Rapid intravenous glucose tolerance tests have been performed in women living at high altitude in an environment of chronic hypoxia (average values: barometric pressure 445 mm. Hg, alveolar p02 46.0 mm. Hg, arterial p02 45.1 mm. Hg). The hypoxic group had a curve of the same shape but with lower values when compared with that of women born and living at sea level.
At sea level pregnancy modified the curve obtained when compared with that of nonpregnant women, but at high altitude pregnancy did not modify the curve. As a possible explanation a higher basal level of insulin in the high altitude group is suggested.