title: Elevated levels of C-reactive protein and interleukin-6 in patients with obstructive sleep apnea syndrome are decreased by nasal continuous positive airway pressure.
abstract: BACKGROUND
  C-reactive protein (CRP) and interleukin (IL)-6 are important risk factors for atherosclerosis and coronary heart disease. In the present study, we examined serum levels of CRP and IL-6, IL-6 production by monocytes, and the effect of nasal continuous positive airway pressure (nCPAP) in patients with obstructive sleep apnea syndrome (OSAS).
  
  
  RESULTS
  After polysomnography, venous blood was collected at 5 AM from 30 patients with OSAS and 14 obese control subjects. Serum levels of CRP and IL-6 and spontaneous production of IL-6 by monocytes were investigated. In addition, the effects of 1 month of nCPAP were studied in patients with moderate to severe OSAS. Levels of CRP and IL-6 were significantly higher in patients with OSAS than in obese control subjects (CRP P<0.001, IL-6 P<0.05). IL-6 production by monocytes was also higher in patients with OSAS than in obese control subjects (P<0.01). In patients with OSAS, the primary factors influencing levels of CRP were severity of OSAS and body mass index and those influencing levels of IL-6 were body mass index and nocturnal hypoxia. nCPAP significantly decreased levels of both CRP (P<0.0001) and IL-6 (P<0.001) and spontaneous IL-6 production by monocytes (P<0.01).
  
  
  CONCLUSIONS
  Levels of CRP and IL-6 and spontaneous production of IL-6 by monocytes are elevated in patients with OSAS but are decreased by nCPAP. Therefore, OSAS is associated with increased risks for cardiovascular morbidity and mortality, and nCPAP may be useful for decreasing these risks.
authors.affiliation: First Department of Internal Medicine, Showa University, Tokyo, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Yokoe
authors.forename: Kenji
authors.initials: K
authors.lastname: Minoguchi
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Matsuo
authors.forename: Naruhito
authors.initials: N
authors.lastname: Oda
authors.forename: Hideko
authors.initials: H
authors.lastname: Minoguchi
authors.forename: Gen
authors.initials: G
authors.lastname: Yoshino
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Hirano
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Adachi
mesh_terms: D002097:C-Reactive Protein / Q000032:analysis*; D006801:Humans; D015850:Interleukin-6 / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000276:immunology; D009666:Nose; D017286:Polysomnography; D011175:Positive-Pressure Respiration; D020181:Sleep Apnea, Obstructive / Q000276:immunology* / Q000378:metabolism / Q000628:therapy*
chemical_list: D015850:Interleukin-6; D002097:C-Reactive Protein