Objective: The present study attempted to determine whether patients with chronic obstructive pulmonary disease (COPD) get the minimum daily amount of physical activity recommended in the guidelines established by the American College of Sports Medicine (ACSM), as well as to characterize the consequences of noncompliance with those guidelines.
Methods: This study involved 23 patients (median age: 61--range, 59-69 years; FEV1: 39% of predicted--range, 34-53%; BMI: 24 kg/m(2)--range, 21-27 kg/m(2)). The following parameters were evaluated: daily physical activity (DynaPort activity monitor); pulmonary function; muscle force; exercise tolerance; quality of life; functional status; and various indices of disease severity (GOLD, BODE and MRC).
Results: Based on compliance with the guidelines (minimum of 30 minutes of walking per day), 12 patients were considered "physically active", and 11 were considered "physically inactive". No significant differences were observed between the two groups in terms of age, gender, BMI, muscle force, ventilatory reserve, hyperinflation or quality of life. The inactive group presented more impaired pulmonary function and lower exercise tolerance, as well as lower MRC and BODE scores (p < 0.05). In their daily life, patients in the inactive group also walked for less time and more slowly than did those in the active group (p < 0.05). The MRC and BODE indices were superior to the GOLD index in predicting compliance with the guidelines, both presenting a specificity of 0.83, compared with 0.50 for the GOLD index. The BODE index score increased significantly with each day of inactivity.
Conclusion: A large number of COPD patients do not walk more than 30 minutes per day and are therefore not getting the minimum daily amount of physical activity recommended by the ACSM. Inactivity correlates with a higher mortality rate. The MRC and BODE indices proved superior to the GOLD index in predicting whether patients are physically inactive in their daily lives.