Characteristics and Prevalence of Early Chronic Obstructive Pulmonary Disease in a Middle-Aged Population: Results from a Nationwide-Representative Sample

INTRODUCTION: Few studies have examined the prevalence and associated factors of early chronic obstructive pulmonary disease (COPD) in Asians. OBJECTIVE: To evaluate the prevalence of early COPD and its associated factors among non-institutionalized middle-aged Korean adults. METHODS: A total of 3195 participants aged 40–49 years from the 2016–2018 Korea National Health and Nutrition Examination Survey were included in this study. Patients (1) aged less than 50 years, (2) with a minimum of 10 pack-years of smoking, and (3) with forced expiratory volume in 1 s/forced vital capacity (FEV(1)/FVC) below the lower limit of normal were diagnosed with early COPD. The prevalence and odds ratio (OR) for early COPD were measured using multivariate logistic regression analysis, and the demographic data, anthropometric measurements, socioeconomic status, and lifestyle factors were considered covariates. RESULTS: The overall prevalence of early COPD among the middle-aged Korean population was 2.4% (4.4% in men and 0.4% in women), while that in participants with ≥10 pack-years was 8.2% (8.1% in men and 11.3% in women). A multivariate logistic regression model showed that male sex, urban residence, chronic sputum production, and hypertriglyceridemia were associated with increased ORs for early COPD in middle-aged, non-institutionalized Korean adults. CONCLUSION: Early COPD is prevalent among middle-aged smokers in Korea. Efforts are needed to reduce the potential negative effects of early COPD on public health in Korea and other Asian countries.