title: Age-related testosterone decline in a Brazilian cohort of healthy military men.
abstract: BACKGROUND
  Androgen decline in the aging man has become a topic of increasing clinical relevance worldwide, as the reduction in testosterone levels has been reported to be accompanied by loss of muscle mass, accumulation of central adiposity, impaired mobility and increase risk of bone fractures. Although well-established in studies conducted in developed countries, progressive decline in serum testosterone levels with age has been poorly investigated in Brazil.
  
  
  OBJECTIVE
  To determine the pattern of blood testosterone concentrations decline with age in a cohort of Brazilian healthy military men.
  
  
  METHODS
  We retrospectively reviewed data on serum testosterone measurements of healthy individuals that had undergone a routine check-up at the Military Biology Institute. Blood samples were obtained early in the morning, and total testosterone concentration was determined using a commercial chemoluminescent immunoassay. Mean values were analyzed in five age groups: ≤ 40, 41 to 50, 51 to 60, 61 to 70, and > 70 years.
  
  
  METHODS
  Mean total testosterone levels.
  
  
  RESULTS
  1,623 subjects were included in the analysis; mean age was 57 years (24 to 87), and mean testosterone level was 575.5 ng/dL (25.0 to 1308.0 ng/dL). The evaluation of age-related changes in total testosterone levels revealed a progressive reduction in serum levels of this hormone with increasing age. Testosterone levels below 300 ng/dL were reported in 321 participants, a prevalence of nearly 20% in the study population.
  
  
  CONCLUSIONS
  In agreement with other findings, a reduction of total testosterone levels with age was reported for healthy Brazilian men.
authors.affiliation: Federal University of Sao Paulo, Sao Paulo, SP, Brazil. anardozza@globo.com
authors.forename: Archimedes
authors.initials: A
authors.lastname: Nardozza Júnior
authors.forename: Sergio dos Santos
authors.initials: Sdos S
authors.lastname: Szelbracikowski
authors.forename: Aguinaldo Cesar
authors.initials: AC
authors.lastname: Nardi
authors.forename: Jose Carlos de
authors.initials: JC
authors.lastname: Almeida
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging / Q000097:blood*; D001938:Brazil; D006801:Humans; D007006:Hypogonadism / Q000097:blood / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D008889:Military Personnel; D012189:Retrospective Studies; D013739:Testosterone / Q000097:blood* / Q000172:deficiency
chemical_list: D013739:Testosterone