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.