title: The impact of obstructive sleep apnea syndrome on renin and aldosterone.
abstract: OBJECTIVE
  Obstructive Sleep Apnoea Syndrome (OSAS) is a respiratory disorder characterized by recurrent airflow obstruction caused by total or partial collapse of the upper airway. OSAS is an established independent factor of cardiovascular risk together with other risk factors such as smoking and increased lipids. The aim of our study was to measure serum levels of aldosterone and renin in OSAS patients that did not suffer from arterial hypertension and compare them to matched healthy subjects in order to reveal the impact of chronic intermittent hypoxia on the renin-angiotensin-aldosterone system.
  
  
  METHODS
  The patients that enrolled in this study were 19 OSAS patients who had undergone overnight polysomnography and had an Apnoea Hypopnoea Index (AHI) greater than 10 events/hour. They were compared to 20 healthy non-OSAS closely matched controls. Serum aldosterone and direct renin concentration were measured by radioimmunoassay.
  
  
  RESULTS
  Aldosterone concentration follows a diurnal variation; therefore, all blood samples were obtained at the same time (6 AM). There were no significant differences in serum aldosterone levels between the two studied groups of OSAS patients and the healthy subjects group (140.6 pg/ml ± 25.2 vs. 133.2 pg/ml ± 18.5 with p = 0.223). Similar were the results for the renin levels (25.0 ± 6.9 vs. 24.9 ± 4.4 with p = 0.360).
  
  
  CONCLUSIONS
  Our study suggests that patients with OSAS, but without existing hypertension have aldosterone and renin levels similar to healthy subjects. According to our findings a direct connection between OSAS and the development of arterial hypertension may not be established via sympathetic system activation.
authors.affiliation: Department of Pulmonary Medicine, University Hospital of Patras, Rio Patras, Greece. spircos@upatras.gr.
authors.forename: D
authors.initials: D
authors.lastname: Lykouras
authors.forename: K
authors.initials: K
authors.lastname: Theodoropoulos
authors.forename: F
authors.initials: F
authors.lastname: Sampsonas
authors.forename: O
authors.initials: O
authors.lastname: Lagiou
authors.forename: M
authors.initials: M
authors.lastname: Lykouras
authors.forename: A
authors.initials: A
authors.lastname: Spiropoulou
authors.forename: C
authors.initials: C
authors.lastname: Flordellis
authors.forename: T
authors.initials: T
authors.lastname: Alexandrides
authors.forename: K
authors.initials: K
authors.lastname: Karkoulias
authors.forename: K
authors.initials: K
authors.lastname: Spiropoulos
mesh_terms: D000328:Adult; D000450:Aldosterone / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D002940:Circadian Rhythm / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography / Q000379:methods; D012083:Renin / Q000097:blood*; D012084:Renin-Angiotensin System / Q000502:physiology; D012307:Risk Factors; D020181:Sleep Apnea, Obstructive / Q000097:blood* / Q000175:diagnosis* / Q000503:physiopathology
chemical_list: D015415:Biomarkers; D000450:Aldosterone; D012083:Renin