According to the theory of ox-idative stress, atherosclerosis is the resultof the oxidative modification of low densi-ty lipoproteins (LDL) in the arterial wallby reactive oxygen species (ROS). Evidencesuggests that common risk factors for ath-erosclerosis increase the risk of the pro-duction of free ROS, not only from theendothelial cells, but also from the smoothmuscle cells and the adventitial cells.