title: Increased low-grade inflammation and plasminogen-activator inhibitor-1 level in nondippers with sleep apnea syndrome.
abstract: OBJECTIVE
  Patients with sleep apnea syndrome have an increased risk of cardiovascular events and frequently show a nondipper pattern (blunted nocturnal decline <10%) of systolic blood pressure. We investigated neurohumoral activation and risk factors in relation to nocturnal blood pressure dipping pattern and sleep apnea syndrome.
  
  
  METHODS
  We conducted sleep polysomnography and ambulatory blood pressure monitoring and measured high-sensitivity C-reactive protein, tissue-type plasminogen activator inhibitor-1, and neurohumoral factors in 121 outpatients with suspected sleep apnea syndrome who were classified into four groups on the basis of the presence or the absence of dipping/nondipping and sleep apnea syndrome.
  
  
  RESULTS
  Nondippers with sleep apnea syndrome had higher high-sensitivity C-reactive protein (overall P < 0.001), plasminogen activator inhibitor-1 (overall P = 0.004), and aldosterone levels (overall P = 0.010) than any of the other three groups. After adjustment for significant covariates such as age, sex, body mass index, waist circumference, smoking, alcohol drinking, aspirin use, presence of diabetes, and insulin, nondippers with sleep apnea syndrome still had a higher high-sensitivity C-reactive protein level than nondippers without sleep apnea syndrome (geometric mean: 1.47 vs. 0.37 mg/l, P = 0.001). In multiple linear regression analysis controlling for confounding factors related with sleep apnea syndrome, high-sensitivity C-reactive protein was significantly correlated with 3% oxygen desaturation index (P = 0.047). Plasminogen activator inhibitor-1 level was also highest in the nondippers with sleep apnea syndrome but not independent of obesity. Plasminogen activator inhibitor-1 level correlated with insulin (r = 0.32, P = 0.002) and high-sensitivity C-reactive protein levels (r = 0.26, P = 0.005).
  
  
  CONCLUSIONS
  Nondipper status was associated with an increased high-sensitivity C-reactive protein level in patients who also had sleep apnea syndrome but not in those who did not. High-sensitivity C-reactive protein level was closely affected by the desaturation level. Plasminogen activator inhibitor-1 level is also increased in nondippers with sleep apnea syndrome and is related to insulin and high-sensitivity C-reactive protein levels.
authors.affiliation: Division of Cardiovascular Medicine, Department of Medicine, Jichi Medical University School of Medicine, Tochigi, Japan. george@jichi.ac.jp
authors.forename: Joji
authors.initials: J
authors.lastname: Ishikawa
authors.forename: Satoshi
authors.initials: S
authors.lastname: Hoshide
authors.forename: Kazuo
authors.initials: K
authors.lastname: Eguchi
authors.forename: Shizukiyo
authors.initials: S
authors.lastname: Ishikawa
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Pickering
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Shimada
authors.forename: Kazuomi
authors.initials: K
authors.lastname: Kario
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure / Q000502:physiology*; D002097:C-Reactive Protein / Q000378:metabolism*; D005260:Female; D006801:Humans; D007249:Inflammation / Q000097:blood* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D017395:Plasminogen Activator Inhibitor 1 / Q000097:blood*; D017286:Polysomnography; D012891:Sleep Apnea Syndromes / Q000097:blood* / Q000150:complications / Q000503:physiopathology
chemical_list: D017395:Plasminogen Activator Inhibitor 1; D002097:C-Reactive Protein