Effects of altitude acclimatization on blood composition of women

Abstract

The effects of altitude acclimatization on blood composition were studied in eight University of Missouri (elev 700 ft) coeds who lived on the summit of Pikes Peak (elev 14,000 ft) for 10 weeks. During the period of altitude exposure the following changes were observed: a transient increase in heart rate, the maximum being reached on 1st day of exposure; an early rapid increase in hematocrit and hemoglobin which later became more gradual; an early and sustained reduction in plasma volume; a rapid initial increase and a more gradual later increase in plasma protein concentration which was attributable to elevations in both the albumin and the globulin fractions; a sustained decrease in the albumin-to-globulin ratio; a slight but sustained increase in serum oncotic pressure; a slight but sustained decrease in blood water content and serum osmolarity; and finally, an unaltered total leukocyte count, but a significant increase in lymphocytes and significant decrease in monocytes. It is concluded that the hematopoietic response to altitude is markedly less in women than that usually observed in men. In women at least, dietary iron supplementation enhances the rate of hematocrit increase at altitude. And finally, the loss of plasma volume is felt to be real and not due to simple dehydration. high altitude; hypoxia; blood volume; blood hydration; plasma proteins; hematopoiesis; leukocytes; sex differences; iron supplement Submitted on April 3, 1968