International Journal of Health Sciences & Research (www.ijhsr.org) 185 Vol.6; Issue: 1; January 2016 International Journal of Health Sciences and Research www.ijhsr.org ISSN: 2249-9571 Original Research Article Oxidative Stress and Thrombotic Disorders: Study in Patients with Venous Thromboembolism Selma Bereksi Reguig 1* , Samira Bouanane 2* , Hafida Merzouk 3* , Nabila Soufi 4** , Sid Ahmed Merzouk 3*** 1 PhD student, 2 Dr, 3 Professor, 4 Assistant Professor, * Laboratory of Physiology, Physiopathology and Biochemistry of Nutrition, Department of Biology, Faculty of Natural and Life Sciences, Earth and Universe, University of Tlemcen 13000, Algeria. ** Cardiology Department, University Hospital Center of Tlemcen 13000, Algeria. *** Department of Technical Sciences, Faculty of Engineering, University of Tlemcen 13000, Algeria. Corresponding Author: Samira Bouanane Received: 11/12/2015 Revised: 26/12/2015 Accepted: 29/12/2015 ABSTRACT We aimed to investigate biochemical markers and the oxidant/antioxidant balance in patients with venous thromboembolism. This study was conducted as a prospective case-control study. 70 patients with venous thromboembolism enrolled to the study and 80 healthy subjects without risk factors for venous thromboembolism were selected as control group. Venous blood samples were obtained from venous thromboembolism patients during the initial diagnosis and from the control subjects. Biochemical parameters (triglycerides and HDL-cholesterol) and oxidative stress markers (malondialdehyde, carbonyl proteins, superoxide anion expressed as reduced Nitroblue Tetrazolium, nitric oxide expressed as nitrite, reduced glutathione, vitamin C, catalase, superoxide dismutase) were assayed by biochemical methods. Plasma triglyceride was increased and HDL-cholesterol levels were decreased in venous thromboembolism patients compared to control. Malondialdehyde, carbonyl proteins levels and catalase activity were high while nitric oxide and vitamin C were low in venous thromboembolism patients than control. Reduced glutathione concentrations, superoxide anion and superoxide dismutase activity were found not significant respectively. Oxidative stress may be one of the causative factors in venous thromboembolism and probably contributes to additional disorders. Keywords: antioxidants, free radicals, lipids, oxidants, thrombosis. INTRODUCTION Cardiovascular diseases (CVDs) are the leading cause of mortality world- wide. Endothelial dysfunction appears in the early stages of the pathogenesis of vascular disorders and it is closely related to the progression of severe clinical complications. [1] Venous thromboembo- lism (VTE) is a common thrombotic disease that encompasses both deep vein thrombosis (DVT) and pulmonary embolism (PE). VTE is increasingly reported in Africa, where confinement to bed and surgery are responsible for 18 to 57% of cases. [2] In Algeria, the prevalence of this disease is on the rise but there are no published data on its frequency or on the thrombogenic potential of associated risk factors. DVT is the first and the most clinical form of VTE, a complex vascular disease associated with various etiological factors. [3] DVT affects 1-2% of society