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Asian J Androl. 2013 May;15(3):368-74. doi: 10.1038/aja.2012.170. Epub 2013 Mar 25.

Serum testosterone levels and excessive erythrocytosis during the process of adaptation to high altitudes.

Author information

1
High Altitude Research Institute and Department of Biological and Physiological Sciences, Faculty of Sciences and Philosophy, Universidad Peruana Cayetano Heredia, Lima 31, Peru. gustavo.gonzales@upch.pe

Abstract

Populations living at high altitudes (HAs), particularly in the Peruvian Andes, are characterized by a mixture of subjects with erythrocytosis (16 g dl(-1)<haemoglobin (Hb)≤21 g dl(-1)) and others with excessive erythrocytosis (EE) (Hb>21 g dl(-1)). Elevated haemoglobin values (EE) are associated with chronic mountain sickness, a condition reflecting the lack of adaptation to HA. According to current data, native men from regions of HA are not adequately adapted to live at such altitudes if they have elevated serum testosterone levels. This seems to be due to an increased conversion of dehydroepiandrosterone sulphate (DHEAS) to testosterone. Men with erythrocytosis at HAs show higher serum androstenedione levels and a lower testosterone/androstenedione ratio than men with EE, suggesting reduced 17beta-hydroxysteroid dehydrogenase (17beta-HSD) activity. Lower 17beta-HSD activity via Δ4-steroid production in men with erythrocytosis at HA may protect against elevated serum testosterone levels, thus preventing EE. The higher conversion of DHEAS to testosterone in subjects with EE indicates increased 17beta-HSD activity via the Δ5-pathway. Currently, there are various situations in which people live (human biodiversity) with low or high haemoglobin levels at HA. Antiquity could be an important adaptation component for life at HA, and testosterone seems to participate in this process.

PMID:
23524530
PMCID:
PMC3752551
DOI:
10.1038/aja.2012.170
[Indexed for MEDLINE]
Free PMC Article

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