Autoantibodies against oxidized LDLs and atherosclerosis in type 2 diabetes

OBJECTIVE: The aim of our study was to examine, in type 2 diabetic patients, the relationship between autoantibodies against oxidatively modified LDL (oxLDL Ab) and two indexes of atherosclerosis, intimal-medial thickness of the common carotid artery (CCA-IMT), which reflects early atherosclerosis, and the ankle-brachial index (ABI), which reflects advanced atherosclerosis. RESEARCH DESIGN AND METHODS: Thirty newly diagnosed type 2 diabetic patients, 30 type 2 diabetic patients with long duration of disease, and 56 control subjects were studied. To detect oxLDL Ab, the ImmunoLisa Anti-oxLDL Antibody ELISA was used. ABI was estimated at rest by strain-gauge plethysmography. Carotid B-mode imaging was performed on a high-resolution imaging system (ATL HDI 5000). RESULTS: In patients with long duration of disease, IgG oxLDL Ab were significantly higher and ABI significantly lower compared with the other two groups. We found a correlation between IgG oxLDL Ab and CCA-IMT in all diabetic patients. A significant inverse correlation between IgG oxLDL Ab and ABI only in patients with long duration of disease was seen, demonstrating a close relationship between these autoantibodies and advanced atherosclerosis. CONCLUSIONS: IgG OxLDL Ab may be markers of the advanced phase of the atherosclerotic process and the response of the immunological system to the oxLDL, which are present within atherosclerotic lesions.