Water balance and acute mountain sickness before and after arrival
at high altitude: 4,350 m.
Westerterp, Klaas R, Paul Robach, Loek Wouters, and Jean-Paul
Richalet.
Department of Human Biology, University of Limburg, P.O. Box 616,
6200 MD Maastricht, The Netherlands, and Association pour la
Recherche en Physiologie de l'Environnement, F-93012 Bobigny Cedex,
France
APStracts 3:0073A, 1996.
The present study is a first attempt to measure water balance and its
components at altitude, using labeled water and bromide dilution, and
relating the results with acute mountain sickness (AMS). Water
intake, total water output and water output in urine and feces were
measured over a 4-day interval before and a subsequent 4-day interval
after transport to 4,350 m. Total body water and extracellular water
were measured at the start and at the end of the two intervals. There
was a close relationship between energy intake and water intake and
the relation was unchanged by the altitude intervention. Subjects
developing AMS reduced energy intake and water intake
correspondingly. The increase in TBW in subjects developing AMS was
accompanied by a reduction in total water loss. They did not show the
increased urine output, compensating for the reduced evaporative
water loss at altitude. Subjects showed a significant increase in TBW
after 4 days at altitude. Subjects with AMS showed the biggest shifts
in ECW relative to TBW. In conclusion, fluid retention in relation to
AMS is independent of a change in water requirements due to altitude
exposure. Subjects developing AMS were those showing a fluid shift of
at least 1 l from the intracellular to the extracellular compartment
or from the extracellular to the intracellular compartment.
Received 26 June 1995; accepted in final form 23 January 1996.
APS Manuscript Number A687-5.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 8 February 96