Levels of Oxidized LDL and Advanced Glycation End Products–Modified LDL in Circulating Immune Complexes Are Strongly Associated With Increased

OBJECTIVE—High cholesterol levels in circulating immune complexes (IC), surrogate markers of modified LDL, are associ-ated with increased carotid intima-media thickness (IMT) and cardiovascular events in type 1 diabetes. Different modifications of LDL are involved in IC formation, but which of these are predictive of vascular events is not known. Therefore, we mea-sured oxidized LDL (oxLDL), advanced glycation end products– modified LDL (AGE-LDL), and malondialdehyde-modified LDL (MDA-LDL) in IC and determined their relationship with in-creased carotid IMT and compared the strength of the association with that observed with conventional risk factors. RESEARCH DESIGN AND METHODS—Levels of oxLDL, AGE-LDL, and MDA-LDL were measured in circulating IC isolated from sera of 479 patients of the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions an