Effect of acetazolamide on visuomotor performance at altitude in healthy people older than 40 years: RCT

Abstract

<b>Introduction:</b> Hypoxia at high altitude may lead to cognitive impairment yet preventive therapy remains to be established, especially for older people. <b>Objective:</b> To investigate whether acetazolamide prevents altitude-induced impairment of visuomotor performance in people ≥40y. <b>Method:</b> In this randomized placebo-controlled parallel-design trial, 59 healthy lowlanders aged 40-75y were assigned to acetazolamide (375mg/d, n=34) or placebo (n=25), administered one day before ascent and while staying at high altitude (3100m). Visuomotor performance was assessed at 760m and 3100m after arrival and in the next morning by a computer-assisted test (Motor Task Manager). It quantified deviation of a participant-controlled cursor affected by rotation during target tracking. Primary outcome was post-sleep recall of adaptation to rotation. Additionally, adaptation, immediate recall and correct test execution were evaluated. <b>Results:</b> Compared to 760m, performance with placebo at 3100m was worse during adaptation and immediate recall as mean deviation increased by 1.9° (95%CI 0.3 to 3.5, p=0.024) and 1.1° (0.4 to 1.8, p=0.002). Post-sleep recall was unaffected (p=0.994) but correct test execution was 14% (9 to 19, p&lt;0.001) less likely. Acetazolamide improved post-sleep recall by 5.6° (2.6 to 8.6, p&lt;0.001) and post-sleep probability of correct test execution by 36% (30 to 42, p&lt;0.001) compared to placebo. <b>Conclusion:</b> In healthy individuals older than 40 years, altitude impaired adaptation, immediate recall, and correct execution of a visuomotor task. Preventive acetazolamide treatment improved visuomotor performance after sleep at altitude and increased the probability of correct test execution.