Prospective real-world analysis of asthma patients with preserved and reduced physical activity.

BACKGROUND: Asthma is a highly heterogeneous airway disease, and the clinical characteristics of asthma patients with preserved and reduced physical activity are poorly understood.

OBJECTIVE: We aimed to investigate the risk factors and clinical phenotypes associated with reduced physical activity in a wide range of patients with asthma.

METHODS: We conducted a prospective observational study of 138 patients with asthma, including patients with asthma without chronic obstructive pulmonary disease (COPD) (n = 104) and asthma-COPD overlap (n = 34), and 42 healthy controls. Physical activity levels were measured for two weeks using a triaxial accelerometer at baseline and one year later.

RESULTS: Higher eosinophils and body mass index (BMI) were associated with reduced physical activity in patients with asthma without COPD. Cluster analysis of asthma without COPD revealed four asthma phenotypes. We identified a cluster with preserved physical activity (n = 43) that was characterized by good symptom control and lung function and included a high proportion of biologics users (34.9%). Multivariate regression analysis revealed that patients with late-onset eosinophilic (n = 21), high BMI non-eosinophilic (n = 14), and symptom-predominant asthma phenotypes (n = 26) had lower levels of physical activity than controls. Asthma-COPD overlap patients also had significantly lower physical activity levels than controls. Similar trends in physical activity levels were observed in each asthma group at one-year follow-up.

CONCLUSION: This study showed the clinical features of asthma patients with preserved and reduced physical activity. Reduced physical activity was observed in various asthma phenotypes and in asthma-COPD overlap.