Variations of the sensitivity of the human body to a stable hypoxic stimulus

The individual, age-related, and professional variations of the sensitivity to a stable hypoxic stimulus have been studied in healthy male subjects. Hypoxia was induced using the method of rebreathing with modifications. An algorithm have been suggested for detecting the point when the oxygen saturation level of blood oxyhemoglobin started to decrease in comparison with the initial value upon gradual reduction of the gas in the inhaled air. We have found that age-related differences in the oxyhemoglobin saturation with oxygen under the conditions of hypoxia were nonsignificant in subjects at the ages from 21 to 50 years. At the same time, the average sensitivity to hypoxia in the subjects performing their professional duties in a modified atmosphere (hyperoxia) was lower than in those of the conventional professions.