Introduction:

EPO is a glycosylated alpha globulin produced in more than 90% by kidneys through adult life, being a key hormone that regulated the erythrocytic mass. However, there are some modifications in the levels of this hormone that may be related to smoking, anemia, EPOC and migration to from low to higher altitudes, inducing hypoxic processes. Depending on the individual, it may produced the disease named as acute mountain sickness.

Objective:

To describe erythropoietin level modifications, reticulocytes count and its influence, on the adaptive process to altitude.

Methodology:

This is a transversal descriptive study including 11 participants from low altitudes places, whose EPO serum concentration and reticulocytes count was determined during 28 days.

Results:

Eight participants presented a progressive increase in EPO serum levels, one participant exhibited a constant level and two more showed atypical results according to previous literature.

Conclusion:

EPO is a key factor for determining the erythropoiesis beginning, as its objective is to improve the oxygen provision during altitude adaptation processes by increasing its concentration in blood due to hypoxic stimulus. Besides, hypoxia is a determinant factor in the beginning and development of acute mountain sickness. The reticulocytes count depends also on the EPO proliferative and anti-apoptotic stimulus, and on the serum concentrations of B12 vitamin, iron and folic acid.