Exercise‐induced respiratory symptoms are poor predictors of bronchoconstriction

Abstract

Exercise-induced asthma (EIA) is a possible cause of poor physical performance in children. No data are available on the value of respiratory symptoms to discriminate children with bad physical fitness from children with EIA. We evaluated respiratory symptoms in school-age children during and after exercise in relation to EIA. The population of 149 primary schools (849 classes with 15,241 children) was enrolled in the study. EIB was assessed using the 6-min free-running-test (6MFRT) in 15,241 children. At the end or at premature arrest of the 6MFRT, signs reported by the children and clinical symptoms observed by supervising physicians were recorded. Peak flow measurements were obtained before and 5 and 10 min after the 6MFRT, a decrease of 15% or more being defined as significant. The 6MFRT was positive in 7.4% of primary schoolchildren. Girls were more likely to have a positive test than boys (8.5% vs. 6.4%, P < 0.001), and children living in urban areas more than those living in rural areas (8.9% vs. 7.0%, P < 0.01). Premature arrest was seen in 3.5% (i.e., n = 353) of the children. The main reasons for premature arrest were dyspnea and chest pain. Among them, only 21% had a positive 6MFRT, while 89% with a positive 6MFRT could terminate the test. Premature arrest, breathlessness, chest tightness, wheezing, and cough had a positive predictive value to detect a EIA of 21.9%, 20.8%, 36.4%, 41.2%, and 28.3%, respectively, and a sensitivity of 10.8%, 29.5%, 14.9%, 4.8%, and 13.0%, respectively. In conclusion, EIA was detected in 7.4% of schoolchildren. A slightly higher incidence was observed in girls and children from an urban area. Neither premature arrest nor clinical signs and symptoms were good predictors of EIA in primary schoolchildren.

Exercise test using dry air in random adolescents: Temporal profile and predictors of bronchoconstriction

“…The first visit consisted of an interview about asthma, medication, measurements of height, weight, fractional exhaled nitric oxide (FeNO) and venous blood samples for analyses of Immunoglobulin E (IgE) sensitization and eosinophil cationic protein (ECP). The second visit (at an average of 12 (6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19) days later (median (interquartile range)) consisted of a standardized exercise challenge test on a treadmill with dry-air inhalation to detect EIB. 5 Ethical approval was obtained from the ethics review board in Uppsala, Sweden (Dnr 2011/413).…”

“…4 In subjects without asthma, a prevalence of 10 to 20% was reported. [4][5][6] Some studies have reported a higher prevalence in girls than in boys, 7,8 while others have not revealed any gender differences. 9,10 Exercise test is recommended to confirm EIB as exercise-induced symptoms have poor predictive value for EIB.…”

“…9,10 Exercise test is recommended to confirm EIB as exercise-induced symptoms have poor predictive value for EIB. 7,11,12 Guidelines from the European Respiratory Society (ERS) 13 and the American Thoracic Society (ATS) 14 and the recent EIB clinical practice guideline from the ATS recommend laboratory exercise testing, that is, a standardized exercise-challenge test. 5 This test should be performed on a treadmill or bicycle while controlling for relative humidity, that is, breathing dry air.…”

Recurrent wheeze and cough in young children: is it asthma?

“…In addition, exercise-induced cough has been shown to be a poor predictor of bronchoconstriction. (32) Nonetheless, considering asthma as a diagnosis in the absence of wheeze is not unjustified. If the child is not wheezing during consultation, accurate identification of wheeze from history-taking alone can be difficult.…”

Post-Exercise Airway Narrowing in Healthy Primary School Children

“…Field studies in unselected primary school children have described the distribution of lung function changes after exercise (3,4) or tested prevalence of exercise induced bronchoconstriction (EIB) in relation with respiratory symptoms (5,6). In these studies, the response was expressed as largest fall in forced expiratory volume in 1 s (FEV1) within 10 -15 min of exercise cessation (3,4) or considered positive when peak expiratory flow decreased 15% or more (5,6). To the best of our knowledge, whether significant change in airway caliber occurs in healthy children during the recovery from exercise has not been documented.…”