CHRONIC USE OF LIGHT OR HEAVY CIGARETTES AND CAROTID IMT

Objective: to evaluate the effect of chronic use of light or heavy cigarettes on carotid intima media thickness (IMT). Methods: data from 1113 never-, 377 former- and 315 current-smokers were analysed. Among 692 former/current smokers, 435 were light- and 257 were heavy-smokers (packyear≥30). 522 were users of high-nicotine (≥0.7mg) cigarettes, 615 of high-tar (≥7mg) cigarettes and 616 of high-carbon monoxide (CO) (≥7mg) cigarettes. Results: Years of smoking and number of cigarettes smoked per day (Cig/die) correlated with IMT better than packyear. In former smokers, the years elapsed since smoking cessation (YESSC) was a strong determinant of lower IMT. These variables, together with traditional risk factors were used as covariates in the successive categorized analysis. IMT was higher in current- (1.07±0.25 mm) lower in former- (1.05±0.34 mm) and lowest in never-smokers (0.93±0.27 mm) (p<0.0001). Similarly, IMT was higher in heavy- (1.13±0.36 mm) lower in light- (1.01±0.26 mm) and lowest in never-smokers (all p<0.0001). On average, even after data adjustment for confounders, no difference in IMT was observed when low-nicotine vs high-nicotine or low-tar vs high-tar or low-CO vs high-CO cigarettes consumers were compared. Conclusions: light and heavy cigarettes have the same proatherogenic effect. Packyear, Cig/die, years of smoking and YESSC (in former-smoker) are important covariates that have to be taken into account when smoking habit is considered as vascular risk factor. Funding: Research here described was supported in part by Philip Morris USA Inc. and Philip Morris International.