Exercise-induced Asthma Research Articles

Predictors and reproducibility of exercise-induced bronchoconstriction in cold air

BackgroundPhysical activity is an important part of life, and hence exercise-induced bronchoconstriction (EIB) can reduce the quality of life. A standardized test is needed to diagnose EIB. The American Thoracic Society (ATS) guidelines recommend an exercise challenge in combination with dry air. We investigated the feasibility of a new, ATS guidelines conform exercise challenge in a cold chamber (ECC) to detect EIB. The aim of this study was to investigate the surrogate marker reaction to methacholine, ECC and exercise challenge in ambient temperature for the prediction of a positive reaction and to re-evaluate the reproducibility of the response to an ECC.MethodsSeventy-eight subjects aged 6 to 40 years with suspected EIB were recruited for the study. The subjects performed one methacholine challenge, two ECCs, and one exercise challenge at an ambient temperature. To define the sensitivity and specificity of the predictor, a receiver-operating characteristic curve was plotted. The repeatability was evaluated using the method described by Bland and Altman (95% Limits of agreement).ResultsThe following cut-off values showed the best combination of sensitivity and specificity: the provocation dose causing a 20% decrease in the forced expiratory volume in 1 s (PD20FEV1) of methacholine: 1.36 mg (AUC 0.69, p < 0.05), the maximal decrease in FEV1 during the ECC: 8.5% (AUC 0.78, p < 0.001) and exercise challenges at ambient temperatures: FEV1 5.2% (AUC 0.64, p = 0.13). The median decline in FEV1 was 14.5% (0.0–64.2) during the first ECC and 10.7% (0.0–52.5) during the second ECC. In the comparison of both ECCs, the Spearman rank correlation of the FEV1 decrease was r = 0.58 (p < 0.001). The 95% limits of agreement (95% LOAs) for the FEV1 decrease were − 17.7 to 26.4%.ConclusionsThe surrogate markers PD20FEV1 of methacholine and maximal decrease in FEV1 during ECC can predict a positive reaction in another ECC, whereas the maximal FEV1 decrease in an exercise challenge at an ambient temperature was not predictive. Compared with previous studies, we can achieve a similar reproducibility with an ECC.Clinical trial registrationNCT02026492 (retrospectively registered 03/Jan/2014).

Do Urban Minority Parents and Children Agree on Asthma Symptoms with Exercise, Worries, and Confidence in Disease Management?

ObjectiveProviders commonly rely on parent reports of a child's asthma symptoms; however, children as young as 7 years can report on their own health. Our study compared parent and child reports of asthma symptoms with exercise, worries about developing an asthma attack, and confidence in disease management. MethodsWe recruited children ages 7 to 10 years with asthma from 4 Bronx, NY, schools, as well as their parents. The parents and children completed interview surveys with parallel questions regarding perceived asthma symptoms, asthma-related worries, and confidence in disease management. We used McNemar tests for paired data to compare parent and child responses. ResultsWe analyzed data for 105 parent-child pairs. Mean child age was 8.5 years (standard deviation, 0.99); 53% were male, and 82% were Hispanic. Children were more likely than their parents to report ever having an exercise-induced asthma attack (85% vs 48%; P < .001) and that they “worry a lot” about developing an asthma attack during exercise (63% vs 45%; P = .01). Children felt more confident about using an inhaler correctly (76% of the children were “very sure” vs 60% of the parents; P = .009) and were more likely to report having an inhaler available in case of an attack (38% of the children were “very sure” vs 20% of the parents; P = .003). ConclusionsIn this school-based sample of urban children with asthma, we found disagreement between parent and child reports of symptoms with exercise, worry about developing an attack, and confidence in medication use. These findings suggest that including child reports during history taking could help providers identify children in need of enhanced asthma management.

A Meta-analysis of Diagnostic Test Agreement Between Eucapnic Voluntary Hyperventilation and Cardiopulmonary Exercise Tests for Exercise-Induced Bronchoconstriction.

Exercise-induced bronchoconstriction (EIB) is very common in athletes. Cardiopulmonary exercise tests (CPET) have traditionally been used for the diagnosis of EIB. However, alternative indirect bronchoprovocation tests have recently been used as surrogate tests. One of these is the eucapnic voluntary hyperventilation (EVH). This meta-analysis studied the agreement between the two tests. An extensive search in PubMed and Medline was conducted for studies where participants underwent both CPET and EVH with measurement of forced expiratory volume in 1-second (FEV1). After extracting data using two-by-two contingency tables, pooled positive and negative agreements were first calculated between the two tests, with EVH benchmarked against CPET, and then, pooled positive and negative agreements were calculated with CPET benchmarked against EVH. The pooled positive and negative agreements between EVH and CPET (with CPET as the reference) were 0.62 [(95% confidence interval 0.54-0.70), I2 77%] and 0.61 [(0.56-0.65)), I2 81%]. The pooled positive and negative agreements between CPET and EVH (with EVH as the reference) were 0.36 [(0.30-0.42), I2 93%] and 0.82 [(0.77-0.86), I2 78%]. The average of positive test results with EVH across all studies was greater than that of CPETs (58.84% vs. 39.51%). Results of this meta-analysis show poor positive agreement between the two tests but high negative agreement (specifically using EVH as reference), suggesting that either test can be used for correctly identifying those without EIB. Results also suggest that the chances of a test resulting positive are higher with EVH than with CPET.

Exercise-induced bronchoconstriction and therapeutic modulation in Iraqi girls intermediate school students

EIB (Exercise-Induced Bronchoconstriction) describes the narrowing that occurs in the airway follow a short period of exercise. EIB is found in 8-10% of normal children population as occult bronchospasm during or after physical activities. The mechanismsofEIB are related to rapid ventilation and mouth breathing which cause heat and water loss during breathing leading to bronchoconstriction. Peak Expiratory Flow Rate (PEFR) measured pre and post-exercise in students aged 12-16 years in girl intermediate school. Any female shows PEFR values reduction 15% after 6 minutes continuous free running considered as asthmatic patient, this give an incidence rate of asthmatic patient of 9% in female students in this age. Treatment of EIB, Zafirlukast treatment gives (85.7%) protection rate. While salbutamol inhalation gives a protection rate 88%. Only 66.6 % of girls with EIB give an improvement in PEFR values after sodium cromoglycate treatment. A regular measurement of PEFR in school students appears to be a good indicator of EIB, while inhalation of salbutamol 15 minutes before exercise give a good protection against EIB attacks at least for 4 hours.

Assessing Exercise-Induced Bronchoconstriction in Children; The Need for Testing.

Objective: Exercise-induced bronchoconstriction (EIB) is a specific morbidity of childhood asthma and a sign of insufficient disease control. EIB is diagnosed and monitored based on lung function changes after a standardized exercise challenge test (ECT). In daily practice however, EIB is often evaluated with self-reported respiratory symptoms and spirometry. We aimed to study the capacity of pediatricians to predict EIB based on information routinely available during an outpatient clinic visit.Methods: A clinical assessment was performed in 20 asthmatic children (mean age 11.6 years) from the outpatient clinic of the MST hospital from May 2015 to July 2015. During this assessment, video images were made. EIB was measured with a standardized ECT performed in cold, dry air. Twenty pediatricians (mean years of experience 14.4 years) each evaluated five children, providing 100 evaluations, and predicted EIB severity based on their medical history, physical examination, and video images. EIB severity was predicted again after additionally providing baseline spirometry results.Results: Nine children showed no EIB, four showed mild EIB, two showed moderate, and five showed severe EIB. Based on clinical information and spirometry results, pediatricians detected EIB with a sensitivity of 84% (95% CI 72–91%) and a specificity of 24% (95% CI 14–39%).The agreement between predicted EIB severity classifications and the validated classifications after the ECT was slight [Kappa = 0.05 (95% CI 0.00–0.17)]. This agreement still remained slight when baseline spirometry results were provided [Kappa = 0.19 (95% CI 0.06–0.32)].Conclusion: Pediatricians' prediction of EIB occurrence was sensitive, but poorly specific. The prediction of EIB severity was poor. Pediatricians should be aware of this in order to prevent misjudgement of EIB severity and disease control.

Enantioselective disposition of (R,R)-formoterol, (S,S)-formoterol and their respective glucuronides in urine following single inhaled dosing and application to doping control.

Formoterol is a long-acting beta2-adrenoceptor agonist (LABA) used for the treatment of asthma and exercise-induced bronchoconstriction. Formoterol is usually administered as a racemic (rac-) mixture of (R,R)- and (S,S)-enantiomers. While formoterol is restricted by the World Anti-Doping Agency (WADA), inhalation of formoterol is permitted to a predetermined dose (54μg/24hours) and a urine threshold of 40ng/mL. However, chiral switch enantiopure (R,R)-formoterol is available, effectively doubling the therapeutic advantage for the same threshold. The aim of this study was to investigate whether formoterol exhibits enantioselective urinary pharmacokinetics following inhalation. Six healthy volunteers were administered a 12μg inhaled dose of rac-formoterol. Urine was collected over 24 hours and analyzed by enantioselective ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) assay. Total (free drug plus conjugated metabolite) median (min-max) rac-formoterol urine levels following inhalation were 1.96 (1.05-13.4) ng/mL, 1.67 (0.16-9.67) ng/mL, 0.45 (0.16-1.51) ng/mL, 0.61 (0.33-0.78) ng/mL, and 0.17 (0.08-1.06) ng/mL at 2, 4, 8, 12, and 24hours, respectively, well below the 2019 urine threshold. The proportion of conjugation differed between enantiomers with glucuronide conjugation much greater for (R,R)-formoterol (around 30%-60% of total) compared to (S,S)-formoterol (0%-30%). There was clear evidence of inter-individual enantioselectivity observed in the ratios of (R,R):(S,S)-formoterol, where (S,S)- was predominant in free formoterol, and (R,R)- predominant in the conjugated metabolite. In conclusion, rac-formoterol delivered by inhalation exhibits enantioselective elimination in urine following single-dose administration. Enantioselective assays should be employed in doping control to screen for banned beta2-agonist chiral switch products such as (R,R)-formoterol, and total hydrolyzed rac-formoterol is warranted to account for inter-individual differences in enantioselective glucuronidation.

Exercise-induced bronchoconstriction, temperature regulation and the role of heat shock proteins in non-asthmatic recreational marathon and half-marathon runners

Exercise is the most common trigger of bronchospasm. Heat shock protein (HSP) expression was linked to asthmatic patients. The prevalence and pathophysiology of exercise-induced bronchoconstriction (EIB) in non-professional non-asthmatic runners is unknown. We sought to investigate the frequency of EIB and cytokine changes in non-professional non-asthmatic marathon and half marathoners with and without EIB. Testing was performed before the marathon (baseline), immediately post-marathon at the finish area (peak), and 2–7 days after the marathon (recovery): immunosorbent assays for measurement of HSP70, blood count analysis, spirometry and temperature measurements. We experienced a decline in FEV1 of ≥10% in 35.29% of marathon and 22.22% of half marathon runners. Runners with EIB had significantly higher HSP70 serum concentrations at baseline than those without EIB (987.4 ± 1486.7 vs. 655.6 ± 1073.9; p = 0.014). Marathoners with EIB had significantly increased WBC before participating in the competition (7.4 ± 1.7 vs. 6.0 ± 1.5; p = 0.021). After recovery we found increased HSP70 serum concentrations in marathoners with EIB compared to those without (2539.2 ± 1692.5 vs. 1237.2 ± 835.2; p = 0.032), WBC (7.6 ± 1.8 vs. 6.4 ± 1.6; p = 0.048) and PLT (273.0 ± 43.0 vs 237.2 ± 48.3; p = 0.040). At all measured skin sites skin temperatures in runners were significantly lower immediately after participating in the competition when compared to temperature before the race (skin temperature baseline vs. peak: abdominal: 33.1 ± 0.2 vs. 30.0 ± 0.4; p < 0.001; upper arm: 31.6 ± 0.2 vs. 29.4 ± 0.3; p < 0.001; upper leg: 30.7 ± 0.3 vs. 29.4 ± 0.2; p = 0.014; lower leg: 30.6 ± 1.0 vs. 30.2 ± 1.5; p = 0.007). We found a higher than expected number of non-professional athletes with EIB. HSP70 serum concentrations and elevated WBC could indicate a predisposition to EIB.

Airway hyperresponsiveness in young children with respiratory symptoms: A five-year follow-up

BackgroundRecurrent wheezing in early life is transient in most children. The significance of airway hyperresponsiveness (AHR) in persistence of respiratory symptoms from infancy to early childhood is controversial. ObjectiveWe evaluated whether AHR in wheezy infants predicts doctor-diagnosed asthma (DDA) or AHR at the age of 6 years. MethodsSixty-one wheezy infants (age 6-24 months) were followed up to the median age of 6 years. Lung function and AHR with methacholine challenge test were assessed at infancy and 6 years. The exercise challenge test was performed at the age of 6 years. Atopy was assessed with skin prick tests. ResultsAt 6 years, 21 (34%) of the children had DDA. Children with DDA had higher logarithmic transformed dose-response slope (LOGDRS) to methacholine in infancy than children without DDA (0.047 vs 0.025; P = .033). Furthermore, AHR to methacholine in infancy and at 6 years were associated with each other (r = 0.324, P = .011). Children with exercise-induced bronchoconstriction (EIB) at 6 years were more reactive to methacholine in infancy than those without EIB (P = .019). ConclusionIncreased AHR in symptomatic infants was associated with increased AHR, DDA, and EIB at median the age of 6 years, suggesting early establishment of AHR.

Study of Serum Level of Lipoxin A4 in Exercise-Induced Bronchoconstriction in Asthmatic Children

AbstractBackground: Asthma is a chronic lung disease character-ized by wheezy chest, resulting from allergic inflammation and hyperresponsivness of the bronchi to various stimuli. Exercise-induced broncho constriction is a common manifes-tation of asthma in children and adolescents, occurring in up to 90% of asthmatic children. Lipoxins are the first agents determined to be anti-inflammatory endogenous lipid mediators involved in the resolution of inflammation. Since there is defective lipoxin biosynthesis in patients with severe asthma, we hypothesized that Lipoxin A4 may be related to develop-ment of exercise induced bronchoconstriction.Aim of Study: It was to measure serum level of lipoxin A4 before and after exercise to evaluate its role in exercise induced bronchoconstriction in asthmatic children.Patients and Methods: The study was carried out on fifteen children with mild intermittent or mild persistant asthma with positive response to exercise challenge test and fifteen children with mild intermittent or mild persistant asthma with negative response to exercise challenge test who attended to the outpatient clinic of Chest and Allergic Diseases, Pediatric Department, Tanta University Hospital. Also it was carried on fifteen apparently healthy children with matched age and sex served as a control group. All studied children were subjected to full history taking, thorough clinical exam-ination, plain chest X-ray, pulmonary function tests (FEV 1and PEFR) by spirometer before and after exercise challenge test, eosinophilic count, serum Lipoxin A4 by ELISA before and immediately after exercise challenge test. Data was analyzed by using SPSS.Results: There was significant more decrease in serum Lipoxin A4 after exercise in asthmatic children with exercise induced bronchoconstriction as compared to asthmatic children without exercise induced bronchoconstriction. Regarding pulmonary function tests (FEV 1 and PEFR), there was signif-icant more decrease in FEV 1 after exercise in asthmatic children with exercise induced bronchoconstriction as com-pared to asthmatic children without exercise induced bron-choconstriction but, there was no significant difference between the asthmatic children with exercise induced bronchoconstric-tion and asthmatic children without exercise induced bron-choconstriction regarding the decrease in PEFR after exercise. And there was no statistical significant difference between subject's sex, age, residence nor BMI.Conclusion: There was inverse correlation between serum LXA4 levels and a reduction in FEV 1 after exercise in asth-matic children. The demonstration of lower levels of lipoxin A4 in association with exercise induced bronchoconstriction suggest that the development of exercise-induced bronchoc-onstriction in asthmatic children may be due to reduced endogenous lipoxin biosynthetic capability. This association not affected by ages and sex of patients.

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.].

Fluticasone furoate/vilanterol versus fluticasone propionate in patients with asthma and exercise-induced bronchoconstriction

Objective: To investigate whether once-daily (OD) fluticasone furoate (FF)/vilanterol (VI) provides greater long-term protection from postexercise fall in forced expiratory volume in 1 s (FEV1) than twice-daily (BD) fluticasone propionate (FP) in patients with asthma and exercise-induced bronchoconstriction. Methods: A randomized, double-blind, crossover study was conducted in patients (aged 12–50 years) on low-/mid-dose maintenance inhaled corticosteroid. Following a 4-week run-in period (FP 250 µg BD), patients with a ≥ 20% decrease in postexercise FEV1 received FF/VI 100/25 µg OD or FP 250 µg BD for 2 weeks. Exercise challenges were carried out 23 h after the first dose of study medication, and 12 and 23 h after evening clinic dose at the end of the 2-week treatment period. After a 2-week washout period (FP 250 µg), patients crossed over treatments, with procedures and tests repeated. The primary endpoint was mean maximal percentage decrease from pre-exercise FEV1 following exercise challenge 12-h postevening dose on Day 14. Results: The mean maximal percentage decrease from pre-exercise FEV1 after the 12-h exercise challenge (Day 14) was 15.02% with FF/VI, and 16.71% with FP (difference, −1.69; 95% confidence interval, −3.76 to 0.39; p = 0.109). After the 23-h exercise challenge (Day 14), respective mean maximal decreases were 11.90% and 14.05% (difference, −2.15; 95% confidence interval, −4.31 to 0.01). Conclusion: The study failed to show a difference between FF/VI and FP at providing long-term protection from exercise-induced bronchoconstriction.

Ventilatory Demand During Stepping and Running: Implications for Exercise-Induced Bronchoconstriction in Children.

Single-step tests have been proposed as simple and inexpensive challenges to diagnose exercise-induced bronchoconstriction (EIB) in the pediatric population. Work performed and the resulting ventilation, however, might be substantially lower in stepping than running. This might decrease the diagnostic yield of step-based challenges. In a cross-sectional study, 53 children with asthma with exercise-related symptoms (34 boys, age 6-18 y) underwent an incremental stepping test, a 6-min constant stepping test, and a treadmill running test on different days. Constant and incremental stepping tests presented with lower metabolic demands (V̇O2 1.42 ± 0.48 and 1.34 ± 0.55 L/min, respectively), ventilatory demands (V̇O2 45 ± 14 and 43 ± 16 L/min, respectively), and cardiovascular demands (160 ± 20 and 161 ± 19 beats/min, respectively) than the treadmill running test (1.65 ± 0.60 L/min, 54 ± 17 L/min, and 172 ± 7 beats/min, respectively) (P < .05). Between-test agreement in diagnosing EIB was poor (kappa 0.217-0.361). Although EIB prevalence was higher after the treadmill running test (60%) compared to constant (53%) and incremental (47%) stepping tests, 7 subjects developed EIB only in stepping. Clinical and resting functional characteristics did not differ in discordant subjects (ie, EIB negative in a given test but positive in another) versus concordant subjects (ie, EIB negative or positive in both tests). EIB was not related to individual test ability in eliciting high to very-high ventilation (≥ 40% or ≥ 60% maximum voluntary ventilation, respectively). Moreover, a negative stepping test but a positive treadmill test (and vice versa) was not associated with greater ventilatory demands. Lower prevalence of EIB in stepping compared to treadmill running is not related to less ventilation demand in the former modality. Although stepping might be useful as a screening EIB test due its portability and low cost, a negative test should be confirmed with a running-based test in symptomatic children.

Serum levels of periostin and exercise-induced bronchoconstriction in asthmatic children

BackgroundPeriostin is induced by IL-13 and has been studied as a biomarker of asthma. The present study explored the relationship between serum levels of periostin and exercise-induced bronchoconstriction (EIB) in asthmatic children. MethodsThe study population consisted of 86 children 6–15 years old divided into an asthmatic group (n = 56) and healthy controls (n = 30). We measured the levels of periostin in serum and performed pulmonary function tests including baseline measurements, post-bronchodilator inhalation tests, exercise bronchial provocation tests (BPTs), and mannitol BPTs. ResultsThe 56 asthmatic children were divided into four groups: asthmatics with positive exercise BPT and positive mannitol BPT (n = 30), asthmatics with positive exercise BPT but negative mannitol BPT (n = 7), asthmatics with negative exercise BPT but positive mannitol BPT (n = 10), and asthmatics with negative exercise BPT and negative mannitol BPT (n = 9). Serum levels of periostin in asthmatic children with both positive exercise and mannitol BPT were significantly greater than those in asthmatic children with both negative exercise and mannitol BPT (95.0 [75.0–104.0] vs. 79.0 [68.0–82.5] ng/mL, P = 0.008) and controls (74.0 [69.75–80.0] ng/mL, P < 0.001). Periostin levels were significantly correlated with both the maximum decrease in %FEV1 and mannitol PD15 value. ConclusionSerum levels of periostin in asthmatic children with both positive exercise and mannitol BPT were significantly greater than those in asthmatic children with both negative exercise and mannitol BPT and also greater than in healthy controls.

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

PurposeAsthma 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 methodsA 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.ResultsThere 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.ConclusionThe 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.

Asthma and exercise-induced respiratory disorders in athletes. The position paper of the Polish Society of Allergology and Polish Society of Sports Medicine.

Exercise-induced respiratory symptoms describe acute airway narrowing that occurs as a result of exercise. It includes exercise-induced bronchoconstriction (EIB) and exercise-induced asthma (EIA) issues. To provide clinicians with practical guidelines, a multidisciplinary panel of stakeholders was convened to review the pathogenesis of EIB/EIA and to develop evidence-based guidelines for the diagnosis and treatment. Recommendations for the diagnosis and treatment of EIB were developed. High-intensity exercise in polluted environment (cold air, humidity, contamination, allergens) may increase the risk of EIB and asthma symptoms in athletes. Diagnostic procedures should include history taking, physical examination, atopy assessment and functional tests of the respiratory system. A strong recommendation was made for regular use of inhaled glucocorticosteroids and avoidance of short-acting β2-agonists as the only treatment. The treatment of asthma in athletes should always take into account current anti-doping regulations. This position paper reflects the currently available evidence.

Asthma prevalence and control levels among Special Olympics athletes, and asthma-related knowledge of their coaches.

The prevalence of asthma among athletes with intellectual disabilities, and the asthma knowledge levels of their coaches, is unknown. Special Olympics Canada athletes completed a demographic questionnaire (n=208). Athletes who identified as having ever or current asthma completed the Asthma Control Questionnaire and the Mini Asthma Quality of Life Questionnaire and were measured for height, weight and lung function (n=73). National level coaches (n=27) completed a questionnaire pertaining to asthma knowledge. The prevalence of ever and current asthma were 35.5% (n=73) and 21.1% (n=44), respectively. Athletes with asthma reported that they had inadequately controlled asthma, but good quality of life. Coaches correctly answered 43% true/false questions on the survey, indicating suboptimal asthma knowledge. Athletes with intellectual disabilities appear to have a greater prevalence of asthma than the general population; however, coaches of these athletes appear to have limited knowledge pertaining to asthma and exercise-induced asthma.

Inconsistent calculation methodology for the eucapnic voluntary hyperpnoea test affects the diagnosis of exercise-induced bronchoconstriction

IntroductionThe eucapnic voluntary hyperpnoea (EVH) challenge is used to screen for exercise-induced bronchoconstriction. Several criteria have been proposed to determine the decrease in lung function (fall index, FI) following EVH....

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.

ALGORITHM FOR THE DIAGNOSIS AND TREATMENT OF EXERCISE-INDUCED BRONCHOSPASM

Introduction Exercise-induced bronchospasm (EIB) is the acute onset of transient bronchoconstriction of the lower airways during or immediately following exercise. The prevalence of EIB in the general population is only 5-20% compared to up to 90% in asthmatic patients. In EIB, the initial bronchodilation from exercise is then followed by bronchoconstriction resulting in subsequent symptoms. Case Description A 15-year-old boy with severe asthma on high-dose combination therapy and significant recurrent episodes of shortness of breath, chest tightness, and difficulty breathing with activities presented to our Day Program for evaluation and treatment. During his exercise challenge, his FEV1 decreased from a baseline of 125% predicted to 48% predicted (>77%). He was diagnosed with EIB. His eNO and leukotriene E4 (LTE4) levels were unremarkable, and urinary prostaglandin E2 was present. Bronchoscopy was essentially normal. Two different pre-treatment regiments involving pre-exercise warm-up, tiotropium, montelukast, albuterol, and ipratropium bromide followed by a standardized free run were all insufficient to fully block the drop in FEV1, and nebulized cromolyn was ultimately required. Since cromolyn in the United States is only available in nebulized form, we were unable to transition him to an MDI. Discussion Severe EIB can still occur in patients with normal baseline spirometry and can lead to a reduction in quality of life. Repeated exercise challenges are critical in assessing response to EIB interventions. Cromolyn is an effective therapy and the lack of metered dose inhalers limits it use. Exercise-induced bronchospasm (EIB) is the acute onset of transient bronchoconstriction of the lower airways during or immediately following exercise. The prevalence of EIB in the general population is only 5-20% compared to up to 90% in asthmatic patients. In EIB, the initial bronchodilation from exercise is then followed by bronchoconstriction resulting in subsequent symptoms. A 15-year-old boy with severe asthma on high-dose combination therapy and significant recurrent episodes of shortness of breath, chest tightness, and difficulty breathing with activities presented to our Day Program for evaluation and treatment. During his exercise challenge, his FEV1 decreased from a baseline of 125% predicted to 48% predicted (>77%). He was diagnosed with EIB. His eNO and leukotriene E4 (LTE4) levels were unremarkable, and urinary prostaglandin E2 was present. Bronchoscopy was essentially normal. Two different pre-treatment regiments involving pre-exercise warm-up, tiotropium, montelukast, albuterol, and ipratropium bromide followed by a standardized free run were all insufficient to fully block the drop in FEV1, and nebulized cromolyn was ultimately required. Since cromolyn in the United States is only available in nebulized form, we were unable to transition him to an MDI. Severe EIB can still occur in patients with normal baseline spirometry and can lead to a reduction in quality of life. Repeated exercise challenges are critical in assessing response to EIB interventions. Cromolyn is an effective therapy and the lack of metered dose inhalers limits it use.

Prevalence of asthma, allergic rhinitis and atopic dermatitis in school children of the Mexican Bajío region

The prevalence of allergic diseases markedly varies according to the geographical region. To determine the prevalence of asthma, allergic rhinitis and atopic dermatitis in children of six and seven years of age. Cross-sectional study that included a sample of almost 15 thousand children in five cities of Mexico. To obtain the prevalence of allergic diseases and their symptoms, the parents of the children answered The International Study of Asthma and Allergies in Childhood questionnaire. 95% confidence intervals (CI) were estimated for proportions. Of the total sample, 7466 (52.5 %) were boys and 7463 (47.5%) girls. In general, the prevalence of asthma, exercise-induced asthma and current asthma was 6.1 % (95% CI = 5.7%-6.5%), 2.1 % (95% CI = 1.9%-2.3%) and 11.6 % (95% CI = 11.1% -12.1%), respectively. On the other hand, the prevalence of allergic rhinitis was 5.4 % (95% CI = 5.1%-5.8%), rhinitis with conjunctivitis, 19.2 % (95% CI = 18.6%-19.8%), and current rhinitis, 52.8% (95% CI = 52.0%-53.6%). The prevalence of atopic dermatitis and current dermatitis was 3.4 % (95% CI = 3.1%-3.7%) and 7.8% (95 % CI = 7.4%-8.2%), respectively. Our results indicate that the prevalence of allergic diseases in school children is similar to that observed in previous studies in Mexico.