Pain and physical performance in people with COPD

Abstract

Patients with Chronic Obstructive Pulmonary Disease (COPD) have been shown to experience significant pain that interferes with their daily activities and quality of life. The purpose of this study was to examine if pain is associated with functional exercise capacity (assessed with the six-minute walk test, 6MWT), physical activity (assessed by accelerometry), and muscle performance (maximal knee extensor torque) in people with COPD. Twenty-six people with moderate to severe COPD completed the McGill Pain Questionnaire (MPQ), the Brief Pain Inventory (BPI), the Short Form-36 (SF-36), and a form to list medications and comorbidities. After spirometric testing, participants performed the 6MWT. Physical activity was monitored for two days using a tri-axial accelerometer (DynaPort MiniMod). At least 3 days after the 6MWT, maximal and fatiguing concentric contractions of knee extensors were assessed. Pain severity was negatively correlated with the 6MWT (p<0.05), and quality of life (p<0.05), whereas it was positively correlated with body mass index (BMI) (p<0.001), and the number of comorbidities (p<0.001). Subjects with severe pain showed lower standing and activity times (p<0.01), lower 6MWT (p<0.05), higher BMI (p<0.001), a higher number of comorbidities (p<0.001) and lower quality of life (p<0.01) compared to subjects with minimal or no pain. Pain in patients with COPD is associated with low functional exercise capacity, reduced physical activity, and high BMI. Pain can adversely affect physical activity and quality of life in patients with COPD. Early evaluation of pain needs to be considered in the assessment and treatment plan for people with COPD.