BackgroundImpaired lung function is associated with mortality rate from cardiovascular and all other death causes. There were previous studies on the relationship between lung function impairment and metabolic syndrome, but they are insufficient. This study was conducted on Koreans to analyze each component of metabolic syndrome as well as its variability between sexes.Methods1,370 subjects underwent a health examination at the Eulji General Hospital Health Center. We examined the association between lung function measurement (forced expiratory volume for 1 second [FEV1], forced vital capacity [FVC], FEV1/FVC) and metabolic syndrome using Student t-test, Pearson partial correlation coefficient, and analysis of covariance for statistical analysis, and we adopted metabolic syndrome defined by American Heart Association/National Heart, Lung, and Blood Institute in Asia.ResultsMen with metabolic syndrome tended to experience lung function impairment. In terms of association to each metabolic syndrome component, metabolic syndrome components in men were associated with pulmonary function impairment and the more metabolic syndrome diagnostic criteria factors the patients had, the more severe their pulmonary function tended to decline. In women, waist circumference, triglyceride and high-density lipoprotein cholesterol were associated with pulmonary function change.ConclusionIn men, all metabolic syndrome components were associated with pulmonary function impairment, and the more metabolic syndrome components men had, the more severe their pulmonary functions decline. In women, components of metabolic syndrome were not associated with pulmonary function impairment.