title: Cardiac autonomic changes after 40 hours of total sleep deprivation in women.
abstract: OBJECTIVE
  The effect of total sleep deprivation on heart rate variability (HRV) in groups of postmenopausal women on oral hormone therapy (HT) (on-HT, n = 10, 64.2 (1.4) years), postmenopausal women without HT (off-HT, n = 10, 64.6 (1.4) years) and young women (n = 11, 23.1 (0.5) years) was studied using a prospective case-control setup.
  
  
  METHODS
  Polysomnography was performed over an adaptation night, a baseline night, and a recovery night after 40 h of total sleep deprivation. Time and frequency domain and nonlinear HRV from overnight electrocardiogram recordings were compared between groups during baseline and recovery nights. Further, the changes in HRV from baseline to recovery were analysed and compared between groups. Finally, correlations of HRV to percentages of sleep stages and measures of sleep fragmentation were analysed during baseline and recovery.
  
  
  RESULTS
  Young women had higher HRV than older women; the most marked difference was between young and on-HT postmenopausal women. Sleep deprivation induced a decrease in frequency domain HRV in young and in off-HT women, an increase in α2 in off-HT women, and an increase in mean heart rate in on-HT women. The sleep deprivation effect was mainly uncorrelated to changes in sleep parameters.
  
  
  CONCLUSIONS
  Acute total sleep deprivation has a deleterious effect on the autonomic nervous system in young women, but an even more pronounced effect in postmenopausal women. Hormone therapy use in late postmenopause does not give protection against these changes. These harmful effects may partly explain the increased cardiovascular morbidity and overall mortality associated with sleep loss.
authors: Department of Clinical Neurophysiology, TYKS-SAPA, Hospital District of Southwest Finland, Turku, Finland; Sleep Research Unit, Department of Physiology, University of Turku, Turku, Finland. Electronic address: irina.virtanen@tyks.fi.
authors: Irina
authors: I
authors: Virtanen
authors: Sleep Research Unit, Department of Physiology, University of Turku, Turku, Finland; Department of Cardiology, Turku University Hospital and University of Turku, Turku, Finland; Department of Cardiology, Satakunta Central Hospital, Pori, Finland.
authors: Nea
authors: N
authors: Kalleinen
authors: Department of Physiology, University of Helsinki, Helsinki, Finland; Department of Adolescent Psychiatry, Helsinki University Hospital, Helsinki, Finland; Department of Mental Health and Substance Abuse Services, National Institute for Health and Welfare, Helsinki, Finland.
authors: Anna S
authors: AS
authors: Urrila
authors: Department of Clinical Neurophysiology, TYKS-SAPA, Hospital District of Southwest Finland, Turku, Finland.
authors: Cecilia
authors: C
authors: Leppänen
authors: Sleep Research Unit, Department of Physiology, University of Turku, Turku, Finland; Department of Obstetrics and Gynecology, Turku University Hospital and University of Turku, Turku, Finland.
authors: Päivi
authors: P
authors: Polo-Kantola
mesh_terms: D000367:Age Factors; D001341:Autonomic Nervous System / Q000187:drug effects / Q000503:physiopathology*; D004562:Electrocardiography; D015914:Estrogen Replacement Therapy; D005260:Female; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D008593:Menopause / Q000502:physiology; D008875:Middle Aged; D017286:Polysomnography; D012892:Sleep Deprivation / Q000503:physiopathology*; D055815:Young Adult
keywords: Autonomic nervous system; Heart rate variability; Menopause; Sleep; Sleep deprivation; Women