title: The natural anticoagulant protein S is decreased in male smokers.
abstract: Protein S is a natural anticoagulant plasma protein; familial deficiency is associated with thrombotic complications. Since smoking carries an increased risk of myocardial infarction and stroke, we investigated the protein S system of men who smoke. In plasma, free protein S is functionally active and protein S bound to C4b binding protein is inactive. Male smokers (n = 24) have lower total protein S than nonsmokers (n = 24) (16.8 +/- 4.3 micrograms/ml versus 19.8 +/- 5.1 micrograms/ml, p less than 0.02). C4b binding protein levels are higher (p less than 0.05) in smokers (212 +/- 47 micrograms/ml versus 186 +/- 52 micrograms/ml). Free protein S is significantly lower in smokers (6.9 +/- 2.3 micrograms/ml versus 8.0 +/- 1.9 micrograms/ml, p = 0.02). These alterations in protein S may contribute to the thrombotic complications associated with smoking.
authors.affiliation: Cardiology Division, University of Iowa.
authors.forename: B D
authors.initials: BD
authors.lastname: Scott
authors.forename: C T
authors.initials: CT
authors.lastname: Esmon
authors.forename: P C
authors.initials: PC
authors.lastname: Comp
mesh_terms: D000328:Adult; D006023:Glycoproteins / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017293:Protein S; D012907:Smoking / Q000097:blood*
chemical_list: D006023:Glycoproteins; D017293:Protein S