Aim: Walking distance is generally accepted as a functional capacity determinant in chronic obstructive pulmonary disease (COPD). However, the use of gait speed in COPD patients has not been directly investigated. Thus, the aim of our study was to assess the use of gait speed as a functional capacity indicator in COPD patients.
Methods: A total 511 patients with mild-to-very severe COPD and 113 healthy controls were included. The lung functions (pulmonary function test), general health- and disease-related quality of life (Medical Outcomes Study 36-Item Short-Form of Health Survey, St George's Respiratory Questionnaire), and gait speed (6-minute walk test) were assessed.
Results: The mean gait speed values were slower in moderate (75.7 ± 14.0 m/min), severe (64.3 ± 16.5 m/min), and very severe (60.2 ± 15.5 m/min) COPD patients than controls (81.3 ± 14.3 m/min). There were significant correlations between gait speed and age, dyspnea-leg fatigue severities, pulmonary function test results (FEV(1), FVC, FVC%, FEV(1)/FVC ratio, PEF, PEF%), and all subscores of Medical Outcomes Study 36-Item Short-Form of Health Survey and activity, impact and total subscores of St George's Respiratory Questionnaire in patients with moderate, severe, and very severe COPD. However, these correlations were higher especially in patients with severe and very severe COPD.
Conclusions: As a conclusion, according to our results gait speed slows down with increasing COPD severity. Also, gait speed has correlations with age, clinical symptoms, pulmonary functions, and quality of life scores in COPD patients. Thus, we consider that gait speed might be used as a functional capacity indicator, especially for patients with severe and very severe COPD.
Keywords: Chronic obstructive pulmonary disease; functional capacity; gait speed.