Physical activity in relation to risk of chronic obstructive pulmonary disease among Chinese adults: an 11-year...

Chronic obstructive pulmonary disease (COPD) is a leading cause of chronic morbidity and mortality worldwide. Despite its significant public health burden, few studies have reported on the association of physical activity with incident COPD. This study aimed to determine the association between physical activity and the risk of incident COPD.

This prospective cohort study analyzed data from 49,482 participants aged 30-79 years enrolled in the China Kadoorie Biobank study in Tongxiang. Baseline assessments were carried out between August 2004 and January 2008. Physical activity was measured using an interviewer-administered questionnaire and quantified as metabolic equivalent of task hours per day (MET-h/day). Participants were categorized into quartile-based activity groups for analyses. All participants were followed up from the date of baseline survey until the date of COPD diagnosis, death, loss to follow-up, or 31 December 2017, whichever occurred first. Incident COPD events were obtained periodically through linkage with national insurance electronic systems and death registries. Cox proportional hazards regression was employed to estimate adjusted hazard ratios of COPD in relation to physical activity.

The average of the physical activity level of participants was 31.1 ± 15.1 MET-hours/day. During 551,266 person-years (median 11.5 years) of follow-up, 1,470 incident COPD cases (744 men and 726 women) were documented. After adjusting for socio-demographic status, lifestyle factors (cigarette and alcohol consumption, secondhand smoke exposure, meat and fresh fruit consumption, sleep duration), BMI, and household cooking fuel type, participants with physical activity levels in the highest vs. lowest quartile exhibited a 30% reduced risk of incident COPD (HR = 0.70, 95%CI, 0.54-0.91) in smoking men. However, no significant association was observed in women (HR = 0.99, 95%CI, 0.77-1.27) or non-smoking men (HR = 1.05, 95%CI, 0.41-2.46).

Physical activity is inversely associated with incident COPD risk in smoking men but not in women or non-smoking men.