Forearm endothelial response in smokeless tobacco users compared with cigarette smokers and nonusers of tobacco

Study Objective. To compare brachial artery flow-mediated dilation (FMD) in subjects who use smokeless tobacco, smoke cigarettes, or do not use any tobacco product. Design. Cross-sectional study. Setting. University-affiliated outpatient clinic. Subjects. Seventeen apparently healthy volunteers who for more than I year smoked at least 10 cigarettes/day, used at least two containers of smokeless tobacco/week, or did not use any tobacco product. Measurements and Main Results. Baseline characteristics of subjects were similar among the three groups except for mean age and serum cotinine level. Baseline brachial artery diameter, endothelium-dependent FMD induced by reactive hyperemia, and endothelium-independent dilation induced by administration of sublingual nitroglycerin were measured. Mean FMD over baseline was 4.1% +/- 0.7% in subjects who used smokeless tobacco, 3.9% +/- 5.1% in cigarettes smokers, and 12.2% +/- 5.7% in nonusers of tobacco (p=0.01). Endo thelium-independent dilation induced by nitroglycerin was not statistically different among the three groups. Conclusion. Brachial artery FMD, a surrogate for endothelial dysfunction, was significantly impaired in smokeless tobacco users and cigarette smokers compared with nonusers of tobacco.