Risk factors for lung function impairment among the general non-smoking Korean population

SETTING: Nationwide general population in South Korea. OBJECTIVE: Except for tobacco smoking, risk factors for the impairment of lung function have not been widely evaluated. We evaluated the risk factors for lung function impairment among the general non-smoking Korean population. DESIGN: A total of 8164 non-smokers from the spirometry data set of the Korean National Health and Nutrition Examination Surveys IV and V (2008-2010) were included in the study. After sex stratification, multiple survey logistic regression analyses were performed to estimate the association between potential risk factors and impaired lung function in this nationwide cross-sectional study. RESULTS: The proportion of non-smokers among the general Korean population with forced expiratory volume in 1 s (FEV1) < 80% of predicted, forced vital capacity (FVC) < 80% of predicted and FEV1/FVC ratio < 0.7 were respectively 46.2%, 50.3% and 30.2%. In multiple survey logistic regression analyses, lung function impairment was associated with tuberculosis (TB) and asthma in female non-smokers and asthma in male non-smokers. CONCLUSIONS: TB and asthma are risk factors for lung function impairment among Korean non-smokers. To prevent further lung function impairment, a careful control system for these factors should be considered when setting health policy priorities.