title: Alcohol has a dose-related effect on parasympathetic nerve activity during sleep.
abstract: BACKGROUND
  The aim of this study was to identify the acute effects of ethanol on the relationship between sleep and heart rate variability (HRV) during sleep.
  
  
  METHODS
  Ten healthy male university students were enrolled in this study. An alcoholic beverage was given to each subject at a dosage of 0 (control), 0.5 (low dose: LD), or 1.0 g (high dose: HD) of pure ethanol/kg of body weight. All experiments were performed at 3-week intervals. On the day of the experiment, a Holter electrocardiogram was attached to the subject for a 24-hour period, and the subject was instructed to drink the above-described dosage of alcoholic beverage 100 minutes before going to bed; polysomnography was then performed for 8 hours. Power spectral analysis of the HRV was performed using the maximum entropy method, and the low- (LF: 0.04 to 0.15 Hz) and high-frequency (HF: 0.15 to 0.4 Hz) components along with LF/HF ratio were calculated.
  
  
  RESULTS
  As alcohol consumption increased, the heart rate increased and the spectral power of HRV measured at each frequency range decreased. Higher doses of ethanol also increased the LF/HF ratio compared with the measured ratio of the control group.
  
  
  CONCLUSIONS
  Acute ethanol intake inhibits parasympathetic nerve activity and results in predominance of sympathetic nerve activity during sleep, in a dosage-dependent manner. The results of this study suggest that ethanol interferes with the restorative functions of sleep.
authors.affiliation: Department of Neuropsychiatry, Akita University, School of Medicine, Akita, Japan. sagawa@psy.med.akita-u.ac.jp
authors.forename: Yohei
authors.initials: Y
authors.lastname: Sagawa
authors.forename: Hideaki
authors.initials: H
authors.lastname: Kondo
authors.forename: Namiko
authors.initials: N
authors.lastname: Matsubuchi
authors.forename: Takaubu
authors.initials: T
authors.lastname: Takemura
authors.forename: Hironobu
authors.initials: H
authors.lastname: Kanayama
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Kaneko
authors.forename: Takashi
authors.initials: T
authors.lastname: Kanbayashi
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Hishikawa
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Shimizu
mesh_terms: D004305:Dose-Response Relationship, Drug; D015716:Electrocardiography, Ambulatory; D000431:Ethanol / Q000494:pharmacology*; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006801:Humans; D008297:Male; D010275:Parasympathetic Nervous System / Q000187:drug effects* / Q000502:physiology*; D017286:Polysomnography; D012890:Sleep / Q000187:drug effects* / Q000502:physiology*; D013997:Time Factors; D055815:Young Adult
chemical_list: D000431:Ethanol