Is asthma over- or under-diagnosed in athletes?

Exercise-induced bronchoconstriction in athletes - A qualitative assessment of symptom perception

BACKGROUND

A poor relationship between perceived respiratory symptoms and objective evidence of exercise-induced bronchoconstriction (EIB) in athletes is often reported; however, the reasons for this disconnect remain unclear. The primary aim of this study was to utilise a qualitative-analytical approach to compare respiratory symptoms in athletes with and without objectively confirmed EIB.

METHODS

Endurance athletes who had previously undergone bronchoprovocation test screening for EIB were divided into sub-groups, based on the presence or absence of EIB ± heightened self-report of dyspnoea: (i) EIB-Dys- (ii) EIB + Dys+ (iii) EIB + Dys- (iv) EIB-Dys+. All athletes underwent a detailed semi-structured interview.

RESULTS

Twenty athletes completed the study with an equal distribution in each sub-group (n = 5). Thematic analysis of individual narratives resulted in four over-arching themes: 1) Factors aggravating dyspnoea, 2) Exercise limitation, 3) Strategies to control dyspnoea, 4) Diagnostic accuracy. The anatomical location of symptoms varied between EIB + Dys + athletes and EIB-Dys + athletes. All EIB-Dys + reported significantly longer recovery times following high-intensity exercise in comparison to all other sub-groups. Finally, EIB + Dys + reported symptom improvement following beta-2 agonist therapy, whereas EIB-Dys + deemed treatment ineffective.

CONCLUSION

A detailed qualitative approach to the assessment of breathlessness reveals few features that distinguish between EIB and non-EIB causes of exertional dyspnoea in athletes. Important differences that may provide value in clinical work-up include (i) location of symptoms, (ii) recovery time following exercise and (iii) response to beta-2 agonist therapy. Overall these findings may inform clinical evaluation and development of future questionnaires to aid clinic-based assessment of athletes with dyspnoea.

Advances in the diagnosis of exercise-induced bronchoconstriction

Exercise-induced bronchoconstriction (EIB) describes the post exercise phenomenon of acute airway narrowing in association with physical activity. A high prevalence of EIB is reported in both athletic and recreationally active populations. Without treatment, EIB has the potential to impact upon both health and performance. It is now acknowledged that clinical assessment alone is insufficient as a sole means of diagnosing airway dysfunction due to the poor predictive value of symptoms. Furthermore, a broad differential diagnosis has been established for EIB, prompting the requirement of objective evidence of airway narrowing to secure an accurate diagnosis. This article provides an appraisal of recent advances in available methodologies, with the principle aim of optimising diagnostic assessment, treatment and overall clinical care.

Practical approach to exercise-induced bronchoconstriction in athletes

Exercise-induced bronchoconstriction (EIB) is highly prevalent in athletes of all abilities and can impact on their health and performance. The majority of athletes with exertional dyspnoea will be initially assessed and managed in primary care. This report provides a practical and pragmatic approach to the assessment and management of a young athlete presenting with suspected EIB in this setting.

Misdiagnosis of exercise-induced bronchoconstriction in professional soccer players

BACKGROUND

Physicians typically rely heavily on self-reported symptoms to make a diagnosis of exercise-induced bronchoconstriction (EIB). However, in elite sport, respiratory symptoms have poor diagnostic value. In 2009, following a change in international sports regulations, all elite athletes suspected of asthma and/or EIB were required to undergo pulmonary function testing (PFT) to permit the use of inhaled β(2)-agonists. The aim of this study was to examine the diagnostic accuracy of physician diagnosis of asthma/EIB in English professional soccer players.

METHODS

Sixty-five players with a physician diagnosis of asthma/EIB were referred for pulmonary function assessment. Medication usage and respiratory symptoms were recorded by questionnaire. A bronchial provocation test with dry air was conducted in 42 players and a mannitol challenge in 18 players. Five players with abnormal resting spirometry performed a bronchodilator test.

RESULTS

Of the 65 players assessed, 57 (88%) indicated regular use of asthma medication. Respiratory symptoms during exercise were reported by 57 (88%) players. Only 33 (51%) of the players tested had a positive bronchodilator or bronchial provocation test. Neither symptoms nor the use of inhaled corticosteroids were predictive of pulmonary function tests' outcome.

CONCLUSION

A high proportion of English professional soccer players medicated for asthma/EIB (a third with reliever therapy only) do not present reversible airway obstruction or airway hyperresponsiveness to indirect stimuli. This underlines the importance of objective PFT to support a symptoms-based diagnosis of asthma/EIB in athletes.

Exercise-induced bronchoconstriction in Tunisian elite athletes is underdiagnosed

Many studies have shown an increased risk of developing exercise-induced bronchoconstriction among the athletic population, particularly at the elite level. Subjective methods for assessing exercise-induced bronchoconstriction such as surveys and questionnaires have been used but have resulted in an underestimation of the prevalence of airway dysfunction when compared with objective measurements. The aim of the present study was to compare the prevalence of exercise-induced bronchoconstriction among Tunisian elite athletes obtained using an objective method with that using a subjective method, and to discuss the possible causes and implications of the observed discrepancy. As the objective method we used spirometry before and after exercise and for the subjective approach we used a medical history questionnaire. All of the recruited 107 elite athletes responded to the questionnaire about respiratory symptoms and medical history and underwent a resting spirometry testing before and after exercise. Post-exercise spirometry revealed the presence of exercise-induced bronchoconstriction in 14 (13%) of the elite athletes, while only 1.8% reported having previously been diagnosed with asthma. In conclusion, our findings indicate that medical history-based diagnoses of exercise-induced bronchoconstriction lead to underestimations of true sufferers.

Swimming and asthma: factors underlying respiratory symptoms in competitive swimmers

BACKGROUND

Swimming is recommended for asthmatics. However, many competitive swimmers report asthmatic symptoms. While some studies identify the swimming environment as a trigger for allergy and asthmatic symptoms, even more studies suggest swimming to be suitable for people with allergies and asthma. The factors behind the symptoms were studied first by determining the prevalence of asthma, allergy and self-reported asthmatic symptoms in experienced Finnish swimmers and then by examining the relationships between the reported symptoms and the main triggering factors: medical history, environment and exercise intensity.

MATERIALS AND METHODS

Top swimmers (n = 332) of the Finnish Swimming Association registry (N = 4578) were asked to complete a structured questionnaire on their medical history, swimming background, swimming environment and symptoms in different swimming intensities. Two hundred experienced swimmers, 107 females and 93 males, with an average age of 18.5 [standard deviation (SD) = 3.0] years and a swimming training history of 9 (SD = 3.8) years completed the questionnaire.

RESULTS

Physician-diagnosed asthma was reported by 32 swimmers (16%), including 24 (12%) with exercise-induced asthma. Physician-diagnosed allergy was reported by 81 (41%) swimmers. Asthmatic symptoms during swimming were described by 84 subjects (42%). Most symptoms occurred when swimming exceeded speeds corresponding to the lactic/anaerobic threshold. Family history of asthma was significant and the most important risk factor for asthmatic symptoms.

CONCLUSIONS

The prevalence of asthma in swimmers was higher than in the general population but not different from that in other endurance athletes. Family history of asthma and increased swimming intensity had the strongest associations with the reported asthmatic symptoms.

Exercise-induced bronchoconstriction and atopy in Tunisian athletes

Background

This study is a cross sectional analysis, aiming to evaluate if atopy is as a risk factor for exercise induced bronchoconstriction (EIB) among Tunisian athletes.

Methods

Atopy was defined by a skin prick test result and EIB was defined as a decrease of at least 15% in forced expiratory volume in one second (FEV1) after 8-min running at 80–85% HRmaxTheo. The study population was composed of 326 athletes (age: 20.8 ± 2.7 yrs – mean ± SD; 138 women and 188 men) of whom 107 were elite athletes.

Results

Atopy was found in 26.9% (88/326) of the athletes. Post exercise spirometry revealed the presence of EIB in 9.8% of the athletes including 13% of the elite athletes. Frequency of atopy in athletes with EIB was significantly higher than in athletes without EIB [62.5% vs 23.1%, respectively].

Conclusion

This study showed that atopic Tunisian athletes presented a higher risk of developing exercise induced bronchoconstriction than non-atopic athletes.

Gender differences in the prevalence of airway hyperresponsiveness and asthma in athletes

BACKGROUND

Although athletes have a high prevalence of airway hyperresponsiveness (AHR) and asthma, little is known about possible gender differences in regard to these features. We looked at the comparative prevalence of AHR, physician-diagnosed asthma and respiratory symptoms during exercise in female (F) and male (M) athletes.

METHOD

A retrospective analysis was done on 2 groups of athletes: Group 1 (n=100) taking part in a study on the prevalence of AHR to methacholine (PC(20)<16mg/ml) and Group 2 (n=698), taking part in a provincial survey on the prevalence of physician-diagnosed asthma. Subjects from both groups filled the same questionnaire on respiratory symptoms during exercise (breathlessness, wheezing and chest tightness).

RESULTS

In Group 1, prevalence of AHR was significantly higher in female (60%) compared with male (21.5%, p<0.0001) athletes despite a similar prevalence of physician-diagnosed asthma (F: 17.1%, M: 15.4%, p>0.05). Respiratory symptoms during exercise were more frequently reported in females (37.1%, M: 16.9%, p=0.02); however, when corrected for the PC(20), this difference became non-significant. In Group 2, the prevalence of physician-diagnosed asthma was not different between genders (F: 12.5%, M: 14%, p>0.05) but respiratory symptoms during exercise were more often reported in female (19.4%) than in male (12.2%, p=0.01) athletes.

CONCLUSIONS

This analysis shows a higher prevalence of AHR and exercise-induced respiratory symptoms in female compared to male athletes, but a similar prevalence of physician-diagnosed asthma. This suggested that the increase in respiratory symptoms in female athletes failed to translate into a higher prevalence of physician-diagnosed asthma.

Chinese response to allergy and asthma in Olympic athletes

China is going to host the Games of the XXIX Olympiad from 8-24 August 2008 in Beijing. The number of athletes and accompanying individuals expected to arrive at China for the Beijing Olympics is estimated at over 10 000 and among them at least 2 000 (20%) are suspected to suffer from respiratory allergies. It is important to monitor the pollen counts and improve air quality in Beijing because Olympic athletes would be exposed to airborne allergens and pollutants during competitions which could hinder peak performance. The main pollen and spore families in Beijing are Artemisia, Ambrosia, Chenopodiaceae and Gramineae. They can reach around 307 000 grains of pollen/1000 m(3) of air in August. Economic development in China is usually linked with worsening of air quality. Due to the adoption of various control measures, the ambient air quality in a number of areas in Beijing has actually improved. The ambient air TSP and SO(2) levels in Beijing have been decreasing in the last decade. However, ambient air NO(x) level has been increasing due to the increased number of motor vehicles. Nevertheless, dedicated medical facilities in Beijing will provide medical services to athletes and delegations from all over the world during the Beijing Olympic Games.

Pharmaceutical treatment of asthma symptoms in elite athletes - doping or therapy?

Asthma, exercise-induced bronchoconstriction, and airway hyper-responsiveness are often found in elite athletes, perhaps as a consequence of their sport or maybe because asthma is a common disorder in young adults. Inhaled beta2-agonists (IBA) are frequently used in elite athletes, but due to regulations introduced by the International Olympic Committee, the use of anti-asthmatic therapy might change. Drugs that make ergogenic effect persist are prohibited in all athletes, whether or not they take part in competitions and systemic steroids and beta2-agonists are among such drugs. On the other hand, opinion is more divided about the use of inhaled corticosteroids (ICS) and IBA. In humans, no effect has been found on the oxygen uptake, performance or distance run with therapeutic doses of IBA, either in asthmatics or non-asthmatics, whereas others report an ergogenic effect and better lung function of high doses of a beta2-agonist in non-asthmatics. Anti-asthmatic treatment is necessary for asthmatics, but should not be used by non-asthmatic elite athletes due to both possible systemic effects and furthermore, side effects of both ICS and IBA.

Exercise-induced bronchoconstriction in athletes-should we screen?

The fact that exercise-induced bronchoconstriction (EIB) may be both over- and underdiagnosed in athletes has led to calls for widespread screening for the condition. This article assesses such a strategy by employing the standard framework used when evaluating any screening policy. This approach highlights a number of concerns and allows recommendations to help optimize the success of such a strategy if it were to be implemented.

Prevalence of exercise-induced bronchospasm in a cohort of varsity college athletes

INTRODUCTION

Exercise-induced bronchospasm (EIB) occurs more commonly in elite athletes than in the general population. There have been relatively few prevalence studies examining EIB in college athletes despite studies which have shown significant morbidity from asthma attacks related to exercise occurring in athletes in this age group. None of the previous studies utilized eucapnic voluntary hyperpnea (EVH) testing, which is the currently recommended test to document EIB in Olympians.

METHODS

Varsity athletes at The Ohio State University underwent EVH testing to assess for EIB.

RESULTS

One hundred seven athletes from 22 sports participated. Forty-two of 107 athletes (39%) were EIB positive according to EVH results. Thirty-six of 42 EIB-positive athletes (86%) had no prior history of EIB or asthma. There were no significant differences in the prevalence of EIB according to sex of the athlete (P=0.65) or ventilation demands of the sport (P=0.64). Symptoms were not predictive of EIB (P=0.44). The prevalence of EIB was 36% in athletes with negative symptoms and 35% for those with positive symptoms. Athletes in high-ventilation sports were significantly more symptomatic (48%) than athletes in low-ventilation sports (25%) (P=0.02); however, there was no difference in the prevalence of EIB between the two groups (P=0.64).

CONCLUSIONS

Varsity athletes show a high incidence of EIB when objectively diagnosed by a variety of pulmonary function criteria. Sex of the athlete or ventilation demands of the sport does not affect the prevalence of EIB. The use of symptoms to diagnose EIB is not predictive of whether athletes have objectively documented EIB. Empiric diagnosis and treatment of EIB on the basis of subjective symptoms alone may lead to an increased number of inaccurate diagnoses and increased morbidity.

Making the diagnosis of asthma in the athlete

This article encompasses a discussion of the clinical presentation and features as various diagnostic modalites of bronchoprovocation and differential diagnosis used in screening for asthma in the athlete. A comparative analysis of these modalities, including questionnaire, treadmill, eucapneic hyperventilation, as well as field challenge, is provided with sensitivities and specificities, predictive value, and application to clinical practice. The indication and mechanics of each diagnostic modality is discussed, providing the clinician with a comprehensive understanding of the principles and procedures used to diagnosis asthma in the athlete.