Urine and plasma proteins in men at 5,400 m

Abstract

Urine and plasma proteins were measured before, during, and after ascent from 800 to 5,400 m altitude on Mount Logan, in completely unacclimatized men who had made the ascent by plane in 40 min, and in acclimatized individuals who had climbed up and had lived at 5,400 m for 6 weeks. Protein excretion rates were increased, and creatinine excretion and clearance rates decreased, with increases in plasma creatinine levels, in both groups at 5,400 m. These changes were similar and therefore independent of acclimatization and of polycythemia. There was no evidence, from clearances of proteins and of polyvinylpyrrolidone, of any change in glomerular sieving, and the character of the proteinuria was qualitatively normal. Increases in plasma protein occurred only in those in whom there was evidence of dehydration. In the unacclimatized, after abrupt ascent, transferrin levels were decreased, possibly as a means of enhancing iron supply to the developing red cells, but after acclimatization transferrin levels rose to above normal levels. hypoxia; altitude; proteinuria