Fig. 5.
Increased affinity of hemoglobin for oxygen in high-altitude samples, relative to hypothetical subjects derived from the standard oxygen dissociation curve (ODC). The ODC is mathematically derived from the Hill’s equation, with a P50 of 26.8 mmHg and the Hill coefficient of 1.3922 × 10−4 mmHg-2.7 (6). The depicted values of alveolar oxygen partial pressure in Amhara and Oromo are estimated based on the assumption of 47 mmHg water vapor pressure, 40 mmHg arterial partial pressure of carbon dioxide, and 0.8 respiratory exchange ratio (24).