Association between Lung Function and Metabolic Syndrome Independent of Insulin in Japanese Men and Women

PURPOSE: We examined the cross-sectional association between lung function and metabolic syndrome (MetS), independent of fasting immunoreactive insulin (F-IRI). METHODS: A total of 3,072 middle-aged, apparently healthy subjects who participated in a general health check-up were included. Lung function, which was expressed as forced vital capacity (%FVC predicted) or forced expiratory volume in 1 second (FEV1% predicted) was examined. Multivariable logistic regression analysis was performed to assess the association between lung function and MetS. RESULTS: Men with the lowest quartile of FVC% predicted, or those with the lowest quartile of FEV1% predicted, had a 3.5-fold or 2.6-fold increased risk of MetS, respectively, compared with those with the highest quartile of FVC% predicted or FEV1% predicted. F-IRI had a positive, significant, and independent association with MetS in both sexes. CONCLUSION: Impaired lung function increased the risk of MetS, independent of F-IRI and smoking in men, but not in women.