title: Electroencephalogram and cardiovascular responses to noise during daytime sleep in shiftworkers.
abstract: Intermittent noise occurring during sleep has been found to induce heart rate, peripheral vasomotor and electroencephalogram (EEG) changes. This study analysed these responses during the daytime and night-time sleep of shiftworkers doing a three shift system, to determine the influence of the inversion of the sleep-wake cycle on the sensitivity to noise. A group of 14 shiftworkers [aged 37 (SD 5) years] underwent an habituation daytime sleep, two experimental daytime sleeps and a night-time sleep. Traffic noises were presented during sleep [truck, 71 dB(A); motorbike, 67 dB(A); and car, 64 dB(A)] at a rate of nine each hour. The EEG measurements of sleep, electrocardiogram and finger pulse amplitude were recorded continuously. The results were expressed by computing the percentage of observed cardiac response (%HRR) and vasoconstrictive response (%FPR), magnitude of heart rate variation (heart rate response; HRR), percentage of reduction of the digital blood flow (finger pulse response, FPR), cardiac cost (CC = % HRR x HRR) and vasomotor cost (VC = % FPR x FPR). The results showed that, compared to night-time sleep, there was change in the structure of daytime sleep, that is an increase in slow wave sleep (SWS), especially stage 4 sleep decrease of stage 2 and rapid eye movement (REM) sleep latencies, and an earlier SWS and REM sleep barycentric point. During daytime sleep the % FPR was significantly smaller in SWS than in stage 2 or REM sleep. Large differences were observed in % HRR, HRR and CC between daytime sleep stages (SWS less than stage 2 less than REM sleep).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Laboratoire de Physiologie et de Psychologie Environnementales, UMR 32, CNRS/INRS, Strasbourg, France.
authors.forename: A
authors.initials: A
authors.lastname: Nicolas
authors.forename: V
authors.initials: V
authors.lastname: Bach
authors.forename: P
authors.initials: P
authors.lastname: Tassi
authors.forename: G
authors.initials: G
authors.lastname: Dewasmes
authors.forename: J
authors.initials: J
authors.lastname: Ehrhart
authors.forename: A
authors.initials: A
authors.lastname: Muzet
authors.forename: J P
authors.initials: JP
authors.lastname: Libert
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology*; D002320:Cardiovascular Physiological Phenomena; D004569:Electroencephalography; D004651:Employment; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D009622:Noise; D012890:Sleep / Q000502:physiology*; D012894:Sleep Stages / Q000502:physiology; D013997:Time Factors