title: C reactive protein levels are increased in non-allergic but not allergic asthma: a multicentre epidemiological study.
abstract: BACKGROUND
  High sensitivity C reactive protein (HsCRP) is an inflammatory marker known to be related to smoking, obesity, and cardiovascular disease. A study was undertaken to determine whether HsCRP is related to respiratory symptoms, asthma, atopy, and bronchial hyperresponsiveness in population samples from three countries.
  
  
  METHODS
  HsCRP was measured in 1289 subjects from three centres in ECRHS II: Reykjavik, Uppsala and Tartu. The HsCRP values ranged from <0.01 mg/l to 70.0 mg/l and were divided into four equal groups (< or = 0.45, 0.46-0.96, 0.97-2.21, and >2.21 mg/l).
  
  
  RESULTS
  HsCRP increased with increasing body mass index (r = 0.41; p<0.0001) and was higher in smokers than in never smokers (p = 0.02). A significant relationship was found between increased HsCRP levels and respiratory symptoms such as wheeze, attacks of breathlessness after effort, and nocturnal cough (p<0.0001). The crude odds ratio (95% CI) for the probability of non-allergic asthma was 3.57 (1.83 to 6.96) for subjects in the 4th quartile compared with the 1st quartile of HsCRP. This association remained significant after adjusting for study centre, age, sex, body weight, and smoking history (OR 2.19 (95% CI 1.04 to 4.63)). No significant relationship was observed between HsCRP and allergic asthma or bronchial responsiveness.
  
  
  CONCLUSIONS
  Raised levels of HsCRP are significantly associated with respiratory symptoms and non-allergic asthma but not with allergic asthma.
authors.affiliation: Department of Allergy, Respiratory Medicine and Sleep, Landspitali University Hospital, 108 Reykjavík, Iceland.
authors.forename: I S
authors.initials: IS
authors.lastname: Olafsdottir
authors.forename: T
authors.initials: T
authors.lastname: Gislason
authors.forename: B
authors.initials: B
authors.lastname: Thjodleifsson
authors.forename: I
authors.initials: I
authors.lastname: Olafsson
authors.forename: D
authors.initials: D
authors.lastname: Gislason
authors.forename: R
authors.initials: R
authors.lastname: Jögi
authors.forename: C
authors.initials: C
authors.lastname: Janson
mesh_terms: D000328:Adult; D001249:Asthma / Q000097:blood* / Q000503:physiopathology; D015992:Body Mass Index; D016535:Bronchial Hyperreactivity / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism*; D004417:Dyspnea / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D012120:Respiration Disorders / Q000097:blood; D012907:Smoking / Q000009:adverse effects
chemical_list: D002097:C-Reactive Protein