Patients with COPD Become More Physically Inactive Over Time, Worsening Their Disease

Physical activity declines over time in patients with chronic obstructive pulmonary disease (COPD), independent of disease severity. This decline is also associated with worsening lung function and loss of quality of life and health status, according to findings published in the American Journal of Respiratory and Critical Care Medicine.

Researchers from the Pulmonary Research Institute at LungenClinic in Grosshansdorf, Germany, measured physical activity, airflow obstruction (FEV₁), exercise capacity (6-minute walk distance), and other factors in order to assess changes in physical activity for COPD patients in relation to severity and changes in other disease components. The researchers also wanted to look at the longitudinal association between sustained physical inactivity and disease progression. The authors noted that there is little understood about the role of physical activity in the course of COPD.

“Physical inactivity is associated with morbidity and mortality in COPD, but the association between objectively measured physical activity and other disease components over time has not been well studied,” lead author Benjamin Waschki, MD, explained in a press release. “In our prospective cohort study, we evaluated the longitudinal association between changes in physical activity and disease progression in 137 patients with COPD and 26 patients with chronic bronchitis.”

Steps per day, total daily energy expenditure, and daily physical activity level decreased by 393, 76 kcal, and 0.04 per year, respectively, independent of the severity of COPD symptoms at baseline, the researchers found. The decline in physical activity level was linked to an increase in airflow obstruction (as demonstrated by a decline in FEV₁) and an increase in total score on the St. George’s Respiratory Questionnaire, a measure of the impact of obstructive airway disease on overall health, daily life, and perceived well being.

The researchers additionally found that sustained physical activity was linked to greater declines in six minute walk distance results, independent of FEV₁ measurements. Plus, sustained physical activity was linked to declines in fat free mass, compared to some level of physical activity.

The authors wrote that there was no significant observed association between physical inactivity and systemic inflammation over time among the patients studied.

“Treatment guidelines call for regular physical activity for COPD patients at all levels of severity, and our study clearly supports this recommendation,” Waschki continued. “Regular exercise will improve their health and quality of life.”