Prevalence of respiratory symptoms in an athlete population

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.

The Diamond League athletic series: does the air quality sparkle?

Urban air pollution can have negative short- and long-term impacts on health, including cardiovascular, neurological, immune system and developmental damage. The irritant qualities of pollutants such as ozone (O₃), nitrogen dioxide (NO₂) and particulate matter (PM) can cause respiratory and cardiovascular distress, which can be heightened during physical activity and particularly so for those with respiratory conditions such as asthma. Previously, research has only examined marathon run outcomes or running under laboratory settings. This study focuses on elite 5-km athletes performing in international events at nine locations. Local meteorological and air quality data are used in conjunction with race performance metrics from the Diamond League Athletics series to determine the extent to which elite competitors are influenced during maximal sustained efforts in real-world conditions. The findings from this study suggest that local meteorological variables (temperature, wind speed and relative humidity) and air quality (ozone and particulate matter) have an impact on athletic performance. Variation between finishing times at different race locations can also be explained by the local meteorology and air quality conditions seen during races.

The benefits of a systematic assessment of respiratory health in illness-susceptible athletes

Respiratory tract illness is a leading cause of training and in-competition time loss in elite athletes. Asthma is known to be prevalent in athletes, but the coexistence of other respiratory problems in those deemed to be susceptible to respiratory tract illness is unknown. The aim of this study was to apply a comprehensive prospective approach to identify respiratory problems and explore relationships in athletes with heightened respiratory illness susceptibility.UK World Class Performance Programme athletes prospectively completed a systematic review of respiratory health with validated questionnaires and respiratory-focused investigations, including studies of nasal flow, exhaled nitric oxide, spirometry, bronchoprovocation testing and allergy testing.Systematic respiratory health assessment was completed by 122 athletes (55 females, mean±sd age 24±4 years). At least one respiratory health issue, requiring intervention, was identified in 97 (80%) athletes and at least two abnormalities were found in 73 (60%). Sinonasal problems were the most commonly identified problem (49%) and 22% of athletes had a positive indirect bronchoprovocation test. Analysis revealed two respiratory health clusters: 1) asthma, sinus problems and allergy; and 2) laryngeal and breathing pattern dysfunction. Respiratory illness susceptible athletes had 3.6±2.5 episodes in the year prior to assessment and were more likely to have allergy (OR 2.6, 95% CI 1.0-6.5), sinonasal problems (2.6, 1.1-6.0) and symptoms of laryngeal (5.4, 1.8-16.8) and breathing pattern dysfunction (3.9, 1.1-14.0) than nonsusceptible athletes (all p<0.05).A systematic approach to respiratory assessment identifies a high prevalence and coexistence of multiple respiratory problems in illness-susceptible athletes.

Prevalence of exercise-induced bronchoconstriction and laryngeal obstruction in adolescent athletes

OBJECTIVES

To study the prevalence of exercise-induced bronchoconstriction (EIB) and exercise-induced laryngeal obstruction (EILO) in adolescent athletes.

METHODS

All adolescents (n = 549) attending first year at a sports high school in 2016 and 2017, were invited to answer a questionnaire on respiratory symptoms. The 367 responding participants were divided into two groups based on whether they reported exercise-induced dyspnea (dyspnea group) or not (nondyspnea group). Randomly selected participants in each group were invited to undergo two standardized exercise tests, an EIB test and a continuous laryngoscopy exercise (CLE) test, to investigate EILO.

RESULTS

In total, 98 participants completed an EIB test, 75 of whom also completed a CLE test. Positive EIB tests: eight of 41 in the dyspnea group and 16 of 57 in the nondyspnea group. Positive CLE tests: 5 of 34 in the dyspnea group and three of 41 in the nondyspnea group. The estimated prevalence of EIB was 23.1% (95% confidence interval [CI]: 14.5-33.8) and of EILO 8.1% (95% CI: 2.5-18.5) in the whole study population. No differences in prevalence of EIB or EILO were found between the dyspnea and the nondyspnea groups.

CONCLUSION

EIB was highly prevalent in this cohort of adolescent athletes. EILO was less prevalent, but represents an important differential diagnosis to EIB. Self-reported exercise-induced dyspnea is a weak indicator for both EIB and EILO and standardized testing should be provided.

High prevalence of exercise-induced stridor during Parkrun: a cross-sectional field-based evaluation

BACKGROUND AND OBJECTIVE

The differential diagnosis for exercise-associated breathlessness is broad, however, when a young athletic individual presents with respiratory symptoms, they are most often prescribed inhaler therapy for presumed exercise-induced asthma (EIA). The purpose of this study was therefore to use a novel sound-based approach to assessment to evaluate the prevalence of exertional respiratory symptoms and characterise abnormal breathing sounds in a large cohort of recreationally active individuals.

METHODS

Cross-sectional field-based evaluation of individuals completing Parkrun. PHASE 1: Prerace, clinical assessment and baseline spirometry were conducted. At peak exercise and immediately postrace, breathing was monitored continuously using a smartphone. Recordings were analysed retrospectively and coded for signs of the predominant respiratory noise. PHASE 2: A subpopulation that reported symptoms with at least one audible sign of respiratory dysfunction was randomly selected and invited to attend the laboratory on a separate occasion to undergo objective clinical workup to confirm or refute EIA.

RESULTS

Forty-eight participants (22.6%) had at least one audible sign of respiratory dysfunction; inspiratory stridor (9.9%), expiratory wheeze (3.3%), combined stridor+wheeze (3.3%), cough (6.1%). Over one-third of the cohort (38.2%) were classified as symptomatic. Ten individuals attended a follow-up appointment, however, only one had objective evidence of EIA.

CONCLUSIONS

The most common audible sign, detected in approximately 1 in 10 individuals, was inspiratory stridor, a characteristic feature of upper airway closure occurring during exercise. Further work is now required to further validate the precision and feasibility of this diagnostic approach in cohorts reporting exertional breathing difficulty.

The influence of chlorine in indoor swimming pools on the composition of breathing phase of professional swimmers

OBJECTIVES

Swimming is one of the most popular forms of physical activity. Pool water is cleaned with chlorine, which - in combination with compounds contained in water - could form chloramines and trichloromethane in the swimmer's lungs. The aim of the present study was to examine the effect of swimming training in an indoor pool on the composition of swimmers' respiratory phase metabolomics, and develop a system to provide basic information about its impact on the swimmer's airway mucosa metabolism, which could help to assess the risk of secondary respiratory tract diseases i.e. sport results, condition, and health including lung acute and chronic diseases).

DESIGN

A group of competitive swimmers participated in the study and samples of their respiratory phase before training, immediately after training, and 2 h after training were assessed.

METHODS

Sixteen male national and international-level competitive swimmers participated in this study. Respiratory phase analysis of the indoor swimming pool swimmers was performed. Gas chromatography combined with mass spectrometry (GCMS) was used in the measurements. All collected data were transferred to numerical analysis for trends of tracking and mapping. The breathing phase was collected on special porous material and analyzed using GCMS headspace.

RESULTS

The obtained samples of exhaled air were composed of significantly different metabolomics when compared before, during and after exercise training. This suggests that exposition to indoor chlorine causes changes in the airway mucosa.

CONCLUSION

This phenomenon may be explained by occurrence of a chlorine-initiated bio-reaction in the swimmers' lungs. The obtained results indicate that chromatographic exhaled gas analysis is a sensitive method of pulmonary metabolomic changes assessment. Presented analysis of swimmers exhaled air indicates, that indoor swimming may be responsible for airway irritation caused by volatile chlorine compounds and their influence on lung metabolism.

The difference in risk of chronic pulmonary disease morbidity and mortality between former elite athletes and ordinary men in Finland

The impact of a history of competitive sports on later smoking behaviour and occurrence of chronic pulmonary diseases is poorly known. We investigated how a history of elite level sports predicted later pulmonary disease morbidity and mortality. Chronic pulmonary disease incidence was assessed from national hospital and cause-of-death registers from 1970 to 2015 among Finnish male former elite athletes (n = 2078) and matched controls (n = 1453) alive in 1970 (mean age 45.0 years). Hazard ratios (HRs) were calculated by Cox proportional hazards model. In 1985, cohort members reported on their smoking habits, engagement in physical activity/sports and physician-diagnosed chronic diseases. The risk of any chronic pulmonary disease or death was lower among former athletes than controls (age-adjusted HR 0.61; 95% CI 0.46-0.83). The risk was significantly lower among endurance (HR 0.54), mixed (HR 0.61), and power sports athletes (HR 0.66) compared to controls. The age- and smoking pack-year-adjusted HRs of incident diseases from the time of the 1985 questionnaire until the end of follow-up in former athletes was 0.58 (95% CI 0.37-0.93) compared to controls. In 1985 athletes smoked less and their cumulative smoking quantity was lower than that of controls. Former athletes were more physically active and self-reported less physician-diagnosed emphysema. The risk of any chronic pulmonary disease was lower among former athletes than controls even after considering smoking status and cumulative smoking quantity. Ability to compete at the highest level of sports in young adulthood associated with a reduced risk of pulmonary disease in later life.

Impacts of exposure to humidex on the risk of childhood asthma hospitalizations in Hefei, China: Effect modification by gender and age

BACKGROUND

With global climate change, there is growing concern about the effects of temperature changes on childhood asthma. However, current research only focuses on the effects of temperature, while ignoring the adverse effects of humidity on children.

OBJECTIVES

Our study aimed to quantify the impact of humidex on childhood asthma hospitalizations, which combined temperature and humidity, and further to assess how the effect is modified by individual-factors, such as age and gender.

METHODS

Poisson generalized linear models combined with distributed lag nonlinear models were used to estimate the association between daily childhood asthma hospitalizations and humidex from 2013 to 2016. Air pollutions (CO, O_3, and NO₂) and wind velocity were modelled simultaneously using DLNM, as well as day of week, seasonality and long-term trend.

RESULTS

Low humidex was associated with an increased risk of admissions for asthma in children. The adverse effect appeared on the 4th day, with the RR of 1.045 (95%CI: 1.007-1.084) and lasted until the 7th day (RR: 1.045, 95%CI: 1.006-1.085). Compared with the male, there was an immediate effect on female exposed to low humidex. And the female seems to be more sensitive to low humidex. Besides, the significant effects of humidex on children asthma were detected in the children with preschool and school-age, whereas not for the subgroup of infants. And the school-age children are most sensitive to low humidex.

CONCLUSIONS

Low humidex was associated with the increased risk of admissions for childhood asthma in Hefei. Children suffering from asthma should avoid exposure to the low humidex environment, especially in female and school-age children. In addition, the index of humidex was more significant for disease prevention and public health than the average temperature. These findings may provide epidemiology evidence for formulating precaution guidelines to reduce the risk of childhood asthma hospitalizations.

Cough in exercise and athletes

In the general population, particularly in individuals with asthma, cough is a common symptom, often reported after exertion, although regular exercise may be associated with a reduction in the prevalence of cough. In athletes, exercise-induced cough is also a particularly frequent symptom. The main etiologies of cough in athletes are somewhat similar to non-athletes, including asthma/airway hyperresponsiveness, upper airways disorders such as allergic or non-allergic rhinitis, and exercise-induced laryngeal obstruction, although these conditions are more frequently observed in athletes. In these last, this symptom can also be related to the high ventilation and heat exchange experienced during exercise, particularly during exposure to cold/dry air or pollutants. However, gastroesophageal reflux, a common cause of cough in the general population, despite being highly prevalent in athletes, has not been reported as a main cause of cough in athletes. Cough may impair quality of life, sleep and exercise performance in the general population and probably also in athletes, although there are few data on this. The causes of cough should be documented through a systematic evaluation, the treatment adapted according to identified or most probable cough etiology and pattern of presentation, while respecting sports anti-doping regulations. More research is needed on exercise-induced persistent cough in the athlete to determine its pathophysiology, optimal management and consequences.

Asthma and Asthma Medication Are Common among Recreational Athletes Participating in Endurance Sport Competitions

Background

Asthma prevalence is high among elite endurance athletes, but little is known about its prevalence among competitive recreational athletes. The aim of this study was to determine the prevalence of self-reported asthma and asthma medication use among competitive recreational endurance athletes and their association with training.

Methods

A web survey on asthma and medication was conducted among 38,603 adult participants of three Swedish endurance competitions (cross-country running, cross-country skiing, and swimming).

Results

The overall response rate was 29%. The prevalence of self-reported asthma (physician-diagnosed asthma and use of asthma medication in the last 12 months) was 12%. Among those reporting asthma, 23% used inhaled corticosteroids and long-acting beta-agonists daily. We found no association between training volume and daily use of asthma medication, except a trend in relation to short-acting beta-agonists. Independent predictors of self-reported asthma were female sex, allergic rhinitis, previous eczema, family history of asthma, cycling, and training for >5 h 50 min/week.

Conclusions

The prevalence of self-reported asthma among Swedish competitive recreational endurance athletes appears to be higher than that in the general Swedish population. A large proportion of recreational athletes were reported with asthma use medications, indicating an association between high physical activity and self-reported asthma among competitive recreational athletes.

Impact of detecting and treating exercise-induced bronchoconstriction in elite footballers

Our aim was to evaluate the prevalence of exercise-induced bronchoconstriction (EIB) in elite football players and assess subsequent impact of therapy on airway health and exercise performance. 97 male professional football players completed an airway health assessment with a eucapnic voluntary hyperpnoea (EVH) challenge to diagnose EIB. Players demonstrating a positive result (EVH+) were prescribed inhaler therapy depending on severity, including inhaled corticosteroids and inhaled short-acting β2-agonists, and underwent repeat assessment after 9 weeks of treatment. Eight players (EVH+ n=3, EVH- n=5) completed a peak oxygen uptake (V'O2peak) test at initial and follow-up assessment. Out of the 97 players, 27 (28%) demonstrated a positive EVH result. Of these, 10 had no prior history (37%) of EIB or asthma. EVH outcome was not predictable by respiratory symptoms. Seven (24%) of the 27 EVH+ players attended follow-up and demonstrated improved post-challenge spirometry (forced expiratory volume in 1 s pre-test -22.9±15.4%, post-test -9.0±1.6%; p=0.018). At follow-up V'O2peak improved by 3.4±2.9 mL·kg-1·min-1 in EVH+ players compared to 0.1±2.3 mL·kg-1·min-1 in EVH- players. Magnitude of inference analysis indicated treatment was possibly beneficial (74%) for exercise capacity. Elite football players have a high EIB prevalence. Treatment with inhaler therapy reduces EIB severity.

Cough in exercise and athletes

Cough is the most common respiratory symptom reported by athletes and can significantly impact on health status, ability to train and athletic performance. The presence of cough in an athlete is typically taken to indicate exercise-induced bronchoconstriction (EIB), yet in many athletes with chronic cough there is no objective evidence of airway hyper-responsiveness (AHR) or heightened airway inflammation. Moreover, cough in athletes often fails to respond to a therapeutic asthma strategy, thus further work is urgently needed to progress our understanding of the pathophysiology of exercise-associated cough in this unique population. This article provides an overview of the current state of knowledge of exercise-associated cough in athletes. The article summarises our understanding of pathophysiological basis of cough in this context and provides a pragmatic clinical approach to this problem.

Cough in the Athlete: CHEST Guideline and Expert Panel Report

BACKGROUND

Cough is a common symptom experienced by athletes, particularly after exercise. We performed a systematic review to assess the following in this population: (1) the main causes of acute and recurrent cough, either exercise-induced or not, (2) how cough is assessed, and (3) how cough is treated in this population. From the systematic review, suggestions for management were developed.

METHODS

This review was performed according to the CHEST methodological guidelines and Grading of Recommendations Assessment, Development and Evaluation framework until April 2015. To be included, studies had to meet the following criteria: participants had to be athletes and adults and adolescents aged ≥ 12 years and had to complain of cough, regardless of its duration or relationship to exercise. The Expert Cough Panel based their suggestions on the data extracted from the review and final grading by consensus according to a Delphi process.

RESULTS

Only 60 reports fulfilled the inclusion criteria, and the results of our analysis revealed only low-quality evidence on the causes of cough and how to assess and treat cough specifically in athletes. Although there was no formal evaluation of causes of cough in the athletic population, the most common causes reported were asthma, exercise-induced bronchoconstriction, respiratory tract infection (RTI), upper airway cough syndrome (UACS) (mostly from rhinitis), and environmental exposures. Cough was also reported to be related to exercise-induced vocal cord dysfunction among a variety of less common causes. Although gastroesophageal reflux disease (GERD) is frequent in athletes, we found no publication on cough and GERD in this population. Assessment of the causes of cough was performed mainly with bronchoprovocation tests and suspected disease-specific investigations. The evidence to guide treatment of cough in the athlete was weak or nonexistent, depending on the cause. As data on cough in athletes were hidden in a set of other data (respiratory symptoms), evidence tables were difficult to produce and were done only for cough treatment in athletes.

CONCLUSIONS

The causes of cough in the athlete appear to differ slightly from those in the general population. It is often associated with environmental exposures related to the sport training environment and occurs predominantly following intense exercise. Clinical history and specific investigations should allow identification of the cause of cough as well as targeting of the treatment. Until management studies have been performed in the athlete, current guidelines that exist for the general population should be applied for the evaluation and treatment of cough in the athlete, taking into account specific training context and anti-doping regulations.

Medical Care for Swimmers

Swimming is one of the most popular sports worldwide. Competitive swimming is one of the most watched sports during the Olympic Games. Swimming has unique medical challenges as a result of a variety of environmental and chemical exposures. Musculoskeletal overuse injuries, overtraining, respiratory problems, and dermatologic conditions are among the most common problems swimmers encounter. Although not unique to swimming, overtraining is a serious condition which can have significant negative impact on swimmers' health and performance. This review article is an attempt to discuss various issues that a medical team should consider when caring for swimmers.

Perception of bronchoconstriction following methacholine and eucapnic voluntary hyperpnea challenges in elite athletes

OBJECTIVE

Self-reported respiratory symptoms are poor predictors of exercise-induced bronchoconstriction (EIB) in athletes. The objective of this study was to determine whether athletes have an inadequate perception of bronchoconstriction.

METHODS

One hundred thirty athletes and 32 nonathletes completed a standardized questionnaire and underwent eucapnic voluntary hyperpnea (EVH) and methacholine inhalation test. Perception scores were quoted on a modified Borg scale before each spirometry measurement for cough, breathlessness, chest tightness, and wheezing. Perception slope values were also obtained by plotting the variation of perception scores before and after the challenges against the fall in FEV1 expressed as a percentage of the initial value [(perception scores after - before)/FEV1].

RESULTS

Up to 76% of athletes and 68% of nonathletes had a perception score of ≤0.5 at 20% fall in FEV1 following methacholine. Athletes with EIB/airway hyperresponsiveness (AHR) had lower perception slopes to methacholine than nonathletes with asthma for breathlessness only (P=.02). Among athletes, those with EIB/AHR had a greater perception slope to EVH for breathlessness and wheezing (P=.02). Female athletes had a higher perception slope for breathlessness after EVH and cough after methacholine compared with men (P<.05). The age of athletes correlated significantly with the perception slope to EVH for each symptom (P<.05).

CONCLUSIONS

Minimal differences in perception of bronchoconstriction-related symptoms between athletes and nonathletes were observed. Among athletes, the presence of EIB/AHR, older age, and female sex were associated with slightly higher perception scores.

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.

Are former athletes more prone to asthma?

OBJECTIVE

We have designed the present study to compare prevalent lifetime cases of diagnosed asthma or exercise-induced asthma, as well as current related respiratory symptoms, across two different levels of former athletes and non-athletes.

METHODS

Demographic, behavioral, and asthma history information, as well as current related respiratory symptoms, were obtained through a questionnaire from 627 subjects (290 former elite and 201 non-elite athletes that competed between 1969 and 2005, and 136 control subjects that had never been athletes).

RESULTS

Non-athletes presented a higher percentage of subjects reporting the existence of symptoms associated with exercise or vigorous activities. Former athletes who reported having practiced mostly in indoor facilities presented significant lower risk for asthma than outdoor athletes (Odds Ratio = 0.48, 95% CI = 0.25-0.94). Multiple regression analysis (where "B" refers to unstandardized coefficients) showed that former elite (B = -0.85, p < .001) and non-elite athletes (B = -0.70, p < .001) were less prone to be affected by asthma-related symptoms than non-athletes. Athletes with careers that lasted more than 20 years were more likely to possess asthma-related symptoms than the ones with shorter careers (3-7 years, B = -0.47, p < .001; 8-14 years, B = -0.42, p < .01; 15-20, B = -0.32, p < .05).

CONCLUSIONS

Non-athletes seem to have a higher prevalence of respiratory symptoms. Among former athletes, career characteristics seem to play a crucial role, with special emphasis to its duration, where the most lengthy seem to be more associated with respiratory symptoms.

Pathogenesis of exercise-induced bronchoconstriction

This article presents the various potential mechanisms responsible for the development of exercise-induced bronchoconstriction (EIB). Although the etiology of EIB is multifactorial, and the physiologic processes involved may vary between individuals (especially between those with and without asthma), drying of the small airways with an associated inflammatory response seems prerequisite for EIB. Dysregulated repair processes following exercise-induced airway epithelial injury may also serve as basis for EIB development/progression.

Illness data from the US Open Tennis Championships From 1994 to 2009

OBJECTIVE

To examine the incidence of illness and highlight gender differences in tennis players competing in a major professional tennis tournament over a 16-year period between 1994 and 2009.

DESIGN

Descriptive epidemiology study of illness trends in professional tennis players.

SETTING

Archival data from the US Open Tennis Championships.

PARTICIPANTS

Participants in the US Open Tennis Championships main draw from 1994 to 2009.

MAIN OUTCOME MEASURES

Illness data collected at the US Open Tennis Championships between 1994 and 2009 were classified using guidelines presented in a sport-specific consensus statement. Each case was categorized according to the medical system effected and impact on play availability during the tournament. Illness rates were determined based on the exposure of an athlete to a match event and were calculated as the ratio of illness cases per 1000 match exposures (ME).

RESULTS

The average number of illness cases over the 16-year period analyzed was 58.19 ± 12.02 per year (36.74 per 1000 ME) requiring assistance by the medical staff. Statistical analyses showed a significant fluctuation in illness cases related to the dermatological (DERM), gastrointestinal, renal/urogenital/gynecological, neurological, ophthalmic and otorhinolaryngological (ENT), and infectious medical systems (P < 0.05). The ENT and DERM conditions were the most commonly reported types of illness for both men and women.

CONCLUSIONS

Numerous medical systems are susceptible to illness in tennis players. Sport-specific factors may influence susceptibility to common illnesses experienced by professional tennis players.

Cardiorespiratory screening in elite endurance sports athletes: the Quebec study

BACKGROUND

Cardiorespiratory disorders are common in athletes. However, these conditions are often underdiagnosed, which potentially results in impaired performance and increased health risks. The aim of this study was to evaluate, in a research setting, the prevalence of cardiorespiratory disorders in athletes in order to determine the potential value of a screening program.

METHODS

One hundred thirty-three athletes were studied. Each subject underwent a physical examination. A eucapnic voluntary hyperventilation (EVH) test and a methacholine inhalation test were performed to confirm the diagnosis of asthma. A cardiovascular evaluation was also performed, including maximal exercise test with electrocardiogram, 24-hour ambulatory blood pressure monitoring, 24-hour Holter monitoring, and blood sampling.

RESULTS

Seventy-four (56%) athletes had airway hyperresponsiveness to EVH or the methacholine inhalation test. Among those with airway hyperresponsiveness, 45 (61%) athletes were only hyperresponsive to EVH, and 10 (14%) were only hyperresponsive to the methacholine inhalation test (using the criteria of a PC20 ≤ 4 mg/mL). Thirty-two (24%) athletes had a known diagnosis of asthma, while 34 (26%) athletes received a new asthma diagnosis. Ninety-seven (73%) athletes were sensitized to common airborne allergens. Forty-seven (35%) athletes completed the cardiovascular evaluation. Three (6%) and 7 (15%) athletes had a previous or new diagnosis of cardiovascular disease, respectively. Resting systemic hypertension was documented in 2 (4%) athletes and exaggerated blood pressure response to exercise was found in 12 (26%) athletes.

CONCLUSION

This cardiorespiratory screening data set in athletes showed a high prevalence of exercise-induced asthma and exercise hypertension, which in many cases were not previously diagnosed.

Managing respiratory problems in athletes

Respiratory problems are common in athletes of all abilities and can significantly impact upon their health and performance. In this article, we provide an overview of respiratory physiology in athletes. We also discuss the assessment and management of common clinical respiratory conditions as they pertain to athletes, including airways disease, respiratory tract infection and pneumothorax. We focus on providing a pragmatic approach and highlight important caveats for the physician treating respiratory conditions in this highly specific population.

Etiology of dyspnea in elite and recreational athletes

BACKGROUND

Breathing complaints are common in athletes. Studies have suggested that the prevalence of asthma and exercise-induced bronchoconstriction (EIB) is higher in elite athletes than the general population. Vocal cord dysfunction (VCD) may mimic asthma and EIB as a cause of dyspnea in athletes. However, the majority of studies to date have primarily relied on symptoms to diagnose VCD, and there are limited data on coexistence of asthma, EIB, and/or VCD. It is well established that symptoms alone are inadequate to accurately diagnose EIB and VCD. Our goal was to define via objective testing the prevalence of asthma, EIB, VCD alone, or in combination in a cohort of athletes with respiratory complaints.

METHODS

A retrospective chart review was done of 148 consecutive athletes (collegiate, middle school, high school, and recreational) referred to a tertiary care center's asthma center for evaluation of respiratory complaints with exercise. An evaluation including medical history, physical examination, and objective testing including pulmonary function testing (PFT), eucapnic voluntary hyperventilation, and video laryngostroboscopy, were performed.

RESULTS

The most common symptom was dyspnea on exertion (96%), with < 1% complaining of either hoarseness or stridor. The most common diagnosis prior to referral was asthma (40%). Only 16% had PFTs prior to referral. Following evaluation by a pulmonologist, 52% were diagnosed with EIB, 17% with asthma, and 70% with VCD. Of those diagnosed with asthma before our evaluation, the diagnosis of asthma was confirmed, with PFTs in only 19 of 59 (32%) athletes based on our testing. Vocal cord dysfunction was more common in females and in adolescent athletes. Coexistence of multiple disorders was common, such as EIB and asthma (8%), EIB and VCD (31%), and VCD and asthma (6%).

CONCLUSIONS

Asthma and EIB are common etiologies of dyspnea in athletes, both competitive and recreational. However, VCD is also common and can coexist with either asthma or EIB. Vocal cord dysfunction may contribute to exercise-related respiratory symptoms more frequently in middle school- and high school-aged athletes than in college athletes. Effective treatment of dyspnea requires appropriate identification and treatment of all disorders. Classic symptoms of stridor and/or hoarseness are often not present in athletes with VCD. Accurate diagnosis of asthma, EIB, and VCD requires objective testing and can prevent exposure of patients to medications that are ineffective and have potential adverse side effects. Furthermore, there is need for increased awareness of VCD as a common cause of respiratory complaints in athletes, either as a single diagnosis or in combination with EIB, especially in females, as well as middle school and high school athletes.

Airway remodeling and inflammation in competitive swimmers training in indoor chlorinated swimming pools

BACKGROUND

Airway disorders are common in regular chlorinated swimming pool attendees, particularly competitive athletes, but the impact of intense swimming training on airway function and structure remains unclear.

OBJECTIVE

This study aimed to evaluate airway inflammation and remodeling in elite swimmers.

METHODS

Twenty-three elite swimmers were tested during off-training season. All had exhaled nitric oxide measurement, methacholine test, eucapnic voluntary hyperpnea challenge, allergy skin prick tests, and bronchoscopy with bronchial biopsies. Clinical data and tissues from 10 age-matched mild-asthmatic and 10 healthy nonallergic subjects were used for comparison.

RESULTS

Swimmers had increased airway mucosa eosinophil and mast cell counts than did controls (P < .05). They had more goblet cell hyperplasia and higher mucin expression than did healthy or asthmatic subjects (P < .05). A greater submucosal type I and III collagen expression and tenascin deposition was also observed in swimmers than in controls (P < .05). Neither exhaled nitric oxide nor airway responsiveness to methacholine or eucapnic voluntary hyperpnea challenge correlated with these inflammatory and remodeling changes.

CONCLUSION

Intense, long-term swimming training in indoor chlorinated swimming pools is associated with airway changes similar to those seen in mild asthma, but with higher mucin expression. These changes were independent from airway hyperresponsiveness. The long-term physiological and clinical consequences of these changes remain to be clarified.

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.

Australian association for exercise and sports science position statement on exercise and asthma

Asthma, a chronic inflammatory disorder of the airways is associated with variable obstruction to the airways and is provoked by many triggers including exercise. The management of asthma is primarily pharmacological, but exercise, despite causing bronchoconstriction in almost all asthmatics, is an important adjunct to treatment. With adequate control of the hyperresponsive airways obtained with inhaled corticosteroids (ICS) and inhaled beta 2 agonists (IBA), used as both a pre-exercise preventive agent and a reliever if necessary, all asthmatics should benefit from an exercise program. Some have realised this benefit with such success as to become Olympic and world champions in many sports. Exercise programs should be individually tailored, follow established guidelines and result in similar benefits to those obtained by non-asthmatics. However asthmatics must try to avoid or minimise triggers whenever possible. A specific benefit of a physical training program is that it allows asthmatics to exercise with less bronchoconstriction at the same exercise stress, although it does not abolish or reduce airway hyperresponsiveness (AHR).

Bronchial challenges and respiratory symptoms in elite swimmers and winter sport athletes: Airway hyperresponsiveness in asthma: its measurement and clinical significance

This study was aimed at the following: (1) the prevalence of airway hyperresponsiveness (AHR) and exercise-induced bronchoconstriction (EIB) in swimmers and winter sport athletes according to the previously recommended regulatory sport agencies criteria, (2) the relationship between respiratory symptoms and AHR/EIB, (3) the impact of the chosen cutoff value for AHR on its prevalence, and (4) the effect on the prevalence of the positive eucapnic voluntary hyperpnea (EVH) test of using the highest vs the lowest spirometric post-EVH values to calculate the magnitude of the airway response. We compared the prevalence of respiratory symptoms with responses to methacholine challenge and EVH in 45 swimmers, 45 winter sport athletes, and 30 controls. Two methacholine challenge cutoffs for AHR were analyzed: <or= 4 mg/mL (the sport agencies' criteria for AHR) and <or= 16 mg/mL. Sixty percent of swimmers, 29% of winter sport athletes, and 17% of controls had evidence of EIB or AHR (with the <or= 4 mg/mL criteria). Among athletes with a methacholine provocative concentration inducing a 20% decrease in the FEV(1) between 4 and 16 mg/mL, 43% of swimmers and 100% of winter sport athletes were symptomatic (P < .05). Prevalence of positive EVH tests were 39% in swimmers, 24% in winter sport athletes, and 13% in controls when the highest FEV(1) value measured at each time point post-EVH was used to identify maximal response for calculation of airway response, although these prevalences were higher if we used the lowest value. This study suggests that AHR/EIB is frequent in swimmers, whereas the frequently reported respiratory symptoms in winter sport athletes are often not related to AHR/EIB. Furthermore, the choice of methods for assessing methacholine challenge and EVH responses influences the prevalences of AHR and EIB.

TRIAL REGISTRATION

clinicaltrials.gov; Identifier NCT 00686491 and NCT 00686452.

The respiratory health of swimmers

Regular physical activity is recognized as an effective health promotion measure. Among various activities, swimming is preferred by a large portion of the population. Although swimming is generally beneficial to a person's overall health, recent data suggest that it may also sometimes have detrimental effects on the respiratory system. Chemicals resulting from the interaction between chlorine and organic matter may be irritating to the respiratory tract and induce upper and lower respiratory symptoms, particularly in children, lifeguards and high-level swimmers. The prevalence of atopy, rhinitis, asthma and airway hyper-responsiveness is increased in elite swimmers compared with the general population. This may be related to the airway epithelial damage and increased nasal and lung permeability caused by the exposure to chlorine subproducts in indoor swimming pools, in association with airway inflammatory and remodelling processes. Currently, the recommended management of swimmers' respiratory disorders is similar to that of the general population, apart from the specific rules for the use of medications in elite athletes. Further studies are needed to better understand the mechanisms related to the development or worsening of respiratory disorders in recreational or competitive swimmers, to determine how we can optimize treatment and possibly help prevent the development of asthma.

Exercise-induced bronchoconstriction: The effects of montelukast, a leukotriene receptor antagonist

Exercise-induced bronchoconstriction (EIB) is very common in both patients with asthma and those who are otherwise thought to be normal. The intensity of exercise as well as the type of exercise is important in producing symptoms. This may make some types of exercise such as swimming more suitable and extended running more difficult for patients with this condition. A better understanding of EIB will allow the physician to direct the patient towards a type of exercise and medications that can result in a more active lifestyle without the same concern for resulting symptoms. This is especially important for schoolchildren who are usually enrolled in physical education classes and elite athletes who may desire to participate in competitive sports. Fortunately several medications (short- and long-acting beta(2)-agonists, cromolyn, nedocromil, inhaled corticosteroids, and more recently leukotriene modifiers) have been shown to be effective in preventing or attenuating the effects of exercise in many patients. In addition, inhaled beta(2)-agonists have been shown to quickly reverse the airway obstruction that develops in patients and continue to be the reliever medications of choice. Inhaled corticosteroids are increasingly being recommended as regular therapy now that the role of inflammation and airway injury has been identified in EIB. With the discovery that there is a release of mediators such as histamine and leukotrienes from cells in the airway following exercise with resulting airway obstruction in susceptible individuals, interest has turned to attenuating their effects with mediator antagonists especially those that block the effects of leukotrienes. Studies with an oral leukotriene antagonist, montelukast, have shown beneficial effects in adults and children aged as young as 6 years with EIB. These effects can be demonstrated as soon as two hours and as long as 24 hours after administration without a demonstrated loss of a protective effect after months of treatment. The studies leading up to and resulting in an approval of montelukast for EIB for patients aged 15 years and older are reviewed in this paper.

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.

Asthma and the elite athlete: summary of the International Olympic Committee's consensus conference, Lausanne, Switzerland, January 22-24, 2008

Respiratory symptoms cannot be relied on to make a diagnosis of asthma and/or airways hyperresponsiveness (AHR) in elite athletes. For this reason, the diagnosis should be confirmed with bronchial provocation tests. Asthma management in elite athletes should follow established treatment guidelines (eg, Global Initiative for Asthma) and should include education, an individually tailored treatment plan, minimization of aggravating environmental factors, and appropriate drug therapy that must meet the requirements of the World Anti-Doping Agency. Asthma control can usually be achieved with inhaled corticosteroids and inhaled beta(2)-agonists to minimize exercise-induced bronchoconstriction and to treat intermittent symptoms. The rapid development of tachyphylaxis to beta(2)-agonists after regular daily use poses a dilemma for athletes. Long-term intense endurance training, particularly in unfavorable environmental conditions, appears to be associated with an increased risk of developing asthma and AHR in elite athletes. Globally, the prevalence of asthma, exercise-induced bronchoconstriction, and AHR in Olympic athletes reflects the known prevalence of asthma symptoms in each country. The policy of requiring Olympic athletes to demonstrate the presence of asthma, exercise-induced bronchoconstriction, or AHR to be approved to inhale beta(2)-agonists will continue.

Sideline management of asthma

The timely, efficient, and effective sideline management of asthma must be grounded on an understanding of the disease processes, awareness of evidence-based therapeutic intervention, and thorough knowledge of the individual athlete's medical history and current physical condition. There is accumulating evidence that exercise-induced airway narrowing, if unrecognized or inadequately treated, can progress to a severe life-threatening status and should always be viewed as a potential medical emergency. A widening range of therapeutic measures is currently available to prevent and to treat exercise asthma, and treatment must be tailored to the individual circumstances to optimize response.

Sideline management of asthma

The timely, efficient, and effective sideline management of asthma must be based on an understanding of the disease processes, awareness of evidence-based therapeutic intervention, and thorough knowledge of the individual athlete's past and present medical history. There is accumulating evidence that exercise-induced airway narrowing, if unrecognized or inadequately treated, can progress to a severe life-threatening status and should always be viewed as a potential medical emergency. A widening range of therapeutic measures is currently available to prevent and treat exercise asthma, and treatment must be tailored to the individual circumstances in order to optimize response.

Physiological and pathophysiological down-regulation of cough

Recent clinical studies have emphasized the up-regulation (sensitization) of cough in pathological conditions of the airways. However there are also many situations where voluntary and reflex cough can be down-regulated. These include: (1) chemical stimulation of breathing by hypercapnia or hypoxia or both, establishing that cough sensitivity can be inversely related to drive to breathing; (2) voluntary inhibition of cough, probably similar in mechanism to the depression of cough that can be induced by hypnosis and other branches of alternative medicine; (3) the placebo effect of many antitussive treatments; (4) sleep; (5) general anaesthesia; (6) central nervous disorders such as coma, stroke, Parkinson's disease and several other conditions where the defect in the protective reflexes may lead to aspiration pneumonia; (7) increased activity in various afferent inputs from viscera in the thorax and abdomen; (8) a number of bronchopulmonary clinical disorders. The list is long, but regrettably the nervous mechanisms of these down-regulations have been little studied. In addition there are a number of situations, such as exercise, coitus, talking and singing which, while important to coughing humans, have been not investigated in relation to cough. Most of the studies have been with experimental animals, and their extension to human research is desirable. In view of the importance of cough and other defensive reflexes in maintaining human well-being, far more research is needed. The field is wide-open.

Return to play following exercise-induced bronchoconstriction

OBJECTIVE

To review evidence-based support for return to play criteria following acute exercise-induced bronchoconstriction.

DATA SOURCES

Electronic databases Ovid Medline and PubMed were searched for papers relating to exercise related asthma and bronchoconstriction and return to play criteria. Additional references from the bibliographies of retrieved articles were also reviewed.

DATA SYNTHESIS

There is clear evidence that exercise-induced airways narrowing is increasing in prevalence among athletes from school children to Olympians to professionals, yet there have been no studies specifically addressing return to play criteria. Although deaths from exercise associated bronchoconstriction were previously thought to be rare, recent reports of such deaths call for increased awareness by physicians, athletic trainers, and coaches of the potential fatal consequences of unrecognized episodes or of inadequate treatment.

CONCLUSIONS

No agreed-upon protocol for safe return to play following an acute episode of exercise induced bronchoconstriction has been published. A specific detailed protocol for return to play would assist physicians and other heath professionals to determine with greater confidence that an athlete is fully recovered and can safely return to play.

Long-acting beta 2-adrenoceptor agonists and exercise-induced asthma: lessons to guide us in the future

The safety and efficacy of long-acting beta(2)-adrenoceptor agonists (LABAs) taken intermittently for the prevention of exercise-induced asthma (EIA) in children is well established. However, the safety and efficacy of LABAs taken twice daily, either alone or in combination with inhaled corticosteroids, for the prevention of EIA is not as clear because of issues of tolerance (defined as being less responsive to the influence of LABAs). There have been many observations on short-acting beta(2)-adrenoceptor agonists (SABAs) and EIA that should have alerted us to the potential for tolerance and desensitization to occur with LABAs. For example, we expected that the use of LABAs for EIA would overcome the problem of the short duration of protection of SABAs, and to some extent they have. The protective period of a LABA is two to three times longer in duration than that of a SABA. However, when a LABA is taken daily it is apparent that the duration of its protective effect is reduced and there is a risk of EIA occurring well within the 12-hour administration schedules. Furthermore, daily use of LABAs attenuates the bronchodilator effect of SABAs, an effect that is greater the more severe the bronchoconstriction. This 'tolerance' increases both the time and the amount of therapy that is needed to recover from bronchoconstriction, and thus, could potentially impact on the success of rescue therapy should severe EIA occur. The daily use of LABAs also increases the sensitivity of the bronchial smooth muscle to contractile agents. This increase in sensitivity is almost equivalent to the extent to which inhaled corticosteroids reduce sensitivity to the same contractile agents. The increased sensitivity to contractile agents may occur either by a reduction in the inhibitory effect of beta(2)-adrenoceptor agonists on release of mediators from mast cells or by a direct effect on the bronchial smooth muscle. These unwanted effects of LABAs are not necessarily reduced by concomitant treatment with inhaled corticosteroids. As the number of children being treated with LABAs increases, it is predicted that problems with breakthrough EIA will also increase. We need to know the percentage of children taking a LABA daily who are requiring either extra doses of a beta(2)-adrenoceptor agonist to prevent (or reverse) EIA or other provocative stimuli. If this percentage is significant then we may need to reconsider the position of LABAs in the treatment of children with asthma who regularly perform strenuous physical activity.

Presence of lobeline-like sensations in exercising patients with left ventricular dysfunction

Since there is evidence that lobeline-induced sensations, associated with discomfort in the mouth, throat and chest arise by stimulating juxtapulmonary or J receptors, we were interested in investigating if similar sensations are felt by patients with left ventricular dysfunction (LVD) in whom a natural stimulation of these receptors would occur by transient interstitial oedema or during augmentation of the stimulus, by increased pulmonary blood flow during exercise. Threshold doses of lobeline produced three or more respiratory sensations simultaneously in 9 out of 10 patients, which was greater than the response of the controls (P < 0.01). With mild exercise, a greater number of patients (7) than controls (1) reported feeling two or more sensations (P < 0.01); in fact half the controls did not express a respiratory sensation with equivalent exercise (P < 0.05). The predominant lobeline-like sensations reported by patients with exercise were a feeling of heat or burning and pressure in the throat or chest (P < 0.05). The presence of cough in three patients and in none of the controls was noteworthy. The mean latency with which sensations appeared during exercise in patients (4.4 +/- 0.3 min) was almost half that in controls (7.4 +/- 0.2 min) (P < 0.005). Since, respiratory sensations in response to lobeline and exercise were intensified in patients compared to controls and since both lobeline and exercise-induced sensations were similar (P < 0.05), we speculate that a common origin exists. Despite important caveats, that we discuss, in our view these respiratory sensations and cough arise from stimulation of J receptors.