Declining exercise tolerance may signal COPD progression

Decreasing exercise tolerance over 3 years is linked to accelerated lung function decline and air trapping progression in patients with mild-to-moderate chronic obstructive pulmonary disease (COPD), according to a study.

A total of 213 patients with mild-to-moderate COPD participated in the study. These patients completed questionnaires, spirometry, chest CT, and cardiopulmonary exercise testing (CPET) and underwent acute exacerbation assessment yearly for 3 years.

Analysis of 3-year CPET data showed that 61.5 percent of patients had longitudinal exercise decline. Each 5-percent decrease in exercise tolerance was associated with greater progression of air trapping (adjusted difference, 0.18 percent per year, 95 percent confidence interval [CI], 0.01–0.34; p=0.033) and a rapid decline in post-bronchodilator FEV1 (adjusted difference, −4.2 ml/year, 95 percent CI, −8.3 to −0.1; p=0.044).

When compared with patients who did not show exercise tolerance decline, those who did appeared to have greater progression of emphysema (adjusted difference, 0.40 percent/year, 95 percent CI, 0.10–0.69; p=0.008) and air trapping (adjusted difference, 1.26 percent/year, 95 percent CI, 0.41–1.84; p=0.002).

These findings suggest that longitudinal exercise decline may be a marker of disease progression in mild-to-moderate COPD. Monitoring exercise tolerance may facilitate detection of early disease progression in this population.