title: Evidence for geographical and racial variation in serum sex steroid levels in older men.
abstract: BACKGROUND
  Despite considerable racial and geographical differences in human phenotypes and in the incidence of diseases that may be associated with sex steroid action, there are few data concerning variation in sex steroid levels among populations. We designed an international study to determine the degree to which geography and race influence sex steroid levels in older men.
  
  
  METHODS
  Using mass spectrometry, concentrations of serum androgens, estrogens, and sex steroid precursors/metabolites were measured in 5003 older men from five countries. SHBG levels were assessed using radioimmunoassay.
  
  
  RESULTS
  There was substantial geographical variation in the levels of sex steroids, precursors, and metabolites, as well as SHBG. For instance, Asian men in Hong Kong and Japan, but not in the United States, had levels of total testosterone approximately 20% higher than in other groups. Even greater variation was present in levels of estradiol, SHBG, and dihydrotestosterone. Group differences in body mass index did not explain most geographical differences. In addition, body mass index-independent racial differences were present; Black men had higher levels of estrogens (estradiol, estrone), and Asian men had lower levels of glucuronidated androgen metabolites.
  
  
  CONCLUSIONS
  On a global scale, there are important geographical and racial differences in the concentrations of serum sex steroids and SHBG in older men.
authors.affiliation: Bone and Mineral Unit, Oregon Health & Science University, Portland, Oregon 97239, USA. orwoll@ohsu.edu
authors.forename: Eric S
authors.initials: ES
authors.lastname: Orwoll
authors.forename: Carrie M
authors.initials: CM
authors.lastname: Nielson
authors.forename: Fernand
authors.initials: F
authors.lastname: Labrie
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Barrett-Connor
authors.forename: Jane A
authors.initials: JA
authors.lastname: Cauley
authors.forename: Steven R
authors.initials: SR
authors.lastname: Cummings
authors.forename: Kristine
authors.initials: K
authors.lastname: Ensrud
authors.forename: Magnus
authors.initials: M
authors.lastname: Karlsson
authors.forename: Edith
authors.initials: E
authors.lastname: Lau
authors.forename: P C
authors.initials: PC
authors.lastname: Leung
authors.forename: Osten
authors.initials: O
authors.lastname: Lunggren
authors.forename: Dan
authors.initials: D
authors.lastname: Mellström
authors.forename: Alan L
authors.initials: AL
authors.lastname: Patrick
authors.forename: Marcia L
authors.initials: ML
authors.lastname: Stefanick
authors.forename: Kozo
authors.initials: K
authors.lastname: Nakamura
authors.forename: Noriko
authors.initials: N
authors.lastname: Yoshimura
authors.forename: Joseph
authors.initials: J
authors.lastname: Zmuda
authors.forename: Liesbeth
authors.initials: L
authors.lastname: Vandenput
authors.forename: Claes
authors.initials: C
authors.lastname: Ohlsson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000097:blood / Q000378:metabolism; D001774:Blood Chemical Analysis / Q000379:methods; D015331:Cohort Studies; D005843:Geography; D012739:Gonadal Steroid Hormones / Q000032:analysis / Q000097:blood* / Q000378:metabolism; D006723:Hong Kong; D006801:Humans; D007564:Japan; D008297:Male; D013058:Mass Spectrometry; D008954:Models, Biological; D044469:Racial Groups / Q000706:statistics & numerical data; D012738:Sex Hormone-Binding Globulin / Q000032:analysis / Q000378:metabolism; D014300:Trinidad and Tobago; D014481:United States
chemical_list: D012739:Gonadal Steroid Hormones; D012738:Sex Hormone-Binding Globulin