Impact of Exercise Capacity Upon Respiratory Functions, Perception of Dyspnea, and Quality of Life in Patients with Chronic Obstructive Pulmonary Disease

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is associated with a high prevalence of morbidity and mortality worldwide. We investigated the effects of exercise capacity upon respiratory functions, perception of dyspnea, and quality of life (QoL) in patients with COPD. METHODS: A total of 512 COPD patients formed the study cohort. They were divided into four subgroups according to the distance walked in the 6-minute walking test (6MWT). We compared respiratory functions, perception of dyspnea, and QoL between groups. RESULTS: Patients who walked >350 m had significantly better disease-specific QoL scores (p < 0.001) than those of other groups. A negative correlation was found between the walking distance and anxiety, depression, and dyspnea scores (p < 0.001). CONCLUSIONS: In patients who walked <350 m, the reduced walking distance adversely affected respiratory functions, psychological symptoms, and QoL.