Self-reported Symptoms after Induced and Inhibited Bronchoconstriction in Athletes

Abstract

PurposeA change in the perception of respiratory symptoms after treatment with inhaled beta2 agonists is often used to aid diagnosis of exercise-induced bronchoconstriction (EIB). Our aim was to test the association between subjective ratings of respiratory symptoms and changes in airway caliber after induced and inhibited bronchoconstriction in athletes with EIB.MethodsEighty-five athletes with diagnosed or suspected EIB performed a eucapnic voluntary hyperpnea (EVH) challenge with dry air. Of the 45 athletes with hyperpnea-induced bronchoconstriction [i.e., post-EVH fall in forced expiratory volume in 1 s (FEV1) ≥10%, EVH−], 36 were randomized in a double-blind, placebo-controlled, crossover study. Terbutaline (0.5 mg) or placebo was administered by inhalation 15 min before EVH. Spirometry (for FEV1) was performed before and after EVH, and respiratory symptoms were recorded 15 min after EVH on visual analog scales.ResultsTerbutaline inhibited bronchoconstriction (i.e., maximal fall in FEV1 <10% after EVH) in 83% of the EVH-positive athletes, with an average degree of bronchoprotection of 53% (95% confidence interval [CI], 45% to 62%). Terbutaline reduced group mean symptom scores (P < 0.01), but the degree of bronchoprotection did not correlate with individual differences in symptom scores between terbutaline and placebo. Of the 29 athletes who had less than 10% FEV1 fall after EVH in the terbutaline condition, almost half (48%) rated at least one respiratory symptom higher under terbutaline, and more than one quarter (28%) had a higher total symptom score under terbutaline.ConclusionSelf-reports of respiratory symptoms in conditions of induced and inhibited bronchoconstriction do not correlate with changes in airway caliber in athletes with EIB. Therefore, subjective ratings of respiratory symptoms after treatment with inhaled beta2 agonists should not be used as the sole diagnostic tool for EIB in athletes.

Exercise and Asthma

“…108 It has been reported that nearly 80% of family physicians and 50% of respirologists begin empiric treatment with β 2 -agonists based solely on reported symptoms. 109 However, it was recently observed that one-third of individuals with a physician's diagnosis of asthma have no evidence of this disease. 110 It was also previously documented that in athletes, under-as well as overdiagnosis of asthma seems common.…”

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

“…The diagnosis of EIB in athletes, is often suspected by clinicians following an assessment of symptoms alone; with treatment frequently commenced without objective confirmation (4). This is despite evidence from several studies indicating that there is a poor relationship between the presence of respiratory symptoms and objective evidence of EIB (5)(6)(7)(8). It is thus recommended that respiratory symptoms should not be relied upon and that objective testing (e.g.…”

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

“…Of the 60 studies focusing on EIB, 41 studies incorporated both male and female subjects, and only 19 reported sex differences in measured outcomes ( Figure 4 ). However, not all studies focusing on EIB reported its prevalence; only 15 studies that included both males and females contained EIB prevalence data [ 43 , 44 , 51 , 53 , 55 , 58 , 61 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 ]. These studies collectively enrolled 2077 athletes and were 65% observational studies, 21% randomized control trials, and 14% clinical trials ( Figure 4 ).…”

“…In this regard, 9% of the studies included used self-reporting data via questionnaires. The JTF recommends that a diagnosis of EIB is confirmed by demonstration of airway reversibility or challenge in association with a history consistent with EIB, because self-reported symptoms are not always accurate [ 73 , 97 ].…”