Background: Impaired lung function is an independent predictor of cardiovascular mortality. We assessed the relationships of lung function with insulin resistance (IR), metabolic syndrome (MetS), systemic inflammation and coronary artery calcification score (CACS) measured by computed tomography (CT) scan an indicator of coronary atherosclerosis.
Methods: We identified 4905 adult male patients of the Health Promotion Center in Samsung Medical Center between March 2005 and February 2008 and retrospectively reviewed the following data for these patients: pulmonary function, CT-measured CACS, anthropometric measurement, fasting glucose, insulin, lipid profiles, serum C-reactive protein (CRP) and homeostatic model assessment (HOMA-IR). MetS was defined according to the AHA/NHLBI criteria.
Results: When the subjects were divided into four groups according to quartiles of FVC or FEV(1) (% pred), serum CRP level, HOMA-IR, prevalence of MetS and CACS significantly increased as the FVC or FEV(1) (% pred) decreased. The odds ratios (ORs) for MetS in the lowest quartiles of FVC and FEV(1) (% pred) were 1.85 (95% CI, 1.49-2.30; p<0.001) and 1.47 (95% CI, 1.20-1.81; p<0.001) respectively. The ORs for the presence of coronary artery calcification in the lowest quartiles of FVC and FEV(1) (% pred) were 1.31 (95% CI, 1.09-1.58; p=0.004) and 1.22 (95% CI, 1.02-1.46; p=0.029) respectively. Obesity, CRP, HOMA-IR, and the presence of coronary artery calcium were independent risk predictors for impaired lung function.
Conclusion: Metabolic syndrome, insulin resistance, coronary atherosclerosis, and systemic inflammation are closely related to the impaired lung function.