Asthma in elite athletes: Who cares?

Asthma or exercise-induced bronchoconstriction (EIB) is highly prevalent in athletes and if untreated has the potential to impact on their health and performance. The condition can be diagnosed and managed effectively yet there is concern that the care afforded to elite athletes with this condition is often sub-optimal. In this respect, it is apparent that more could be done to protect athletes from developing airway dysfunction (e.g. by reducing exposure to irritant environments); that the diagnosis of asthma in athletes is often made without secure objective evidence and that athletes may be advised to reduce activity levels in order to improve symptoms. Moreover there appears to be poor surveillance of airway health in athletes when a diagnosis of asthma has been made. Overall this raises the question of who cares about athletes with asthma? The article that follows presents the case of why this is an important clinical area for physicians. The review provides an overview of asthma in athletes with the overall aim of ensuring that respiratory health in this unique population is optimised

Bronchoprovocation testing for diagnosis of EIB in Athletes: Is one test enough?

Background: Exercise-induced bronchoconstriction (EIB) is highly prevalent in athletes and impacts on their health and performance. The gold-standard means for diagnosing EIB is indirect bronchoprovocation testing, however the repeatability of this methodology is not established. Aims and objectives: To evaluate the short-term test-retest repeatability of eucapnic voluntary hyperpnea (EVH). Methods: Twenty-five recreationally active men (n=21) and women (n=4) were recruited. Participants were required to attend on two separate occasions separated by a period of fourteen days. Participants performed spirometry before and following (at 3,5,10 and 15 mins) an EVH challenge (6 minutes at 85% maximum voluntary ventilation). Difference in forced expiratory volume in one second (FEV1) between visits was analysed using Bland-Altman methodology. Results: 22 subjects completed both visits (n=3 excluded - unwell), mean (SD) age 25 (±4) yrs, FEV1 102 (±8.6) % predicted. There was no significant difference in maximum fall in FEV1 post EVH between visits (P>0.05), however Bland-Altman analysis revealed wide limits of agreement (-10.36-7.9%) for the difference in fall in FEV1 between visits. A diagnosis of EIB (>10% fall in FEV1) was established in two athletes at visit one whereas this increased to five athletes at visit 2. Importantly, only one athlete had a diagnosis of EIB confirmed at both visits. Conclusion: In this cohort of athletes EVH demonstrated poor repeatability over a fixed two-week period. The findings highlight the need for caution when considering confirming or refuting a diagnosis of EIB based on a solitary indirect bronchoprovocation test and a cut-off value of 10% fall in FEV1

P17 Dietary nitrate supplementation increases fractional exhaled nitric oxide : implications for the assessment of airway health in athletes

Background: Fractional exhaled nitric oxide (FeNO) is a simple tool that has an established role in the assessment of airway inflammation in athletes. Specifically, FeNO provides information concerning asthma phenotypes, aetiology of respiratory symptoms, response to anti-inflammatory agents, course of disease and adherence to medication. It is recognised that FeNO can be influenced by a variety of external factors (e.g. atopic status, exercise, respiratory tract infection), however, there remains limited research concerning the impact of dietary nitrate ingestion. The primary aim of this study was therefore to evaluate the effect of acute dietary nitrate supplementation on FeNO and resting pulmonary function parameters. Method: The study was conducted as a randomised double-blind placebo-controlled trial. Thirty male endurance trained athletes (age: 28 ± 6 yrs; BMI: 23 ± 2 kg.m-2) free from cardio-respiratory and metabolic disease, and stable at time of study entry (i.e. entirely asymptomatic without recent respiratory tract infection) attended the laboratory on two separate occasions. On arrival to the laboratory, athletes consumed either 140ml nitrate-rich beetroot juice (15.2 mmol nitrate) (NIT) or nitrate-depleted beetroot juice (0 mmol nitrate) (PLA). In accordance with international guidelines all athletes performed resting FeNO and forced spirometry (2.5hrs post ingestion). Airway inflammation was evaluated using established FeNO thresholds: (intermediate [≥25ppb] and high [>50ppb]). Results: All athletes demonstrated normal baseline lung function (FEV1 % predicted >80%). A three-fold rise in resting FeNO was observed following NIT (median [IQR]): 32ppb [37] in comparison to PLA: 10ppb [12] (P0.05). Conclusion: Dietary nitrate ingestion should be considered when employing FeNO for the assessment of airway health in athletes. Our findings have implications concerning the decision to initiate or modify inhaler therapy. Further research is therefore required to determine the impact of chronic dietary nitrate ingestion on pulmonary function and bronchoprovocation testing in athletes with pre-existing asthma and/or exercise-induced bronchoconstriction

A vascular cause of unexplained exertional wheeze : Keeping a high index of suspicion

© 2019 A 31-year-old female was referred with a history of unexplained exertional breathlessness. The patient had normal resting lung function and a CT thorax showed no significant abnormality. Closer scrutiny of the flow-volume loop confirmed an elevated Empey's index. Cardiopulmonary exercise testing with continuous laryngoscopy was conducted to evaluate the upper airway response to exercise which confirmed loud biphasic wheeze. A bronchoscopy revealed no stenosis nor intraluminal narrowing, however, a contrast CT confirmed a right-sided aortic arch and aberrant left subclavian artery. Following multidisciplinary review, the patient opted for a surgical approach to treatment however despite initially reporting an improvement in symptoms and exercise capacity continued to suffer exertional wheeze two-years post-surgery. This clinical report describes a rare vascular cause of exertional wheeze but also provides a cautionary note in terms of providing a guarded prognosis for adults undergoing surgical intervention for tracheal compression arising from congenital vascular abnormalities

Vitamin D and omega-3 polyunsaturated fatty acid supplementation in athletes with exercise-induced bronchoconstriction: a pilot study.

OBJECTIVE: The aim of this pilot study was to determine the combined effect of vitamin D and omega-3 polyunsaturated fatty acid (PUFA) supplementation on airway function and inflammation in recreational athletes with exercise-induced bronchoconstriction (EIB). METHODS: Ten recreational athletes with EIB participated in a single-blind, placebo-controlled trial over six consecutive weeks. All subjects attended the laboratory on three occasions. Each visit was separated by a period of 3 weeks: visit 1 (usual diet), visit 2 (placebo) and visit 3 (SMARTFISH(®) NutriFriend 2000; 30 µg vitamin D3-3000 mg eicosapentaenoic acid, 3000 mg docosahexaenoic acid) consumed once daily for a period of 3 weeks. Venous blood was collected at the beginning of each trial to determine vitamin D status. Spirometry was performed pre- and post-eucapnic voluntary hyperpnoea (EVH). RESULTS: The Maximum fall in FEV1 (ΔFEV1max) post-EVH was not different between visits (usual diet: -15.9 ± 3.6%, placebo: -16.1 ± 6.1%, vitamin D + omega-3 PUFA: -17.8 ± 7.2%). Serum vitamin D remained unchanged between visits. CONCLUSION: Vitamin D and omega-3 PUFA supplementation does not attenuate the reduction in lung function post-EVH. This finding should be viewed as preliminary until the results of randomised controlled trials are made available

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

BACKGROUND AND OBJECTIVE: The differential diagnosis for exercise-associated breathlessness is broad, however, when a young athletic individual presents with respiratory symptoms, they are most often prescribed inhaler therapy for presumed exercise-induced asthma (EIA). The purpose of this study was therefore to use a novel sound-based approach to assessment to evaluate the prevalence of exertional respiratory symptoms and characterise abnormal breathing sounds in a large cohort of recreationally active individuals. METHODS: Cross-sectional field-based evaluation of individuals completing Parkrun. PHASE 1: Prerace, clinical assessment and baseline spirometry were conducted. At peak exercise and immediately postrace, breathing was monitored continuously using a smartphone. Recordings were analysed retrospectively and coded for signs of the predominant respiratory noise. PHASE 2: A subpopulation that reported symptoms with at least one audible sign of respiratory dysfunction was randomly selected and invited to attend the laboratory on a separate occasion to undergo objective clinical workup to confirm or refute EIA. RESULTS: Forty-eight participants (22.6%) had at least one audible sign of respiratory dysfunction; inspiratory stridor (9.9%), expiratory wheeze (3.3%), combined stridor+wheeze (3.3%), cough (6.1%). Over one-third of the cohort (38.2%) were classified as symptomatic. Ten individuals attended a follow-up appointment, however, only one had objective evidence of EIA. CONCLUSIONS: The most common audible sign, detected in approximately 1 in 10 individuals, was inspiratory stridor, a characteristic feature of upper airway closure occurring during exercise. Further work is now required to further validate the precision and feasibility of this diagnostic approach in cohorts reporting exertional breathing difficulty

High fidelity estimates of paratransit energy consumption from per-second GPS tracking data

Paratransit, in particular the minibus taxi, is the mainstay of public transport in sub-Saharan Africa. These vehicles are often second-hand, ageing, fuel inefficient, and expensive to operate - issues that electrification can ameliorate. However, modeling and planning large-scale transitions to electric paratransit require reliable estimates of vehicle energy consumption. This paper provides such estimates by applying a vehicle kinetic model to per-second GPS data gathered on minibus taxis. Data include 62 trips across three routes with different driving conditions near Stellenbosch, South Africa. We find a range of energy consumption from 0.29 to 0.51 kWh/km (mean = 0.39 kWh/km). Past estimates in literature relied on per-minute GPS data, which we show leads to inaccurate energy consumption estimates. We recommend new kWh/km values for modeling vehicle operations and grid impact, and discuss how future work can utilize our analysis to advance the transition to electric paratransit sub-Saharan Africa

Eucapnic Voluntary Hyperpnea Testing in Asymptomatic Athletes.

Letter to the Edito