Metabolic Syndrome, Insulin Resistance and Systemic Inflammation as Risk Factors for Reduced Lung Function in Korean Nonsmoking Males

The aim of this study was done to assess the association of lung function with insulin resistance (IR), systemic inflammation, and metabolic syndrome (MetS). In 9,581 apparently healthy non-smoking male adults, pulmonary function, fasting glucose, insulin, lipid profiles and serum high-sensitivity C-reactive protein (hs-CRP) levels were measured, and homeostatic model assessment (HOMA) was used to assess IR. The presence of MetS was defined according to the AHA/NHLBI criteria. The prevalence of MetS was 19.3%. The odds ratio of MetS for restrictive ventilatory pattern was 1.55 (95% confidence interval, 1.12-2.14), and that for obstructive ventilatory pattern was 1.39 (0.66-2.94) after adjustment for confounders. When subjects were divided in 4 groups according to quartiles of FVC or FEV1 (% predicted [pred]), HOMA-IR significantly increased as the FVC or FEV1 (% predicted [pred]) decreased. Individuals in the lowest FVC or FEV1 quartile had the highest hs-CRP level. Prevalence of MetS increased as FVC or FEV1 (% predicted [pred]) quartiles decreased. The abdominal obesity, hs-CRP and HOMA-IR were the independent predictors for the lowest FVC and FEV1 (% predicted [pred]) even after adjustment for confounders. These results indicate that MetS, IR, and systemic inflammation are important risk factors for reduced lung function in nonsmoking Korean males.