title: Plasma suPAR is lowered by smoking cessation: a randomized controlled study.
abstract: BACKGROUND
  Soluble urokinase plasminogen activator receptor (suPAR) is a stable inflammatory biomarker. In patients, suPAR is a marker of disease presence, severity and prognosis. In the general population, suPAR is predictive of disease development, such as diabetes and cardiovascular disease and, in smokers, predictive of long-term lung cancer development. Whether smoking cessation impacts the suPAR level is unknown.
  
  
  METHODS
  Forty-eight smokers were randomized into three groups of 16: (i) continued to smoke 20 cigarettes per day, (ii) refrained from smoking and used transdermal nicotine patches and (iii) refrained from smoking and used placebo patches. Nonsmokers were included for comparison. suPAR and C-reactive protein (CRP) levels were measured by ELISA.
  
  
  RESULTS
  At baseline, the suPAR level was significantly higher in the 48 smokers (median 3·2 ng mL, IQR (2·5-3·9)) than in 46 never smokers (1·9 ng/mL (1·7-2·2)). In smokers randomized to smoking cessation, suPAR levels after 4 weeks of stopping were decreased and no longer significantly different from the never smokers values. SuPAR decreased in both those who received a placebo as well as nicotine patch. Interestingly, those with the highest suPAR level at time of smoking were also those with the highest level of suPAR after smoking cessation. In contrast, smoking or smoking cessation had no influence on CRP levels.
  
  
  CONCLUSIONS
  Our study suggests that the suPAR level may aid to personalize the risk of smoking by identifying those smokers with the highest risk of developing disease and who may have the most benefit of smoking cessation.
authors.affiliation: Clinical Research Centre, Copenhagen University Hospital Hvidovre, Copenhagen, Denmark.
authors.forename: Jesper
authors.initials: J
authors.lastname: Eugen-Olsen
authors.affiliation: Clinical Research Centre, Copenhagen University Hospital Hvidovre, Copenhagen, Denmark.
authors.forename: Steen
authors.initials: S
authors.lastname: Ladelund
authors.affiliation: Digestive Disease Centre, Bispebjerg Hospital, Copenhagen, Denmark.
authors.forename: Lars Tue
authors.initials: LT
authors.lastname: Sørensen
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000378:metabolism; D001772:Blood Cell Count; D002097:C-Reactive Protein / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008297:Male; D010349:Patient Compliance; D055293:Receptors, Urokinase Plasminogen Activator / Q000378:metabolism*; D012907:Smoking / Q000097:blood*; D016540:Smoking Cessation; D061485:Tobacco Use Cessation Devices; D055815:Young Adult
chemical_list: D015415:Biomarkers; D055293:Receptors, Urokinase Plasminogen Activator; D002097:C-Reactive Protein
keywords: Biomarker; inflammation; lifestyle; prognosis; risk