The complex association of metabolic syndrome and its components with computed tomography-determined emphysema index

Background: Recent reports have suggested the association between emphysema and cardiovascular disease (CVD); however, there are few reports regarding association of emphysema severity with metabolic syndrome and its components representing CVD risk factors. Methods: A retrospective cross-sectional study was performed in 2814 adult male subjects over age 40 who visited the Health Promotion Center in Samsung Medical Center for a health checkup program. Results: We classified patients according to the quintiles of forced expiratory volume in 1?sec (FEV₁) and emphysema index (EI). FEV₁ percentage predicted values (% pred) was inversely associated with prevalence of metabolic syndrome and most of its components, such as abdominal obesity, hypertension, fasting hyperglycemia, and low high-density lipoprotein cholesterol. Although there was no association between prevalence of metabolic syndrome and EI, hypertension was positively associated with EI (P<0.001) and high triglycerides (TGs) were inversely associated with EI (P=0.021). These associations persisted after adjustment of other variables (P<0.001 in hypertension and P=0.039 in high TGs). Conclusion: The computed tomography-determined EI has a complex association with components of metabolic syndrome that is associated with increased prevalence of hypertension but decreased prevalence of high TGs, whereas FEV₁ (% pred) has an inverse association with metabolic syndrome and most of its components with consistent direction.