Physical Activity Declines in COPD Patients

Lung function and health status decreases across all levels of severity.

Patients with chronic obstructive pulmonary disease (COPD) experience a decline in lung function and health status at all levels of severity for the condition, a recent study found.

Published online in the American Journal of Respiratory and Critical Care Medicine, the study found that sustained physical inactivity is linked to progression of exercise intolerance and depleted muscles.

"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, said 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."

Independent of COPD severity at baseline, steps per day, total daily energy expenditure, and daily physical activity level (PAL) decreased by 393, 76 kcal, and 0.04 per year, respectively, the study noted. Decreased PAL was significantly linked to increased airflow obstruction and a greater total score on the St. George's Respiratory Questionnaire. This test evaluates the effect of obstructive airway disease on overall health, daily life, and perceived physical well-being.

Sustained physical inactivity was associated with higher declines in 6-minute walk distance and fat free mass compared with some level of physical activity. Meanwhile, there was no significant relationship found between physical inactivity and systemic inflammation over time.

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