Cognitive performance in high-altitude Andean residents compared with low-altitude populations: From childhood to older age.

Abstract

This is the first study of HA residence and neurocognition across the life span. Given the physiological challenges of HA living, the impact on cognition appears to be subtle and related only to the speed of more complex cognitive operations, rather than to their accuracy. Moreover, the impact on cognition does not appear to differ with increasing age or for different degrees of genetic admixture. Further studies recruiting HA participants with a broader range of native Andean ancestry will help to address the issue of to what extent Amerindian ancestry provides neuroprotection to chronic hypoxia in those living at HA.

Exaggerated systemic oxidative‐inflammatory‐nitrosative stress in chronic mountain sickness is associated with cognitive decline and depression

“…Researchers have suggested that the Andean model of HA living, defined by cerebral hypoperfusion and polycythaemia, is phenotypically maladaptive given that it carries a higher risk of stroke and migraine and is associated with increased morbidity and earlier mortality (Virues-Ortega et al 2009, Jansen & Basnyat, 2011. In support of this, Bolivians born and bred at the same altitude and location to that used in the present study exhibited slower psychomotor speed in attention and digit symbol coding tasks that persisted across the lifespan, reflecting a 'speed-accuracy' trade-off such that slower may be surer (Hill et al 2014). The present findings further extend the albeit limited literature identifying impairments in learning/memory and attention/information processing that were especially pronounced in CMS+.…”

“…In support of this, Bolivians born and bred at the same altitude and location to that used in the present study exhibited slower psychomotor speed in attention and digit symbol coding tasks that persisted across the lifespan, reflecting a ‘speed–accuracy’ trade‐off such that slower may be surer (Hill et al . ). The present findings further extend the albeit limited literature identifying impairments in learning/memory and attention/information processing that were especially pronounced in CMS+.…”

“…In the few studies published to date, cognitive function has been shown to be slightly impaired in well-adapted elderly Andean HA dwellers relative to sea-level-based lowlander controls (Yan et al 2011;Hill et al 2014;Davis et al 2015b). In contrast, albeit in the only study conducted to date, the authors observed an inverse relationship between altitude of residence and (age-adjusted) dementia mortality rate.…”

The Influence of Prolonged High Altitude Deployment on Psychomotor Functions Among Chinese Military Plateau Motor Vehicle Operators: Does Deployment Duration Matter?

“…However, in some other studies, cognitive and psychomotor impairments were not observed after 7-month or 1-year residence at HA [17,19]. Thus, there may be a strong adaptive process for the brain to compensate for oxygen delivery constraint, which can mask altitude related psychomotor impairments [18]. Further question is how much time the adaptation to HA need to outweigh the adverse effects and when the adaptation process cannot reverse the altitude related impairments.…”

“…But, another study showed that 7-month residence at moderate altitudes (2,260 m) of young adults from LA did not cause signi cant cognitive impairments [17]. Hill et al [18] observed slower psychomotor speed in digit symbol coding tasks and attention among native HA adolescents and younger adults than control group. But these altitude differences disappeared in the earlier or later life span between two groups.…”