Reduction of physical activity in patients with chronic obstructive pulmonary disease

Background: Patients with chronic obstructive pulmonary disease (COPD) decrease their physical activity However, it is unknown at which stage of the disease the reduction occurs and whether dyspnea is a limiting factor. Aim: To compare physical activity between patients with COPD and controls of similar age and to assess its association with disease severity. Material and Methods: We studied 112 patients with mild to very severe COPD and 55 controls. Lung function, six-minutes walking test (SMWT), and physical activity through the International Physical Activity Questionnaire (IPAQ) were measured. Results: Compared to controls, physical activity was significantly reduced in COPD patients (1823 +/- 2598 vs. 2920 +/- 3040 METs min/week; p = 0.001). Patients were more frequently sedentary (38 vs. 11%), while controls were more often very active (31 vs. 19%) or moderately active (58 vs. 43%). Physical activity was reduced from Global Initiative for Obstructive Chronic Lung Disease (GOLD) stage 2 and from Modified Medical Research Council (MMRC) dyspnea grade 1. Weak relationships were observed between lung function, SMWT and physical activity. Conclusions: Physical activity decreases early in the course of the disease and when dyspnea is still mild, among patients with COPD. (Rev Med Chile 2011; 139: 1562-1572).