Progression of physical inactivity in COPD patients: the effect of time and climate conditions – a multicenter prospective cohort study

Abstract

Purpose

Longitudinal data on the effect of time and environmental conditions on physical activity (PA) among COPD patients are currently scarce, but this is an important factor in the design of trials to test interventions that might impact on it. Thus, we aimed to assess the effect of time and climate conditions (temperature, day length and rainfall) on progression of PA in a cohort of COPD patients.

Patients and methods

This is a prospective, multicenter, cohort study undertaken as part of the EU/IMI PROactive project, in which we assessed 236 COPD patients simultaneously wearing two activity monitors (Dynaport MiniMod and Actigraph GT3X). A multivariable generalized linear model analysis was conducted to describe the effect of the explanatory variables on PA measures, over three time points (baseline, 6 and 12 months).

Results

At 12 months (n=157; FEV₁% predicted=57.7±21.9) there was a significant reduction in all PA measures (Actigraph step count (4284±3533 vs 3533±293)), Actigraph moderate- to vigorous-intensity PA ratio (8.8 (18.8) vs 6.1 (15.7)), Actigraph vector magnitude units (374,902.4 (265,269) vs 336,240 (214,432)), MiniMod walking time (59.1 (34.9) vs 56.9 (38.7) mins) and MiniMod PA intensity (0.183 (0) vs 0.181 (0)). Time had a significant, negative effect on most PA measures in multivariable analysis, after correcting for climate factors, study center, age, FEV₁% predicted, 6MWD and other disease severity measures. Rainfall was the only climate factor with a negative effect on most PA parameters.

Conclusion

COPD patients demonstrate a significant decrease in PA over 1 year follow-up, which is further affected by hours of rainfall, but not by other climate considerations.

Keywords:

• physical activity
• chronic obstructive pulmonary disease
• elapsed time
• climate

View correction statement:

Progression Of Physical Inactivity In COPD Patients: The Effect Of Time And Climate Conditions – A Multicenter Prospective Cohort Study [Corrigendum]

Acknowledgment

This study is supported EU Innovative Medicines Initiative Joint Undertaking (IMU JU) #115011.

Author contributions

All authors contributed to data analysis, drafting or revising the article, gave final approval of the version to be published, and agree to be accountable for all aspects of the work.

Disclosure

JGA received payments for consulting and lecture fees to her Institution from AstraZeneca and lecture fees from Esteeve and Chiesi, outside the submitted work. MIP received personal fees from Phillips, grants from EU and travel expenses from CBQC, outside the submitted work. TvdM is currently a part-time employee of GSK London. The authors report no other conflicts of interest in this work.