Abstract 5828: Carotid Artery Plaque is More Strongly Associated With Prior Cardiovascular Risk Factor Levels Than With Current Risk Factor Levels
Background: Carotid artery atherosclerosis develops progressively in response to cardiovascular risk factor exposure over time. We compare the associations between internal carotid artery (ICA) plaque and risk factors measured at time points separated by 24 years.
Materials and Methods: The extent of carotid artery atherosclerosis was measured in 1995–1998 by blinded review of carotid ultrasound studies in 1593 men and 1784 women of the Framingham Offspring cohort (average age 59 years). Associations with cardiovascular risk factors measured in 1970 –75 and in 1995–1998 were studied by multivariable logistic regression.
Results: Age, increased systolic blood pressure and pack-years smoked are associated with carotid atherosclerosis in both men and women while body mass index is not. The association between total cholesterol levels and carotid artery plaque (stenosis ≥ 25%) is significant for baseline cholesterol measurements for men and women with odds ratio of 1.004 per mg/dL (1.001,1.008 95%CI) and 1.011 mg/dL (1.006, 1.015 95%CI) in 1971–75 but not significant for recent serum cholesterol levels with odds ratio of 1.00 mg/dL; (0.996,1.003 95% CI) and 1.002 mg/dL (0.998, 1.006 95% CI) respectively. Except for diabetes, the associations between risk factors and carotid plaque tended to be qualitatively stronger for baseline risk factors than those seen on the current examination, 24 years later. ICA intima-media thickness (IMT ≥ 1.5 mm) was also more strongly related to earlier risk factor exposure.
Conclusions: Carotid artery plaque is more strongly associated with prior cholesterol levels than to current cholesterol levels. The extent of carotid atherosclerosis (plaque) reflects previous risk factor levels better than current levels.