title: Effect of nasal continuous positive airway pressure treatment on plasma adrenomedullin levels in patients with obstructive sleep apnea syndrome: roles of nocturnal hypoxia and oxidant stress.
abstract: 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 and oxidative stress caused by obstructive sleep apnea would increase circulating adrenomedullin (ADM) levels in untreated OSAS patients as compared to an age and body mass index (BMI)-matched control group and an age-matched, but normal-BMI control group. We further hypothesized that nasal continuous positive airway pressure (nCPAP) treatment may decrease OSAS-induced hypoxic stress, oxidative stress and ADM levels. To examine these hypotheses, we measured circulating ADM and reactive oxygen species (ROS) from leukocytes before and after nCPAP therapy in OSAS patients. The circulating levels of ADM and amount of ROS in untreated OSAS patients were significantly greater than those in the controls. No differences in ADM levels were found between the increased-BMI controls and normal-BMI controls. We observed that nCPAP treatment decreased sleep apneas, nocturnal oxyhemoglobin desaturation, the circulating ADM, and ROS production by leukocytes in OSAS patients. The ADM levels were associated with the magnitude of oxyhemoglobin desaturation rather than the number of sleep apneas. These observations suggest that nCPAP therapy could reduce OSAS-induced nocturnal hypoxemia, generation of ROS, and ADM in patients with OSAS.
authors.affiliation: Department of Geriatric Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, 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: Yasuyoshi
authors.initials: Y
authors.lastname: Ouchi
mesh_terms: D053607:Adrenomedullin / Q000097:blood* / Q000502:physiology; D050197:Atherosclerosis / Q000209:etiology; D045422:Continuous Positive Airway Pressure / Q000379:methods*; D006801:Humans; D000860:Hypoxia / Q000150:complications*; D018799:Intercellular Adhesion Molecule-1 / Q000097:blood; D007962:Leukocytes / Q000378:metabolism; D018384:Oxidative Stress; D017382:Reactive Oxygen Species / Q000378:metabolism; D020181:Sleep Apnea, Obstructive / Q000378:metabolism / Q000628:therapy*
chemical_list: C507862:ADM protein, human; D017382:Reactive Oxygen Species; D018799:Intercellular Adhesion Molecule-1; D053607:Adrenomedullin