title: Increased sympathetic and decreased parasympathetic cardiac tone in patients with sleep related alveolar hypoventilation.
abstract: OBJECTIVE
  To assess autonomic function by heart rate variability (HRV) during sleep in patients with sleep related alveolar hypoventilation (SRAH) and to compare it with that of patients with obstructive sleep apnea (OSA) and control patients.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Sleep Unit, University Hospital of University of Navarra.
  
  
  METHODS
  Fifteen idiopathic and obesity related-SRAH patients were studied. For each patient with SRAH, a patient with OSA, matched in age, sex, body mass index (BMI), minimal oxygen saturation (SatO2), and mean SatO2 was selected. Control patients were also matched in age, sex, and BMI with patients with OSA and those with SRAH, and in apnea/hypopnea index (AHI) with patients with SRAH.
  
  
  METHODS
  N/A.
  
  
  RESULTS
  Time- and frequency-domain HRV measures (R-R, standard deviation of normal-to-normal RR interval [SDNN], very low frequency [VLF], low frequency [LF], high frequency [HF], LF/HF ratio) were calculated across all sleep stages as well as during wakefulness just before and after sleep during a 1-night polysomnography. In patients with SRAH and OSA, LF was increased during rapid eye movement (REM) when compared with control patients, whereas HF was decreased during REM and N1-N2 sleep stages. The LF/HF ratio was equally increased in patients with SRAH and OSA during REM and N1-N2. Correlation analysis showed that LF and HF values during REM sleep were correlated with minimal SatO2 and mean SatO2.
  
  
  CONCLUSIONS
  Patients with SRAH exhibited an abnormal cardiac tone during sleep. This fact appears to be related to the severity of nocturnal oxygen desaturation. Moreover, there were no differences between OSA and SRAH, supporting the hypothesis that autonomic changes in OSA are primarily related to a reduced nocturnal oxygen saturation, rather than a consequence of other factors such as nocturnal respiratory events.
authors.affiliation: Sleep Unit and Clinical Neurophysiology Section, University Clinic of Navarra, Pamplona, Spain.
authors.forename: Jose-Alberto
authors.initials: JA
authors.lastname: Palma
authors.forename: Elena
authors.initials: E
authors.lastname: Urrestarazu
authors.forename: Jon
authors.initials: J
authors.lastname: Lopez-Azcarate
authors.forename: Manuel
authors.initials: M
authors.lastname: Alegre
authors.forename: Secundino
authors.initials: S
authors.lastname: Fernandez
authors.forename: Julio
authors.initials: J
authors.lastname: Artieda
authors.forename: Jorge
authors.initials: J
authors.lastname: Iriarte
mesh_terms: D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D006321:Heart / Q000294:innervation / Q000502:physiology / Q000503:physiopathology; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010275:Parasympathetic Nervous System / Q000502:physiology / Q000503:physiopathology; D017286:Polysomnography; D012890:Sleep / Q000502:physiology; D020182:Sleep Apnea, Central / Q000503:physiopathology*; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology; D013564:Sympathetic Nervous System / Q000502:physiology / Q000503:physiopathology
keywords: Autonomic nervous system; heart rate variability; hypoxia; obesity hypoventilation syndrome; sleep apnea; sleep disordered breathing