LDL oxidative modification and carotid atherosclerosis: Results of a multicenter study

ObjectiveSerum LDL conjugated diene concentration is a marker of oxidative modification of LDL. We investigated the relationship between LDL conjugated dienes and cross-sectional subclinical atherosclerosis assessed by carotid IMT in high-risk subjects of a multicenter study.MethodsSerum LDL conjugated dienes and ultrasonographically assessed carotid intima-media thickness (IMTmean, IMTmax and IMTmean-max) were available for 553 subjects from Finland, France, Italy, the Netherlands, and Sweden.ResultsIn multivariate regression analysis, gender (p < 0.001), age (p < 0.001), systolic blood pressure (IMTmean, p = 0.01; IMTmean-max, p = 0.05) and serum LDL conjugated dienes (p = 0.02 for both IMTmean and IMTmean-max) were the strongest determinants of IMT variation, adjusted for study center, ultrasound videotape reader and serum LDL cholesterol. Pack-years of smoking, added into the regression model, did not destroy the significant association between increased serum LDL conjugated dienes and IMT. Ratio of LDL conjugated dienes to LDL particle cholesterol was higher in subjects of Northern recruiting centers than of Southern centers (r = 0.39, p < 0.0001).ConclusionsThere was a cross-sectional association between in vivo increased LDL oxidative modification and subclinical atherosclerosis after adjustment for traditional risk factors. The subjects in Northern countries of Europe had more oxidatively modified lipids per cholesterol in LDL particle than subjects in Southern countries.

► This is a substudy of a multicenter IMPROVE study of atherosclerosis risk factors. ► LDL oxidation was measured as the amount of serum LDL conjugated dienes. ► An association between LDL oxidative modification and atherosclerosis was found. ► Subjects in North had more oxidized LDL than subjects in South.