title: Association of interleukin-6 and C-reactive protein with subclinical carotid atherosclerosis (the Rancho Bernardo Study).
abstract: Studies of interleukin-6 (IL-6) and C-reactive protein (CRP) as predictors of atherosclerosis have had mixed results. The purpose of this study was to assess the associations of IL-6 and CRP with the severity of subclinical carotid atherosclerosis measured 12 years later. Participants were 392 adults (56.9% women, mean age 63.2 years) from the Rancho Bernardo Study who had biomarkers measured from 1984 to 1987 and carotid intima-media thickness (IMT) measured from 1996 to 1998. Age-adjusted mean carotid IMT was significantly greater in men than women. After adjusting for traditional cardiovascular risk factors, carotid IMT increased significantly with increasing IL-6 quartiles (p <0.001). In similar analyses, the association between CRP quartiles and carotid IMT was weaker but remained statistically significant (p <0.05). In multiple regression analysis, IL-6 was significantly associated with carotid IMT regardless of CRP. Conversely, CRP was significantly associated with carotid IMT when IL-6 was not included in the model, but this association became nonsignificant when IL-6 was included. In conclusion, baseline IL-6 and CRP were significantly associated with carotid atherosclerosis independent of traditional cardiovascular disease risk factors. The association of IL-6 was independent of CRP, but not vice versa, suggesting an effect of IL-6 on an earlier state of atherosclerosis.
authors.affiliation: Department of Family and Preventive Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, USA.
authors.forename: Won-Young
authors.initials: WY
authors.lastname: Lee
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Allison
authors.forename: Dong-Jun
authors.initials: DJ
authors.lastname: Kim
authors.forename: Chan-Hee
authors.initials: CH
authors.lastname: Song
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Barrett-Connor
mesh_terms: D050197:Atherosclerosis / Q000097:blood / Q000175:diagnosis*; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism*; D002339:Carotid Arteries / Q000473:pathology*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000097:blood*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies
chemical_list: D015415:Biomarkers; D015850:Interleukin-6; D002097:C-Reactive Protein