title: Serum testosterone, dihydrotestosterone and estradiol concentrations in older men self-reporting very good health: the healthy man study.
abstract: OBJECTIVE
  To determine serum concentrations, intra-individual variability and impact of age-related co-morbidities on serum testosterone (T), dihydrotestosterone (DHT), estradiol (E(2)) and estrone (E(1)) in older men.
  
  
  METHODS
  Observational, repeated measures study.
  
  
  METHODS
  Men (n = 325) with 40 years and older self-reporting very good or excellent health.
  
  
  METHODS
  Standardized history, physical examination and collection of nine blood samples at fixed time intervals were measured over 3 months (three at 20 min intervals on days 1 (fasting) and 2 (non-fasting), one at days 7, 30 and 90). Serum T, DHT, E(2) and E(1) (n = 2900, > 99% of scheduled samples) measured by liquid chromatography-tandem mass spectrometry (LC-MS) were analysed by linear mixed model analysis with fasting, age and obesity as covariables.
  
  
  RESULTS
  Mean serum T did not vary with age (P = 0·76) but obesity (-0·35 nM per body mass index (BMI) unit, P < 0·0001) and ex-smoker status (-1·6 nM, P < 0·001) had significant effects. Serum DHT was increased with age (+0·011 nM per year, P = 0·001) but decreased with obesity (-0·05 nM per BMI unit, P < 0·0001). Serum E(2) did not vary with age (P = 0·31) or obesity (P = 0·12). Overnight fasting increased (by 9-16%, all P < 0·001) and reduced variability in morning serum T, DHT, E(2) and E(1). Non-fasting serum T and DHT were stable over time (day, week, month or 3 months; P > 0·28).
  
  
  CONCLUSIONS
  Serum T, DHT and E(2) displayed no decrease associated with age among men over 40 years of age who self-report very good or excellent health although obesity and ex-smoking status were associated with decreased serum androgens (T and DHT) but not E(2). These findings support the interpretation that the age-related decline in blood T accompanying non-specific symptoms in older men may be due to accumulating age-related co-morbidities rather than a symptomatic androgen deficiency state.
authors.affiliation: Andrology Department, Concord Hospital, Clayton, Vic., Australia.
authors.forename: Gideon
authors.initials: G
authors.lastname: Sartorius
authors.forename: Sasa
authors.initials: S
authors.lastname: Spasevska
authors.forename: Amanda
authors.initials: A
authors.lastname: Idan
authors.forename: Leo
authors.initials: L
authors.lastname: Turner
authors.forename: Elise
authors.initials: E
authors.lastname: Forbes
authors.forename: Anna
authors.initials: A
authors.lastname: Zamojska
authors.forename: Carolyn A
authors.initials: CA
authors.lastname: Allan
authors.forename: Lam P
authors.initials: LP
authors.lastname: Ly
authors.forename: Ann J
authors.initials: AJ
authors.lastname: Conway
authors.forename: Robert I
authors.initials: RI
authors.lastname: McLachlan
authors.forename: David J
authors.initials: DJ
authors.lastname: Handelsman
mesh_terms: D000368:Aged; D013196:Dihydrotestosterone / Q000097:blood*; D004958:Estradiol / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013739:Testosterone / Q000097:blood*
chemical_list: D013196:Dihydrotestosterone; D013739:Testosterone; D004958:Estradiol