The effect of zolpidem on cognitive function and postural control at high altitude. Issue 10 (7th August 2018)

• Record Type: Journal Article
• Authors: Bouzat, Pierre; Séchaud, Guillaume; Banco, Pierre; Davranche, Karen; Casini, Laurence; Baillieul, Sébastien; Manhes, Pauline; Botrè, Fancesco; Mazzarino, Monica; De la Torre, Xavier; Robach, Paul; Verges, Samuel
• Is Part Of: Sleep. Volume 41:Issue 10(2018)
• Publication Date: 2018-08-07
• Subjects: hypoxia -- altitude -- sleep -- cognition -- hypnotics; Sleep -- Physiological aspects -- Periodicals; Sleep disorders -- Periodicals; Sommeil -- Aspect physiologique -- Périodiques; Sommeil, Troubles du -- Périodiques; Sleep disorders; Sleep -- Physiological aspects; Sleep -- physiological aspects; Sleep Wake Disorders; Psychophysiology; Electronic journals; Periodicals; 616.8498
• DOI: 10.1093/sleep/zsy153
• Languages: English
• ISSNs: 0161-8105

Abstract

Abstract: Study Objectives: Sleep is altered at high altitude leading many mountaineers to use hypnotics in order to improve sleep efficiency. While after a full night at altitude the short-acting hypnotic zolpidem does not appear to alter cognitive function, residual adverse effects should be considered following early waking-up as performed by mountaineers. We hypothesized that zolpidem intake at high altitude would alter cognitive function 4 hours after drug intake. Methods: In a randomized double-blind controlled cross-over study, 22 participants were evaluated during two nights at sea level and two nights at 3800 m, 4 hours after zolpidem (10 mg) or placebo intake at 10:00 pm. Polygraphic recording was performed until waking-up at 01:30 am. Sleep quality, sleepiness and symptoms of acute mountain sickness were assessed by questionnaires. Two cognitive tasks (Simon task and duration-production task) were performed at rest and during exercise and postural control was evaluated. Results: Zolpidem increased reaction time in all conditions (zolpidem 407 ± 9 ms vs. placebo 380 ± 11 ms; p < 0.001) and error rate in incongruent trials only (10.2 ± 1.1% vs. 7.8 ± 0.8%; p < 0.01) in the Simon task and increased time perception variability ( p < 0.001). Zolpidem also altered postural parameters (e.g. center of pressure area, zolpidem 236 ± 171.5 mm 2 vs. placebo 119.6 ± 59 mm 2 ; p < 0.001). Zolpidem did not affect apnea-hypopnea index and mean arterial oxygen saturation ( p > 0.05) but increased sleep quality ( p < 0.001). Zolpidem increased symptoms of acute mountain sickness and sleepiness ( p < 0.05). Conclusions: Acute zolpidem intake at high altitude alters cognitive functions and postural control during early wakening which may be deleterious for safety and performances of climbers.