To determine if perceived exercise limitation (EL) in asthmatic children was associated with lung function, demographic factors, and/or other medical comorbidities.

The study included 302 Norwegian children (64% male) with asthma from the Environment and Childhood Asthma birth cohort, evaluated at their 10-year follow-up.

The 302 children selected from the cohort had no respiratory infection in the preceding 4 weeks and met 2 of 3 criteria for asthma: symptoms consistent with asthma, a physician’s diagnosis of asthma, or use of asthma medications. These subjects underwent evaluation of exercise-induced bronchospasm (EIB, assessed by FEV1 pre- and postexercise), bronchial hyperresponsiveness (BHR, assessed by methacholine challenge), a structured interview composed of demographic information and perceived exercise limitations, anthropometric data, and calculation of an asthma severity score. Associations were evaluated through multivariate logistic regression analysis.

A total of 20% (58) of the asthmatic children reported EL. In this group, 8 factors differed significantly compared with those without reported EL; however, after multivariate analysis, only asthma severity score (OR 1.49; 95% CI 1.32–1.67) and overweight status (OR 2.35; 95% CI 1.14–4.82) were independently associated with perceived EL. In a model excluding asthma severity score, additional associations included prenatal smoking, comorbid allergic rhinitis (AR), and children with comorbid AR and atopic eczema. EIB and BHR were associated with EL, only with exclusion of asthma severity and allergic disease from the analysis. Physical activity, sex, and household income were not risk factors for EL. Overweight status remained significant in all models of multivariate analysis reported in this study.

Perceived EL in asthmatic children was independently associated with overweight status and asthma severity score but was not associated with daily physical activity or socioeconomic factors. Being overweight more than doubles the probability of perceived EL.

This study highlights the link between exercise limitation in asthmatic children and being overweight. Many studies regarding exercise limitation in asthma focus on children under specialty care. Results from population-based cohort studies such as this likely reflect more accurately the experience of pediatricians. While factors such as allergic disease and asthma severity may have some effect on perceived exercise limitation, the association with overweight status appears more robust. Awareness of this association may lead to increased focus on weight control for asthmatic children reporting exercise limitation to their pediatrician.