Effects of hypoxia on inhibitory control in high-altitude sedentary males: ameliorative effects and mechanisms of hyperbaric oxygen intervention
Authors: Li Hao , Wang Meiyi , Zhu Yunpeng , Ren Hong , shi Linyu , Ma Hailin 
Published: April 2024

Abstract

Background: Enhanced inhibitory control is crucial for optimal performance in both academic and occupational settings. Current research indicates that exposure to high-altitude hypoxia has a detrimental impact on the ability to exercise inhibitory control among high-altitude migrant populations. However, it remains unclear whether hypoxia affects the inhibitory control ability of sedentary individuals who have been residing in high-altitude environments for generations and how to effectively intervene in such cases.
Objective: To investigate whether the inhibitory control of high-altitude population, specifically Tibetans, is still impacted by hypoxia exposure, and to explore the ameliorating effects and mechanisms of hyperbaric oxygen(HBO) intervention on this phenomenon.
Methods: This study employed the Flanker task to assess inhibitory control ability and was comprised of three studies. In Study 1, firstly, 248 young Tibetan males (M=23.710, SD=1.942) were divided into non-hypoxic and hypoxic groups according to their SaO2 levels, and a one-way between-subjects design was used to examine the differences in inhibitory control between these two groups; secondly, a 2 (group: non-hypoxia group, hypoxia group) × 2 (temperature: high, low) mixed experimental design was used to investigate the potential explanatory role of reduced temperature in hypoxia for subsequent studies. In Study 2, a sample of 406 young Tibetan males (M=24.483, SD=1.581) was recruited to examine the mediating theoretical model of hypoxia’s impact on inhibitory control ability among high-altitude residents through the renal physiological pathway. Study 3 involved a sample of 60 Tibetan young males, aged between 22 and 27 years (M=24.448 years old, SD=1.612), who were randomly assigned into two groups for a controlled study. The experimental group underwent 10 60-minute sessions of hyperbaric oxygen intervention, while the control group received no intervention. Additionally, the moderating effect of glomerular filtration rate (GFR) on executive function improvement through HBO was examined.
Results: The result of study 1 indicated that the correct rate in the non-hypoxic group was significantly higher than that in the hypoxic group for both Flanker consistent (p < 0.001) and inconsistent condition (p < 0.001). Reduced temperature resulted in decreased SaO2 levels in both groups, indicating relative hypoxia (p< 0.001). The findings of study 2 demonstrated that hypoxia has a detrimental effect on inhibitory control ability among high-altitude residents by reducing the GFR(p < 0.001, 95% CI [0.06, 0.13]). The findings from Study 3 revealed that following ten sessions of oxygen intervention, the hyperbaric group exhibited a significantly higher accuracy rate than the control group in both Flanker consistent (p < 0.05) and inconsistent conditions (p < 0.01). For individuals with low GFR, executive function showed a significant upward trend with increasingoxygen intervention time (simple slope =1.372, t = 15.810, p= 0.001).
Conclusion: Tibetan sedentary populations are also vulnerable to the effects of hypoxia, resulting in a decline in inhibitory control ability. However, HBO can enhance their inhibitory control ability, particularly providing protective benefits for highland residents with low GFR.