High serum uric acid levels explains the negative impact of the altitude adaptation index on the brain electroencephalographic Microstate D under high-altitude hypoxic conditions

Objective To explore the mediating role of serum uric acid (SUA) in the relationship between the acclimatization/adaptation index (AAI) and the transition probability of electroencephalographic (EEG) Microstate D within cognitive control networks under hypoxic conditions at 3,650 m. Methods A total of 173 high-altitude residents in Lhasa were recruited. Their peripheral oxygen saturation (SpO₂), hematocrit (HCT), and SUA levels were measured, and resting-state EEG data were recorded. AAI was calculated, and the transition probability of Microstate D was analyzed. Correlation analyses and bootstrap methods were employed to examine the mediating effect of SUA. Results AAI was significantly negatively correlated with SUA, and the maladaptive group exhibited significantly higher SUA levels. SUA mediated the relationship between AAI and the outward transition probabilities from Microstate D to Microstates A and C, but no significant mediating effect was found for inward transition probabilities. Conclusion Under high-altitude hypoxic environments, SUA serves as a key mediator through which AAI modulates the outward transitions of Microstate D. Regulating SUA levels and enhancing AAI may play a crucial role in preserving cognitive control network function in high-altitude populations.