Investigation of the differences between the Tibetan and Han populations in the hemoglobin–oxygen affinity of red blood cells and in the adaptation to high-altitude environments

ABSTRACTObjective: High altitude is characterized by low oxygen pressure, resulting in multiple adaptive responses. Tibetans who have lived in the plateau for thousands of years have developed unique phenotypes, such as downregulation of the HIF pathway through EPAS1 and EGLN1 gene mutation. However, the changes of hemoglobin–oxygen affinity under hypoxia environment remain elusive.Methods: A blood cell analyzer and a blood oxygen analyzer were used to conduct routine blood tests and measure the oxygen affinity P50 in in the Han population that rapidly entered the plateau (for 3–7 days), the plateau-acclimatized Han population (residing for 30 days on the plateau), the plateau Han population (more than 10 years on the plateau), and the Tibetan population.Results: The Han population that rapidly entered the plateau had increasing higher P50 values, RBCs counts and hemoglobin (HGB) levels, while the acclimatized Han population, the plateau Han population and Tibetan all had significantly lower P50 values. H...