title: Cardiac autonomic impairment during sleep is linked with disease severity in Parkinson's disease.
abstract: OBJECTIVE
  Cardiac physiology during sleep in Parkinson's disease (PD) remains poorly explored. We studied heart rate variability (HRV) across sleep stages in PD patients and correlated the results with clinical features.
  
  
  METHODS
  Cross-sectional study comprising 33 patients with PD and 29 controls matched for age, gender, and number of apneas/hypopneas per hour. HRV measures, (mean R-R interval, SDNN, ULF, VLF, LF, HF and LF/HF) were calculated separately for all sleep stages as well as wakefulness just before and after sleep during one-night polysomnography. Correlation analysis was performed between HRV values and PD patients' characteristics.
  
  
  RESULTS
  The mean R-R interval was lower in all sleep stages in PD patients when compared with controls. VLF and LF were lower during REM sleep in PD patients. HF during N1-N2 stage was higher in PD. We found inverse correlations between VLF and LF during REM sleep and UPDRS-ON and UPDRS-OFF.
  
  
  CONCLUSIONS
  VLF and LF during REM sleep might constitute surrogate markers of disease severity.
  
  
  CONCLUSIONS
  These findings provide additional clinical evidence of the autonomic impairment commonly observed in PD, and prove that cardiac autonomic dysfunction during REM sleep is correlated with disease severity.
authors: Sleep Unit and Clinical Neurophysiology Section, University Clinic of Navarra, Pamplona, Spain. jpalmaca@unav.es
authors: Jose-Alberto
authors: JA
authors: Palma
authors: Elena
authors: E
authors: Urrestarazu
authors: Manuel
authors: M
authors: Alegre
authors: Maria A
authors: MA
authors: Pastor
authors: Miguel
authors: M
authors: Valencia
authors: Julio
authors: J
authors: Artieda
authors: Jorge
authors: J
authors: Iriarte
mesh_terms: D000368:Aged; D001342:Autonomic Nervous System Diseases / Q000209:etiology / Q000503:physiopathology*; D003430:Cross-Sectional Studies; D003627:Data Interpretation, Statistical; D005260:Female; D006331:Heart Diseases / Q000209:etiology / Q000503:physiopathology*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications / Q000503:physiopathology*; D017286:Polysomnography; D012044:Regression Analysis; D012890:Sleep / Q000502:physiology*; D012894:Sleep Stages / Q000502:physiology; D012895:Sleep, REM / Q000502:physiology; D014851:Wakefulness / Q000502:physiology