title: Relation between serum testosterone, serum estradiol, sex hormone-binding globulin, and geometrical measures of adult male proximal femur strength.
abstract: BACKGROUND
  Although previous studies have indicated associations between circulating testosterone (T) or estradiol (E2) concentrations and bone mineral density, the relationship between gonadal steroids and skeletal geometry is not well defined.
  
  
  OBJECTIVE
  Our objective was to uncover the relation between circulating T or E2 and proximal femur geometry in a diverse sample of men.
  
  
  METHODS
  We used data on 808 men enrolled in the Boston Area Community Health/Bone Study. Serum concentrations of total and calculated free T and E2 were obtained via early-morning blood sampling. The geometry of the proximal femur at three sites (the narrow neck, intertrochanter, and shaft) was obtained using the Hip Structural Analysis technology. Analyses adjusted for subjects' age, height, total body lean mass and fat mass, and level of physical activity were performed.
  
  
  METHODS
  In-home interviews accompanied by subject visits to the General Clinical Research Center at Boston University School of Medicine were performed.
  
  
  METHODS
  A randomly selected cohort of men living in Boston, MA (ages 30-79 yr) was included in the study.
  
  
  METHODS
  These were not applicable.
  
  
  METHODS
  Bone mineral density and bone outer diameter, cross-sectional area (measuring bone material), and section modulus (an index of bending strength) were calculated.
  
  
  RESULTS
  In age-adjusted models, E2 was positively associated with hip strength parameters, whereas T was not. Adjustment for age and other parameters resulted in substantial reductions in, but not complete elimination of, associations between E2 and hip strength parameters.
  
  
  CONCLUSIONS
  Circulating E2 is strongly associated with proximal femur strength, an association that is partially mediated by body composition.
authors.affiliation: New England Research Institutes, 9 Galen Street, Watertown, Massachusetts 02472, USA. ttravison@neriscience.com
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Travison
authors.forename: Andre B
authors.initials: AB
authors.lastname: Araujo
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Beck
authors.forename: Rachel E
authors.initials: RE
authors.lastname: Williams
authors.forename: Richard V
authors.initials: RV
authors.lastname: Clark
authors.forename: Benjamin Z
authors.initials: BZ
authors.lastname: Leder
authors.forename: John B
authors.initials: JB
authors.lastname: McKinlay
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001823:Body Composition; D015519:Bone Density; D003430:Cross-Sectional Studies; D004958:Estradiol / Q000097:blood*; D005269:Femur / Q000033:anatomy & histology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012738:Sex Hormone-Binding Globulin / Q000032:analysis*; D013739:Testosterone / Q000097:blood*
chemical_list: D012738:Sex Hormone-Binding Globulin; D013739:Testosterone; D004958:Estradiol