title: The effect of smoking on carotid intima-media thickness progression rate and rate of lumen diameter reduction.
abstract: OBJECTIVE
  The purpose of the study was to investigate the long-term associations between smoking habits, environmental tobacco smoke exposure (ETS), carotid intima-media thickness (IMT) progression rate, and rate of lumen diameter reduction in the carotid artery during a 16-year follow-up. Another objective was to investigate if an effect of smoking on progression rate could be explained by increased low grade inflammation.
  
  
  METHODS
  The study population included 2992 middle-aged men and women in the 1991-1994 (baseline) and the 2007-2012 (re-examination) investigation of the Malmö Diet and Cancer Study cardiovascular cohort. Associations between smoking, progression of carotid IMT and lumen diameter reduction due to plaque protrusion were assessed by linear regression.
  
  
  RESULTS
  IMT progression rates and rate of lumen diameter reduction increased from never smokers with no ETS through former, moderate and heavy smokers, even after adjustment for traditional risk factors (e.g., differences in yearly progression rates (mm/year) of maximal IMT in the carotid bifurcation compared to never smokers; former smokers 0.0074 (95% CI: 0.0018-0.0129), moderate smokers 0.0106 (95% CI: 0.0038-0.0175), and heavy smokers 0.0146 (95% CI: 0.0061-0.0230)). Former smokers showed distinct lowering of progression rates after more than five years since smoking cessation. Smoking and former smoking was associated with increased low grade inflammation, however, the effect of smoking on atherosclerotic progression rate remained fairly unchanged after such adjustment.
  
  
  CONCLUSIONS
  The effect of smoking and former smoking on carotid IMT progression rates and change in lumen reduction due to plaque protrusion could not be explained by differences in traditional risk factors or low grade inflammation.
authors.affiliation: Department of Clinical Sciences, Lund University, Skåne University Hospital, SE-205 02 Malmö, Sweden. Electronic address: Kristina.hansen@med.lu.se.
authors.forename: Kristina
authors.initials: K
authors.lastname: Hansen
authors.affiliation: Department of Clinical Sciences, Lund University, Skåne University Hospital, SE-205 02 Malmö, Sweden. Electronic address: Gerd.ostling@med.lu.se.
authors.forename: Gerd
authors.initials: G
authors.lastname: Östling
authors.affiliation: Department of Clinical Sciences, Lund University, Skåne University Hospital, SE-205 02 Malmö, Sweden. Electronic address: Margaretha.M.Persson@skane.se.
authors.forename: Margaretha
authors.initials: M
authors.lastname: Persson
authors.affiliation: Department of Clinical Sciences, Lund University, Skåne University Hospital, SE-205 02 Malmö, Sweden. Electronic address: Peter.nilsson@med.lu.se.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Nilsson
authors.affiliation: Department of Clinical Sciences, Lund University, Skåne University Hospital, SE-205 02 Malmö, Sweden. Electronic address: Olle.melander@med.lu.se.
authors.forename: Olle
authors.initials: O
authors.lastname: Melander
authors.affiliation: Department of Clinical Sciences, Lund University, Skåne University Hospital, SE-205 02 Malmö, Sweden. Electronic address: Gunnar.engstrom@med.lu.se.
authors.forename: Gunnar
authors.initials: G
authors.lastname: Engström
authors.affiliation: Department of Clinical Sciences, Lund University, Skåne University Hospital, SE-205 02 Malmö, Sweden. Electronic address: Bo.hedblad@med.lu.se.
authors.forename: Bo
authors.initials: B
authors.lastname: Hedblad
authors.affiliation: Department of Clinical Sciences, Lund University, Skåne University Hospital, SE-205 02 Malmö, Sweden. Electronic address: Maria.rosvall@med.lu.se.
authors.forename: Maria
authors.initials: M
authors.lastname: Rosvall
mesh_terms: D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging / Q000453:epidemiology; D059168:Carotid Intima-Media Thickness; D016893:Carotid Stenosis / Q000000981:diagnostic imaging / Q000453:epidemiology*; D015331:Cohort Studies; D018450:Disease Progression; D005260:Female; D006801:Humans; D016014:Linear Models; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D058226:Plaque, Atherosclerotic / Q000000981:diagnostic imaging / Q000453:epidemiology*; D011446:Prospective Studies; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology*; D016540:Smoking Cessation; D013548:Sweden / Q000453:epidemiology; D014028:Tobacco Smoke Pollution / Q000706:statistics & numerical data*
chemical_list: D014028:Tobacco Smoke Pollution
keywords: Atherosclerosis; Inflammation; Intima–media thickness; Lumen reduction; Progression; Smoking