title: Nocturnal cardiac autonomic profile in young primary insomniacs and good sleepers.
abstract: We investigated cardiac vagal and sympathetic activity in 13 young primary insomniacs (PI; 24.4±1.6years) and 14 good sleepers (GS; 23.3±2.5years) during nocturnal sleep. Pre-ejection period (PEP; inversely related to beta-adrenergic sympathetic activity), interval between consecutive R-waves (RR), and vagal-related indices of time- and frequency-domain heart rate variability were computed during pre-sleep wakefulness and undisturbed arousal-free sleep stages (N2, SWS, REM) as well as across the whole night irrespective of the presence of disruptive sleep events (e.g. sleep arousals/awakenings) and/or sleep stage transitions. Groups exhibited a similar vagal activity throughout each undisturbed sleep stage as well as considering the whole night, with a higher modulation during sleep compared to prior wakefulness. However, PEP was constantly shorter (higher sympathetic activity) during pre-sleep wakefulness and each sleep stage in PI compared to GS. Moreover, pre-sleep RR intervals were positively associated with sleep efficiency and negatively associated with wake after sleep onset in PI. Altogether our findings indicated a dysfunctional sympathetic activity but a normal parasympathetic modulation before and during sleep in young adults with insomnia.
authors.affiliation: Department of General Psychology, University of Padua, Italy; Center for Health Sciences, SRI International, Menlo Park, CA, USA. Electronic address: massimiliano.dezambotti@sri.com.
authors.forename: Massimiliano
authors.initials: M
authors.lastname: de Zambotti
authors.affiliation: Department of General Psychology, University of Padua, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Cellini
authors.affiliation: Center for Health Sciences, SRI International, Menlo Park, CA, USA; Brain Function Research Group, School of Physiology, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: Fiona C
authors.initials: FC
authors.lastname: Baker
authors.affiliation: Center for Health Sciences, SRI International, Menlo Park, CA, USA; Department of Psychology, University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Ian M
authors.initials: IM
authors.lastname: Colrain
authors.affiliation: Department of General Psychology, University of Padua, Italy.
authors.forename: Michela
authors.initials: M
authors.lastname: Sarlo
authors.affiliation: Department of General Psychology, University of Padua, Italy.
authors.forename: Luciano
authors.initials: L
authors.lastname: Stegagno
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001341:Autonomic Nervous System / Q000503:physiopathology*; D002307:Cardiography, Impedance; D004569:Electroencephalography; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D017286:Polysomnography; D007319:Sleep Initiation and Maintenance Disorders / Q000473:pathology* / Q000503:physiopathology*; D012894:Sleep Stages / Q000502:physiology*; D013997:Time Factors; D055815:Young Adult
keywords: Activity; Heart rate variability; Hyper-arousal; Impedance cardiography; Insomnia