NOS3 and atherosclerosis: Aortic IMT in this study increased in group K (+) as was also found in studies conducted by Aliet al (2012).36 Increased aortic and entire blood vessels’ IMT are due to the pathological conditions such as apoptosis and excessive proliferation as a compensation mechanism.37 In the previous study, the increase of IMT as a complication of endothelial dysfunction leads to the atherosclerosis process.38 Cigarette smoke exposure underlies the endothelial dysfunction by the reduction of e-NOS level and increase of VCAM-1 expression.39