Abstract MP79: Association of Long-term Risk Factor Levels with Carotid Atherosclerosis: The Chicago Healthy Aging Magnetic Resonance Imaging Plaque Study (CHAMPS)
Background: The absence of risk factors (RFs) in early middle-age is associated with a markedly lower risk for cardiovascular disease across the lifespan. However, the mechanism for this association is not fully understood.
Methods: We performed carotid MRI on 440 randomly-selected participants of the Chicago Healthy Aging Study in 2009-11, whose RFs were measured in 1967-73. We examined association of the burden of RFs at baseline with measures of carotid atherosclerosis (i.e., wall thickness and lipid-rich necrotic core (LRNC)) at follow-up. High resolution carotid MR images were acquired (Siemens, 1.5T) using Time of Flight and standard, Turbo Spin Echo T1 and T2 sequences; 16 consecutive images were acquired, and centered on the bifurcation. Risk groups were defined according to RFs present ~40 years earlier (baseline examination): blood pressure, cholesterol, diabetes, and smoking. Participants were divided into 4 groups (See Table footnote for definitions). The association of wall thickness measures and LRNC with baseline low-risk status was assessed in models adjusted for age, current RF, and mean wall thickness.
Results: Among 423 ppts with evaluable images, the mean age was 32±5 y at baseline and 71±5 y at follow-up; 65% were male, 84% white, and 37% were “Low Risk” at baseline. Higher risk status at baseline was associated with greater burden of carotid atherosclerosis as measured by mean and maximum wall thickness and LRNC, with the lowest burden among individuals with low-risk status (see Table). In age-adjusted models, low-risk status was associated with a lower risk for LRNC in older age [OR 0.58 (95% CI, 0.35-0.97)]. This association persisted after adjustment for current RF burden [0.59 (0.35-0.99)] and mean wall thickness [0.57 (0.33-0.99)].
Conclusions: The presence of low-risk status in early life is associated with a lower prevalence of carotid LRNC in older age. These findings suggest that the decades-long protective effect of low risk status might be mediated through a lower burden of high-risk plaque.
- © 2013 by American Heart Association, Inc.