Wearable device-measured bouted and sporadic physical activity patterns and incident COPD: A prospective cohort study from UK Biobank.

Objectives: Moderate-to-vigorous physical activity (MVPA) is associated with a reduced risk of chronic obstructive pulmonary disease (COPD), but the optimal accumulation patterns are unclear. We aimed to investigate the associations between accelerometer-measured bouted and sporadic MVPA and incident COPD in the UK Biobank.

Study Design: Prospective cohort study.

Methods: We included 94161 COPD-free participants (median age of 61.74 years at baseline) from the UK Biobank who wore a wrist accelerometer. A random forest classifier was used to differentiate sporadic and bouted MVPA. Multivariable Cox proportional hazard models and restricted cubic splines were used to examine the MVPA-COPD associations.

Results: During a median follow-up of 7.95 years, 1380 incident COPD cases were identified. Bouted MVPA was inversely associated with COPD incidence in an L-shaped manner, with hazard ratios of 0.62 (95 % CI: 0.52-0.75) for intermediate vs lowest quintile and 0.43 (95 % CI: 0.34-0.55) for highest vs lowest quintile. In those with insufficient bouted MVPA, sporadic MVPA had a U-shaped association with incident COPD, with hazard ratios of 0.82 (95 %: CI: 0.67-0.99) for intermediate vs lowest quintile and 1.11 (95 % CI: 0.88-1.39) for highest vs lowest quintile.

Conclusions: Bouted MVPA is a key factor in reducing COPD incidence, while modest sporadic MVPA may offer protection when bouted MVPA is insufficient.