Journal of Applied Physiology, Vol 80, Issue 4 1118-1125, Copyright © 1996 by American Physiological Society
Water turnover and body composition during long-term exposure to high altitude (4,900-7,600 m)
C. Fusch, W. Gfrorer, C. Koch, A. Thomas, A. Grunert and H. Moeller
Division of Neonatology, University Women's Hospital, Bern, Switzerland.
Thirteen healthy subjects (11 men and 2 women; 30.2 +/- 5.4 yr; 73.5 +/-
10.3 kg; 178.9 +/- 10.4 cm; body mass index, 22.9 +/- 1.6 kg/m2)
participated at the 62-day expedition to the Broad Peak (8,047 m),
Pakistan. Weight, body water, and water turnover (deuterium dilution and
elimination) were measured eight times to assess long-term changes. Body
weight fell during the ascent to the base camp [from 73.2 +/- 9.8
(baseline) to 71.7 +/- 9.7 kg; P < 0.05] and decreased until the end of
the base camp stay (66.7 +/- 7.2 kg; P < 0.0001). Body compartments
changed at different rates. Total body water decreased during the ascent
(from 43.1 +/- 7.3 to 41.0 +/- 7.7 liters; P < 0.05) and remained
unchanged until the base camp was reached (41.2 +/- 6.9 liters; P <
0.01) but decreased further during the base camp stay (40.6 +/- 5.2
liters). Water content of the body (total body water-to-body weight ratio)
fell during the ascent (from 58.6 +/- 3.4 to 55.8 +/- 4.4%; P < 0.01),
approached the baseline value during the base camp (57.4 +/- 4.0 and 58.3
+/- 5.1%), and increased again until the end of the base camp (60.6 +/- 3.4
and 60.9 +/- 4.3%). The compartment of the solids increased during the
ascent (from 30.2 +/- 3.4 to 32.2 +/- 4.9 kg; P < 0.01) and approached
the baseline value on arrival at the base camp (30.5 +/- 4.7 kg). Until the
end of the base camp, the compartment of the solids fell (26.9 +/- 2.6 and
26.1 +/- 4.0 kg), indicating that weight loss was due to a loss of body
solids, presumably mostly fat mass. Water turnover during the pretest
period (sea level) was 45 +/- 7 ml.kg-1.day-1; it increased during the
ascent (56 +/- 11 and 60 +/- 10 ml.kg-1.day-1) but remained constant during
the base camp stay (63 +/- 12, 58 +/- 9, and 56 +/- 10 ml.kg-1.day-1). It
increased during the ascent to Broad Peak (73 +/- 20 ml.kg-1.day-1; P <
0.05) and even more during the descent to civilization (83 +/- 17
ml.kg-1.day-1; P < 0.05).
