/cough, and in 94(9.4%) children bronchoconstriction induced during PE lesson was documented. There is a correlation between the results of the ETC and bronchoconstriction after PE (OR: 2.55; 95%CI: 1.07-6.05; p = 0.034). Exposure to higher air pressure and higher humidity independently increase the risk of clinical symptoms reported during or after PE lesson. Exposure to cat's allergens increase the risk of bronchoconstriction (independently from atopy status). We showed significant interaction between presence of asthma and current ICS therapy as a risk of physical inactivity at school (OR: 4; 95%CI: 1.3-12; p < 0.001).

CONCLUSION

This study showed an effect of cat allergen and environmental factors (humidity, air pressure) on the appearance of exercise related cough/bronchoconstriction during activity class in a natural environment at school in a large urban population of schoolchildren.

Exercise-induced bronchospasm related to different phenotypes of rhinitis without asthma in primary schoolchildren: the French Six Cities Study

BACKGROUND

Exercise-induced bronchospasm (EIB) is frequent among asthmatic children. However, opinions differ on the relation between EIB and rhinitis in the absence of asthma.

OBJECTIVES

We assessed the relationship between EIB and various phenotypes of rhinitis according to asthmatic status at the general population level in the Six Cities Study.

METHODS

Of 7781 schoolchildren with a mean age of 10 years underwent an EIB test and skin prick test to assess allergic sensitization. Their parents completed a standardized questionnaire recording asthma-like symptoms and past-year rhinoconjunctivitis, ever hay fever (EHF), and a score for allergic rhinitis (SFAR) ≥7 as a marker of 'past-year allergic rhinitis'. Exercise-induced bronchospasm was defined as a fall in peak expiratory flow rate ≥15% after exercise.

RESULTS

Of the 6813 schoolchildren retained for analysis, 227 (3.33%) experienced EIB after exercise. Odds ratios [95% confidence intervals] between EIB and allergic rhinitis phenotypes in the absence of asthma were 1.56 [0.92-2.63] for EHF, 1.97 [1.16-3.35] for past-year rhinoconjunctivitis, and 1.84 [1.16-2.91] for a SFAR ≥7. Results were unchanged after adjustment for confounders. Multiple correspondence analysis showed that EIB, although related to asthma, constitutes a separate entity. Exercise-induced bronchospasm was not significantly related to familial history of asthma.

CONCLUSION

In our large population-based sample of children, different phenotypes of atopic rhinitis were associated with EIB, independently of asthma. Exercise-induced bronchospasm, although related to asthma, seems to constitute a separate entity.

CLINICAL RELEVANCE

In this large (6813) sample of 10-year children drawn from the general population, EIB is associated with rhinitis phenotypes in the absence of asthma. Furthermore, it constitutes an entity independent from asthma and is not related to a familial history of asthma. Thus, investigating these symptoms could be important in this disease, as a specific nasal treatment might improve EIB in these children.

Prevalence of exercise-induced bronchoconstriction and exercise-induced laryngeal obstruction in a general adolescent population

BACKGROUND

Exercise-induced respiratory symptoms are common among adolescents. Exercise is a known stimulus for transient narrowing of the airways, such as exercise-induced bronchoconstriction (EIB) and exercise-induced laryngeal obstruction (EILO). Our aim was to investigate the prevalence of EIB and EILO in a general population of adolescents.

METHODS

In this cross-sectional study, a questionnaire on exercise-induced dyspnoea was sent to all adolescents born in 1997 and 1998 in Uppsala, Sweden (n=3838). A random subsample of 146 adolescents (99 with self-reported exercise-induced dyspnoea and 47 without this condition) underwent standardised treadmill exercise tests for EIB and EILO. The exercise test for EIB was performed while breathing dry air; a positive test was defined as a decrease of ≥10% in FEV1 from baseline. EILO was investigated using continuous laryngoscopy during exercise.

RESULTS

The estimated prevalence of EIB and EILO in the total population was 19.2% and 5.7%, respectively. No gender differences were found. In adolescents with exercise-induced dyspnoea, 39.8% had EIB, 6% had EILO and 4.8% had both conditions. In this group, significantly more boys than girls had neither EIB nor EILO (64.7% vs 38.8%; p=0.026). There were no significant differences in body mass index, lung function, diagnosed asthma or medication between the participants with exercise-induced dyspnoea who had or did not have a positive EIB or EILO test result.

CONCLUSIONS

Both EIB and EILO are common causes of exercise-induced dyspnoea in adolescents. EILO is equally common among girls and boys and can coexist with EIB.

Physical activity and respiratory symptoms in children: the Generation R Study

BACKGROUND

To assess the relationship between physical activity in second year of life and respiratory symptoms during the pre-school period.

METHODS

This study was embedded in the Generation R Study, a large prospective birth-cohort study in Rotterdam, the Netherlands. Physical activity was measured in the second year of life by an Actigraph accelerometer in a subgroup of 347 children (182 boys, 165 girls; mean age 25.1 months) and data were expressed as counts per 15 sec in categories: light activity (302-614 counts/15 sec), moderate activity (615-1,230 counts/15 sec), and vigorous activity (≥1,231 counts/15 sec). Respiratory symptoms were assessed by the International Study of Asthma and Allergies in Childhood Questionnaire in the third and fourth year of life.

RESULTS

Physical activity levels were not associated with wheezing symptoms in the third and fourth year of life (OR: 0.98; 95% CI: 0.92-1.05 and OR: 0.99; 95% CI: 0.92-1.07 for total activity, respectively), nor associated with shortness of breath symptoms (OR: 0.98; 95% CI: 0.92-1.05 and OR 1.03; 95% CI: 0.96-1.11 for total activity, respectively).

CONCLUSION

These results suggest that physical activity may not play an important role in the development of respiratory symptoms in pre-school children.