title: The relationships between sex hormones and sexual function in middle-aged and older European men.
abstract: BACKGROUND
  Limited data are available exploring the associations between sex hormones, multiple domains of sexual functioning, and sexual function-related distress in nonpatient samples in Europe.
  
  
  OBJECTIVE
  The aim of the study was to investigate the relationships between serum testosterone (T), estradiol (E2), and dihydrotestosterone (DHT) and sexual function in a multicenter population-based study of aging in men.
  
  
  METHODS
  Using stratified random sampling, 2838 men aged 40-79 yr completed the European Male Ageing Study-Sexual Function Questionnaire and provided a blood sample for hormone measurements. T, E2, and DHT were measured using gas chromatography-mass spectrometry.
  
  
  METHODS
  We conducted a community-based population survey in eight European centers.
  
  
  METHODS
  Self-reported sexual function (overall sexual function, sexual function-related distress, erectile dysfunction, masturbation) was measured.
  
  
  RESULTS
  Total and free T, but not E2 or DHT, was associated with overall sexual function in middle-aged and older men. E2 was the only hormone associated with sexual function-related distress such that higher levels were related to greater distress. Free T levels were associated with masturbation frequency and erectile dysfunction in the fully adjusted models, such that higher T was associated with less dysfunction and greater frequency. Moreover, there was a T threshold for the relationship between total T, sexual function, and erectile dysfunction. At T concentrations of 8 nmol/liter or less, T was associated with worse sexual functioning, whereas at T levels over 8 nmol/liter, the relationship came to a plateau.
  
  
  CONCLUSIONS
  These findings suggest that different hormonal mechanisms may regulate sexual functioning (T) vs. the psychological aspects (E2) of male sexual behavior. Moreover, there was a T threshold for overall sexual function such that at levels greater than 8 nmol/liter the relationship between T and sexual function did not become stronger.
authors.affiliation: Institute of Psychological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom. d.b.o'connor@leeds.ac.uk
authors.forename: Daryl B
authors.initials: DB
authors.lastname: O'Connor
authors.forename: David M
authors.initials: DM
authors.lastname: Lee
authors.forename: Giovanni
authors.initials: G
authors.lastname: Corona
authors.forename: Gianni
authors.initials: G
authors.lastname: Forti
authors.forename: Abdelouahid
authors.initials: A
authors.lastname: Tajar
authors.forename: Terence W
authors.initials: TW
authors.lastname: O'Neill
authors.forename: Neil
authors.initials: N
authors.lastname: Pendleton
authors.forename: Gyorgy
authors.initials: G
authors.lastname: Bartfai
authors.forename: Steven
authors.initials: S
authors.lastname: Boonen
authors.forename: Felipe F
authors.initials: FF
authors.lastname: Casanueva
authors.forename: Joseph D
authors.initials: JD
authors.lastname: Finn
authors.forename: Aleksander
authors.initials: A
authors.lastname: Giwercman
authors.forename: Thang S
authors.initials: TS
authors.lastname: Han
authors.forename: Ilpo T
authors.initials: IT
authors.lastname: Huhtaniemi
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Kula
authors.forename: Fernand
authors.initials: F
authors.lastname: Labrie
authors.forename: Michael E J
authors.initials: ME
authors.lastname: Lean
authors.forename: Margus
authors.initials: M
authors.lastname: Punab
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Silman
authors.forename: Dirk
authors.initials: D
authors.lastname: Vanderschueren
authors.forename: Frederick C W
authors.initials: FC
authors.lastname: Wu
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging / Q000502:physiology; D013196:Dihydrotestosterone / Q000097:blood; D007172:Erectile Dysfunction / Q000453:epidemiology; D004958:Estradiol / Q000097:blood; D005060:Europe / Q000453:epidemiology; D008401:Gas Chromatography-Mass Spectrometry; D012739:Gonadal Steroid Hormones / Q000097:blood*; D006304:Health Status; D006801:Humans; D008019:Life Style; D016014:Linear Models; D008297:Male; D008418:Masturbation; D008875:Middle Aged; D019529:Sexuality / Q000502:physiology* / Q000523:psychology; D011795:Surveys and Questionnaires; D013739:Testosterone / Q000097:blood; D044465:White People
chemical_list: D012739:Gonadal Steroid Hormones; D013196:Dihydrotestosterone; D013739:Testosterone; D004958:Estradiol