title: [Association between serum direct bilirubin with metabolic syndrome and its components based on a longitudinal health check-up study].
abstract: OBJECTIVE
  To investigate the association between serum direct bilirubin (DBIL) with metabolic syndrome (MS) and its components.
  
  
  METHODS
  A dynamic health check-up cohort study was set up from 2006 to 2011. 5 258 participants who satisfied the two basic rules: 1) being free of MS at the 1(st) health check-up program; 2) having at least two intact health checks were included in this study. With generalized estimating equation (GEE) model, after adjusting for items as age, gender, smoking, drinking, alanine aminotransferase, aspartate aminotransferase, γ-glutamyltransferase, uric acid, blood urea nitrogen and white blood cells, the multivariable relative risks (RRs) of DBIL with MS and their components were analyzed.
  
  
  RESULTS
  The RRs of DBIL for MS was 0.722 (95%CI: 0.654-0.797), which showing a dose-response. Serum DBIL was negatively associated with obesity and hyperlipidemia. Taking factors as gender and age into account, in the <45 years and 45-55 years groups, the RRs of DBIL for MS in females appeared as 0.516 (95%CI: 0.349-0.761) and 0.435 (95%CI: 0.256-0.740). And in males of <45 years and 45-55 years, the RRs of DBIL for MS were 0.738 (95% CI: 0.644-0.846) and 0.790 (95% CI:0.667-0.937), respectively.
  
  
  CONCLUSIONS
  The elevated DBIL levels in serum appeared an early biomarker for MS and its components (obesity and hyperlipidemia). In particular,they may play a role in reducing the risk of MS in both females and males before 55 years of age.
authors.affiliation: Shengli Oil Field Central Hospital, Dongying 257000, China.
authors.forename: Qicai
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Department of Epidemiology, School of Public Health, Shandong University, Jinan 250012, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Xiao
authors.affiliation: Tianjin Entry-Exit Inspection and Quarantine Bureau, Tianjin 300457, China.
authors.forename: Pengpeng
authors.initials: P
authors.lastname: Zhang
authors.affiliation: Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310051, China.
authors.forename: Lili
authors.initials: L
authors.lastname: Chen
authors.affiliation: Department of Epidemiology, School of Public Health, Shandong University, Jinan 250012, China.
authors.forename: Xiaoxiao
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of Epidemiology, School of Public Health, Shandong University, Jinan 250012, China.
authors.forename: Shumei
authors.initials: S
authors.lastname: Wang
mesh_terms: D000328:Adult; D001663:Bilirubin / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood*; D008875:Middle Aged; D009765:Obesity; D014527:Uric Acid; D005723:gamma-Glutamyltransferase
chemical_list: D015415:Biomarkers; D014527:Uric Acid; D005723:gamma-Glutamyltransferase; D001663:Bilirubin