National trend in the prevalence and mortality of young COPD in South Korea from 2008 to 2017

Background Chronic obstructive pulmonary disease (COPD) has traditionally been regarded as a disease of older adults; however, impaired lung development and early-life exposures may predispose younger individuals to COPD. Data on the prevalence and mortality of young COPD in Asian populations remain limited. We aimed to investigate temporal trends in prevalence and mortality among young adults with COPD in South Korea. Methods We conducted a nationwide serial cross-sectional study using the National Health Information Database linked to national cause-of-death data from 2008 to 2017. Adults aged 20–50 years were included. COPD was identified using ICD-10 codes (J41–J44), defined as ≥ 2 outpatient diagnoses or ≥ 1 hospitalization for COPD. Crude and age- and sex-standardized prevalence and mortality rates were calculated. Mortality risks were assessed using Poisson regression models adjusting for age, sex, income level, residence, and Charlson comorbidity index. Results The crude prevalence of young COPD increased steadily from 2.4% in 2008 to 7.8% in 2017, with similar trends observed after age standardization and across both sexes. In 2017, COPD prevalence increased with age, reaching 9.6% among individuals aged 40–50 years. Young adults with COPD had a higher burden of comorbidities than those without COPD. Although overall mortality declined over time, individuals with COPD consistently exhibited higher mortality rates. COPD was associated with increased all-cause mortality (adjusted incidence rate ratio [IRR] 1.18, 95% CI 1.14–1.23). Cause-specific mortality risks were significantly higher for lung cancer (adjusted IRR 3.16, 95% CI 2.62–3.83), as well as for diseases of the nervous, respiratory, and musculoskeletal systems. Conclusions Young COPD is relatively common in South Korea and its prevalence has increased substantially over the past decade. Despite their young age, individuals with COPD experience a significant burden of comorbidities and increased mortality. These findings highlight the need for greater clinical awareness and early preventive strategies for COPD in younger populations.