Aims: To assess the relationship between regulated on activation, normal T-cell expressed and secreted (RANTES) and carotid atherosclerotic plaque burden and plaque characteristics.
Methods and results: Gadolinium-enhanced magnetic resonance imaging (MRI) of the carotid artery was performed in 1901 participants from the Atherosclerosis Risk in Communities (ARIC) Study. Wall thickness and volume, lipid-core volume, and fibrous cap thickness (by MRI) and plasma RANTES levels (by ELISA) were measured. Regression analysis was performed to study the associations between MRI variables and RANTES. Among 1769 inclusive participants, multivariable regression analysis revealed that total wall volume [beta-coefficient (β) = 0.09, P = 0.008], maximum wall thickness (β = 0.08, P = 0.01), vessel wall area (β = 0.07, P = 0.02), mean minimum fibrous cap thickness (β = 0.11, P = 0.03), and high-sensitivity C-reactive protein (β = 0.09, P = 0.01) were positively associated with RANTES. Total lipid-core volume showed positive association in unadjusted models (β = 0.18, P = 0.02), but not in fully adjusted models (β = 0.13, P = 0.09). RANTES levels were highest in Caucasian females followed by Caucasian males, African-American females, and African-American males (P < 0.0001). Statin use attenuated the relationship between RANTES and measures of plaque burden.
Conclusion: Positive associations between RANTES and carotid wall thickness and lipid-core volume (in univariate analysis) suggest that higher RANTES levels may be associated with extent of carotid atherosclerosis and high-risk plaques. Associations between fibrous cap thickness and RANTES likely reflect the lower reliability estimate for fibrous cap measurements compared with wall volume or lipid-core volume measurements. Statin use may modify the association between RANTES and carotid atherosclerosis. Furthermore, RANTES levels vary by race.