Studies supporting the nicotine regulation model of smoking, suggested that smokers compensate the low amount of nicotine from low-nicotine cigarette by changing smoking frequency or other aspects of smoking behaviour. Aim of this study was to evaluate the effect of chronic use of light or heavy cigarettes on carotid artery intima media thickness (IMT): 96 current-, 150 former- and 418 never-smokers were recruited. 161 were light-smokers (pack-years<30) and 85 heavy-smokers (pack-years 6530); 63 subjects were users of cigarettes with low-nicotine (<0.7mg), 183 with high-nicotine ( 650.7mg), 35 with low-tar (<7mg) and 211 with high-tar ( 657mg). IMT in former- (1.05\ub10.33 mm) and current-smokers (1.16\ub10.27 mm) was significantly greater than in never-smokers (0.95\ub10.29 mm) (both p<0.002). The difference between former and current smokers was significant (p=0.015). IMT of light- (1.05\ub10.29 mm) and heavy-smokers (1.17\ub10.34 mm) was higher than in never-smokers (both p<0.001). The difference between heavy- and light-smokers was also significant (p<0.01). On average, IMT of low- (1.09\ub10.25 mm) and high-nicotine (1.08\ub10.33 mm) cigarette consumers was greater than in never-smokers (both p<0.002). No difference in IMT was observed when low- and high-nicotine cigarette consumers were compared. IMT in patients who smoked low-tar (1.083\ub10.29 mm) or high-tar (1.085\ub10.31 mm) cigarettes was greater than in never-smokers (p=0.03 and 0.0001, respectively). No differences were observed between low- and high-tar cigarette smokers. In conclusion light and heavy cigarettes have the same proatherogenic effect
