title: Serum bilirubin levels are inversely associated with PAI-1 and fibrinogen in Korean subjects.
abstract: OBJECTIVE
  Oxidative stress may contribute to atherosclerosis and increased activation of the coagulation pathway. Bilirubin may reduce activation of the hemostatic system to inhibit oxidative stress, which would explain its cardioprotective properties shown in many epidemiological studies. This study investigated the association of serum bilirubin with fibrinogen and plasminogen activator inhibitor-1 (PAI-1), respectively.
  
  
  METHODS
  A cross-sectional analysis was performed on 968 subjects (mean age, 56.0 ± 11.2 years; 61.1% men) undergoing a general health checkup. Serum biochemistry was analyzed including bilirubin subtypes, insulin resistance (using homeostasis model of assessment [HOMA]), C-reactive protein (CRP), fibrinogen, and PAI-1.
  
  
  RESULTS
  Compared with subjects with a total bilirubin (TB) concentration of <10.0 μmol/L, those with a TB concentration of >17.1 μmol/L had a smaller waist circumference, a lower triglyceride level, a lower prevalence of metabolic syndrome, and decreased HOMA-IR and CRP levels. Correlation analysis revealed linear relationships of fibrinogen with TB and direct bilirubin (DB), whereas PAI-1 was correlated with DB. After adjustment for confounding factors, bilirubin levels were inversely associated with fibrinogen and PAI-1 levels, respectively. Multivariate regression models showed a negative linear relationship between all types of bilirubin and fibrinogen, whereas there was a significant linear relationship between PAI-1 and DB.
  
  
  CONCLUSIONS
  High bilirubin concentrations were independently associated with low levels of fibrinogen and PAI-1, respectively. The association between TB and PAI-1 was confined to the highest TB concentration category whereas DB showed a linear association with PAI-1. Bilirubin may protect against the development of atherothrombosis by reducing the hemostatic response.
authors.affiliation: Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea; Health Promotion Center, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea.
authors.forename: Hyun Sun
authors.initials: HS
authors.lastname: Cho
authors.affiliation: Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea; Division of Hepatology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea.
authors.forename: Sung Won
authors.initials: SW
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea; Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea. Electronic address: 13900@catholic.ac.kr.
authors.forename: Eun Sook
authors.initials: ES
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea; Health Promotion Center, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea.
authors.forename: Juyoung
authors.initials: J
authors.lastname: Shin
authors.affiliation: Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea; Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea.
authors.forename: Sung Dae
authors.initials: SD
authors.lastname: Moon
authors.affiliation: Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea; Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea.
authors.forename: Je Ho
authors.initials: JH
authors.lastname: Han
authors.affiliation: Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea.
authors.forename: Bong Yun
authors.initials: BY
authors.lastname: Cha
mesh_terms: D000328:Adult; D050197:Atherosclerosis / Q000097:blood* / Q000453:epidemiology*; D001663:Bilirubin / Q000097:blood*; D001777:Blood Coagulation / Q000502:physiology*; D003430:Cross-Sectional Studies; D005260:Female; D005340:Fibrinogen / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017395:Plasminogen Activator Inhibitor 1 / Q000097:blood*; D015995:Prevalence; D056910:Republic of Korea / Q000453:epidemiology; D012189:Retrospective Studies; D012307:Risk Factors; D055815:Young Adult
chemical_list: D017395:Plasminogen Activator Inhibitor 1; D005340:Fibrinogen; D001663:Bilirubin
keywords: Atherosclerosis; Bilirubin; Fibrinogen; Plasminogen activator inhibitor-1