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 patients with asthma 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 2 weeks using a triaxial accelerometer at baseline and 1 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 4 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 noneosinophilic (n = 14), and symptom-predominant asthma phenotypes (n = 26) had lower levels of physical activity than controls. Patients with asthma-COPD overlap also had significantly lower physical activity levels than controls. Similar trends in physical activity levels were observed in each asthma group at 1-year follow-up. CONCLUSION: This study showed the clinical features of patients with asthma with preserved and reduced physical activity. Reduced physical activity was observed in various asthma phenotypes and in asthma-COPD overlap.