Prevalence of lower airway dysfunction in athletes: a systematic review and meta-analysis by a subgroup of the IOC consensus group on ‘acute respiratory illness in the athlete’

ObjectiveTo report the prevalence of lower airway dysfunction in athletes and highlight risk factors and susceptible groups.DesignSystematic review and meta-analysis.Data sourcesPubMed, EBSCOhost and Web of Science (1 January 1990 to 31 July 2020).Eligibility criteriaOriginal full-text studies, including male or female athletes/physically active individuals/military personnel (aged 15–65 years) who had a prior asthma diagnosis and/or underwent screening for lower airway dysfunction via self-report (ie, patient recall or questionnaires) or objective testing (ie, direct or indirect bronchial provocation challenge).ResultsIn total, 1284 studies were identified. Of these, 64 studies (n=37 643 athletes) from over 21 countries (81.3% European and North America) were included. The prevalence of lower airway dysfunction was 21.8% (95% CI 18.8% to 25.0%) and has remained stable over the past 30 years. The highest prevalence was observed in elite endurance athletes at 25.1% (95% CI 20.0% to 30.5%) (Q=293, I2=91%), those participating in aquatic (39.9%) (95% CI 23.4% to 57.1%) and winter-based sports (29.5%) (95% CI 22.5% to 36.8%). In studies that employed objective testing, the highest prevalence was observed in studies using direct bronchial provocation (32.8%) (95% CI 19.3% to 47.2%). A high degree of heterogeneity was observed between studies (I2=98%).ConclusionLower airway dysfunction affects approximately one in five athletes, with the highest prevalence observed in those participating in elite endurance, aquatic and winter-based sporting disciplines. Further longitudinal, multicentre studies addressing causality (ie, training status/dose–response relationship) and evaluating preventative strategies to mitigate against the development of lower airway dysfunction remain an important priority for future research.

Bronchial provocation test measured by using the forced oscillation technique to assess airway responsiveness

Background: The bronchial provocation test (BPT) performed by using the forced oscillation technique (FOT) is cooperated without forced expiratory effort. However, a comparison of the application value and safety of BPTs measured by using the FOT and the standardized dosimeter method is lacking, which limits its clinical practice. Objective: We aimed to analyze the diagnostic value and safety of the BPT as measured by the FOT in patients with asthma and in healthy subjects. Methods: This was a randomized cross-over clinical study. Airway responsiveness was measured by using the FOT and the aerosol provocation system (APS) dosimeter method in all the participants. The between-test interval was 24 hours. The diagnostic value and safety of the two tests were analyzed. Results: Asthma control status was assessed based on ACT scores, and patients with asthma (including 27 uncontrolled, 34 partially controlled, and 32 controlled) were collected, and 69 healthy subjects were recruited. Receiver operating characteristic curves revealed slightly superior screening capability of cumulative dose of methacholine causing a 20% decrease (PD20)‐forced expiratory volume in the first second of expiration when measured by using the APS-dosimeter method (area under the curve [AUC] 0.981 [95% confidence interval {CI}, 0.952‐1.000]) over that of cumulative dose of inhaled methacholine at the inflection point when respiratory resistance began to increase continuously (Dmin) by using the FOT (AUC 0.959 [95% CI, 0.924‐0.994]). The sensitivity and specificity were 98.9% and 98.6%, respectively, with the APS-dosimeter method, and 100% and 87.0%, respectively, with the FOT. It took an average of 9.0 minutes (range, 6.0‐11.0 minutes) when using the FOT and an average of 17.0 minutes (range, 14.0‐25.0 minutes) when using APS-dosimeter method (p < 0.01) in all the participants. The measurement time for the FOT was reduced by 47.1% than the APS-dosimeter. The incidence rate of the adverse events with the FOT was slightly higher than that with the APS-dosimeter method (p < 0.05). Both tests were well tolerated. No serious adverse event was found. Conclusion: The FOT, characterized as being simple, safe, and time saving, could be used to assess airway hyperresponsiveness in patients with asthma and worthy of clinical application.

Hyperreactivity of the bronchi in children, whooping cough convalescents

Objective: to assess the presence and degree of bronchial hyperreactivity in convalescents of whooping cough based on the results of bronchial provocation tests.Materials and methods. Using bronchial provocative samples with a 0,02/0,33% histamine solution and 0,33% methacholine solution on a PROVOTEST-2 apparatus from PARI, bronchial hyperreactivity was studied in 12 pertussis convalescents aged 7 to 17 years. The level of endogenous nitrogen monoxide in exhaled air (FeNO) was measured using a portable NObreath electrochemical analyzer (from Bedfont Scientific Ltd.).The results. According to the results of BPP, 6 of 12 convalescents of whooping cough were found to have bronchial hyperreactivity of varying degrees. When conducting a breath test with a histamine solution, bronchial hyperreactivity was recorded in three children, in a sample with methacholine, in five. In 3 out of 6 children with revealed signs of bronchial hyperreactivity, the history of atopy was not burdened, which suggests a connection between the pertussis and the development of bronchial hyperreactivity. A significant increase in the level of endogenous nitric monoxide (above 16 ppb) was observed in 2 out of 10 patients. Follow-up observation showed that the duration of cough with whooping cough ranged from 3 to 6 months, and in patients with positive results of several tests it was maximum. Two out of three children with bronchial asthma showed elevated levels of FeNO and samples with methacholine. Follow-up observation showed that whooping cough aggravated bronchial asthma and demanded correction therapy.Conclusion. A pilot study on the evaluation of bronchial provocative tests suggests that the formation of bronchial hyperreactivity in convalescents of whooping cough is probable, including without a history of atopy, which increases the risk of developing bronchial asthma, however, additional studies are required for a final conclusion.