title: Rates and determinants of site-specific progression of carotid artery intima-media thickness: the carotid atherosclerosis progression study.
abstract: OBJECTIVE
  Carotid intima-media thickness (IMT) progression rates are increasingly used as an intermediate outcome for vascular risk. The carotid bifurcation (BIF) and internal carotid artery (ICA) are predilection sites for atherosclerosis. IMT measures from these sites may be a better estimate of atherosclerosis than common carotid artery (CCA) IMT. The study aim was to evaluate site-specific IMT progression rates and their relationships to vascular risk factors compared with baseline IMT measurements.
  
  
  METHODS
  In a community population (n=3383), ICA-IMT, BIF-IMT, CCA-IMT, and vascular risk factors were evaluated at baseline and at 3-year follow-up.
  
  
  RESULTS
  Mean (SD) IMT progression was significantly greater at the ICA (0.032 [0.109] mm/year) compared with the BIF (0.023 [0.108] mm/year) and the CCA (0.001 [0.040] mm/year) (P<0.001). Only ICA-IMT progression significantly correlated with baseline vascular risk factors (age, male gender, hypertension, diabetes, and smoking). Change in risk factor profile over follow-up, estimated using the Framingham risk score, was a predictor of IMT progression only. For all arterial sites, correlations were stronger, by a factor of 2 to 3, for associations with baseline IMT compared with IMT progression.
  
  
  CONCLUSIONS
  Progression rates at the ICA rather than the CCA yield greater absolute changes in IMT and better correlations with vascular risk factors. Vascular risk factors correlate more strongly with baseline IMT than with IMT progression. Prospective data on IMT progression and incident vascular events are required to establish the true value of progression data as a surrogate measure of vascular risk.
authors.affiliation: Department of Clinical Neurosciences, St. George's Hospital Medical School, Cranmer Terrace, Tooting, London, United Kingdom.
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Mackinnon
authors.forename: Paula
authors.initials: P
authors.lastname: Jerrard-Dunne
authors.forename: Matthias
authors.initials: M
authors.lastname: Sitzer
authors.forename: Alexandra
authors.initials: A
authors.lastname: Buehler
authors.forename: Stefan
authors.initials: S
authors.lastname: von Kegler
authors.forename: Hugh S
authors.initials: HS
authors.lastname: Markus
mesh_terms: D000328:Adult; D000368:Aged; D002339:Carotid Arteries / Q000000981:diagnostic imaging / Q000473:pathology*; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging / Q000473:pathology*; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging / Q000473:pathology*; D016893:Carotid Stenosis / Q000000981:diagnostic imaging / Q000473:pathology*; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D015897:Comorbidity; D003920:Diabetes Mellitus / Q000453:epidemiology; D018450:Disease Progression; D005260:Female; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology; D017539:Tunica Intima / Q000000981:diagnostic imaging / Q000473:pathology; D017540:Tunica Media / Q000000981:diagnostic imaging / Q000473:pathology; D014463:Ultrasonography
chemical_list: D008076:Cholesterol, HDL; D008078:Cholesterol, LDL