title: Associations of total testosterone, sex hormone-binding globulin, calculated free testosterone, and luteinizing hormone with prevalence of abdominal aortic aneurysm in older men.
abstract: BACKGROUND
  Abdominal aortic aneurysm (AAA) is associated with mortality in older adults, and increasing aortic diameter predicts incident cardiovascular events. Although AAA occurs predominantly in men, its association with male sex hormones is unclear.
  
  
  OBJECTIVE
  The objective of the study was to examine whether male sex hormones are independently associated with AAA or increased abdominal aortic diameter.
  
  
  METHODS
  This was a cross-sectional analysis.
  
  
  METHODS
  Participants included 3620 community-dwelling men aged 70-88 yr.
  
  
  METHODS
  Abdominal aortic diameter was measured with ultrasound. Early morning sera were assayed for total testosterone, SHBG, and LH. Free testosterone was calculated using mass action equations.
  
  
  RESULTS
  AAA (aortic diameter > or =30 mm) was present in 262 men (7.2%). Men with AAA had lower serum total and free testosterone (mean +/- sd 14.5 +/- 6.0 vs. 15.5 +/- 5.6 nmol/liter, P = 0.005 and 256 +/- 87 vs. 280 +/- 97 pmol/liter, P < 0.001, respectively) compared with men without. LH was higher in men with AAA (median, interquartile range: 4.9, 3.1-7.9 vs. 4.3, 3.0-6.4 IU/liter, P = 0.013). In multivariate analysis adjusting for potential confounders, free testosterone was negatively associated with AAA (odds ratio per 1 sd increase: 0.84, 95% confidence interval 0.72-0.98, P = 0.026). LH was positively associated (odds ratio 1.14, 95% confidence interval 1.03-1.25, P = 0.008). Comparable results were seen with aortic diameter analyzed as a continuous variable.
  
  
  CONCLUSIONS
  Lower free testosterone and higher LH levels are independently associated with AAA in older men. Impaired gonadal function may be involved in arterial dilatation as well as occlusive vascular disease in older men. Additional studies are needed to clarify direction of causality and determine possible scope for preventive intervention.
authors.affiliation: School of Medicine and Pharmacology, Level 2, T Block, Fremantle Hospital, Alma Street, P.O. Box 480, Fremantle, Western Australia 6959, Australia. byeap@cyllene.uwa.edu.au
authors.forename: Bu B
authors.initials: BB
authors.lastname: Yeap
authors.forename: Zoë
authors.initials: Z
authors.lastname: Hyde
authors.forename: Paul E
authors.initials: PE
authors.lastname: Norman
authors.forename: S A Paul
authors.initials: SA
authors.lastname: Chubb
authors.forename: Jonathan
authors.initials: J
authors.lastname: Golledge
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001012:Aorta, Abdominal / Q000000981:diagnostic imaging*; D017544:Aortic Aneurysm, Abdominal / Q000097:blood* / Q000000981:diagnostic imaging / Q000453:epidemiology*; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D006801:Humans; D007118:Immunoassay; D007986:Luteinizing Hormone / Q000097:blood*; D008297:Male; D015995:Prevalence; D012044:Regression Analysis; D012307:Risk Factors; D012738:Sex Hormone-Binding Globulin / Q000378:metabolism*; D011795:Surveys and Questionnaires; D013739:Testosterone / Q000097:blood*; D014463:Ultrasonography
chemical_list: D012738:Sex Hormone-Binding Globulin; D013739:Testosterone; D007986:Luteinizing Hormone