Impaired osmoregulation at high altitude. Studies on Mt Everest
Blume, F.D.; Boyer, S.J.; Braverman, L.E.; Cohen, A.; Dirkse, J.; Mordes, J.P.
JAMA 252(4): 524-526
1984
ISSN/ISBN: 0098-7484 PMID: 6429358 Document Number: 222212
Osmoregulation was studied in 13 mountaineers who had experienced long-term exposure to high altitude on Mt Everest. Serum osmolality increased from 290 +or- 1 to 295 +or- 2 mOsm/kg at 5400 m and finally to 302 +or- 4 mOsm/kg at 6300 m after a mean of 26.5 days above 5400 m. Despite that degree of osmoconcentration, plasma arginine-vasopressin concentration remained unchanged: 1.1 +or- 0.1 mu U/ml at sea level, 0.8 +or- 0.1 at 5400 m and 0.9 +or- 0.1 at 6300 m. Urinary vasopressin excretion was also similar at all 3 altitudes.