title: [Chemoreflexsensitivity is reduced in obstructive sleep apnea and might be modulated by the autonomic system].
abstract: BACKGROUND
  Chemoreflexes are important mechanisms for regulating ventilatory and cardiovascular function, which are supposed to be influenced in obstructive sleep apnea (OSA).
  
  
  METHODS
  For determination of chemoreflexsensitivity (CHRS) the ratio of the RR-interval shift in the surface ECG during 5 min inhalation of oxygen via a nose mask was formed in 15 patients with suspected OSA. Noradrenaline plasma concentrations were measured and were correlated to CHRS.
  
  
  RESULTS
  Patients with OSA showed a reduced CHRS. CHRS was correlated to the severity of sleep apnea (respiratory disturbance index [RDI]; r = -0.622; p = 0.013), and to minimal nocturnal oxygen saturation (r = 0.594; p = 0.032). Reduced CHRS was associated with higher noradrenaline concentrations (r = -0.542; p = 0.037).
  
  
  CONCLUSIONS
  CHRS is reduced in patients with OSA and correlates with the severity of OSA. Further on, CHRS might be modulated by the autonomic system. Therefore, the determination of CHRS enables to estimate sympathetic activation in these patients.
authors.affiliation: Klinik für Kardiologie, Pneumologie und Angiologie, Universitätsklinikum Düsseldorf. steinest@uni-duesseldorf.de
authors.forename: Stephan
authors.initials: S
authors.lastname: Steiner
authors.forename: Marcus G
authors.initials: MG
authors.lastname: Hennersdorf
authors.forename: Bodo E
authors.initials: BE
authors.lastname: Strauer
mesh_terms: D000328:Adult; D000368:Aged; D001341:Autonomic Nervous System / Q000503:physiopathology; D002628:Chemoreceptor Cells / Q000503:physiopathology*; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000097:blood; D010100:Oxygen / Q000097:blood; D012018:Reflex / Q000502:physiology*; D012680:Sensitivity and Specificity; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis / Q000503:physiopathology*; D013223:Statistics as Topic
chemical_list: D010100:Oxygen; D009638:Norepinephrine