Background: To investigate the association between serum concentrations of total bilirubin (TBil) in the physiological range and metabolic syndrome (MS) in middle-aged and elderly Chinese, as well as any associations between serum TBil concentrations and insulin resistance, hyperinsulinemia, and systemic inflammation.
Methods: A cross-sectional study was conducted on 1423 individuals recruited from an urban community of Shanghai (average age 62.3 years) to investigate the relationship between bilirubin and cardiovascular diseases. Metabolic syndrome was defined according to the National Cholesterol Education Program Adult Treatment Panel III criteria for Asian Americans.
Results: Total bilirubin concentrations were significantly lower in individuals with MS compared with those without (0.65 ± 0.21 vs 0.69 ± 0.22 mg/dL, respectively; P=0.002). The adjusted mean concentration of TBil decreased gradually with an increase in the number of components of MS (P(trend) < 0.0001). After adjustment for a range of potential confounders (e.g. age, sex, body mass index, smoking, alcohol intake, homeostasis model assessment of insulin resistance etc.), each 1 SD increase in TBil was found to be associated with a 17% reduction in the risk of MS (odds ratio 0.83; 95% confidence interval 0.73-0.95; P=0.006). Furthermore, after adjustment for all covariables, each 1 SD increase in TBil was found to be associated with lower odds of central obesity, hypertriglyceridemia, low high-density lipoprotein-cholesterol, and hyperglycemia. Serum TBil concentrations were inversely associated with hyperinsulinemia, insulin resistance, and systemic inflammation.
Conclusions: Serum TBil concentrations within the physiological range were inversely associated with MS and insulin resistance, hyperinsulinemia, and systemic inflammation in middle-aged and elderly Chinese.
© 2011 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and Blackwell Publishing Asia Pty Ltd.