Single polymorphism nucleotide rs1333049 on chromosome 9p21 is associated with carotid plaques but not with common carotid intima-media thickness in older adults. A combined analysis of the Three-City and the EVA studies.

OBJECTIVES: To address the relationship of rs1333049, the 9p21 variant showing the strongest association with coronary heart disease (CHD), with carotid plaques and plaque-free common carotid artery intima-media thickness (CCA-IMT) in older adults from 2 French population-based cohorts.
METHODS: We genotyped for rs1333049, 4097 CHD-free participants including 3191 aged 65-86 years from the Three-City (3C) Study and 906 aged 59-71 years from the Vascular Aging Study (EVA). Plaque-free mean CCA-IMT and the presence of carotid plaques were assessed.
RESULTS: In multivariate analysis, each C allele copy of rs1333049 was associated with baseline carotid plaques (odds ratio (OR)=1.24; 95% confidence interval (CI)=1.13-1.36; p<0.001) but not with baseline CCA-IMT (p=0.19). Among the EVA participants, the C allele was associated with 4-year plaques progression (p=0.04) but not with CCA-IMT progression.
CONCLUSION: The chromosome 9p21 locus might influence CHD risk through carotid plaques development.