title: Attenuated heart rate response is associated with hypocretin deficiency in patients with narcolepsy.
abstract: OBJECTIVE
  Several studies have suggested that hypocretin-1 may influence the cerebral control of the cardiovascular system. We analyzed whether hypocretin-1 deficiency in narcolepsy patients may result in a reduced heart rate response.
  
  
  METHODS
  We analyzed the heart rate response during various sleep stages from a 1-night polysomnography in patients with narcolepsy and healthy controls. The narcolepsy group was subdivided by the presence of +/- cataplexy and +/- hypocretin-1 deficiency.
  
  
  METHODS
  Sleep laboratory studies conducted from 2001-2011.
  
  
  METHODS
  In total 67 narcolepsy patients and 22 control subjects were included in the study. Cataplexy was present in 46 patients and hypocretin-1 deficiency in 38 patients.
  
  
  METHODS
  None.
  
  
  RESULTS
  All patients with narcolepsy had a significantly reduced heart rate response associated with arousals and leg movements (P < 0.05). Heart rate response associated with arousals was significantly lower in the hypocretin-1 deficiency and cataplexy groups compared with patients with normal hypocretin-1 levels (P < 0.04) and patients without cataplexy (P < 0.04). Only hypocretin-1 deficiency significantly predicted the heart rate response associated with arousals in both REM and non-REM in a multivariate linear regression.
  
  
  CONCLUSIONS
  Our results show that autonomic dysfunction is part of the narcoleptic phenotype, and that hypocretin-1 deficiency is the primary predictor of this dysfunction. This finding suggests that the hypocretin system participates in the modulation of cardiovascular function at rest.
authors.affiliation: Danish Center for Sleep Medicine, Glostrup University Hospital, Glostrup Hospital, Denmark. gertrud_l@yahoo.dk
authors.forename: Gertrud Laura
authors.initials: GL
authors.lastname: Sorensen
authors.forename: Stine
authors.initials: S
authors.lastname: Knudsen
authors.forename: Eva Rosa
authors.initials: ER
authors.lastname: Petersen
authors.forename: Jacob
authors.initials: J
authors.lastname: Kempfner
authors.forename: Steen
authors.initials: S
authors.lastname: Gammeltoft
authors.forename: Helge Bjarup Dissing
authors.initials: HB
authors.lastname: Sorensen
authors.forename: Poul
authors.initials: P
authors.lastname: Jennum
mesh_terms: D000328:Adult; D001143:Arousal; D001341:Autonomic Nervous System / Q000503:physiopathology*; D005260:Female; D006339:Heart Rate; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000172:deficiency*; D008297:Male; D009290:Narcolepsy / Q000175:diagnosis / Q000503:physiopathology*; D009479:Neuropeptides / Q000172:deficiency*; D000068797:Orexins; D017286:Polysomnography / Q000379:methods; D012894:Sleep Stages
chemical_list: C000596229:HCRT protein, human; D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D000068797:Orexins