title: Comparison of plasma levels of natural anticoagulants (protein C and protein S) among Jordanian smokers and non-smokers.
abstract: BACKGROUND
  Protein C (PC) with its cofactor free protein S (FPS) are important anticoagulants. Any defect in the PC system is a risk factor for venous thrombosis.
  
  
  OBJECTIVE
  To assess the effect of intensity of smoking, and the dose-response for the number of cigarettes smoked on PC and FPS plasma levels.
  
  
  METHODS
  A comparative study was designed and carried out on a convenient sample of 50 healthy non-smokers and 150 non-symptomatic Jordanian male smokers. PC and FPS levels were measured using an automated system (Stago Analyzer, USA).
  
  
  RESULTS
  The plasma level of PC among smokers was 7.2% lower than that among non-smokers (p = 0.02). Moreover, smokers had 15.6% lower circulating FPS than non-smokers (p = 0.001). Furthermore, data showed significant negative correlations between both PC and FPS levels and the intensity of smoking (r = -0.21%, r = -0.23%, respectively; p = 0.01) and the period of smoking (r = -0.15%, r = -0.23%, respectively; p = 0.01, 0.12, respectively).
  
  
  CONCLUSIONS
  The PC and FPS plasma levels were significantly lower in smokers than non-smokers. Both PC and FPS levels correlated inversely with the period and intensity of smoking, and FPS was more sensitive to smoking than PC.
authors.affiliation: Department of Pediatrics, Jordan University of Science and Technology, Irbid, Jordan. sweedan@just.edu.jo
authors.forename: Suleimman A
authors.initials: SA
authors.lastname: Al-Sweedan
authors.forename: Mohammed
authors.initials: M
authors.lastname: Mueen
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Al-Sheyyab
authors.forename: Hashem
authors.initials: H
authors.lastname: Jaddou
mesh_terms: D000293:Adolescent; D000328:Adult; D000925:Anticoagulants / Q000032:analysis / Q000097:blood*; D005260:Female; D006801:Humans; D007597:Jordan; D008297:Male; D008875:Middle Aged; D011486:Protein C / Q000032:analysis / Q000378:metabolism*; D017293:Protein S / Q000032:analysis / Q000378:metabolism*; D012907:Smoking / Q000097:blood* / Q000453:epidemiology
chemical_list: D000925:Anticoagulants; D011486:Protein C; D017293:Protein S