Segment-specific associations of carotid intima-media thickness with cardiovascular risk factors: the Coronary Artery Risk Development in Young Adults (CARDIA) study.
OBJECTIVE
We propose to study possible differences in the associations between risk factors for cardiovascular disease (myocardial infarction and stroke) and carotid intima-media thickness (IMT) measurements made at 3 different levels of the carotid bifurcation.


METHODS
We conducted a cross-sectional study of a cohort of whites and blacks of both genders with a mean age of 45 years. Traditional cardiovascular risk factors were determined in cohort members. Carotid IMT was measured from high-resolution B-mode ultrasound images at 3 levels: the common carotid artery, the carotid artery bulb (bulb), and the internal carotid artery. Associations with risk factors were evaluated by multivariate linear regression analyses.


RESULTS
Of 3258 who underwent carotid IMT measurements, common carotid artery, bulb, and internal carotid artery IMT were measured at all 3 separate levels in 3023 (92.7%). A large proportion of the variability of common carotid artery IMT was explained by cardiovascular risk factors (26.8%) but less so for the bulb (11.2%) and internal carotid artery (8.0%). Carotid IMT was consistently associated with age, low-density lipoprotein cholesterol, smoking, and hypertension in all segments. Associations with fasting glucose and diastolic blood pressure were stronger for common carotid artery than for the other segments. Hypertension, diabetes, and current smoking had qualitatively stronger associations with bulb IMT and low-density lipoprotein cholesterol with internal carotid artery IMT.


CONCLUSIONS
In our cohort of relatively young white and black men and women, a greater proportion of the variability in common carotid IMT can be explained by traditional cardiovascular risk factors than for the carotid artery bulb and internal carotid arteries.
Polak
Joseph F
JF
Department of Radiology, #299, Tufts Medical Center, 800 Washington St, Boston, MA 02111, USA. jpolak@tuftsmedicalcenter.org
Person
Sharina D
SD
Wei
Gina S
GS
Godreau
Ayleen
A
Jacobs
David R
DR
Harrington
Anita
A
Sidney
Stephen
S
O'Leary
Daniel H
DH
D000328:Adult; D000367:Age Factors; D044383:Black People / Q000208:ethnology; D002318:Cardiovascular Diseases / Q000208:ethnology / Q000209:etiology / Q000473:pathology*; D002339:Carotid Arteries / Q000473:pathology*; D002340:Carotid Artery Diseases / Q000208:ethnology / Q000209:etiology / Q000473:pathology*; D015331:Cohort Studies; D003324:Coronary Artery Disease / Q000208:ethnology / Q000209:etiology / Q000473:pathology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D017539:Tunica Intima / Q000473:pathology*; D017540:Tunica Media / Q000473:pathology*; D044465:White People / Q000208:ethnology