Abstract
Background: The associations between physical activity (PA) and all-cause mortality remain under-investigated among individuals with impaired lung function. Methods: With 201,596 participants from the UK Biobank cohort, baseline pre-bronchodilation lung function tests and a modified International Physical Activity Questionnaire were used to assess lung function status (normal, restricted, obstructed) and PA attributes (volume, intensity, duration). All-cause mortality was determined through linkage to the National Health Services Register. Cox proportional hazard regression was applied to characterize the associations between PA metrics and all-cause mortality among people with different lung function statuses. Dose-response relationships between PA metrics and all-cause mortality risks were examined using restricted cubic splines (number of knots = 4). Results: Over a 11.81-year median follow-up, 5.24% of participants died. All-cause mortality risk declined with increasing total PA volume, plateauing at 1800 MET-min/week without further reduction in individuals with and without impaired lung function. Similar trends were observed for PA intensity and duration, with both factors demonstrating reduced mortality risk that plateaued after reaching a specific threshold. Notably, 24.1% (95% CI: 16.7%, 30.8%) and 43.1% (95% CI: 36.1%, 49.7%) lower mortality risk was observed among individuals with and without impaired lung function for PA with 1201-1800 MET-min/wk. Conclusions: PA was associated with a decreased risk of all-cause mortality among individuals with and without impaired lung function, suggesting that those with impaired lung function might also benefit from PA.