ASSOCIATION OF HIGH PLASMA ANTIOXIDANT CAPACITY WITH NEW LESION FORMATION IN CAROTID ATHEROSCLEROSIS - A PROSPECTIVE-STUDY

Background In atherosclerosis, both reductions and elevations in plasm a levels of antioxidants have been reported. This study investigated t otal antioxidant capacity of plasma from subjects with atherosclerotic disease. Materials and methods The study population consisted of 48 m en with or without carotid atherosclerosis. At baseline (1990) carotid arteries were evaluated by duplex sonography and plasma samples were obtained for testing antioxidant capacity by two different test system s. One assay system used neutrophils from healthy volunteers as a sour ce of oxygen free radicals activating the non-fluorescent dichlorofluo rescin diacetate in the presence of antioxidant containing plasma hom study subjects. In the other test system, total plasma antioxidants we re detected colorimetrically by using 2,2'-azino-di-(3-ethylbenzthiazo line sulphonate), metmyoglobin and superoxide in the presence of plasm a. Carotid arteries were re-evaluated for the development of new plaqu es 5 years later (1995). Results Increased baseline total antioxidant capacity of plasma was significantly associated with the development o f new atherosclerotic lesions during a period of 5 years. Conclusions Endogenous antioxidant capacity of plasma is increased in patients wit h active atherosclerotic disease. As scavenging of oxygen free radical s is thought to protect from atherogenesis, elevated antioxidative cap acity may represent an adaptive mechanism.