title: Long-term oxygen administration reduces plasma adrenomedullin levels in patients with obstructive sleep apnea syndrome.
abstract: OBJECTIVE
  Obstructive sleep apnea syndrome (OSAS) is recognized as one of the risk factors of hypertension and cardiovascular disorders. In the current study, we hypothesized that the hypoxic stress caused by obstructive sleep apnea would increase circulating adrenomedullin (ADM) levels in untreated OSAS patients compared to an age-matched control group. We further hypothesized that oxygen administration treatment may decrease OSAS-induced hypoxic stress and ADM levels.
  
  
  METHODS
  We examined short-term and long-term oxygen administration effects on circulating ADM in 48 OSAS patients.
  
  
  RESULTS
  The circulating levels of ADM in untreated OSAS patients were significantly greater than those in the controls. We did not observe a significant effect in 2 weeks of oxygen administration on the circulating ADM in the patients, but we observed a significant effect in long-term oxygen administration for more than 3 months on plasma ADM levels. Long-term oxygen therapy decreased both the magnitude of arterial oxygen desaturation and plasma ADM levels in patients but did not decrease blood pressure.
  
  
  CONCLUSIONS
  These observations suggest that long-term oxygen therapy could reduce OSAS-induced nocturnal hypoxemia and plasma ADM levels in patients with OSAS.
authors.affiliation: Department of Geriatric Medicine, Faculty of Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Shinji
authors.initials: S
authors.lastname: Teramoto
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Yamaguchi
authors.forename: Yoko
authors.initials: Y
authors.lastname: Hanaoka
authors.forename: Masaki
authors.initials: M
authors.lastname: Ishii
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Hibi
authors.forename: Yasuyoshi
authors.initials: Y
authors.lastname: Ouchi
mesh_terms: D053607:Adrenomedullin / Q000097:blood*; D000328:Adult; D045422:Continuous Positive Airway Pressure / Q000379:methods; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000209:etiology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000008:administration & dosage*; D010101:Oxygen Consumption; D010102:Oxygen Inhalation Therapy / Q000379:methods*; D017286:Polysomnography; D020181:Sleep Apnea, Obstructive / Q000097:blood* / Q000150:complications / Q000628:therapy*; D016896:Treatment Outcome
chemical_list: D053607:Adrenomedullin; D010100:Oxygen