Individual factors affecting oxygen saturation under acute hypoxia exposure in air personnel

During flight, cabin pressure failure or oxygen system malfunction may lead to an oxygen-deprived environment, which could lead to a physiological state of hypoxia. Personal tolerance will determine cognitive performance level under these conditions. The aim of this study was to examine the influence of different parameters on hypoxia tolerance. As cognitive function was previously found to be associated with oxygen saturation levels (SatO₂), hypoxia tolerance was assessed using this method. A linear mixed models analysis revealed a significant correlation between decreased SatO₂ and BMI, hemoglobin levels, smoking, FEV1/FVC ratio, and age. In a further analysis, higher SatO₂ levels were significantly and independently associated in smokers (p = 0.012) and trainees with BMI above 27.7 kg/m² (p = 0.025 to 0.032). Moreover, non-smoking trainees with hemoglobin value above 15.9 g/dL (p = 0.016), and non-smoking trainees with FEV1/FVC ratio below 0.78 (p = 0.040 to 0.049) were correlated with significantly higher SatO₂. In this analysis, age, sex, and physical activity were not found to be correlated with SatO₂. Higher SatO₂ levels are correlated with higher hypoxia tolerance, hence the aforementioned parameters increase hypoxia tolerance. It is recommended to take these parameters into consideration during dedicated hypoxia trainings.