Endocrine Abstracts

Background: Oxidized low-density lipoprotein (Ox-LDL) is a key factor in the development of arteriosclerosis. It can cause endothelial dysfunction and augment lipid accumulation within the arterial wall. Increased oxidative stress in diabetes contributes to this process. Ox-LDL is a highly immunogenic molecule and it is not clear whether oxidized LDL antibodies (OLAB) are pathogenic or protective in arteriosclerosis? The aim of this study was to evaluate Ox-LDL and its antibody in type 2 diabetes and healthy subjects.

Methods: This nested case–control study included 81 type 2 diabetic patients and 69 non-diabetic healthy persons aged 40 to 65 years. Controls were sex and BMI matched with diabetic patients. Patients with history of cigarette smoking, antioxidant or antihyperlipidemic use, coronary heart disease, hypertension, and renal impairment were excluded. We measured serum level of Ox-LDL (two monoclonal antibody of Mercodia co.) and OLAB by ELISA. Lipid profile, serum electrolytes, and HbA1C (HPLC) were also determined. Ox-LDL and its antibody were compared between diabetic patients and controls and the correlation with lipid profile, HbA1C and BMI were assessed.

Results: Serum Ox-LDL concentration and Ox-LDL to LDL ratio were distinctively higher in controls (15.7±6.9 vs 11.8±5.6, P< 0.005). Ox-LDL concentrations were correlated with LDL-C (rs=0.36, P<0.0005) and total cholesterol (rs=0.31, P<0.0005) in both groups but not with age and HbA1c. In diabetic patients Ox-LDL and its antibody were positively correlated (rs=0.26, P<0.05). Obese diabetic patients (BMI>30) had higher Ox-LDL concentrations compared to diabetic patients with BMI less than 30.

Conclusion: In diabetic patients, Ox-LDL level is lower than non-diabetics and is correlated with its antibodies. Based on previous findings we suppose that the pattern of LDL oxidation enhances Ox-LDL recognition by macrophage via specific legends. This results in low serum Ox-LDL concentrations in diabetes.