[A prospective study of the effect of physical activity on mortality risk in patients with chronic obstructive pulmonary disease in Sichuan Province].

Objective: To investigate the effect of physical activity on mortality risk in patients with chronic obstructive pulmonary disease (COPD) in Sichuan Province. Methods: Based on baseline data from 2004 to 2008 from the China Kadoorie Biobank project site in Pengzhou City, Sichuan Province, a total of 8 501 COPD patients aged 30-79 years were enrolled and followed up for a long period to determine mortality outcomes. Quartiles were used to group physical activity levels. The Cox proportional hazards regression model was used to analyze the effect of physical activity level on mortality outcomes. Results: As of December 31, 2017, the cumulative follow-up of the participants totaled 85 600.58 person-years (mean follow-up duration: 10.07 years). During this period, a total of 2 000 deaths were recorded, yielding a cumulative mortality rate of 23.53%. Among these deaths, 665 were attributed to COPD, corresponding to a cumulative mortality rate of 7.82%; and 1 116 were attributed to cardiovascular and cerebrovascular disease (CVD), corresponding to a cumulative mortality rate of 13.13%. The Cox proportional hazards regression model analysis revealed that, after adjusting for confounding factors, total physical activity was associated with a reduced risk of mortality from COPD, CVD, and all causes in patients with COPD. Compared with the low-level group of total physical activity, the medium-high-level group had the lowest risk of COPD mortality, with an HR of 0.39 (95%CI: 0.30-0.49). The high-level group had the lowest risk of CVD death and all-cause death, with HRs of 0.46 (95%CI: 0.37-0.56) and 0.55 (95%CI: 0.48-0.64), respectively. The lowest risk of COPD death and CVD death was found in the medium-high level of work-based physical activity group, with HRs of 0.36 (95%CI: 0.28-0.46) and 0.43 (95%CI: 0.36-0.51), respectively; the risk of all-cause mortality was lowest in the medium-high and high-level groups, with HRs values of 0.53 (95%CI: 0.46-0.61) and 0.53 (95%CI: 0.45-0.61). The risk of COPD death was lowest in the high-level transportation physical activity group, with an HR of 0.66 (95%CI: 0.53-0.83), and the risk of CVD and all-cause death was lowest in the medium-high level group, with HRs of 0.63 (95%CI: 0.53-0.76) and 0.73 (95%CI: 0.64-0.84), respectively. The risk of COPD death and CVD death was the lowest in the high-level domestic physical activity group, with HRs of 0.66 (95%CI: 0.49-0.89) and 0.76 (95%CI: 0.61-0.95), respectively, and the risk of all-cause death was the lowest in the medium-high level group, with an HR of 0.82 (95%CI: 0.72-0.94). There is no statistical association between leisure physical activity and the risk of death from three types of diseases. Conclusions: Total physical activity, including work-based, transportation-based, and domestic physical activity, reduced the risk of COPD, CVD, and all-cause mortality in patients with COPD in Sichuan Province. The magnitude of mortality risk was influenced by the type and level of physical activity.