title: Relationship between sleep apnea syndrome and sleep blood pressure in patients without hypertension.
abstract: OBJECTIVE
  Ambulatory blood pressure monitoring (ABPM) provides an accurate assessment of blood pressure (BP) and shows non-dipper BP pattern in many sleep apnea syndrome (SAS) patients with hypertension (HTN); however, little information is available on the relationship between the severity of SAS and circadian BP changes in SAS patients without HTN. This study investigated whether SAS patients without HTN would have different BP courses in the severity of SAS.
  
  
  METHODS
  Seventy-four consecutive outpatients without HTN [systolic BP (BPs) at clinic <140mmHg and/or diastolic BP (BPd) at clinic <90mmHg], who received no antihypertensives, underwent overnight polysomnography (PSG) and ABPM. The apnea-hypopnea index (AHI) was calculated from the PSG results; patients were stratified into the following 4 groups based on their AHI: non-SAS, mild-, moderate-, or severe-SAS.
  
  
  RESULTS
  The diurnal BPs and BPd showed no differences in the severity of SAS; however, the sleep BPs, lowest BPs, and pre-awake BPs were significantly higher in the severe-SAS group than the non-SAS group (p=0.02, p=0.04, and p=0.006, respectively). The sleep BPd and pre-awake BPd were significantly higher in the severe-SAS than the non-SAS (p=0.01 and p=0.0003, respectively) and mild-SAS (p=0.01 and p=0.008, respectively) groups.
  
  
  CONCLUSIONS
  The results of this study suggested that SAS affected nocturnal BP elevation even in SAS patients without HTN. The diurnal BP showed no difference in the severity of SAS; however, the severe-SAS group revealed significant nocturnal BP elevation.
authors.affiliation: Division of Cardiology, Department of Internal Medicine, St. Marianna University School of Medicine, 2-16-1 Sugao Miyamae-ku, Kawasaki-city, Kanagawa-prefecture 216-8511, Japan. sekimal@marianna-u.ac.jp
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Sekizuka
authors.forename: Keisuke
authors.initials: K
authors.lastname: Kida
authors.forename: Yoshihiro J
authors.initials: YJ
authors.lastname: Akashi
authors.forename: Kihei
authors.initials: K
authors.lastname: Yoneyama
authors.forename: Naohiko
authors.initials: N
authors.lastname: Osada
authors.forename: Kazuto
authors.initials: K
authors.lastname: Omiya
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Miyake
mesh_terms: D001794:Blood Pressure / Q000502:physiology*; D018660:Blood Pressure Monitoring, Ambulatory; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D012890:Sleep / Q000502:physiology*; D012891:Sleep Apnea Syndromes / Q000503:physiopathology*