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 (FEV(1))/forced vital capacity < lower limit of normal. The risk of rapid decline in FEV(1), defined as ≥ 60 mL/year, was assessed using multivariable logistic regression analysis. In the multivariable model, a significantly higher risk of rapid decline in FEV(1) 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 FEV(1) 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 FEV(1) decline was higher in young adults with COPD than in those without COPD, especially in those with FEV(1) less than the median value and inactive physical activity.