Abstract
BACKGROUND: High altitude (HA) environments expose individuals to chronic hypoxia, which can affect cognitive function. While studies have explored cognitive deficits in lowlanders ascending to HAs, there is limited research on cognitive function among natives of HA. PURPOSE: This study aimed to evaluate cognitive functions in the tribal population of Himachal Pradesh India using the Montreal Cognitive Assessment (MoCA) tool and assess the effect of high and very HAs along with age and gender variation in cognitive functions in these HA natives. METHODS: This study included 359 participants who lived at HAs. Cognitive function was assessed using MoCA. Participants were stratified by altitude (3,000-3,500 m and >3,500 m) and age group (20-40, 41-60 and >60 years). Appropriate statistical analyses were performed to determine the association of altitude, age, and sex with MoCA total and subscale scores. RESULTS: Significant associations were found between altitude and performance on the Naming, Attention, Delayed Recall, and Orientation subscales (p < .001, p < .001, p < .001 and p = .002, respectively). Specifically, a significant age-related decline was observed across the MoCA total score and most subscales (p < .001, Kendall's Tau = 0.48). Gender also had a significant association with the Visuospatial/Executive and Attention subscales (p < .001 for both), with males scoring higher than females. CONCLUSION: Increasing altitude was associated with lower scores on specific cognitive domains. Age is a primary factor influencing cognitive performance in high-altitude natives and is associated with lower MoCA scores. Gender differences were also observed in specific cognitive functions. These findings suggest that altitude, age, and sex play important roles in shaping the cognitive profiles of individuals living at HAs.