Lower lung function and respiratory symptoms are associated with reduced accelerometer-measured physical activity in...

Physical activity (PA) has well-documented cardio-respiratory protective effects in individuals with lung diseases. Whilst most studies examining the relationship between PA, lung function and respiratory symptoms have included self-reported PA data, studies assessing PA objectively using accelerometers are scarce.

To explore the association of sedentary behavior (SED) and moderate-and-vigorous PA (MVPA), assessed using accelerometer data, with lung function and respiratory symptoms, and to compare associations in ever-smokers with never-smokers, within a large sample of middle-aged individuals.

In the population-based, cross-sectional Swedish CArdioPulmonary BioImage Study (SCAPIS), men and women aged 50 to 64 years were included. PA was assessed from triaxial hip acceleration data processed into PA intensity categories. Time spent in SED and MVPA was used. Dynamic spirometry (FEV₁ and FVC) was performed post-bronchodilation and respiratory symptoms were self-reported using a questionnaire.

Complete data were obtained from 25,975 individuals (52% females). Lower lung function and presence of respiratory symptoms were both associated with less MVPA, with stronger associations for lung function. An interaction between lung function and smoking status was found, so that each unit of increase in lung function was associated with a greater increase in MVPA among ever-smokers versus never-smokers.

Lower lung function and presence of respiratory symptoms were both associated with less MVPA in a general middle-aged Swedish population. In addition, the association between lung function and MVPA were stronger among ever-smokers. Further clinical studies are needed to clarify the role of PA in slowing lung function decline and preventing respiratory diseases.