John W. Dickinson

Screening elite winter athletes for exercise induced asthma: a comparison of three challenge methods

Background: The reported prevalence of exercise induced asthma (EIA) in elite winter athletes ranges from 9% to 50%. Many elite winter athletes do not report symptoms of EIA. At present there is no gold standard test for EIA. Objective: To establish the efficacy of screening for EIA and examine the role of the eucapnic voluntary hyperventilation (EVH) challenge and laboratory based and sport specific exercise challenges in the evaluation of elite winter athletes. Methods: 14 athletes (mean (SD) age 22.6 (5.7) years, height 177.2 (7.0) cm, body mass 68.9 (16.9) kg) from the Great Britain short-track speed skating (n = 10) and biathlon teams (n = 4) were studied. Each athlete completed a laboratory based and sport specific exercise challenge as well as an EVH challenge, in randomised order. Results: All 14 athletes completed each challenge. Two had a previous history of asthma. Ten (including the two with a previous history) had a positive test to at least one of the challenges. Ten athletes had a positive response to EVH; of these, only three also had a positive response to the sport specific challenge. No athletes had a positive response to the laboratory based challenge. Conclusions: Elite athletes should be screened for EIA. EVH is a more sensitive challenge in asymptomatic athletes than sport specific and laboratory based challenges. If sporting governing bodies were to implement screening programmes to test athletes for EIA, EVH is the challenge of choice.

Diagnosis of exercise-induced bronchoconstriction: eucapnic voluntary hyperpnoea challenges identify previously undiagnosed elite athletes with exercise-induced bronchoconstriction

Background There is increasing evidence to suggest many elite athletes fail to recognise and report symptoms of exercise-induced bronchoconstriction (EIB), supporting the contention that athletes should be screened routinely for EIB. Purpose To screen elite British athletes for EIB using eucapnic voluntary hyperpnoea (EVH). Methods 228 elite athletes provided written informed consent and completed an EVH challenge with maximal flow volume loops measured at baseline and 3, 5, 10 and 15 min following EVH. A fall of 10% in forced expiratory volume in 1 s (FEV1) from baseline was deemed positive. Two-way analysis of variance was conducted to compare FEV1 at baseline and maximal change following EVH between EVH-positive and EVH-negative athletes who did and did not report a previous diagnosis of EIB. Significance was assumed if p≤0.05. Results Following the EVH challenge 78 athletes (34%) demonstrated EVH positive. 57 out of the 78 (73%) athletes who demonstrated EVH positive did not have a previous diagnosis of EIB. 30 athletes reported a previous diagnosis of asthma, nine (30%) of whom demonstrated EVH negative. There was no significant difference between the magnitude of the fall in FEV1 between athletes who reported a previous diagnosis of EIB and demonstrated EVH positive, and those with no previous diagnosis of EIB who demonstrated EVH positive (mean±SD; −21.6±16.1% vs −17.1±9.7%; p=0.07). Conclusion The high proportion of previously undiagnosed athletes who demonstrated EVH positive suggests that elite athletes should be screened routinely for EIB using a suitable bronchoprovocation challenge.

Misdiagnosis of exercise‐induced bronchoconstriction in professional soccer players

Physicians typically rely heavily on self‐reported symptoms to make a diagnosis of exercise‐induced bronchoconstriction (EIB). However, in elite sport, respiratory symptoms have poor diagnostic value. In 2009, following a change in international sports regulations, all elite athletes suspected of asthma and/or EIB were required to undergo pulmonary function testing (PFT) to permit the use of inhaled β2‐agonists. The aim of this study was to examine the diagnostic accuracy of physician diagnosis of asthma/EIB in English professional soccer players.

Mid-expiratory flow versus FEV1 measurements in the diagnosis of exercise induced asthma in elite athletes

Backround: A fall in FEV1 of ⩾10% following bronchoprovocation (eucapnic voluntary hyperventilation (EVH) or exercise) is regarded as the gold standard criterion for diagnosing exercise induced asthma (EIA) in athletes. Previous studies have suggested that mid-expiratory flow (FEF50) might be used to supplement FEV1 to improve the sensitivity and specificity of the diagnosis. A study was undertaken to investigate the response of FEF50 following EVH or exercise challenges in elite athletes as an adjunct to FEV1. Methods: Sixty six male (36 asthmatic, 30 non-asthmatic) and 50 female (24 asthmatic, 26 non-asthmatic) elite athletes volunteered for the study. Maximal voluntary flow-volume loops were measured before and 3, 5, 10, and 15 minutes after stopping EVH or exercise. A fall in FEV1 of ⩾10% and a fall in FEF50 of ⩾26% were used as the cut off criteria for identification of EIA. Results: There was a strong correlation between ΔFEV1 and ΔFEF50 following bronchoprovocation (r = 0.94, p = 0.000). Sixty athletes had a fall in FEV1 of ⩾10% leading to the diagnosis of EIA. Using the FEF50 criterion alone led to 21 (35%) of these asthmatic athletes receiving a false negative diagnosis. The lowest fall in FEF50 in an athlete with a ⩾10% fall in FEV1 was 14.3%. Reducing the FEF50 criteria to ⩾14% led to 13 athletes receiving a false positive diagnosis. Only one athlete had a fall in FEF50 of ⩾26% in the absence of a fall in FEV1 of ⩾10% (ΔFEV1 = 8.9%). Conclusion: The inclusion of FEF50 in the diagnosis of EIA in elite athletes reduces the sensitivity and does not enhance the sensitivity or specificity of the diagnosis. The use of FEF50 alone is insufficiently sensitive to diagnose EIA reliably in elite athletes.

Inspiratory muscle training: a simple cost-effective treatment for inspiratory stridor

This case study describes the support given to a British elite athlete in the build up to the 2004 Athens Olympic Games. The athlete had complained of breathing symptoms during high intensity training that led to a reduction in performance and premature cessation of training. Following a negative eucapnic voluntary hyperpnoea challenge and observation during high intensity exercise, the athlete was diagnosed with inspiratory stridor. Inspiratory muscle training (IMT) was implemented to attenuate the inspiratory stridor. Following an 11-week IMT programme, the athlete had a 31% increase in mouth inspiratory pressure and a reduction in recovery between high intensity sprints. The athlete reported a precipitous fall in symptoms and was able to complete high intensity training without symptoms. This case shows that IMT is a suitable cost-effective intervention for athletes who present with inspiratory stridor.

Prevalence of bronchoconstriction induced by eucapnic voluntary hyperpnoea in recreationally active individuals

Abstract Objective: Exercise-induced bronchoconstriction (EIB) is more prevalent in elite athletes than in the general population. Many of these athletes provide a positive eucapnic voluntary hyperpnoea (EVH) challenge without previous diagnosis of EIB. It is unknown whether this is specific to elite athletes or whether the same risk applies to recreationally active individuals. The purpose of this study was to investigate the prevalence of a positive EVH challenge in a population of recreationally active individuals. Methods: 136 recreationally active individuals (Age: 21.9 ± 3.7 years; Height: 175 ± 9 cm; Weight: 70.9 ± 10.0 kg) without previous history of asthma or EIB, volunteered to take part in the study. All participants completed an EVH challenge, which was deemed positive if FEV1 fell ≥10% from baseline at two consecutive time points, and was reversible following inhalation of a short acting β2-agonist. Results: 18 of 136 (13.2%) participants had a positive EVH challenge. Of the 18 individuals, the fall in FEV1 from baseline ranged from −12% to −50%. At baseline, percentage predicted FEV1 (97.5 ± 12.5% versus 104.9 ± 10%; p < 0.01), FEV1/FVC ratio (79.5 ± 6.9% versus 87.8 ± 5.5%; p < 0.01), FEF25-75 (3.73 ± 1.00 versus 4.73 ± 1.00 l/s; p < 0.01) and predicted PEF (89.4 ± 8.8% versus 97.5 ± 13.6%; p < 0.05) values for EVH positive participants were significantly lower than EVH negative participants respectively. Conclusions: Overall, 13.2% of recreationally active individuals with no previous history of asthma presented with a positive EVH challenge. Individuals who are recreationally active may benefit from an objective bronchial provocation challenge, given that self-reported symptoms alone only provide a supportive role towards a valid EIB diagnosis.

Eucapnic Voluntary Hyperpnea: Gold Standard for Diagnosing Exercise-Induced Bronchoconstriction in Athletes?

AbstractIn athletes, a secure diagnos is of exercise-induced bronchoconstriction (EIB) is dependent on objective testing. Evaluating spirometric indices of airflow before and following an exercise bout is intuitively the optimal means for the diagnosis; however, this approach is recognized as having several key limitations. Accordingly, alternative indirect bronchoprovocation tests have been recommended as surrogate means for obtaining a diagnosis of EIB. Of these tests, it is often argued that the eucapnic voluntary hyperpnea (EVH) challenge represents the ‘gold standard’. This article provides a state-of-the-art review of EVH, including an overview of the test methodology and its interpretation. We also address the performance of EVH against the other functional and clinical approaches commonly adopted for the diagnosis of EIB. The published evidence supports a key role for EVH in the diagnostic algorithm for EIB testing in athletes. However, its wide sensitivity and specificity and poor repeatability preclude EVH from being termed a ‘gold standard’ test for EIB.

Impact of ethnicity, gender, and dehydration on the urinary excretion of inhaled salbutamol with respect to doping control.

Objective:To examine the impact of dehydration, ethnicity, and gender on urinary concentrations of salbutamol in relation to the threshold stipulated by the World Anti-Doping Agency (WADA). Design:Repeated measures open-label. Participants:Eighteen male and 14 female athletes (9 white males, 9 white females, 2 Afro-Caribbean males, 2 Afro-Caribbean females, 6 Asian [Indian subcontinent] males, and 4 Asian females) were recruited. All participants were nonasthmatic. Interventions:After inhalation of 800 &mgr;g or 1600 &mgr;g of salbutamol, athletes exercised in a hot controlled environment (35°C, 40% relative humidity) at a self-selected pace until a target weight loss (2% or 5%) was achieved. Main Outcome Measures:Urine concentration of free salbutamol. Results:After inhalation of 1600 &mgr;g salbutamol, 20 participants presented with a urine salbutamol concentrations above the current WADA limit (1000 ng/mL) and decision limit (1200 ng/mL) resulting in an adverse analytical finding. There were no differences according to gender or ethnic origin. Conclusions:Dehydration equivalent to a body mass loss greater than 2% concomitant to the acute inhalation of 1600 &mgr;g of salbutamol may result in a urine concentration above the current WADA limit and decision limit leading to a positive test finding independent of gender or ethnic origin. Clinical Relevance:Asthmatic athletes using salbutamol should receive clear dosing advise and education to minimize the risk of inhaling doses of salbutamol that may produce urine concentrations of salbutamol above 1200 ng/mL.

Optoelectronic Plethysmography in Clinical Practice and Research: A Review

Background: Optoelectronic plethysmography (OEP) is a non-invasive motion capture method to measure chest wall movements and estimate lung volumes. Objectives: To provide an overview of the clinical findings and research applications of OEP in the assessment of breathing mechanics across populations of healthy and diseased individuals. Methods: A bibliographic research was performed with the terms “opto-electronic plethysmography,” “optoelectronic plethysmography,” and “optoelectronic plethysmograph” in 50 digital library and bibliographic search databases resulting in the selection of 170 studies. Results: OEP has been extensively employed in studies looking at chest wall kinematics and volume changes in chest wall compartments in healthy subjects in relation to age, gender, weight, posture, and different physiological conditions. In infants, OEP has been demonstrated to be a tool to assess disease severity and the response to pharmacological interventions. In chronic obstructive pulmonary disease patients, OEP has been used to test if patients can dynamically hyperinflate or deflate their lungs during exercise. In neuromuscular patients, respiratory muscle strength and chest kinematics have been analyzed. A widespread application of OEP is in tailoring post-operative pulmonary rehabilitation as well as in monitoring volume increases and muscle contributions during exercise. Conclusions: OEP is an accurate and validated method of measuring lung volumes and chest wall movements. OEP is an appropriate alternative method to monitor and analyze respiratory patterns in children, adults, and patients with respiratory diseases. OEP may be used in the future to contribute to improvements in the therapeutic strategies for respiratory conditions.

The ergogenic effect of long-term use of high dose salbutamol.

Objective:Investigate the effect of inhaling 1600 &mgr;g salbutamol for 6 weeks on endurance, strength, and power performances. Design:Randomized double-blind, mixed-model repeated measures. Participants:Sixteen male athletes (mean ± SD: age, 20.1 ± 1.6 years; height, 179.9 ± 8.2 cm; weight, 74.6 ± 9.1 kg). Interventions:Participants were assigned to either a placebo inhaler (PLA) or inhaled 1600 &mgr;g salbutamol group (SAL). Over 6 weeks, participants inhaled PLA or SAL and completed 4 training sessions per week that focused on endurance, strength, and power. Main Outcome Measures:Participants completed the assessments of peak oxygen consumption (), 3-km time trial, vertical jump height, 1 repetition maximum (1RM) bench and leg press, and peak torque knee flexion and extension. Assessments were undertaken at baseline, week 3, and week 6. Results:Over the 6 weeks, PLA and SAL groups improved (51.7 ± 4.7 vs 56.8 ± 7.1 mL·min−1·kg−1; 53.1 ± 6.1 vs 55.0 ± 6.7 mL·min−1·kg−1); 3-km running time trial (988.6 ± 194.6 vs 947.5 ± 155.5 seconds; 1040.4 ± 187.4 vs 1004.2 ± 199.4 seconds); 1RM bench press (65.7 ± 15.4 vs 70.3 ± 13.8 kg; 64.3 ± 14.0 vs 72.5 ± 15.3 kg); and leg press (250.0 ± 76.4 vs 282.5 ± 63.6 kg; 217.9 ± 54.0 vs 282.8 ± 51.9 kg). The SAL group did not improve significantly greater in any endurance or strength and power measure when compared with the PLA group. Conclusions:Inhaling 1600 µg salbutamol daily over 6 weeks does not result in significant improvements in endurance, or strength and power performances. Clinical Relevance:Athletes using inhaled salbutamol to treat bronchoconstriction during exercise on a daily basis will not gain an advantage over nonasthmatic athletes not using inhaled salbutamol.