title: Metabolic syndrome, testosterone, and cardiovascular mortality in men.
abstract: BACKGROUND
  Interactions among testosterone, metabolic syndrome (MetS), and mortality risk in men remain to be elucidated.
  
  
  OBJECTIVE
  To examine relationships among testosterone, MetS, and cardiovascular mortality risk in U.S. men, middle-aged and older.
  
  
  METHODS
  The analysis included the men aged 40 years and above in Phase 1 (1988-1991) of the Third National Health and Nutrition Examination Survey (NHANES III). Serum testosterone and sex hormone binding globulin were measured, and free testosterone and bioavailable testosterone were calculated. MetS was determined according to the Adult Treatment Panel III (ATP-III) criteria.
  
  
  METHODS
  Cardiovascular and other causes of mortality were obtained from the NHANES III-linked follow-up file through December 31, 2006. Multivariate Cox regression models were applied to assess associations of interest.
  
  
  RESULTS
  Of 596 men included in the analysis, 187 men were found to have MetS. During a median follow-up of 15.6 years, 97 men died of cardiovascular causes (cardiovascular mortality rate: 9.84 and 5.77 per 1,000 person-years for those with and without MetS, respectively). Higher calculated bioavailable testosterone (CBT) was associated with a lower odds of MetS (odds ratio: 0.80 for each ng/mL, 95% confidence interval [CI]: 0.76-0.84, P < 0.001) and lower risk of cardiovascular mortality (hazard ratios [HRs]: 0.72 for each log ng/mL, 95% CI: 0.54-0.96, P = 0.03) in subjects with MetS. The influence of CBT was not observed in those without MetS (HR: 0.84 for each log ng/mL, 95% CI: 0.68-1.04, P = 0.10).
  
  
  CONCLUSIONS
  The combination of lower bioavailable testosterone and ATP-III-defined MetS is associated with an increased cardiovascular mortality in the men aged 40 years and above.
authors.affiliation: Cardiovascular Center and Health Management Center, National Taiwan University Hospital Yun-Lin Branch, Dou-Liou, Taiwan.
authors.forename: Jou-Wei
authors.initials: JW
authors.lastname: Lin
authors.forename: Jen-Kuang
authors.initials: JK
authors.lastname: Lee
authors.forename: Cho-Kai
authors.initials: CK
authors.lastname: Wu
authors.forename: James L
authors.initials: JL
authors.lastname: Caffrey
authors.forename: Man-Huei
authors.initials: MH
authors.lastname: Chang
authors.forename: Juey-Jen
authors.initials: JJ
authors.lastname: Hwang
authors.forename: Nicole
authors.initials: N
authors.lastname: Dowling
authors.forename: Yu-Sheng
authors.initials: YS
authors.lastname: Lin
mesh_terms: D000328:Adult; D000368:Aged; D002318:Cardiovascular Diseases / Q000097:blood / Q000209:etiology / Q000401:mortality*; D006801:Humans; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood / Q000150:complications / Q000175:diagnosis*; D008875:Middle Aged; D009749:Nutrition Surveys; D012738:Sex Hormone-Binding Globulin / Q000032:analysis; D013739:Testosterone / Q000097:blood / Q000172:deficiency*
chemical_list: D012738:Sex Hormone-Binding Globulin; D013739:Testosterone