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

BACKGROUND AND OBJECTIVE: Guidelines recommend exercise tests using dry air to diagnose exercise-induced bronchoconstriction (EIB). Lung function changes subsequent to these tests have not been investigated in a general adolescent population, and it remains unknown whether signs of airway inflammation, measured using exhaled nitric oxide (FeNO), can predict a positive response. The aim of this study was to investigate the temporal aspect of decline in forced expiratory volume in 1 s (FEV1 ) after an exercise test using dry air, and to investigate predictors of EIB. METHODS: From a cross-sectional study on adolescents aged 13-15 years (n = 3838), a random subsample of 146 adolescents (99 with and 47 without self-reported exercise-induced dyspnoea) underwent standardized treadmill exercise tests for EIB while breathing dry air. RESULTS: Of the adolescents, 34% had a positive EIB test (decline of ≥10% in FEV1 from baseline) within 30 min. Of the subjects with EIB, 53% showed the greatest decline in FEV1 at 5 to 10 min (mean decline 18.5%), and the remaining 47% of the subjects showed the greatest decline at 15 to 30 min (mean decline 18.9%) after exercise. Increased FeNO (>20 ppb), female gender and self-reported exercise-induced dyspnoea were independently associated with a positive EIB test. CONCLUSION: When assessing general adolescents for EIB with exercise test using dry air, there is a temporal variation in the greatest FEV1 decline after exercise. Therefore, lung function should be measured for at least 30 min after the exercise. Increased FeNO, female gender and self-reported exercise-induced dyspnoea can be predictors of a positive EIB test.

The relationship between exercise induced bronchial obstruction and health related quality of life in female and male adolescents from a general population.

BACKGROUND: Previous studies have observed that exercise-induced bronchoconstriction (EIB) is more common and more strongly related to exercise related breathing problems in female adolescents than male adolescents. However, few studies have investigated the association between EIB and health related quality of life (HRQoL) from a gender perspective. The aim of this study was to examine the association between EIB and HRQoL and physical activity level in female and male adolescents with and without EIB. METHODS: From a population based study on exercise-induced breathing problems among adolescents (13-15 years, n = 3838) a cross sectional study with prospective data collection was carried out in a random subsample of 140 adolescents. The subjects in the sample were tested for EIB with a standardised exercise test, of which 49 adolescents were tested positive. HRQoL was assessed with the Pediatric Quality of Life Inventory (PedsQL) and the adolescents' physical activity levels were measured objectively with accelerometer. RESULTS: The female subjects with EIB reported a lower HRQoL, both in total score (p = 0.03) and physical functioning score (p = 0.009) and had a lower baseline FEV1 compared to females without EIB (88 vs. 94 % predicted, p = 0.001). No differences were found in HRQoL or baseline lung function between males with or without EIB. There were no differences in minutes of moderate to vigorous physical activity per day between females or males with and without EIB. CONCLUSION: In a general population, the female adolescents with EIB had lower HRQoL and poorer baseline lung function compared to counterparts without EIB. These differences were not observed in males. EIB does not appear to affect the level of daily physical activity neither in females nor males.

Comparison between two assessment methods for exercise-induced laryngeal obstructions.

Exercise-induced laryngeal obstructions (E-ILOs) are important differential diagnoses to exercise-induced asthma and are diagnosed by the continuous laryngoscopy exercise (CLE) test. There are two different methods for evaluating the severity of E-ILOs using recordings from the CLE test; the CLE score and EILOMEA. The aim of this study was to investigate the consistency between these methods. Using their respective method, the developers of each method evaluated 60 laryngoscopic recordings from patients with different subtypes and various levels of severity of E-ILOs. The CLE score evaluates glottic and supraglottic obstructions on a 4-grade scale. EILOMEA uses software to calculate the obstruction severity on continuous scales from a still frame of the larynx during maximal obstruction giving three parameters reflecting glottic and supraglottic obstruction. The means of the EILOMEA measures differed significantly for CLE score 1 vs. 2 and 2 vs. 3, but not for 0 vs. 1 for glottic as well as supraglottic obstructions. The EILOMEA method does not distinguish between CLE score 0 and 1, but otherwise the methods correlate. Since previous studies have suggested that only CLE scores of 2 and 3 reflect a severity of E-ILOs of clinical importance, this lack of the EILOMEA method is not crucial for a correct medical evaluation.

Prevalence of exercise-induced bronchoconstriction and exercise-induced laryngeal obstruction in a general adolescent population.

BACKGROUND: Exercise-induced respiratory symptoms are common among adolescents. Exercise is a known stimulus for transient narrowing of the airways, such as exercise-induced bronchoconstriction (EIB) and exercise-induced laryngeal obstruction (EILO). Our aim was to investigate the prevalence of EIB and EILO in a general population of adolescents. METHODS: In this cross-sectional study, a questionnaire on exercise-induced dyspnoea was sent to all adolescents born in 1997 and 1998 in Uppsala, Sweden (n=3838). A random subsample of 146 adolescents (99 with self-reported exercise-induced dyspnoea and 47 without this condition) underwent standardised treadmill exercise tests for EIB and EILO. The exercise test for EIB was performed while breathing dry air; a positive test was defined as a decrease of ≥10% in FEV1 from baseline. EILO was investigated using continuous laryngoscopy during exercise. RESULTS: The estimated prevalence of EIB and EILO in the total population was 19.2% and 5.7%, respectively. No gender differences were found. In adolescents with exercise-induced dyspnoea, 39.8% had EIB, 6% had EILO and 4.8% had both conditions. In this group, significantly more boys than girls had neither EIB nor EILO (64.7% vs 38.8%; p=0.026). There were no significant differences in body mass index, lung function, diagnosed asthma or medication between the participants with exercise-induced dyspnoea who had or did not have a positive EIB or EILO test result. CONCLUSIONS: Both EIB and EILO are common causes of exercise-induced dyspnoea in adolescents. EILO is equally common among girls and boys and can coexist with EIB.

Prevalence of exercise-induced bronchoconstriction and laryngeal obstruction in adolescent athletes.

OBJECTIVES: To study the prevalence of exercise-induced bronchoconstriction (EIB) and exercise-induced laryngeal obstruction (EILO) in adolescent athletes. METHODS: All adolescents (n = 549) attending first year at a sports high school in 2016 and 2017, were invited to answer a questionnaire on respiratory symptoms. The 367 responding participants were divided into two groups based on whether they reported exercise-induced dyspnea (dyspnea group) or not (nondyspnea group). Randomly selected participants in each group were invited to undergo two standardized exercise tests, an EIB test and a continuous laryngoscopy exercise (CLE) test, to investigate EILO. RESULTS: In total, 98 participants completed an EIB test, 75 of whom also completed a CLE test. Positive EIB tests: eight of 41 in the dyspnea group and 16 of 57 in the nondyspnea group. Positive CLE tests: 5 of 34 in the dyspnea group and three of 41 in the nondyspnea group. The estimated prevalence of EIB was 23.1% (95% confidence interval [CI]: 14.5-33.8) and of EILO 8.1% (95% CI: 2.5-18.5) in the whole study population. No differences in prevalence of EIB or EILO were found between the dyspnea and the nondyspnea groups. CONCLUSION: EIB was highly prevalent in this cohort of adolescent athletes. EILO was less prevalent, but represents an important differential diagnosis to EIB. Self-reported exercise-induced dyspnea is a weak indicator for both EIB and EILO and standardized testing should be provided.

Differences in laryngeal movements during exercise in healthy and dyspnoeic adolescents.

OBJECTIVES: To compare glottic and supraglottic movements in healthy adolescents and adolescents experiencing dyspnoea during strenuous exercise. METHODS: Using the continuous laryngoscopy exercise (CLE)-test laryngeal movements during exercise were analysed in healthy controls (n = 28) and compared to subjects with exercise induced bronchoconstriction (EIB) (n = 10), exercise induced laryngeal obstruction (EILO) (n = 10) and subjects experiencing exercise-induced dyspnoea without having any of these diagnoses (n = 31). Images from the video recordings were assessed regarding glottic angle, glottic area and supraglottic area using the software measuring tool EILOMEA. RESULTS: No significant differences were detected between controls, the dyspnoea group without a diagnosis of EIB or EILO and the EIB group regarding glottis angle, glottis area or supraglottic area at maximum effort. All three parameters differed significantly in the EILO group compared to the other groups (p=<0.001). In the group with EILO all but one had supraglottic obstruction (corresponding to a CLE-test score ≥2). Movement of the laryngeal structures, corresponding to a CLE-test score of 1, at glottic and/or supraglottic level was seen in 26 of 35 (74%) of controls, 34 out of 41 (83%) of patients in the dyspnoea group, and in 25 of 38 (66%) of EIB-subjects. CONCLUSION: Minor movements at both glottic and supraglottic level are equally common in healthy controls as among adolescents with exercise induced dyspnoea without EIB or EILO and adolescents with EIB. Adolescents with EILO had a statistically significant more pronounced supraglottic obstruction than the other groups.

Increased prevalence of exercise-induced airway symptoms - A five-year follow-up from adolescence to young adulthood.

BACKGROUND: Exercise-induced airway symptoms are common in adolescents. Little is known about the development of symptoms from adolescence to early adulthood. Therefore, we studied the prevalence, incidence, and remission of exercise-induced airway symptoms (including wheeze, cough, chest and throat tightness, hoarseness, and stridor) in adolescents, over a five-year period. METHODS: In 2011, all adolescents aged 12-13 years in Uppsala (n = 3 838) were invited to answer a questionnaire on exercise-induced airway symptoms. All responding adolescents (n = 2 309) were invited to answer the same questionnaire again after five years. In total, 1 002 adolescents responded (43.4%). RESULTS: The prevalence of exercise-induced airway symptoms increased from 25% at baseline to 49% at follow-up (p < 0.001). More females than males reported symptoms at both time points. The incidence of airway symptoms was 42.2%, with no sex differences. More males than females reported symptom remission (20.2 vs. 10.7%, p < 0.001). Females reported a higher asthma prevalence at follow-up than at baseline (7.6 vs. 15.2%), while males did not (10.9 vs. 8.0%), leading to a sex difference in prevalence at follow-up (p < 0.001). Smoking and baseline respiratory symptoms were associated with an increased risk of reporting symptoms at follow-up. CONCLUSIONS: A twofold increase in the prevalence of exercise-induced airway symptoms over a five-year period was found in this cohort. Females were more likely to report symptoms at both time points. Knowledge of these age-related changes in symptoms and their association to female gender is useful for future studies and healthcare providers.

Exercise-Induced Laryngeal Obstruction-An Overview.

Exertional dyspnea is common in health and disease. Despite having known for centuries that breathlessness can arise from the larynx, exercise-induced laryngeal obstruction is a more prevalent condition than previously assumed. This article provides a brief overview of the history, epidemiology, and pathophysiology of exercise-induced laryngeal obstruction.

Surgical treatment is effective in severe cases of exercise-induced laryngeal obstruction: A follow-up study.

CONCLUSIONS: Surgery is an effective treatment in severe cases of supraglottic exercise-induced laryngeal obstruction (E-ILO). Conservatively treated subjects and subjects tested negative for E-ILO, who still experience breathing problems 1-3 years after diagnosis, tend to adjust their physical activity to a greater extent than surgically treated subjects. OBJECTIVE: To investigate how symptoms and level of physical activity change over time in patients with E-ILO who have undergone surgery, patients with E-ILO treated conservatively and patients who tested negative for laryngeal obstruction at continuous laryngoscopy exercise-test (CLE-test). METHODS: Patients referred for exercise-induced breathing difficulties answered questionnaires at diagnostic CLE-test and at follow-up. Questions regarded exercise-induced breathing problems, current physical activity level, and medical history of asthma and perennial allergy. RESULTS: Out of 84 invited subjects, 59 (70%) answered both questionnaires. Surgically treated subjects had less breathing problems at follow-up compared with conservatively treated subjects and subjects who tested negative (p < 0.001). None of the surgically treated subjects were less physically active or had changed sport due to exercise-induced dyspnoea, whereas 41.7% of the conservatively treated subjects had made such adjustments (p < 0.001).