Abstract 3853: Influence of C-Reactive Protein on Carotid Intima-Media Thickness and Its Progression in Young Adults: The Bogalusa Heart Study
Aims/hypothesis: C-reactive protein (CRP) has been associated with subclinical atherosclerosis as measured by carotid intima-media thickness (IMT) in middle aged and older adults. However, information is limited regarding its relationship to carotid IMT in a younger adult population.
Methods: We examined a biracial (black-white) community-based sample of 1255 and a sub-sample of 281 young adults aged 24 – 44 years both cross-sectionally and longitudinally (average follow-up period: 5.5 years). Carotid IMT of right and left common, bulb, and internal segments was measured by B-mode ultrasonography and the average value was used.
Results: Cross-sectionally, CRP levels were associated with carotid IMT (r = 0.116, P < 0.001) in univariate analysis; in a multiple regression model which also included age, race, sex, and other traditional risk factors, CRP was not a significant predictor of carotid IMT. However, significant interaction effects between CRP and age (P = 0.025) and between CRP and cigarette smoking (P = 0.035) on carotid IMT were identified in the total sample. CRP was a significant predictor of carotid IMT among those in the top tertile of age (age range: 38 – 44 years). Further, CRP exacerbated adverse effects of cigarette smoking on carotid IMT (P = 0.037); cigarette smokers at the top CRP quintile showed greater carotid IMT (0.872 mm) than expected (0.831 mm) under the assumption of no interaction. In the sub-sample of 281 young adults, subjects at the top CRP quintile at baseline vs the other quintiles showed a greater progression rate of carotid IMT (0.024 vs 0.016 mm/year, P = 0.032). Further, similar interaction effects between baseline CRP and age (P = 0.017) and between baseline CRP and cigarette smoking (P = 0.031) were observed, with cigarette smokers at the top CRP quintile at baseline and the older age group subjects showing much greater progression rate.
Conclusion/interpretation: Among asymptomatic, young adults, CRP adversely influences subclinical atherosclerosis, and its progression, with this association potentiated by age and cigarette smoking.