Oxidised LDL and Serum Paraoxanase Activity in Ischemic Stroke Patients: A Case Control Study

Introduction: Oxidative stress by producing lipid peroxidation products like oxidised Low Density Lipoprotein (LDL) acts as independent risk factor in ischemic stroke. When lipid peroxidation overwhelms antioxidative defense mechanism; it results in enhanced formation of oxidized LDL which promotes atherosclerosis. Human serum Paraoxanase (PON 1) which is an ester hydrolase synthesized in the liver prevents the oxidative modification of LDL. Aim: To investigate the level of oxidized LDL as oxidative stress marker and paraoxonase activity as an antioxidant enzyme in ischemic stroke patients and also the relation between Oxidized-Low Density Lipoprotein (Ox-LDL) level and Computed Tomography (CT) findings in ischemic stroke patients. Materials and Methods: The subjects in this study comprised of 40 ischemic stroke patients and 40 age and gender matched controls. Fasting plasma glucose, serum paraoxanase activity, plasma oxidised LDL level, fasting lipid profile were determined. Data was analysed using Statistical Package for Social Sciences (SPSS) version 16.0. Results: Ischemic stroke patients had significantly lower paraoxanase activity (2.26 µg/ml), total cholesterol (>200 mg%) and fasting plasma glucose levels (>126 mg%). Conclusion: Oxidised LDL level >2.26 µg/ml, paraoxanase activity 126 mg% were independent risk factors for stroke. Significantly higher levels of oxidized LDL were seen in patients with infarct in anterior circulation. This study implies that raised oxidized LDL level and low serum paraoxanase activity are independent risk factors of ischemic stroke in patients with no other risk factors.