title: Mild obstructive sleep apnea does not modulate baroreflex sensitivity in adult patients.
abstract: BACKGROUND
  Obstructive sleep apnea (OSA) is a chronic and progressive disease. OSA is associated with increased cardiovascular morbidity and mortality, the risk being more frequently encountered with severe degrees of OSA. Increased sympathetic activation and impaired cardiac autonomic control as reflected by depressed baroreceptor reflex sensitivity (BRS) are possible mechanisms involved in the cardiovascular complications of OSA. However, it is not known at what stage of OSA that changes in BRS appear. The aim of this study was to evaluate BRS in patients with mild OSA.
  
  
  METHODS
  The study population consisted of 81 overweight patients with mild OSA and 46 body weight-matched non-OSA subjects. BRS, apnea-hypopnea index, body mass index, and metabolic parameters were assessed. The phenylephrine test was used to measure BRS.
  
  
  RESULTS
  Patients in the OSA group were slightly but significantly older than the non-OSA population (50.3±9.3 years vs 45.7±11.1 years, P=0.02). Body mass index, percentage body fat, blood pressure, fasting glucose, insulin, and lipid levels did not differ between the OSA patients and non-OSA subjects. Absolute BRS values in patients with mild OSA and non-OSA subjects (9.97±6.70 ms/mmHg vs 10.51±7.16 ms/mmHg, P=0.67) and BRS values proportional to age-related and sex-related reference values (91.4%±22.7% vs 92.2%±21.8%, P=0.84) did not differ from each other. BRS <50% of the sex-specific reference value was found in 6% of patients with mild OSA and in 2% of non-OSA subjects (P=0.29).
  
  
  CONCLUSIONS
  Patients with mild OSA did not show evidence of disturbed BRS in comparison with weight-matched non-OSA controls.
authors.affiliation: Department of Otorhinolaryngology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland.
authors.forename: Henry
authors.initials: H
authors.lastname: Blomster
authors.affiliation: Department of Clinical Physiology and Nuclear Medicine, University of Eastern Finland, Kuopio, Finland.
authors.forename: Tomi P
authors.initials: TP
authors.lastname: Laitinen
authors.affiliation: Department of Internal Medicine, University of Eastern Finland, Kuopio, Finland ; Heart Center, Kuopio University Hospital, Kuopio, Finland.
authors.forename: Juha Ek
authors.initials: JE
authors.lastname: Hartikainen
authors.affiliation: Department of Clinical Physiology and Nuclear Medicine, University of Eastern Finland, Kuopio, Finland.
authors.forename: Tiina M
authors.initials: TM
authors.lastname: Laitinen
authors.affiliation: Department of Clinical Physiology and Nuclear Medicine, University of Eastern Finland, Kuopio, Finland.
authors.forename: Esko
authors.initials: E
authors.lastname: Vanninen
authors.affiliation: Department of Clinical Nutrition, School of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio, Finland ; Department of Medicine, Division of Internal Medicine, University of Helsinki, Helsinki, Finland.
authors.forename: Helena
authors.initials: H
authors.lastname: Gylling
authors.affiliation: Department of Otorhinolaryngology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland.
authors.forename: Johanna
authors.initials: J
authors.lastname: Sahlman
authors.affiliation: Department of Respiratory Medicine, Kuopio University Hospital, Kuopio, Finland.
authors.forename: Jouko
authors.initials: J
authors.lastname: Kokkarinen
authors.affiliation: Department of Respiratory Medicine, Kuopio University Hospital, Kuopio, Finland.
authors.forename: Jukka
authors.initials: J
authors.lastname: Randell
authors.affiliation: Department of Otorhinolaryngology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland.
authors.forename: Juha
authors.initials: J
authors.lastname: Seppä
authors.affiliation: Department of Clinical Nutrition, School of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio, Finland ; Oivauni Sleep Clinic, Kuopio, Finland.
authors.forename: Henri
authors.initials: H
authors.lastname: Tuomilehto
keywords: baroreceptor reflex sensitivity; obstructive sleep apnea