Risk of Rapid Lung Function Decline in Young Adults With Chronic Obstructive Pulmonary Disease: A Community-Based Prospective Cohort Study

It is unclear whether young adults with chronic obstructive pulmonary disease (COPD) are at an increased risk of rapid lung function decline. A total of 2,934 Korean adults aged 40–49 years who had consecutive lung function measurements were included. COPD was defined as pre-bronchodilator forced expiratory volume in 1 second (FEV₁)/forced vital capacity < lower limit of normal. The risk of rapid decline in FEV₁, defined as ≥ 60 mL/year, was assessed using multivariable logistic regression analysis. In the multivariable model, a significantly higher risk of rapid decline in FEV₁ was observed for the COPD group compared with the non-COPD group (adjusted odds ratio, 1.89; 95% confidence interval, 1.18–2.95), which was especially significant in subjects with FEV₁ less than the median value (< 110%pred) (P_interaction = 0.017) and inactive physical activity (P_interaction = 0.039). In conclusion, the risk of rapid FEV₁ decline was higher in young adults with COPD than in those without COPD, especially in those with FEV₁ less than the median value and inactive physical activity.