title: Smoking cessation, but not smoking reduction, reduces plasma homocysteine levels.
abstract: BACKGROUND
  Cigarette smoking has been associated with increased plasma homocysteine levels. Although hyperhomocysteinemia may mediate some of the adverse cardiovascular consequences of smoking cigarettes, the effects of smoking cessation and smoking reduction on homocysteine levels have not been evaluated previously.
  
  
  OBJECTIVE
  The purpose of this study was to determine the effects of smoking cessation and smoking reduction on plasma homocysteine levels.
  
  
  METHODS
  Fifty-one healthy subjects who smoked 35.9 +/- 6.4 cigarettes daily were randomized to continue smoking, reduce smoking to 4-8 cigarettes daily, or to stop smoking. A nicotine inhaler and individualized counseling were provided as aids to smoking cessation.
  
  
  RESULTS
  In subjects who quit smoking, homocysteine levels decreased by 11.6%, from 8.58 +/- 2.31 to 7.53 +/- 2.26 micromol/l (p = 0.013). Significant changes in homocysteine levels were not observed in subjects who reduced smoking or continued to smoke.
  
  
  CONCLUSIONS
  A "harm reduction" strategy of reducing cigarette use may not be sufficient for reducing the vascular risk associated with smoking cigarettes.
authors.affiliation: Center for Tobacco Research and Intervention, Department of Medicine, University of Wisconsin Medical School, Madison, USA.
authors.forename: James H
authors.initials: JH
authors.lastname: Stein
authors.forename: Magda
authors.initials: M
authors.lastname: Bushara
authors.forename: Khalaf
authors.initials: K
authors.lastname: Bushara
authors.forename: Patrick E
authors.initials: PE
authors.lastname: McBride
authors.forename: Douglas E
authors.initials: DE
authors.lastname: Jorenby
authors.forename: Michael C
authors.initials: MC
authors.lastname: Fiore
mesh_terms: D000328:Adult; D003327:Coronary Disease / Q000097:blood / Q000517:prevention & control*; D005260:Female; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010084:Oxidation-Reduction; D012307:Risk Factors; D012907:Smoking / Q000097:blood*; D016540:Smoking Cessation
chemical_list: D006710:Homocysteine