SMOKELESS TOBACCO USE AND ATHEROSCLEROSIS - AN ULTRASONOGRAPHIC INVESTIGATION OF CAROTID INTIMA MEDIA THICKNESS IN HEALTHY MIDDLE-AGED MEN

There is well-documented evidence of accelerated atherosclerosis in sm okers but the mechanisms still remain unclear. The relationship to the use of smokeless tobacco, involving high exposure to nicotine, have n ot been evaluated before. The possible role of nicotine was investigat ed in a clinical study of the intima media thickness in the carotid ar tery of 143 healthy, middle-aged men (35-60 years old) with different tobacco consumption habits. B-mode ultrasonography was performed and b iochemical risk factors for cardiovascular disease (serum lipids, seru m lipoproteins and plasma fibrinogen) were determined. Long term smoke less tobacco users (n = 28) did not differ significantly from never-us ers (n = 40: regarding bulb intima media thickness (0.80 +/- 0.13 vers us 0.78 +/- 0.12 mm) or common carotid intima media thickness (0.67 +/ - 0.11 versus 0.68 +/- 0.11 mm), whereas smokers (n = 29) had signific antly increased wall measurements (bulb 0.87 +/- 0.19, P = 0.002 commo n carotid 0.74 +/- 0.13, P = 0.03) compared to never-users. Only in sm okers were biochemical risk factors significantly altered towards an e levated risk. Significant effects of interaction of smoking and increa sed s-cholesterol levels on carotid intima media thickness were also f ound. Smokeless tobacco users showed similar tendencies, but without d efinite statistical significance. On the basis of these data, it appea rs most likely that the increased occurrence of atherosclerosis in smo kers is caused by other components of tobacco smoke than nicotine. (C) 1997 Elsevier Science Ireland Ltd.