title: Progressive aging does not alter the interaction between autonomic cardiac activity and delta EEG power.
abstract: OBJECTIVE
  We tested the hypothesis that the reductions of the changes in the respective influence of the cardiac sympathetic and vagal activity control and delta EEG activity with aging alter the interactions between the heart rate variability (HRV) and the delta sleep EEG power band.
  
  
  METHODS
  A polysomnography was performed on 16 healthy young men and 19 healthy middle-aged men across the first 3 NREM-REM cycles. Spectral analysis was applied to electrocardiogram and electroencephalogram recordings. High Frequency (HF(nu)) of HRV as well as the maximum of cross-spectrum, coherency, gain and phase shifts between HF(nu) and delta sleep EEG power band were compared between both groups.
  
  
  RESULTS
  Young men experienced more deep sleep than middle-aged men (P<0.001). In middle-aged subjects, HF(nu) was lower than the HF(nu) of their younger counterparts (P<0.001), but they showed similar increases during NREM sleep and similar decreases during REM sleep as the young subjects. Cross-spectrum values, coherency, gain and phase shifts between HF(nu) and delta were identical between the two groups. Modifications in HF(nu) show parallel changes and precede changes in delta EEG band by a similar leads of 11+/-6min in young men and 9+/-7 min in middle-aged men (P=0.23).
  
  
  CONCLUSIONS
  Reduced changes in the respective influence of the cardiac sympathetic and vagal activity and delta EEG activity with progressive aging do not alter the relationship and phase difference between changes in the relative predominant cardiac vagal activity and delta power in middle-aged men.
  
  
  CONCLUSIONS
  Interaction between the cardiac sympathetic and vagal activity with delta EEG activity is maintained in middle-aged men.
authors.affiliation: Sleep Laboratory, Department of Psychiatry, Erasme Hospital, Université Libre de Bruxelles, route de Lennik, 808 Brussels 1070, Belgium. fajuryst@ulb.ac.be
authors.forename: F
authors.initials: F
authors.lastname: Jurysta
authors.forename: P
authors.initials: P
authors.lastname: van de Borne
authors.forename: J-P
authors.initials: JP
authors.lastname: Lanquart
authors.forename: P-F
authors.initials: PF
authors.lastname: Migeotte
authors.forename: J-P
authors.initials: JP
authors.lastname: Degaute
authors.forename: M
authors.initials: M
authors.lastname: Dumont
authors.forename: P
authors.initials: P
authors.lastname: Linkowski
mesh_terms: D000293:Adolescent; D000328:Adult; D000375:Aging / Q000502:physiology*; D017776:Autonomic Pathways / Q000502:physiology; D003700:Delta Rhythm / Q000379:methods*; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012894:Sleep Stages / Q000502:physiology*