Abstract
Background: Age-related declines in free and bioavailable testosterone are frequently reported for Western populations, but interpopulation variation in this pattern has not previously been investigated. Methods: Salivary testosterone was measured using a consistently applied protocol on morning samples collected from men in four populations (USA, Congo, Nepal, and Paraguay) representing different geographical, ecological, and cultural settings. Results: Mean testosterone levels varied significantly between the four populations. The mean testosterone differences between populations were greatest for young men (aged 15-30 years) and insignificant for older men (aged 45-60 years). The slope of age-related decline in testosterone was significant in the USA and Congolese participants, but not in the Nepalese or Paraguayan participants. Conclusions: Age patterns of testosterone decline vary between populations primarily as a result of variation in the peak levels attained in young adulthood. The potential consequences of this variation for other aspects of male health deserve investigation.
Original language | English (US) |
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Pages (from-to) | 3251-3253 |
Number of pages | 3 |
Journal | Human Reproduction |
Volume | 17 |
Issue number | 12 |
State | Published - Dec 1 2002 |
Externally published | Yes |
Keywords
- Ageing
- Population variation
- Salivary testosterone
- Testosterone
ASJC Scopus subject areas
- Reproductive Medicine
- Obstetrics and Gynecology