Phenotypic analysis of asthma in Japanese athletes

Computational Phenotyping of Obstructive Airway Diseases: A Systematic Review

Introduction

Computational sciences have significantly contributed to characterizing airway disease phenotypes, complementing medical expertise. However, comparing studies that derive phenotypes is challenging due to varying decisions made during phenotyping. We conducted a systematic review to describe studies that utilized unsupervised computational approaches for phenotyping obstructive airway diseases in children and adults.

Methods

We searched for relevant papers published between 2010 and 2020 in PubMed, EMBASE, Scopus, Web of Science, and Google Scholar. Additional sources included conference proceedings, reference lists, and expert recommendations. Two reviewers independently screened studies for eligibility, extracted data, and assessed study quality. Disagreements were resolved by a third reviewer. An in-house quality appraisal tool was used. Evidence was synthesized, focusing on populations, variables, and computational approaches used for deriving phenotypes.

Results

Of 120 studies included in the review, 60 focused on asthma, 19 on severe asthma, 28 on COPD, 4 on asthma-COPD overlap (ACO), and 9 on rhinitis. Among asthma studies, 31 focused on adults and 9 on children, with phenotypes related to atopy, age at onset, and disease severity. Severe asthma phenotypes were characterized by symptomatology, atopy, and age at onset. COPD phenotypes involved lung function, emphysematous changes, smoking, comorbidities, and daily life impairment. ACO and rhinitis phenotypes were mostly defined by symptoms, lung function, and sensitization, respectively. Most studies used hierarchical clustering, with some employing latent class modeling, mixture models, and factor analysis. The comprehensiveness of variable reporting was the best quality indicator, while reproducibility measures were often lacking.

Conclusion

Variations in phenotyping methods, study settings, participant profiles, and variables contribute to significant differences in characterizing asthma, severe asthma, COPD, ACO, and rhinitis phenotypes across studies. Lack of reproducibility measures limits the evaluation of computational phenotyping in airway diseases, underscoring the need for consistent approaches to defining outcomes and selecting variables to ensure reliable phenotyping.

Exercise-induced bronchoconstriction in children: Delphi study and consensus document about definition and epidemiology, diagnostic work-up, treatment, and follow-up

BACKGROUND

Exercise-induced bronchoconstriction (EIB) is common in children with asthma but can be present also in children without asthma, especially athletes. Differential diagnosis includes several conditions such as exercise-induced laryngeal obstruction (EILO), cardiac disease, or physical deconditioning. Detailed medical history, clinical examination and specific tests are mandatory to exclude alternative diagnoses. Given the high prevalence of EIB in children and its potential impact on health, sport performance, and daily levels of physical activity, health care professionals should be aware of this condition and able to provide a specific work-up for its identification. The aims of the present study were: (a) to assess the agreement among hospital pediatricians and primary care pediatricians of Emilia-Romagna Region (Italy) about the management of EIB in children and (b) formulate statements in a consensus document to help clinicians in daily clinical practice.

METHODS

According to Delphi method, a panel of specialists scored 40 statements that were then revised and discussed during online meetings to reach full consensus. Statements were then formulated.

RESULTS

To obtain full consensus, the questionnaire was administered in two rounds after full discussion of the uncertain topics on the basis of the latest evidence on EIB published over the last 10 years. Despite an overall agreement on EIB management, some gaps emerged in the sections dedicated to diagnosis and treatment. Nine summary statements on definition, pathogenesis, diagnostic work-up, treatment, and follow-up were eventually formulated.

CONCLUSIONS

This study describes the knowledge of EIB in a group of pediatricians and highlights gaps and uncertainties in diagnosis and treatment. The creation of statements shared by the specialists of the same area may improve the management of EIB in children. However, more research and evidence are needed to better clarify the best treatment and to standardize the best diagnostic protocol limiting useless examinations but at the same time assuring the best management.

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.

A longitudinal study of exercise-induced bronchoconstriction and laryngeal obstruction in high school athletes

BACKGROUND

Exercise-induced bronchoconstriction (EIB) and exercise-induced laryngeal obstruction (EILO) are common in elite athletes. Knowledge of which factors are related to incident EIB and EILO is limited. The aim of this study was to explore the course of EIB and EILO in adolescent athletes over a 2 years period and baseline characteristics related to incident EIB.

METHODS

Questionnaire data on respiratory symptoms, asthma, and aeroallergy and results of objective EIB and EILO tests were collected from 58 participants (27 tested for EILO) at baseline and after 2 years (follow-up). Associations between incident EIB and baseline asthma-like symptoms, exercise-induced symptoms, fractional exhaled nitric oxide (FeNO), aeroallergy, and sex were assessed using logistic regression models.

RESULTS

Ten participants had incident EIB, and eight participants had persistent EIB. Five were EIB positive at baseline but negative at follow-up, while 35 participants were EIB negative at both time points. Having incident EIB was associated with reporting waking up with chest tightness (OR = 4.38; 95% CI: 1.06, 22.09). Reporting an increased number of asthma-like symptoms increased the likelihood of incident EIB (OR = 2.78; 95% CI: 1.16, 6.58). No associations were found between exercise-induced symptoms, FeNO, aeroallergy, or sex and incident EIB. Incident EILO was found in three and persistent EILO in two of the 27 participants tested.

CONCLUSION

Two in nine had incident EIB and one eighth had incident EILO, suggesting that recurrent testing for EIB and EILO may be relevant in young athletes. Particularly, EIB-negative athletes reporting multiple asthma-like symptoms could benefit from recurrent EIB testing.

Asthma in elite athletes - do they have Type 2 or non-Type 2 disease? A new insight on the endotypes among elite athletes

Asthma and exercise-induced bronchoconstriction are highly prevalent in elite athletes compared with the general population. Some athletes have classic asthma with allergic sensitization; however, it seems that a proportion of athletes develop asthma as a result of several years of intensive training. It leads us to believe that asthma in athletes consists of at least two distinct endotypes - classic early-onset, Type 2 mediated asthma, and asthma with later onset caused by exercise which might be classified as non-Type 2 asthma. The purpose of this review is to evaluate the current literature on asthma in athletes focusing on inflammation and examine if asthma in athletes could be characterized as either Type 2- or non-Type 2 asthma.

Overuse of Short-Acting Beta-2 Agonists (SABAs) in Elite Athletes: Hypotheses to Explain It

The use of short-acting beta-2 agonists (SABAs) is more common in elite athletes than in the general population, especially in endurance sports. The World Anti-Doping Code places some restrictions on prescribing inhaled β2-agonists. These drugs are used in respiratory diseases (such as asthma) that might reduce athletes’ performances. Recently, studies based on the results of the Olympic Games revealed that athletes with confirmed asthma/airway hyperresponsiveness (AHR) or exercise-induced bronchoconstriction (EIB) outperformed their non-asthmatic rivals. This overuse of SABA by high-level athletes, therefore, raises some questions, and many explanatory hypotheses are proposed. Asthma and EIB have a high prevalence in elite athletes, especially within endurance sports. It appears that many years of intensive endurance training can provoke airway injury, EIB, and asthma in athletes without any past history of respiratory diseases. Some sports lead to a higher risk of asthma than others due to the hyperventilation required over long periods of time and/or the high environmental exposure while performing the sport (for example swimming and the associated chlorine exposure). Inhaled corticosteroids (ICS) have a low efficacy in the treatment of asthma and EIB in elite athletes, leading to a much greater use of SABAs. A significant proportion of these high-level athletes suffer from non-allergic asthma, involving the th1-th17 pathway.

Management of Exercise-Induced Bronchoconstriction in Athletes

Exercise-induced bronchoconstriction (EIB) is a phenomenon observed in asthma but is also seen in healthy individuals and frequently in athletes. High prevalence rates are observed in athletes engaged in endurance sports, winter sports, and swimming. The pathophysiology of EIB is thought to be related to hyperventilation, cold air, and epithelial damage caused by chlorine and fine particles in inspired air. Several diagnostic procedures can be used; however, the diagnosis of EIB based on self-reported symptoms is not reliable and requires an objective examination. The hyperosmolar inhalation test and eucapnic voluntary hyperpnea test, which involve indirect stimulation of the airway, are useful for the diagnosis of EIB. A short-acting β-agonist is the first choice for prevention of EIB, and an inhaled corticosteroid is essential for patients with asthma. Furthermore, treatment should accommodate antidoping requirements in elite athletes. Tailoring of the therapeutic strategy to the individual case and the prognosis after cessation of athletic activity are issues that should be clarified in the future.

Cysteinyl Leukotriene Synthesis via Phospholipase A2 Group IV Mediates Exercise-induced Bronchoconstriction and Airway Remodeling

It is well known that the prevalence of asthma is higher in athletes, including Olympic athletes, than in the general population. In this study, we analyzed the mechanism of exercise-induced bronchoconstriction by using animal models of athlete asthma. Mice were made to exercise on a treadmill for a total duration of 1 week, 3 weeks, or 5 weeks. We analyzed airway responsiveness, BAL fluid, lung homogenates, and tissue histology for each period. In mice that were treated (i.e., the treatment model), treatments were administered from the fourth to the fifth week. We also collected induced sputum from human athletes with asthma and analyzed the supernatants. Airway responsiveness to methacholine was enhanced with repeated exercise stimulation, although the cell composition in BAL fluid did not change. Exercise induced hypertrophy of airway smooth muscle and subepithelial collagen deposition. Cysteinyl-leukotriene (Cys-LT) levels were significantly increased with exercise duration. Montelukast treatment significantly reduced airway hyperresponsiveness (AHR) and airway remodeling. Expression of PLA₂G4 (phospholipase A₂ group IV) and leukotriene C₄ synthase in the airway epithelium was upregulated in the exercise model, and inhibition of PLA₂ ameliorated AHR and airway remodeling, with associated lower levels of Cys-LTs. The levels of Cys-LTs in sputum from athletes did not differ between those with and without sputum eosinophilia. These data suggest that AHR and airway remodeling were caused by repeated and strenuous exercise. Cys-LTs from the airway epithelium, but not inflammatory cells, may play an important role in this mouse model.