Sleep spindle characteristics and arousability from nighttime transportation noise exposure in healthy young and older individuals. Issue 7 (25th April 2018)

• Record Type: Journal Article
• Authors: Rudzik, Franziska; Thiesse, Laurie; Pieren, Reto; Wunderli, Jean Marc; Brink, Mark; Foraster, Maria; Héritier, Harris; Eze, Ikenna C; Garbazza, Corrado; Vienneau, Danielle; Probst-Hensch, Nicole; Röösli, Martin; Cajochen, Christian
• Is Part Of: Sleep. Volume 41:Issue 7(2018)
• Publication Date: 2018-04-25
• Subjects: road traffic noise -- railway noise -- arousal -- awakening -- EEG -- automatic detection -- intermittency ratio; 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/zsy077
• Languages: English
• ISSNs: 0161-8105

Abstract

Abstract: Study Objectives: Nighttime transportation noise elicits awakenings, sleep-stage changes, and electroencephalographic (EEG) arousals. Here, we investigated the potential sleep-protective role of sleep spindles on noise-induced sleep alterations. Methods: Twenty-six young (19–33 years, 12 women) and 18 older (52–70 years, 9 women) healthy volunteers underwent a repeated measures polysomnographic 6-day laboratory study. Participants spent one noise-free baseline night, followed by four transportation noise-exposure nights (road traffic or railway noise; continuous or intermittent: average sound levels of 45 dB, maximum sound levels of 50–62 dB), and one noise-free recovery night. Sleep stages were scored manually and fast sleep spindle characteristics were quantified automatically using an individual band-pass filtering approach. Results: Nighttime exposure to transportation noise significantly increased sleep EEG arousal indices. Sleep structure and continuity were not differentially affected by noise exposure in individuals with a low versus a high spindle rate. Spindle rates showed an age-related decline along with more noise-induced sleep alterations. All-night spindle rates did not predict EEG arousal or awakening probability from single railway noise events. Spindle characteristics were affected in noise-exposure nights compared to noise-free nights: we observed a reduction of the spindle amplitude in both age groups and of the spindle rate in the older group. Conclusions: We have evidence that spindle rate is more likely to represent a trait phenomenon, which does not seem to play a sleep-protective role in nighttime transportation noise-induced sleep disruptions. However, the marked reduction in spindle amplitude is most likely a sensitive index for noise-induced sleep alterations.