Provocation by eucapnic voluntary hyperpnoea to identify exercise induced bronchoconstriction

Ventilatory response and dyspnea on exertion in children with obesity and respiratory symptoms

We investigated whether the exercise ventilatory response is associated with dyspnea on exertion (DOE) in children with (CWO;n = 25) and without (CWOO;n = 49) obesity, and with obesity and respiratory symptoms (CWORS;n = 14). The ventilatory response to exercise (V̇E/V̇CO2 slope) and ratings of perceived breathlessness (RPB, Borg 0-10 scale) were measured during 6-min cycling at 45 % maximal work rate. The V̇E/V̇CO2 slope (CWOO=34 ± 7; CWO=34 ± 5; CWORS=37 ± 6) and RPB (CWORS=4.0 ± 3.4; CWOO=2.5 ± 1.7; CWO=3.2 ± 2.1) were similar among groups (p > 0.05). A significant association between the V̇E/V̇CO2 slope and RPB in CWORS (r2=0.49;p < 0.05) was observed. To investigate this relationship more closely, children with an RPB≤ 2 were classified as having no or mild DOE (-DOE;n = 39;RPB=1.2 ± 0.7), and those with RPB≥ 3 were classified as having moderate to severe DOE (+DOE;n = 49;RPB=4.7 ± 1.9). +DOE had a higher V̇E/V̇CO2 slope (+DOE=36 ± 6;-DOE=33 ± 5;p = 0.02), higher breathing frequency, and higher V̇E (%max;p < 0.05). These findings suggest a heightened sensitivity to ventilatory demand among children, and that +DOE may be driven by factors other than obesity alone, possibly increased ventilatory response to exercise.

Breathing pattern changes in response to bronchoconstriction in physically active adults

OBJECTIVES

To determine whether Opto-Electronic Plethysmography (OEP) can distinguish Exercise-Induced Bronchoconstriction (EIB) breathing patterns by comparing individuals with and without EIB, and between broncho-constriction and recovery. Breathing pattern was quantified in terms of regional contribution, breathing timing, and the phase between chest sub-compartments which indicates the synchronization in movement of the different sub-compartments.

METHODS

Individuals (n = 47) reporting no respiratory symptoms and no history of any respiratory disease or disorder were assumed to have a healthy breathing pattern. Of 38 participants reporting respiratory symptoms during exercise, and/or a previous diagnosis of asthma or EIB, 10 participants had a positive result to the Eucapnic Voluntary Hyperpnea test, defined as a fall of at least 10% in FEV1 from baseline at two consecutive time points and were classified into the EIB group. OEP data was obtained from 89 markers and an 11-camera motion capture system operating at 100 Hz as follows: pre- and post-EVH challenge, and post-inhaler in participants who experienced a bronchoconstriction, and 2) for the healthy group during tidal breathing.

RESULTS

RCpRCa-Phase (upper versus lower ribcage), RCaS-Phase (lower ribcage versus shoulders), and RCpS-Phase (upper ribcage versus shoulders) differed between bronchoconstriction and rest in athletes with EIB and rest in healthy participants (p < 0.05), in all cases indicating greater asynchrony post-bronchoconstriction, and later movement of the abdominal ribcage (RCa) post-bronchoconstriction. RCpS-Phase was different (p < 0.05) between all conditions (rest, post-bronchoconstriction, and post-inhaler) in EIB.

CONCLUSIONS

OEP can characterize and distinguish EIB-associated breathing patterns compared to rest and individuals without EIB at rest.

Examining the effect of salbutamol use in ozone air pollution by people with exercise-induced bronchoconstriction

Previous studies based on animal models have raised concerns about salbutamol use in ozone air pollution with regard to ozone related lung injury. We conducted a double-blind, randomized, placebo-controlled crossover study including 18 subjects diagnosed with EIB by a eucapnic voluntary hyperpnea (EVH) test. Participants completed 30 min of standardized moderate to vigorous exercise in four conditions: ozone plus salbutamol; room air plus salbutamol; ozone plus placebo medication; and room air plus placebo medication. Spirometry, fraction of exhaled nitric oxide, and symptoms were measured before, immediately after, 30 min after and 1 h after exercise. Measurements between the four conditions were compared using percent change from pre to post exercise. There was a statistically significant difference between the salbutamol and placebo medication groups for spirometric variables including FEV1 (Estimate = 6.3, 95% CI: 4.23-8.37, p < 0.001). No differences were observed between ozone and room air exposures. There were no significant differences in FeNO response between experimental conditions. We found that salbutamol improved pulmonary function in individuals with EIB when exercising in ozone and did not increase eosinophilic airway inflammation as indicated by FeNO. This evidence suggests that it is safe for people with EIB to continue to use salbutamol as proscribed when ozone levels are elevated.

Respiratory muscles's thermographic analysis in asthmatic youth with and without bronchospasm induced by eucapnic voluntary hyperpnea

OBJECTIVE

To compare the thermographic pattern of regions of interest (ROI) of respiratory muscles in young asthmatics with and without bronchospasm induced by eucapnic voluntary hyperpnea (EVH).

MATERIALS AND METHODS

Cross-sectional study carried out with 55 young (55% male and 45% females) aged 12.5 ± 3.3 years, divided in nine nonasthmatics, 22 asthmatics without exercise-induced bronchospasm compatible response (EIB-cr) and 24 asthmatics with EIB-cr. The diagnosis of EIB was given to subjects with a fall in forced expiratory volume in the first second (FEV1) ≥ 10% compared to baseline. Thermographic recordings of respiratory muscles were delimited in ROI of the sternocleidomastoid (SCM), pectoral, and rectus abdominis intention area. Thermal captures and FEV1 were taken before and 5, 10, 15 and 30 min after EVH.

RESULTS

Twenty-four (52.1%) of asthmatics had EIB-cr. There was a decrease in temperature at 10 min after EVH test in the SCM, pectoral and rectus abdominis ROIs in all groups (both with p < 0.05). There was a decrease in temperature (% basal) in asthmatic with EIB-cr compared to nonasthmatics in the rectus abdominis area (p < 0.05).

CONCLUSION

There was a decrease in temperature in the ROIs of different muscle groups, especially in asthmatics. The greater drop in FEV1 observed in individuals with EIB-cr was initially associated with a decrease in skin temperature, with a difference between the nonasthmatics in the abdominal muscle area. It is likely that this decrease in temperature occurred due to a temporary displacement of blood flow to the most used muscle groups, with a decrease in the region of the skin evaluated in the thermography.

Exercise-induced bronchoconstriction, allergy and sports in children

Exercise-induced bronchoconstriction (EIB) is characterized by the narrowing of airways during or after physical activity, leading to symptoms such as wheezing, coughing, and shortness of breath. Distinguishing between EIB and exercise-induced asthma (EIA) is essential, given their divergent therapeutic and prognostic considerations. EIB has been increasingly recognized as a significant concern in pediatric athletes. Moreover, studies indicate a noteworthy prevalence of EIB in children with atopic predispositions, unveiling a potential link between allergic sensitivities and exercise-induced respiratory symptoms, underpinned by an inflammatory reaction caused by mechanical, environmental, and genetic factors. Holistic management of EIB in children necessitates a correct diagnosis and a combination of pharmacological and non-pharmacological interventions. This review delves into the latest evidence concerning EIB in the pediatric population, exploring its associations with atopy and sports, and emphasizing the appropriate diagnostic and therapeutic approaches by highlighting various clinical scenarios.

Exercise-induced bronchoconstriction in elite athletes: a narrative review

Exercise-induced bronchoconstriction (EIB) is the most common chronic disease among elite athletes and when left untreated, can impact both respiratory health and sports performance. In recent years, there has been an increase in the awareness and detection of EIB in elite athletes. This narrative review aims to evaluate the risk, prevention, diagnosis, medication, and anti-doping policies of EIB in elite athletes, and to provide more references for athletes with EIB. The results showed that athletes of endurance, winter, and water sports generally have a higher prevalence of EIB than athletes of other sports. Adaptive warm-up before formal exercise and using heat exchange masks at low temperatures are effective ways for athletes to prevent EIB. For physicians, the exercise challenge test and eucapnic voluntary hyperpnea are the recommended diagnostic methods for EIB in athletes. The treatment of athletes with EIB is medication-based, such as inhaled corticosteroids and beta-2 agonists, but current anti-doping policies should be considered when used.

Unsupervised field-based exercise challenge tests to support the detection of exercise-induced lower airway dysfunction in athletes

Background

Athletes are at risk for developing exercise-induced lower airway narrowing. The diagnostic assessment of such lower airway dysfunction (LAD) requires an objective bronchial provocation test (BPT).

Objectives

Our primary aim was to assess if unsupervised field-based exercise challenge tests (ECTs) could confirm LAD by using app-based spirometry. We also aimed to evaluate the diagnostic test performance of field-based and sport-specific ECTs, compared with established eucapnic voluntary hyperpnoea (EVH) and methacholine BPT.

Methods

In athletes with LAD symptoms, sensitivity and specificity analyses were performed to compare outcomes of (1) standardised field-based 8 min ECT at 85% maximal heart rate with forced expiratory volume in 1 s (FEV₁) measured prechallenge and 1 min, 3 min, 5 min, 10 min, 15 min and 30 min postchallenge, (2) unstandardised field-based sport-specific ECT with FEV₁ measured prechallenge and within 10 min postchallenge, (3) EVH and (4) methacholine BPT.

Results

Of 60 athletes (median age 17.5; range 16-28 years.; 40% females), 67% performed winter-sports, 43% reported asthma diagnosis. At least one positive BPT was observed in 68% (n=41/60), with rates of 51% (n=21/41) for standardised ECT, 49% (n=20/41) for unstandardised ECT, 32% (n=13/41) for EVH and methacholine BPT, while both standardised and unstandardised ECTs were simultaneously positive in only 20% (n=7/35). Standardised and unstandardised ECTs confirmed LAD with 54% sensitivity and 70% specificity, and 46% sensitivity and 68% specificity, respectively, using EVH as a reference, while EVH and methacholine BPT were both 33% sensitive and 85% specific, using standardised ECTs as reference.

Conclusion

App-based spirometry for unsupervised field-based ECTs may support the diagnostic process in athletes with LAD symptoms.

Trial registration number

NCT04275648.

A longitudinal follow-up of continuous laryngoscopy during exercise test scores in athletes irrespective of laryngeal obstruction, respiratory symptoms, and intervention

BACKGROUND

Exercise-induced laryngeal obstruction (EILO) is diagnosed by the continuous laryngoscopy during exercise (CLE) test. Whether or how much CLE test scores vary over time is unknown. This study aimed to compare CLE test scores in athletes over time, irrespective of respiratory symptoms and grade of laryngeal obstruction.

METHODS

Ninety-eight athletes previously screened for EILO were invited for a follow-up CLE test irrespective of CLE scores and respiratory symptoms. Twenty-nine athletes aged 16-27 did a follow-up CLE test 3-23 months after the baseline test. Laryngeal obstruction at the glottic and supraglottic levels was graded by the observer during exercise, at baseline and follow-up, using a visual grade score (0-3 points).

RESULTS

At baseline, 11 (38%) of the 29 athletes had moderate laryngeal obstruction and received advice on breathing technique; among them, 8 (73%) reported exercise-induced dyspnea during the last 12 months. At follow-up, 8 (73%) of the athletes receiving advice on breathing technique had an unchanged supraglottic score. Three (17%) of the 18 athletes with no or mild laryngeal obstruction at baseline had moderate supraglottic obstruction at follow-up, and none of the 3 reported exercise-induced dyspnea.

CONCLUSIONS

In athletes with repeated testing, CLE scores remain mostly stable over 3-24 months even with advice on breathing technique to those with EILO. However, there is some intraindividual variability in CLE scores over time.

TRIAL REGISTRATION

ISRCTN, ISRCTN60543467, 2020/08/23, retrospectively registered, ISRCTN - ISRCTN60543467: Investigating conditions causing breathlessness in athletes.

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.

Diagnostic approach to lower airway dysfunction in athletes: a systematic review and meta-analysis by a subgroup of the IOC consensus on 'acute respiratory illness in the athlete'

OBJECTIVES

To compare the performance of various diagnostic bronchoprovocation tests (BPT) in the assessment of lower airway dysfunction (LAD) in athletes and inform best clinical practice.

DESIGN

Systematic review with sensitivity and specificity meta-analyses.

DATA SOURCES

PubMed, EBSCOhost and Web of Science (1 January 1990-31 December 2021).

ELIGIBILITY CRITERIA

Original full-text studies, including athletes/physically active individuals (15-65 years) who underwent assessment for LAD by symptom-based questionnaires/history and/or direct and/or indirect BPTs.

RESULTS

In 26 studies containing data for quantitative meta-analyses on BPT diagnostic performance (n=2624 participants; 33% female); 22% had physician diagnosed asthma and 51% reported LAD symptoms. In athletes with symptoms of LAD, eucapnic voluntary hyperpnoea (EVH) and exercise challenge tests (ECTs) confirmed the diagnosis with a 46% sensitivity and 74% specificity, and 51% sensitivity and 84% specificity, respectively, while methacholine BPTs were 55% sensitive and 56% specific. If EVH was the reference standard, the presence of LAD symptoms was 78% sensitive and 45% specific for a positive EVH, while ECTs were 42% sensitive and 82% specific. If ECTs were the reference standard, the presence of LAD symptoms was 80% sensitive and 56% specific for a positive ECT, while EVH demonstrated 65% sensitivity and 65% specificity for a positive ECT.

CONCLUSION

In the assessment of LAD in athletes, EVH and field-based ECTs offer similar and moderate diagnostic test performance. In contrast, methacholine BPTs have lower overall test performance.

PROSPERO REGISTRATION NUMBER

CRD42020170915.

Breathing Pattern Disorders Distinguished from Healthy Breathing Patterns Using Optoelectronic Plethysmography

There is no gold standard diagnostic method for breathing pattern disorders (BPD) which is commonly diagnosed through the exclusion of other pathologies. Optoelectronic plethysmography (OEP) is a 3D motion capture technique that provides a comprehensive noninvasive assessment of chest wall during rest and exercise. The purpose of this study was to determine if OEP can distinguish between active individuals classified with and without BPD at rest and during exercise. Forty-seven individuals with a healthy breathing pattern (HBP) and twenty-six individuals with a BPD performed a submaximal exercise challenge. OEP measured the movement of the chest wall through the calculation of timing, percentage contribution, and phase angle breathing pattern variables. A mixed model repeated measures ANOVA analysed the OEP variables between the groups classified as HBP and BPD at rest, during exercise, and after recovery. At rest, regional contribution variables including ribcage percentage contribution (HBP: 71% and BPD: 69%), abdominal ribcage contribution (HBP: 13% and BPD: 11%), abdomen percentage contribution (HBP: 29% and BPD: 31%), and ribcage and abdomen volume index (HPB: 2.5 and BPD: 2.2) were significantly (p < 0.05) different between groups. During exercise, BPD displayed significantly (p < 0.05) more asynchrony between various thoracic compartments including the ribcage and abdomen phase angle (HBP: -1.9 and BPD: -2.7), pulmonary ribcage and abdomen phase angle (HBP: -0.5 and BPD, 0.5), abdominal ribcage and shoulders phase angle (HBP: -0.3 and BPD: 0.6), and pulmonary ribcage and shoulders phase angle (HBP: 0.2 and BPD: 0.6). Additionally, the novel variables inhale deviation (HBP: 8.8% and BPD: 19.7%) and exhale deviation (HBP: -10.9% and BPD: -17.6%) were also significantly (p < 0.05) different between the groups during high intensity exercise. Regional contribution and phase angles measured via OEP can distinguish BPD from HBP at rest and during exercise. Characteristics of BPD include asynchronous and thoracic dominant breathing patterns that could form part of future objective criteria for the diagnosis of BPD.

How to detect young athletes at risk of exercise-induced bronchoconstriction?

Exercise-induced bronchoconstriction (EIB) is a prevalent condition in elite athletes caused by transient airway narrowing during or after exercise. Young athletes nowadays start early to perform high level exercise, highlighting the need to screen for EIB in a younger population. The purpose of this review is to evaluate current evidence of pre-tests with high probability to predict a positive provocation test in young and adolescent athletes, aged 12-24 years and thus indicate whether a young athlete is at risk of having EIB. Up to now, there is no validated screening test available to increase the pre-test probability of a provocation test of EIB in young and adolescent athletes. We would recommend that a clinical guideline committee might consider the development of a flow chart to screen for EIB in adolescent athletes. It could be composed of a symptom-based questionnaire focusing on wheezing during exercise, atopic state, reversibility test (to exclude EIB with asthma) and completed with markers in blood/serum. However, more research is necessary.

Exercise-induced bronchoconstriction in university field hockey athletes: Prevalence, sex differences, and associations with dyspnea symptoms

Introduction

Exercise-induced bronchoconstriction (EIB) is a prevalent condition in athletes. EIB screening studies identify many athletes with undiagnosed EIB. Moreover, there is a poor relationship between EIB and dyspnea symptoms recalled from memory.

Purpose

This study investigated: (I) the prevalence of EIB in British university field hockey athletes; (II) the effect of sex and diagnostic criteria on EIB prevalence; and (III) the association between EIB and contemporaneous dyspnea symptoms.

Methods

52 field hockey athletes (age: 20 ± 2 years; height: 173 ± 9 cm; body mass: 72 ± 10 kg; male = 31; female = 22) completed a eucapnic voluntary hyperpnea (EVH) test with multi-dimensional dyspnea scores measured 3–10 mins post-EVH. A test was deemed positive (EIB⁺) if a fall index (FI) ≥10% in FEV₁ occurred at two consecutive time points post-test (FI_ATS). Two further criteria were used to assess the effect of diagnostic criteria on prevalence: FI_≥10%, determined by a pre-to-post-EVH fall in FEV₁ of ≥10% at any single time-point; and FI_{≥10%−NORM} calculated as FI_≥10% but with the fall in FEV₁ normalized to the mean ventilation achieved during EVH.

Results

EIB prevalence was 19% and greater in males (30%) than females (5%). In EIB⁺ athletes, 66% did not have a previous diagnosis of EIB or asthma and were untreated. Prevalence was significantly influenced by diagnostic criteria (P = 0.002) ranging from 19% (FI_ATS) to 38% (FI_{≥10%−NORM}). Dyspnea symptoms were higher in EIB⁺ athletes (P ≤ 0.031), produced significant area under the curve for receive operator characteristics (AUC ≥ 0.778, P ≤ 0.011) and had high negative prediction values (≥96%).

Conclusion

Overall, 19% of university field hockey athletes had EIB, and most were previously undiagnosed and untreated. EVH test diagnostic criteria significantly influences prevalence rates, thus future studies should adopt the ATS criteria (FI_ATS). Contemporaneous dyspnea symptoms were associated with bronchoconstriction and had high negative prediction values. Therefore, contemporaneous dyspnea scores may provide a useful tool in excluding a diagnosis of EIB.

Application of a Cold Dry Air Provocation Test in Pediatric Patients with Asthma

Asthma is a chronic inflammatory airway disease characterized by reversible airway obstruction and airway hyperreactivity. We proposed a cold dry air (CDA) provocation test and investigated its application in pediatric patients with asthma. We enrolled 72 children and adolescents older than 5 years who presented to our hospital with chronic cough, shortness of breath, and wheezing. We analyzed the results of allergy, pulmonary function, methacholine provocation, and CDA provocation tests. The FEV1 change 5 min after the provocation was recorded as CDA5 dFEV1; that after 15 min was recorded as CDA15 dFEV1. PT10 was the provocation time causing a 10% decrease in FEV1; a decrease of >10% in dFEV1 was considered a positive CDA test. Among the 72 subjects, 51 were diagnosed with asthma. A positive CDA test in patients with asthma correlated with non-eosinophilic asthma. In patients with asthma, sputum eosinophils and eosinophil cationic protein (ECP) levels of the patients with a positive CDA test were significantly lower than those of patients with a negative test. CDA5 dFEV1 correlated with PC20 and total immunoglobulin E. CDA15 dFEV1 correlated with PC20, sputum eosinophils, and ECP. PT10 became shorter as the peripheral blood eosinophil, FVC, FEV1, FEV1/FVC, and FEF25-75 decreased. The CDA provocation test showed airway hyperreactivity to non-specific stimuli, a high correlation with non-eosinophilic asthma, and the possibility of assessing asthma severity via PT10.

International Olympic Committee (IOC) consensus statement on acute respiratory illness in athletes part 2: non-infective acute respiratory illness

Acute respiratory illness (ARill) is common and threatens the health of athletes. ARill in athletes forms a significant component of the work of Sport and Exercise Medicine (SEM) clinicians. The aim of this consensus is to provide the SEM clinician with an overview and practical clinical approach to non-infective ARill in athletes. The International Olympic Committee (IOC) Medical and Scientific Committee appointed an international consensus group to review ARill in athletes. Key areas of ARill in athletes were originally identified and six subgroups of the IOC Consensus group established to review the following aspects: (1) epidemiology/risk factors for ARill, (2) infective ARill, (3) non-infective ARill, (4) acute asthma/exercise-induced bronchoconstriction and related conditions, (5) effects of ARill on exercise/sports performance, medical complications/return-to-sport (RTS) and (6) acute nasal/laryngeal obstruction presenting as ARill. Following several reviews conducted by subgroups, the sections of the consensus documents were allocated to 'core' members for drafting and internal review. An advanced draft of the consensus document was discussed during a meeting of the main consensus core group, and final edits were completed prior to submission of the manuscript. This document (part 2) of this consensus focuses on respiratory conditions causing non-infective ARill in athletes. These include non-inflammatory obstructive nasal, laryngeal, tracheal or bronchial conditions or non-infective inflammatory conditions of the respiratory epithelium that affect the upper and/or lower airways, frequently as a continuum. The following aspects of more common as well as lesser-known non-infective ARill in athletes are reviewed: epidemiology, risk factors, pathology/pathophysiology, clinical presentation and diagnosis, management, prevention, medical considerations and risks of illness during exercise, effects of illness on exercise/sports performance and RTS guidelines.

Asthma diagnosis using patient-reported outcome measures and objective diagnostic tests: now and into the future

PURPOSE OF REVIEW

The global prevalence of asthma continues to increase; however, asthma remains under-diagnosed and under-treated. This results in a significant burden on the healthcare system and preventable patient morbidity and mortality. Over-diagnosis of asthma based on clinical history alone also complicates patient management. This heightens the importance of a prompt and accurate asthma diagnosis. Therefore, a review of the literature was performed regarding both objective diagnostic testing for asthma and using patient-reported outcome measures.

RECENT FINDINGS

The cornerstone of asthma diagnosis remains spirometry with testing for bronchodilator reversibility testing for pediatric and adult populations. This test may need to be repeated at multiple time points due to its low sensitivity. Peak flow measurement, fractional exhaled nitric oxide testing, and allergy testing are useful adjuncts to the diagnosis and phenotyping of asthma. Bronchoprovocation testing is reserved for people with high clinical suspicion for asthma, but negative spirometry. Novel noninvasive testing modalities may play a diagnostic role in the future. The advent of remote digital health monitoring technology has resulted in revisiting patient-reported outcome measures for the diagnosis and monitoring of asthma.

SUMMARY

Overall, improved diagnostic tools for asthma are crucial for earlier recognition and treatment of the disease and improved patient care outcomes worldwide.

Ventilation Rates Achieved in Eucapnic Voluntary Hyperpnea Challenge and Exercise-Induced Bronchoconstriction Diagnosis in Young Patients with Asthma

PURPOSE

Exercise-induced bronchoconstriction (EIB) affects approximately 50% of young asthma patients, impairing their participation in sports and physical activities. Eucapnic voluntary hyperpnea (EVH) is an approved surrogate challenge to exercise for objective EIB diagnosis, but the required minimum target hyperventilation rates remain unexplored in this population. This study aimed to evaluate the association between the achieved ventilation rates (VRs) during a challenge and EIB-compatible response (EIB-cr) in young asthma patients.

METHODS

This cross-sectional study included 72 asthma patients aged 10-20 years. Forced expiratory volume in the first second (FEV1) was measured before and 5, 15, and 30 min after the EVH. The target VR was set at 21 times the individual's baseline FEV1. A decrease of > 10% in FEV1 after the challenge was considered an EIB-cr. The challenge was repeated after 48-72 h in those without an EIB-cr.

RESULTS

Thirty-six individuals had an EIB-cr at initial evaluation. The median VRs achieved was not different between individuals with and without an EIB-cr (19.8 versus 17.9; p = 0.619). The proportion of individuals with an EIB-cr was nor different comparing those who achieved (12/25) or not (24/47) the calculated target VRs (p = 0.804). At the repeated EVH challenge an EIB-cr was observed in 14/36 individuals with a negative response in the first evaluation, with no differences in achieved VRs between the two tests (p = 0.463).

CONCLUSION

Irrespective of the achieved VR, an EIB-compatible response after an EVH challenge must be considered relevant for clinical and therapeutic judgment and negative tests should be repeated.

Effects of high intensity interval training on cardiorespiratory fitness and salivary levels of IL-8, IL-1ra, and IP-10 in adults with asthma and non-asthma controls

OBJECTIVE

The purpose of this study was to determine whether high intensity interval training (HIIT) would lead to improvements in 1) maximal VO₂, V_E, V_E/VCO₂, and V_E/MVV, and/or 2) resting salivary concentrations of pro-inflammatory markers Interleukin (IL-8), interferon-gamma-inducible-protein (CXCL10/IP-10)) and anti-inflammatory marker IL-1 receptor antagonist (IL-1ra) in adults with well-controlled asthma compared to non-asthma controls.

METHODS

Participants completed a maximal exercise test at the beginning (T1) and end (T2) of a 6-week HIIT intervention; saliva samples were obtained at the beginning and 30 min following the first (T1) and last (T2) exercise session.

RESULTS

Adults with asthma (n = 20; age: 21.4 ± 2.4 years) and non-asthma controls (n = 12; age: 22.5 ± 3.4 years) completed the intervention. VO₂max increased from T1 to T2 in both groups (asthma T1 32.9 ± 8, T2 38.6 ± 8.2 ml/kg/min; controls T1 34.5 ± 11.8, T2 38.9 ± 12.3 ml/kg/min). V_Emax also increased in both groups (asthma T1 97.7, T2 110.8 units, p < 0.001, h_p² = <0.04; control T1 106.3, T2 118.1, p < 0.001, h_p² 0.02). An increase in V_E/VCO₂ (F(1, 10)=22.11, p = 0.001) and V_E/MVV (F(1, 10) = 111.30, p < 0.001) was observed in the control group; no differences were observed in the asthma group. No differences in IL-8 or IL-1ra were observed between groups. In the asthma group, resting salivary IP-10 concentrations significantly decreased from T1 (0.025 pg/ug protein) to T2 (0.015 pg/ug protein, p = 0.039, h_p² = 0.3 (moderate effect)).

CONCLUSION

A 6-week HIIT intervention led to a similar increase in VO₂max and V_Emax in those with and without asthma, and a decrease in resting salivary IP-10 levels among adults with asthma.

Airway luminal area and the resistive work of breathing during exercise in healthy young females and males

We examined the relationship between the work of breathing (W_b) during exercise and in vivo measures of airway size in healthy females and males. We hypothesized that sex differences in airway luminal area would explain the larger resistive W_b during exercise in females. Healthy participants (n = 11 females and n = 11 males; 19-30 yr) completed a cycle exercise test to exhaustion where W_b was assessed using an esophageal balloon catheter. On a separate day, each participant underwent a bronchoscopy procedure for optical coherence tomography measures of seven airways. In vivo measures of luminal area were made for the fourth to eighth airway generations. A composite index of airway size was calculated as the sum of the luminal area for each generation, and the total area was calculated based on Weibel's model. We found that index of airway size (males: 37.4 ± 6.3 mm² vs. females: 27.5 ± 7.4 mm²) and airway area calculated based on Weibel's model (males: 2,274 ± 557 mm² vs. females: 1,594 ± 389 mm²) were significantly larger in males (both P = 0.003). When minute ventilation was greater than ∼60 L·min^-1, the resistive W_b was higher in females. At the highest equivalent flow achieved by all subjects, resistance to inspired flow was larger in females and significantly associated with two measures of airway size in all subjects: index of airway size (r = 0.524, P = 0.012) and Weibel area (r = 0.525, P = 0.012). Our findings suggest that innate sex differences in luminal area result in a greater resistive W_b during exercise in females compared with males.NEW & NOTEWORTHY We hypothesized that the higher resistive work of breathing in females compared with males during high-intensity exercise is due to smaller airways. In vivo measures of the fourth to eighth airway generations made using optical coherence tomography show that females tend to have smaller airway luminal areas of the fourth to sixth airway generations. Sex differences in airway luminal area result in a greater resistive work of breathing during exercise in females compared with males.

Reproducibility of eucapnic voluntary hyperpnoea for exercise-induced bronchoconstriction diagnosis in asthmatic children and adolescents

BACKGROUND

Respiratory symptoms after exercise are frequently reported by asthmatic patients, and exercise-induced bronchoconstriction (EIB) is a frequent cause, which requires objective testing for diagnosis. Eucapnic voluntary hyperpnea (EVH) is recommended as a surrogate stimulus for this purpose. Its short-term reproducibility is not yet established in children and young adolescents with asthma.

OBJECTIVE

To evaluate the short-term test-retest agreement and reproducibility of FEV₁ changes after EVH in this population.

METHODS

Asthmatic patients aged between 10 and 20 years underwent EVH for EIB diagnosis on two occasions 2-4 days apart at a specialized university clinic. FEV₁ was measured at 5, 15, and 30 min after EVH with a target ventilation rate 21 times the baseline FEV₁ . EIB was diagnosed as a decrease ≥10% in FEV₁ from baseline.

RESULTS

A total of 26 of 62 recruited individuals tested positive for EIB on both visits (positive group) and 17 on one visit only (divergent group), while 19 tested negative on both visits (negative group). The overall agreement was 72.5% (95%CI 61.6%, 83.6%), and Cohen's kappa coefficient was 0.452. Low bias (0.87%) and high intra-class correlation coefficient (0.854, 95%CI 0.758,0.912; p < .001) for FEV₁ response between test days were found, but with wide limits of agreement (±20.72%). There were no differences in pre-challenge FEV₁ or achieved ventilation rate between visits either between groups (p = .097 and p = .461) or within groups (p = .828 and p = .780). There were no safety issues.

CONCLUSIONS

More than one EVH test should be performed in children and young adolescents with asthma to exclude EIB and minimize misdiagnosis and mistreatment.

High Prevalence of Exercise-induced Laryngeal Obstruction in a Cohort of Elite Cross-country Skiers

INTRODUCTION

Exercise-induced laryngeal obstruction (EILO) is a differential diagnosis for asthma and prevalent in athletes referred for exercise-induced dyspnea. The aim of this study was to estimate the prevalence of EILO in elite cross-country skiers, known for a high prevalence of asthma.

METHOD

Elite cross-country skiers were invited for screening of EILO. Screening consisted of clinical assessment, questionnaires, skin prick test, spirometry, eucapnic voluntary hyperventilation test, and continuous laryngoscopy during exercise test. Current asthma was defined as physician-diagnosed asthma and use of asthma medication during the last 12 months. EILO was defined as ≥2 points at the supraglottic or glottic level during exercise at maximal effort, using a visual grade score system.

RESULT

A total of 89 (51% female) cross-country skiers completed the study. EILO was identified in 27% of the skiers, 83% of whom were female. All skiers with EILO had supraglottic EILO, and there was no glottic EILO. Current asthma was present in 34 (38%) of the skiers, 10 (29%) of whom had concomitant EILO. In the skiers with EILO, a higher proportion reported wheeze or shortness of breath after exercise, compared with skiers without EILO. In skiers with EILO and current asthma, compared with skiers with asthma only, a higher proportion reported wheeze or shortness of breath after exercise. Asthma medication usage did not differ between these groups.

CONCLUSION

EILO is common in elite cross-country skiers, especially females. Asthma and EILO may coexist, and the prevalence of respiratory symptoms is higher in skiers with both. Testing for EILO should be considered in cross-country skiers with respiratory symptoms.

Swimming-induced changes in pulmonary function: special observations for clinical testing

Background

A special improvement in pulmonary function is found in swimmers. In clinical testing the airway reactivity is observed at certain exercise intensity and target ventilation. However, in highly trained swimmers exercising in water the reactions may not function the same way. The aim was to study the combined effects of the water environment and swimming on pulmonary function and the associations with perceived symptoms.

Methods

First, 412 competitive swimmers completed questionnaires concerning respiratory symptoms at different swimming intensities. Then, pulmonary function testing was performed in 14 healthy elite swimmers. Spirometry and maximal voluntary ventilation (MVV) were measured on land and in water before and after swimming. While swimming, minute ventilation (VE) tidal volume (VT) and breathing frequency (fb) were measured during competition speed swimming.

Results

Swimmers reported the most symptoms at competition speed intensity swimming. In the transition from the land into the water swimming body position, the ratio of forced expiratory volume in one second (FEV₁) and forced expiratory capacity (FVC) (FEV₁/FVC) decreased by a mean (SD) 5.3% (3) in females and by 2.2% (5) in males. During competition speed intensity swimming, the minute ventilation (VE) had a mean of 72 and 75% of calculated maximal voluntary ventilation (cMVV) in females and in males, respectively.

Conclusions

Spirometry showed sex differences in water compared to land measurements. These differences should be considered when the effects of swimming are observed. During the intensity that triggered the symptoms the most, the VE was approximately 20% higher than the target ventilations for clinical testing. These findings encourages specific modifications of clinical testing protocols for elite swimmers.

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.

Bronchial Provocation Testing for the Identification of Exercise-Induced Bronchoconstriction

Exercise-induced bronchoconstriction (EIB) occurs in patients with asthma, children, and otherwise healthy athletes. Poor diagnostic accuracy of respiratory symptoms during exercise requires objective assessment of EIB. The standardized tests currently available are based on the assumption that the provoking stimulus to EIB is dehydration of the airway surface fluid due to conditioning large volumes of inhaled air. "Indirect" bronchial provocation tests that use stimuli to cause endogenous release of bronchoconstricting mediators from airway inflammatory cells include dry air hyperpnea (eg, exercise and eucapnic voluntary hyperpnea) and osmotic aerosols (eg, inhaled mannitol). The airway response to different indirect tests is generally similar in patients with asthma and healthy athletes with EIB. Furthermore, the airway sensitivity to these tests is modified by the same pharmacotherapy used to treat asthma. In contrast, pharmacological agents such as methacholine, given by inhalation, act directly on smooth muscle to cause contraction. These "direct" tests have been used traditionally to identify airway hyperresponsiveness in clinical asthma but are less useful to diagnose EIB. The mechanistic differences between indirect and direct tests have helped to elucidate the events leading to airway narrowing in patients with asthma and elite athletes, while improving the clinical utility of these tests to diagnose and manage EIB.

Asthma, atopy, and exercise: Sex differences in exercise-induced bronchoconstriction

Asthma is a chronic inflammatory lung disease affecting approximately 7.7% of the US population. Sex differences in the prevalence, incidence, and severity of asthma have been widely described throughout the lifespan, showing higher rates in boys than girls before puberty, but a reversed pattern in adults. Asthma is often associated with atopy, i.e. the tendency to develop allergic diseases, and can be worsened by environmental stimuli and/or exercise. While not exclusive to patients with asthma, exercise-induced bronchoconstriction (EIB) is a common complication of athletes and individuals who exercise regularly. Currently, there is limited research on sex differences in EIB and its relationship with atopy and asthma in men and women. In this minireview, we summarize the available literature on this topic. Overall, the collective knowledge supports the notion that physiological changes triggered during exercise affect males and females differently, suggesting an interaction among sex, exercise, sex hormones, and atopic status in the course of EIB pathophysiology. Understanding these differences is important to provide personalized management plans to men and women who exercise regularly and suffer from underlying asthma and/or atopy.

Exercise Related Respiratory Problems in the Young-Is It Exercise-Induced Bronchoconstriction or Laryngeal Obstruction?

Complaints of breathlessness during heavy exercise is common in children and adolescents, and represent expressions of a subjective feeling that may be difficult to verify and to link with specific diagnoses through objective tests. Exercise-induced asthma and exercise-induced laryngeal obstruction are two common medical causes of breathing difficulities in children and adolescents that can be challenging to distinguish between, based only on the complaints presented by patients. However, by applying a systematic clinical approach that includes rational use of tests, both conditions can usually be diagnosed reliably. In this invited mini-review, we suggest an approach we find feasible in our everyday clinical work.

Ventilatory responses to constant load exercise following the inhalation of a short-acting ß2-agonist in a laboratory-controlled diesel exhaust exposure study in individuals with exercise-induced bronchoconstriction

OBJECTIVE

Individuals with exercise-induced bronchoconstriction (EIB) use ß₂-agonists to reduce respiratory symptoms during acute exercise. The resultingbronchodilation could increase the dose of inhaled pollutants and impair respiratory function when exercise is performedin air pollution. We aimed to assess respiratory responses in individuals with EIB when completing a cycling bout while being exposed to diesel exhaust (DE) or filtered air (FA) with and without the inhalation of salbutamol (SAL), a short-acting ß₂-agonist.

METHODS

In a double-blind, repeated-measures design, 19 participants with EIB (22-33 years of age) completed four visits: FA-placebo (FA-PLA), FA-SAL, DE-PLA, DE-SAL. After the inhalation of either 400 µg of SAL or PLA, participants sat in the exposure chamber for 60 min, breathing either FA or DE (PM_2.5 = 300 μg/m³). Participants then cycled for 30 min at 50 % of peak work rate while breathing FA or DE. Respiratory responses were assessed via spirometry, work of breathing (WOB), fractional use of ventilatory capacity (V̇_E/V̇_E,CAP), area under the maximal expiratory flow-volume curve (MEFV_AUC), and dyspnea during and following cycling.

RESULTS

Bronchodilation in response to SAL and acute cycling was observed, independent of FA/DE exposure. Specifically, FEV₁ was increased by 7.7 % (confidence interval (CI): 7.2-8.2 %; p < 0.01) in response to SAL, and MEFV_AUC was increased after cycling by 1.1 % (0.9-1.3 %; p = 0.03). Despite a significant decrease in total WOB by 6.2 J/min (4.7-7.5 J/min; p = 0.049) and a reduction in V̇_E/V̇_E,CAP by 5.8 % (5-6 %, p < 0.01) in the SAL exposures, no changes were observed in dyspnea. The DE exposure significantly increased V̇_E/V̇_E,CAP by 2.4 % (0.9-3.9 %; p < 0.01), but this did not affect dyspnea.

DISCUSSION

Our findings suggest that the use of SAL prior to moderate-intensity exercise when breathing high levels of DE, does not reduce respiratory function or exercise ventilatory responses for up to 60 min following exercise.

Inhaled albuterol increases estimated ventilatory capacity in nonasthmatic children without and with obesity

Forced mid-expiratory flow (i.e., isoFEF_25-75) may increase with a short-acting β₂-agonist in nonasthmatic children without bronchodilator responsiveness. This could also increase estimated ventilatory capacity along mid-expiration (V̇Ecap_25-75), especially in vulnerable children with obesity who exhibit altered breathing mechanics. We estimated V̇Ecap_25-75 pre- and post-albuterol treatment in 8-12yo children without (n = 28) and with (n = 46) obesity. A two-way ANOVA was performed to determine effects of an inhaled bronchodilator (pre-post) and obesity (group) on isoFEF_25-75 and V̇Ecap_25-75. There was no group by bronchodilator interaction or main group effect on outcome variables. However, a significant main effect of the bronchodilator was detected in spirometry parameters, including a substantial increase in isoFEF_25-75 (17.1 ± 18.0 %) and only a slight (non-clinical) but significant increase in FEV₁ (2.4 ± 4.3 %). V̇Ecap_25-75 significantly increased with albuterol (+11.7 ± 10.6 L/min; +15.8 ± 13.9 %). These findings imply potentially important increases in ventilatory reserve with a bronchodilator in nonasthmatic children without and with obesity, which could potentially influence respiratory function at rest and during exercise.

Sex Differences in Exercise-Induced Bronchoconstriction in Athletes: A Systematic Review and Meta-Analysis

Exercise-induced bronchoconstriction (EIB) is a common complication of athletes and individuals who exercise regularly. It is estimated that about 90% of patients with underlying asthma (a sexually dimorphic disease) experience EIB; however, sex differences in EIB have not been studied extensively. With the goal of better understanding the prevalence of EIB in males and females, and because atopy has been reported to occur at higher rates in athletes, in this study, we investigated sex differences in EIB and atopy in athletes. A systematic literature review identified 60 studies evaluating EIB and/or atopy in post-pubertal adult athletes (n = 7501). Collectively, these studies reported: (1) a 23% prevalence of EIB in athletes; (2) a higher prevalence of atopy in male vs. female athletes; (3) a higher prevalence of atopy in athletes with EIB; (4) a significantly higher rate of atopic EIB in male vs. female athletes. Our analysis indicates that the physiological changes that occur during exercise may differentially affect male and female athletes, and suggest an interaction between male sex, exercise, and atopic status in the course of EIB. Understanding these sex differences is important to provide personalized management plans to athletes with underlying asthma and/or atopy.

Gender influence on the MVV / FEVı ratio in a population of healthy young adults

INTRODUCTION

Maximal voluntary ventilation (MVV) and flow expiratory volume in the first second (FEVı) are important spirometric parameters. They are both gender-dependent. However, estimating the MVV, which is widely practiced in cardiopulmonary function testing, by multiplying FEVı by a constant value (equal to MVV/FEVı ratio) does not seem to take this into account. The purpose of this study was to compare the MVV/FEVı ratio by gender among healthy young adults.

METHODS

This cross-sectional prospective study involved 67 medical sciences students, including 36 females of the same race, height, and age group. Their ventilatory function was assessed using a computerized spirometer, according to international recommendations. Pearson's test made it possible to correlate different spirometric parameters and linear regression was established between MVV and FEVı. The nonparametric Kruskal-Wallis test was used to compare the MVV/FEVı ratio between females and males. Comparisons by gender were made also between our data and previous prediction equations.

RESULTS

In both females and males, FEVı was the spirometric parameter with which MVV had the highest correlation (r = .91 in females, r = .63 in males). A comparison of the means of the MVV/FEVı ratio by gender showed a statistically significant (p < .005) decrease in females (35.68 vs. 38.87). The previous prediction equations showed statistically significant under and overestimation of MVV values when gender was not taken into account.

CONCLUSION

For the same height, age, and race, the ratio MVV/FEVı was significantly lower for females. So, the use of a preset constant value in estimating the MVV without taking gender into account was methodologically questionable. This work, which could have clinical implications, would benefit from being confirmed in a larger population.

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.

Cut-off values to evaluate exercise-induced asthma in eucapnic voluntary hyperventilation test for children

BACKGROUND AND AIM

The eucapnic voluntary hyperventilation (EVH) testing is a diagnostic tool for diagnostics of exercise-induced bronchoconstriction; while the testing has become more common among children, data on the test's feasibility among children remain limited. Our aim was to investigate EVH testing feasibility among children, diagnostic testing cut-off values, and which factors affect testing outcomes.

METHODS

We recruited 134 patients aged 10-16 years with a history of exercise-induced dyspnoea and 100 healthy control children to undergo 6-min EVH testing. Testing feasibility was assessed by the children's ability to achieve ≥70% of the target minute ventilation of 30 times forced expiratory volume in 1 s (FEV1). Bronchoconstriction was assessed as a minimum of 8%, 10%, 12%, 15% or 20% fall in FEV1. Patient characteristics were correlated with EVH outcomes.

RESULTS

Overall, 98% of the children reached ≥70%, 88% reached ≥80%, 79% reached ≥90% and 62% reached ≥100% of target ventilation in EVH testing; of children with a history of exercise-induced dyspnoea, the decline percentages were as follows: 24% (≥8% fall), 17% (≥10% fall), 10% (≥12% fall), 6% (≥15% fall) and 5% (≥20% fall) in FEV1, compared to 11%, 4%, 3%, 1% and 0% among the healthy controls, respectively. Healthy controls and boys performed testing at higher ventilation rates (p < .05).

CONCLUSION

Eucapnic voluntary hyperventilation testing is feasible among children aged 10-16 years and has diagnostic value in evaluating exercise-induced dyspnoea among children. A minimum 10% fall in FEV1 is a good diagnostic cut-off value. Disease status appears to be important covariates.

Reducing Anxiety and Anxiety Sensitivity With High-Intensity Interval Training in Adults With Asthma

BACKGROUND

Low- and moderate-intensity exercise training has been shown to be effective for reducing general anxiety and anxiety sensitivity among adults with asthma. Exercise frequency and intensity have been shown to play an integral role in reducing anxiety sensitivity; however, less is known about the impact of high-intensity interval training (HIIT) on anxiety in adults with asthma.

METHODS

A 6-week HIIT intervention was conducted with adults with asthma. Participants completed HIIT (10% peak power output for 1 min, 90% peak power output for 1 min, repeated 10 times) 3 times per week on a cycle ergometer. Preintervention and postintervention assessments included the Anxiety Sensitivity Index-3 and the Body Sensations Questionnaire.

RESULTS

Total Anxiety Sensitivity Index-3 (PRE: 17.9 [11.8]; POST 12.4 [13], P = .002, Cohen d = 0.4, n = 20) and Body Sensations Questionnaire (PRE: 2.4 [1.0]; POST: 2.0 [0.8], P = .007, Cohen d = 0.3) improved from preintervention to postintervention.

CONCLUSION

A 6-week HIIT intervention leads to improved anxiety among adults with asthma. Future research should determine the impact of HIIT among adults with asthma with clinical anxiety.

Management of Intermittent and Persistent Asthma in Adolescent and High School Athletes

Asthma is the most common chronic condition during childhood and adolescence, affecting an estimated 8% of children and youngsters below 18 years in the United States and the United Kingdom. In adolescent athletes, asthma-like symptoms may represent a common consequence of regular sport practice. Asthma in young athletes poses several challenges, including the ambiguity of definitions and diagnosis of asthma resulting from exercise-induced symptoms, the best pharmacological treatments, and the nonpharmacological options for the management of disease and the challenges inherent to this age group. At a time when the regular practice of sports is increasingly being recommended for a healthy living, the support network around the young athletes is crucial to reduce the impact of asthma on their physical and emotional well-being. In this review, we examine the main issues around the definitions and clinical differentiations of asthma in young sport athletes. We discuss best practice approaches to improve the adherence to the clinical management, including nonpharmacological strategies directed at the family and trainers of athlete adolescents.

Update in Pediatric Asthma: Selected Issues

Asthma is a complex condition that affects 14% of the world's children and the approach to management includes both pharmacologic as well as non-pharmacologic strategies including attention to complex socioeconomic status phenomena. After an historical consideration of asthma, allergic and immunologic aspects of asthma in children and adolescents are presented. Concepts of socioeconomic aspects of asthma are considered along with environmental features and complications of asthma disparities. Also reviewed are links of asthma with mental health disorders, sleep disturbances and other comorbidities. A stepwise approach to asthma management is discussed that includes pharmacologic and non-pharmacologic strategies in the pediatric population. The role of immunotherapy and use of various immunomodulators are considered as well.

Vascular effects of physical activity are not modified by short-term inhaled diesel exhaust: Results of a controlled human exposure study

BACKGROUND

The combined effects of physical activity and air pollution exposure on vascular function are insufficiently understood, particularly after the inhalation of a β₂-agonist, a vasodilating agent.

OBJECTIVE

To assess the micro- and macrovascular response to physical activity after β₂-agonist use while breathing diesel exhaust (DE) in individuals with exercise-induced bronchoconstriction.

METHODS

On four exposure visits, eighteen adults inhaled either 400 μg of the β₂-agonist salbutamol or placebo before resting for 60 min, followed by a 30-min cycling bout. During rest and cycling, participants inhaled filtered air (FA) or DE (300 μg/m³ of PM_2.5). Microvascular (central retinal arteriolar and venular equivalents, CRAE and CRVE, respectively) and macrovascular parameters (blood pressure (BP)) and heart rate (HR)) were assessed at baseline (T₁), 10 min (T₂) and 70 min (T₃) after cycling.

RESULTS

The cycling bout increased CRAE (T₂-T₁ difference (95th % confidence interval): 4.88 μm (4.73, 5.00 μm), p < 0.001; T₃-T₁ difference: 2.10 μm (1.62, 2.58 μm), p = 0.031) and CRVE (T₂-T₁ difference: 3.78 μm (3.63, 3.92 μm), p < 0.001; T₃-T₁ difference: 3.73 μm (3.63, 3.92 μm), p < 0.001). The exposure to DE had no effect on CRAE (FA-DE difference at T₂: 0.46 μm (-0.02, 0.92 μm); p = 0.790; FA-DE difference at T₃: 1.76 μm (1.36, 2.16 μm), p = 0.213) and CRVE (FA-DE difference at T₂: 0.26 μm (-0.35, 0.88 μm), p = 0.906; FA-DE difference at T₃: 0.55 μm (0.05, 1.06 μm), p = 0.750). Compared to T₁, systolic BP was decreased at T₂ by 2.5 mmHg (2.8, 2.3 mmHg, p = 0.047), independent of inhaled exposure. Heart rate at T₂ was significantly increased by 3 bpm (2, 3 bpm, p = 0.025) after the DE-exposure when compared to FA.

DISCUSSION

Acute physical activity induces a vasodilatory response in the micro- and macrovasculature in healthy adults by increasing CRAE and CRVE, and by reducing systolic BP post exercise, despite breathing DE. The DE-associated increase in HR might be indicative of an increased sympathetic response to physical activity while breathing DE.

Diagnosis of Exercise-induced Bronchoconstriction in Swimmers: Context Matters

Swimmers have a high prevalence of exercise-induced bronchoconstriction (EIB), which may be associated with repeated exposure to chlorinated pool water. The eucapnic voluntary hyperpnea (EVH) test is used to diagnose EIB; however, it fails to replicate the environmental conditions experienced by swimmers. The relationship between the composition of the EVH inspired gas and the development of EIB from swim exercise remains unclear.

PURPOSE

This study aimed to compare the bronchoconstrictive effect of a chlorinated inspirate EVH test and swim test to a laboratory-based EVH test in swimmers.

METHODS

Fifteen collegiate swimmers (n = 5 male, n = 10 female; 21 ± 2 yr) completed 3 d of testing in pseudorandom order; a standard EVH test (EVHL), a pool air EVH test (EVHCl), and a swimming test (Swim). Spirometry was measured at baseline, and 3, 5, 10, 15, and 20 min after each test.

RESULTS

EVHL elicited a forced expired volume in 1 s (FEV1) fall index of -9.7% ± 6.4% compared with -6.6% ± 9.2% and -3.0% ± 7.5% after EVHCl and Swim, respectively (P < 0.05). Using Bland-Altman analysis, we found good agreement between EVHL and EVHCl (bias = -2.8, r = 0.79; P < 0.05) with poor agreement between EVHL and Swim (bias = -6.7, r = 0.20) and between EVHCl and Swim (bias = -3.9, r = 0.50; both P < 0.05). Forced expired flow between 25% and 75% lung volume and peak expired flow were significantly reduced by the EVHL compared with the EVHCl and Swim tests (P < 0.05).

CONCLUSIONS

EVHL elicits a greater forced expired volume in 1-s fall index compared with EVHCl and Swim. The unique aquatic environment of swimmers potentially protects against bronchoconstriction and should be considered in the determination of EIB.

Exercise-induced bronchoconstriction in elite or endurance athletes:: Pathogenesis and diagnostic considerations

OBJECTIVE

To review the pathogenesis and evaluation of exercise-induced bronchoconstriction pertaining to the elite or endurance athlete, as well as propose a diagnostic algorithm based on the current literature.

DATA SOURCES

Studies were identified using Ovid MEDLINE and reference lists of key articles.

STUDY SELECTIONS

Randomized controlled trials were selected when available. Systematic reviews and meta-analyses of peer-reviewed literature were included, as were retrospective studies and observational studies of clinical interest.

RESULTS

Exercise-induced bronchoconstriction (EIB) is the physiologic entity in which exercise induces acute narrowing of the airways and occurs in patients both with and without asthma. It may present with or without respiratory symptoms, and the underlying cause is likely attributable to environment stressors to the airway encountered during exercise. These include the osmotic effects of inhaled dry air, temperature variations, autonomic nervous system dysregulation, sensory nerve reactivity, and airway epithelial injury. Deposition of allergens, particulate matter, and gaseous pollutants into the airway also contribute. Elite and endurance athletes are exposed to these stressors more frequently and in greater duration than the general population.

CONCLUSION

A greater awareness of EIB among elite and endurance athletes is needed, and a thorough evaluation should be performed if EIB is suspected in this population. We propose an algorithm to aid in this evaluation. Symptoms should not be solely relied on for diagnosis but should be taken into the context of bronchoprovocative challenges, which should replicate the competitive environment as closely as possible. Further research is needed to validate these tests' predictive values.

Improved Sprint Performance With Inhaled Long-Acting β2-Agonists Combined With Resistance Exercise

PURPOSE

To investigate the impact of twice-daily inhalation of 100 µg of salmeterol (SAL) or 12 µg of formoterol (FOR) in addition to a strength- and power-training program over a 5-wk period on a 30-m sprint, strength, power, mood, stress, and skinfold thickness.

METHODS

In a randomized, single-blind study, 23 male and 15 female nonasthmatic, recreationally active individuals were recruited (mean [SD] age 26.3 [5.4] y, weight 76.2 [11.5] kg, height 176.9 [8.5] cm). Participants completed 3 standardized whole-body strength- and power-training sessions per week for 5 wk during which they were assigned to an SAL, FOR, or placebo group. Participants used their inhaler twice per day as instructed and completed assessments of sprint, strength, and power at baseline and 1 wk after cessation of the training program. The assessments included a 30-m sprint, vertical jump, 1-repetition-maximum (1RM) bench press, 1RM leg press, peak torque flexion and extension, anthropometric evaluation, and Rest-Q questionnaires.

RESULTS

After 5 wk of strength and power training, 30-m sprint time reduced in the FOR (0.29 [0.11] s, P = .049) and SAL (0.35 [0.05] s, P = .040) groups compared with placebo (+0.01 [0.11] s). No significant change was found in other assessments of strength, mood, or skinfold thickness.

CONCLUSIONS

When strength and power training are combined with the inhalation of FOR or SAL over a 5-wk period, moderately trained individuals experience an improvement in 30-m sprint performance.

Can EVH Results Predict Post-Exercise Changes in FEV1 Following Interval and Continuous Exercise?

The eucapnic voluntary hyperpnea (EVH) challenge is used to determine the presence of exercise-induced bronchoconstriction (EIBC) by monitoring changes in forced expiratory volume in 1 s (FEV₁). However, the predictability of the post-EVH decline in FEV₁ on post-exercise FEV₁ remains unclear. Participants completed an EVH challenge to confirm EIBC and completed a continuous exercise (CONT; n = 21), high-intensity interval exercise (HI; n = 13), and sprint interval exercise (SPRT; n = 8) sessions on separate days. FEV₁ was assessed pre- and post exercise. A 1% decline in FEV₁, post EVH was associated with 0.44%, 0.85%, and 0.56% declines in FEV₁ post CONT, post HI, and post SPRT, respectively. The decline in FEV₁ following the EVH challenge was associated with the decline in FEV₁ following all exercise conditions, with the strongest association being observed following HI. These findings may have implications for exercise prescription and asthma education for recreationally active adults with EIBC.

Cold air exercise screening for exercise induced bronchoconstriction in cold weather athletes

Exercise Induced Bronchoconstriction (EIB) prevalence in cold weather athletes is high. Currently, no standardized cold air exercise provocation test exists. Thus we aimed to determine EIB prevalence using a Cold Air Test (CAT; 5 km outdoor running; -15 °C) compared to the most common EIB screen the Eucapnic Voluntary Hyperpnea (EVH) test in cold weather athletes. Sixteen (9 male; 20-35 years old) cold weather athletes completed EVH 72 h before CAT. Spirometry, Fractional Expired Nitric Oxide (FENO), respiratory symptoms were measured and atopy status was determined. Five and 7 participants were EIB + on the EVH and CAT, respectively. Level of agreement was 50% between tests. FEV₁ recovery was significantly prolonged and Peak Expiratory Flow was decreased after CAT compared to EVH. Predictive characteristics of EIB + included FENO >12 ppb, FEV₁/FVC ratio (<0.75) and BMI < 20. EVH does not always reflect EIB triggered by cold weather exercise. More research is required to understand the best EIB screens for cold weather athletes.

The Effects of Inhaled Terbutaline on 3-km Running Time-Trial Performance

Terbutaline is a prohibited drug except for athletes with a therapeutic use exemption certificate; terbutaline's effects on endurance performance are relatively unknown. Purpose: To investigate the effects of 2 therapeutic (2 and 4 mg) inhaled doses of terbutaline on 3-km running time-trial performance. Methods: A total of 8 men (age 24.3 [2.4] y; weight 77.6 [8] kg; and height 179.5 [4.3] cm) and 8 women (age 22.4 [3] y; weight 58.6 [6] kg; and height 163 [9.2] cm) free from respiratory disease and illness provided written informed consent. Participants completed 3-km running time trials on a nonmotorized treadmill on 3 separate occasions following placebo and 2- and 4-mg inhaled terbutaline in a single-blind, repeated-measures design. Urine samples (15 min postexercise) were analyzed for terbutaline concentration. Data were analyzed using 1-way repeated-measures analysis of variance, and significance was set at P < .05 for all analyses. Results: No differences were observed for completion times (1103 [201] s, 1106 [195] s, 1098 [165] s; P = .913) for the placebo or 2- and 4-mg inhaled trials, respectively. Lactate values were higher (P = .02) after 4 mg terbutaline (10.7 [2.3] mmol·L^-1) vs placebo (8.9 [1.8] mmol·L^-1). Values of forced expiratory volume in the first second of expiration (FEV₁) were greater after inhalation of 2 mg (5.08 [0.2]; P = .01) and 4 mg terbutaline (5.07 [0.2]; P = .02) compared with placebo (4.83 [0.5] L) postinhalation. Urinary terbutaline concentrations were mean 306 (288) ng·mL^-1 and 435 (410) ng·mL^-1 (P = .2) and peak 956 ng·mL^-1 and 1244 ng·mL^-1 after 2 and 4 mg inhaled terbutaline, respectively. No differences were observed between the male and female participants. Conclusions: Therapeutic dosing of terbutaline does not lead to an improvement in 3-km running performance despite significantly increased FEV₁. The findings suggest that athletes using inhaled terbutaline at high therapeutic doses to treat asthma will not gain an ergogenic advantage during 3-km running performance.

A Meta-analysis of Diagnostic Test Agreement Between Eucapnic Voluntary Hyperventilation and Cardiopulmonary Exercise Tests for Exercise-Induced Bronchoconstriction

INTRODUCTION

Exercise-induced bronchoconstriction (EIB) is very common in athletes. Cardiopulmonary exercise tests (CPET) have traditionally been used for the diagnosis of EIB. However, alternative indirect bronchoprovocation tests have recently been used as surrogate tests. One of these is the eucapnic voluntary hyperventilation (EVH). This meta-analysis studied the agreement between the two tests.

METHODS

An extensive search in PubMed and Medline was conducted for studies where participants underwent both CPET and EVH with measurement of forced expiratory volume in 1-second (FEV₁). After extracting data using two-by-two contingency tables, pooled positive and negative agreements were first calculated between the two tests, with EVH benchmarked against CPET, and then, pooled positive and negative agreements were calculated with CPET benchmarked against EVH.

RESULTS

The pooled positive and negative agreements between EVH and CPET (with CPET as the reference) were 0.62 [(95% confidence interval 0.54-0.70), I² 77%] and 0.61 [(0.56-0.65)), I² 81%]. The pooled positive and negative agreements between CPET and EVH (with EVH as the reference) were 0.36 [(0.30-0.42), I² 93%] and 0.82 [(0.77-0.86), I² 78%]. The average of positive test results with EVH across all studies was greater than that of CPETs (58.84% vs. 39.51%).

CONCLUSIONS

Results of this meta-analysis show poor positive agreement between the two tests but high negative agreement (specifically using EVH as reference), suggesting that either test can be used for correctly identifying those without EIB. Results also suggest that the chances of a test resulting positive are higher with EVH than with CPET.

Similar Airway Function after Volitional Hyperpnea in Mild-Moderate Asthmatics and Healthy Controls

BACKGROUND

The beneficial effects of exercise training for asthmatics might relate to repetitive airway stretching. Thus, a training with more pronounced airway stretch using isolated, volitional hyperpnea (HYP) might be similarly or more effective. However, in healthy subjects, a bout of HYP training is known to cause an acute FEV1 decline.

OBJECTIVE

The aim of the present study was therefore to test whether these changes are more pronounced in asthmatics, possibly putting them at risk with HYP training.

METHODS

Nine subjects with mild-moderate asthma (confirmed by mannitol challenge) and 11 healthy subjects performed six 5-min bouts (with 6-min breaks; HYP1) and one 30-min bout (HYP2) of normocapnic HYP at 60% of maximal voluntary ventilation using warm and humid air. FEV1 and airway resistance (R5) were measured before, in breaks (HYP1), and immediately after HYP, and during 60 min of recovery.

RESULTS

In both groups, a significant and similar decrease in FEV1 during HYP1 (asthmatics: -3 ± 3%; healthy subjects: -2 ± 3%), after HYP1 (asthmatics: -2 ± 5%; healthy subjects: -1 ± 4%), and after HYP2 (asthmatics: -4 ± 5%; healthy subjects: -3 ± 3%), and an increase in R5 during and after both HYPs were observed. Maximal changes in FEV1 and R5 did not correlate with baseline lung function or responsiveness to mannitol.

CONCLUSIONS

A bout of HYP does not lead to relevant bronchoconstriction and the observed changes in lung function and airway resistance are neither of the magnitude of clinical relevance, nor do they differ from responses in healthy individuals. Thus, HYP training can safely be tested as an airway-specific exercise training alternative (or add-on) modality to regular aerobic exercise training.

Inconsistent calculation methodology for the eucapnic voluntary hyperpnoea test affects the diagnosis of exercise-induced bronchoconstriction

Introduction

The eucapnic voluntary hyperpnoea (EVH) challenge is used to screen for exercise-induced bronchoconstriction. Several criteria have been proposed to determine the decrease in lung function (fall index, FI) following EVH. We compared three published FI calculation methods to determine if they affect the diagnostic classification.

Methods

The three FIs were calculated for 126 EVH tests. Spirometry was performed in duplicate at baseline and repeated 3, 5, 10, 15 and 20 min following 6 min of EVH. The higher of the two forced expiratory volume in 1 s (FEV₁) measures at all time-points post-hyperpnoea was selected for the calculation of the FIs. The FI_A was determined as the single lowest of the five postchallenge values, and a test was considered positive if FEV₁ decreased ≥10 %. In FI_B, a test was considered positive if FEV₁ decreased ≥10% at two consecutive post-challenge time-points. The FI_C was calculated identically to FI_A, but was normalised to the achieved minute ventilation during the EVH challenge.

Results

Calculation method affected the raw FIs with FI_B generating the smallest and FI_C generating the highest values (p<0.001) and a within-subject range of 7%±10%. The number of positive tests differed between the calculation criteria: FI_A: 62, FI_B: 48 and FI_C: 70, p<0.001. Nineteen participants (15%) tested positive in one or two FI methods only, indicating that the FI method used determined whether the test was positive or negative.

Discussion

Inconsistency in methodology of calculating the FI leads to differences in the diagnostic rate of the EVH test, with potential implications in both treatment and research outcomes.

Exercise-induced bronchoconstriction: prevalence, pathophysiology, patient impact, diagnosis and management

Exercise-induced bronchoconstriction (EIB) can occur in individuals with and without asthma, and is prevalent among athletes of all levels. In patients with asthma, symptoms of EIB significantly increase the proportion reporting feelings of fearfulness, frustration, isolation, depression and embarrassment compared with those without symptoms. EIB can also prevent patients with asthma from participating in exercise and negatively impact their quality of life. Diagnosis of EIB is based on symptoms and spirometry or bronchial provocation tests; owing to low awareness of EIB and lack of simple, standardised diagnostic methods, under-diagnosis and mis-diagnosis of EIB are common. To improve the rates of diagnosis of EIB in primary care, validated and widely accepted symptom-based questionnaires are needed that can accurately replicate the current diagnostic standards (forced expiratory volume in 1 s reductions observed following exercise or bronchoprovocation challenge) in patients with and without asthma. In patients without asthma, EIB can be managed by various non-pharmacological methods and the use of pre-exercise short-acting β2-agonists (SABAs). In patients with asthma, EIB is often associated with poor asthma control but can also occur in individuals who have good control when not exercising. Inhaled corticosteroids are recommended when asthma control is suboptimal; however, pre-exercise SABAs are also widely used and are recommended as the first-line therapy. This review describes the burden, key features, diagnosis and current treatment approaches for EIB in patients with and without asthma and serves as a call to action for family physicians to be aware of EIB and consider it as a potential diagnosis.

The Effect of Different Training Loads on the Lung Health of Competitive Youth Swimmers

Airway hyperresponsiveness (AHR), airway inflammation, and respiratory symptoms are common in competitive swimmers, however it is unclear how volume and intensity of training exacerbate these problems. Thus, our purpose was to measure AHR, inflammation, and respiratory symptoms after low, moderate, and high training loads in swimmers. Competitive youth swimmers (n=8) completed nine weeks of training split into three blocks (Low, Moderate, and High intensity). Spirometry at rest and post-bronchial provocation [Eucapnic Voluntary Hyperpnea (EVH)] and Fractional Exhaled Nitric Oxide (FeNO) were completed at the end of each training block. A weekly self-report questionnaire determined respiratory symptoms. Session Rating of Perceived Exertion (sRPE) quantified internal training loads. Internal load was significantly lower after Moderate training (4840 ± 971 AU) than after High training (5852 ± 737 AU) (p = 0.02, d = 1.17). Pre-EVH FEV1 was significantly decreased after Moderate (4.52 ± 0.69 L) compared to Low (4.74 ± 0.63 L) (p = 0.025, d = 0.326), but not different from High load. Post-EVH FeNO after Moderate training was significantly decreased (9.4 ± 4.9 ppb) compared to Low training (15.4 ± 3.6 ppb) (p = 0.012, r = 0.884). Respiratory symptom frequency was significantly correlated with percent decrease in FEV1 20 minutes post-EVH after Low and Moderate loads (both ρ = -0.71, sig = 0.05), and after High load was significantly correlated with percent decrease in FEV1 at 10 (ρ = -0.74, sig = 0.03), 15 (ρ = -0.91, sig = 0.00), and 20 minutes post (ρ = -0.75, sig = 0.03). In conclusion, Moderate load training resulted in the worst lung health results, suggesting there may be factors other than the total amount of stress within training blocks that influence lung health. Further research is needed to determine the effect of manipulating specific acute training load variables on the lung health of swimmers.

Acute responses to sprint-interval and continuous exercise in adults with and without exercise-induced bronchoconstriction

The purpose was to compare the airway response to sprint interval exercise (SIE) and continuous exercise (CE) in active adults with exercise-induced bronchoconstriction (EIBC), and to compare ventilatory and oxygen delivery responses between adults with and without EIBC. Adults with EIBC (n = 8, 22.3 ± 3.0 years) and adults without EIBC (n = 8, 22.3 ± 3.0 years) completed a SIE (4 × 30 s sprints separated by 4.5 min of active recovery) and CE (20 min at 65% peak power output) session. Lung function was assessed at baseline, during exercise, and up to 20 min post-exercise. Ventilatory parameters and tissue saturation index (TSI) were recorded continuously throughout the sessions. The decline in forced expiratory volume in 1 s was similar following SIE (-8.6 ± 12.6%) and CE (-9.0 ± 9.3%) in adults with EIBC. There were no significant differences in any of the ventilatory parameters or in TSI during SIE or CE between those with and without EIBC. These findings suggest that SIE and CE affect airway responsiveness to a similar extent. Future research using a lower intensity CE protocol in an inactive sample of adults with EIBC is needed.