title: Nocturnal snoring decreases daytime baroreceptor sensitivity.
abstract: BACKGROUND
  In patients with obstructive sleep apnea heart rate variability and baroreceptor sensitivity during night and daytime are impaired. Snoring without obstructive sleep apnea may already influence heart rate variability and baroreceptor sensitivity during daytime.
  
  
  METHODS
  Cardiovascular daytime testing was performed in 11 snorers and age, BMI, and gender matched controls. Sleep apnea and snoring were quantified by sleep recordings. Paced breathing was performed during daytime with ECG, non-invasive blood pressure, and respiration recorded. Heart rate variability and blood pressure variability were analyzed in the time and frequency domain. Baroreceptor sensitivity (alpha gain) was calculated.
  
  
  RESULTS
  In snorers a significant increase in high frequency systolic blood pressure variability (SBPV-HF) compared to control group (0.37 mm Hg(2) vs. 0.11 mm Hg(2) for 12 breaths and 0.35 mm Hg(2) vs. 0.10 mm Hg(2) for 15 breaths) was demonstrated. Furthermore a lower baroreceptor sensitivity was found in snorers compared to controls (9.2 ms/mm Hg vs. 16.2 ms/mm Hg for 12 breaths and 8.5 ms/mm Hg vs. 17.4 ms/mm Hg for 15 breaths per minute) using the paced breathing protocol. Mean heart rate was elevated in snorers as well.
  
  
  CONCLUSIONS
  Snorers may have a reduced parasympathetic tone during daytime rather than an increased sympathetic tone.
authors.affiliation: Sleep Medicine Center, Charité Universitätsmedizin Berlin, Berlin, Germany; Center for Cardiology and Angiology, Charité Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Schöbel
authors.affiliation: Sleep Medicine Center, Charité Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Ingo
authors.initials: I
authors.lastname: Fietze
authors.affiliation: Sleep Medicine Center, Charité Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Glos
authors.affiliation: Sleep Medicine Center, Charité Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Inett
authors.initials: I
authors.lastname: Schary
authors.affiliation: Sleep Medicine Center, Charité Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Blau
authors.affiliation: Center for Cardiology and Angiology, Charité Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Gert
authors.initials: G
authors.lastname: Baumann
authors.affiliation: Sleep Medicine Center, Charité Universitätsmedizin Berlin, Berlin, Germany. Electronic address: thomas.penzel@charite.de.
authors.forename: Thomas
authors.initials: T
authors.lastname: Penzel
mesh_terms: D000328:Adult; D001341:Autonomic Nervous System / Q000503:physiopathology; D001794:Blood Pressure / Q000502:physiology; D015992:Body Mass Index; D016022:Case-Control Studies; D057906:Circadian Clocks / Q000502:physiology; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography / Q000379:methods; D011311:Pressoreceptors / Q000502:physiology*; D012891:Sleep Apnea Syndromes / Q000503:physiopathology; D012913:Snoring / Q000503:physiopathology*
keywords: Baroreceptor sensitivity; Cardiovascular risk; Heart rate variability; Sleep disordered breathing; Snoring