Diagnosing exercise-induced bronchoconstriction: Over-or under-detection?

Fractional exhaled nitric oxide in the assessment of exercise-induced bronchoconstriction: A multicenter retrospective analysis of UK-based athletes

INTRODUCTION

Exercise-induced bronchoconstriction (EIB) is not only highly prevalent in people with asthma, but can also occur independently, particularly in athletes. Fractional exhaled nitric oxide (FeNO) is an indirect biomarker of type 2 airway inflammation that has an established role in the assessment and management of asthma. The aim was to evaluate the value of FeNO in the assessment of EIB in athletes.

METHOD

Multicenter retrospective analysis. In total, 488 athletes (male: 76%) performed baseline FeNO, and spirometry pre- and post-indirect bronchial provocation via eucapnic voluntary hyperpnea (EVH). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for established FeNO thresholds-that is, intermediate (≥25 ppb) and high FeNO (≥40 ppb and ≥ 50 ppb)-and were evaluated against objective evidence of EIB (≥10% fall in FEV₁ ). The diagnostic accuracy of FeNO was calculated using receiver operating characteristics area under the curve (ROC-AUC).

RESULTS

Thirty-nine percent of the athletes had a post-EVH fall in FEV₁ consistent with EIB. FeNO values ≥25 ppb, ≥40 ppb, and ≥ 50 ppb were observed in 42%, 23%, and 17% of the cohort, respectively. The sensitivity of FeNO ≥25 ppb was 55%, which decreased to 37% and 27% at ≥40 ppb and ≥ 50 ppb, respectively. The specificity of FeNO ≥25 ppb, ≥40 ppb, and ≥ 50 ppb was 66%, 86%, and 89%, respectively. The ROC-AUC for FeNO was 0.656.

CONCLUSIONS

FeNO ≥40 ppb provides good specificity, that is, the ability to rule-in a diagnosis of EIB. However, due to the poor sensitivity and predictive values, FeNO should not be employed as a replacement for indirect bronchial provocation in athletes.

Diagnosis and management of allergy and respiratory disorders in sport: An EAACI task force position paper

Allergy and respiratory disorders are common in young athletic individuals. In the context of elite sport, it is essential to secure an accurate diagnosis in order to optimize health and performance. It is also important, however, to consider the potential impact or consequences of these disorders, in recreationally active individuals engaging in structured exercise and/or physical activity to maintain health and well-being across the lifespan. This EAACI Task Force was therefore established, to develop an up-to-date, research-informed position paper, detailing the optimal approach to the diagnosis and management of common exercise-related allergic and respiratory conditions. The recommendations are informed by a multidisciplinary panel of experts including allergists, pulmonologists, physiologists and sports physicians. The report is structured as a concise, practically focussed document, incorporating diagnostic and treatment algorithms, to provide a source of reference to aid clinical decision-making. Throughout, we signpost relevant learning resources to consolidate knowledge and understanding and conclude by highlighting future research priorities and unmet needs.

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'

OBJECTIVE

To report the prevalence of lower airway dysfunction in athletes and highlight risk factors and susceptible groups.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed, EBSCOhost and Web of Science (1 January 1990 to 31 July 2020).

ELIGIBILITY CRITERIA

Original 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).

RESULTS

In 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%).

CONCLUSION

Lower 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.

Asthma medication in athletes: a qualitative investigation of adherence, avoidance and misuse in competitive sport

OBJECTIVES

The purpose of this qualitative study was to utilize the Capability, Opportunity, Motivation - Behavior model (COM-B) to: (1) evaluate athlete knowledge and understanding of current asthma-related anti-doping regulations, (2) explore the impact of environmental and societal influences on athletes with asthma, and (3) examine athlete perception of asthma medication use in competitive sport.Methods: Semi-structured interviews were conducted with ten competitive endurance athletes (five athletes with asthma and five without asthma). Interviews were guided by the COM-B model and transcripts were analyzed inductively and deductively using reflexive thematic analysis.Results: Mapping the experiences and perceptions of athletes against an established behavioral framework identified that: (1) athletes' possess limited knowledge and understanding of the World Anti-Doping Agency (WADA) Prohibited List and Therapeutic use exemption (TUE) policy with respect to asthma medication; (2) the use of sub-optimal diagnostic methods is commonplace and increases the risk of misdiagnosis and unnecessary inhaler therapy; (3) negative media portrayal of high-profile asthma-related doping allegations impacts public opinion and contributes to the perception of wrongdoing within the sporting community.Conclusion: The novel application of behavioral science highlights several factors that may contribute to asthma medication avoidance and promote misuse in competitive sport. The findings from this study provide a foundation for the development and implementation of targeted education programmes, and it is hoped that employing this approach will ultimately improve overall perceptions of asthma treatment in athletes, which is necessary to maintain respiratory health, optimize performance and protect the integrity of sport.

© 2021 The Author(s). Published with license by Taylor & Francis Group, LLC.

The feasibility of eucapnic voluntary hyperpnoea for the diagnosis of exercise-induced bronchoconstriction in a community pulmonary practice

OBJECTIVE

Exercise-induced bronchoconstriction (EIB) is a common condition and is typically treated empirically based on symptoms alone. However, symptoms of EIB are typically nonspecific. Objective testing with eucapnic voluntary hyperpnea (EVH) is a sensitive and specific method to diagnose EIB and may suggest alternative etiologies such as exercise-induced laryngeal obstruction (EILO). To this point, EVH has been primarily utilized in large academic centers and in elite athletes. We intend to discuss the feasibility and clinical application of utilizing EVH to diagnose EIB in a community-based pulmonary practice.

METHODS

Retrospective analysis of 62 patients who completed EVH at The Oregon Clinic Pulmonary Clinic. Patients with inspiratory flow volume loop flattening or clinical symptoms were assessed by otolaryngology for evidence of EILO.

RESULTS

61 of 62 patients were included in the final analysis. 52 of 61 patients (85%) achieved an interpretable test with a maximum voluntary ventilation (MVV) >60%. There was no difference in baseline spirometry or patient characteristics between those who were able to reach an MVV >60% and those who did not. 14 (23%) patients were diagnosed with EIB, 18 (30%) with EILO, and 4 (7%) were diagnosed with both EIB and EILO. Only 1 patient had a non-diagnostic evaluation with MVV <60% and negative for EIB and EILO.

CONCLUSIONS

EVH is a feasible diagnostic modality to evaluate for EIB in a community pulmonary practice and may suggest alternative conditions such as EILO. Accurate diagnosis is paramount to prescribing proper therapy, decreasing inappropriate medication use, and relieving exercise-induced symptoms.