Smokeless nicotine administration is associated with hypertension but not with a deterioration in glucose tolerance in rats.

Cigarette smoking is a major risk factor for coronary heart disease. To further investigate the relationship of nicotine with other cardiac risk factors, we studied the impact of nicotine on blood pressure and glucose tolerance. Adult male Sprague-Dawley rats were randomly assigned to receive nicotine or placebo pellets implanted subcutaneously. Weight gain was controlled by pair-feeding, and was not significantly different between nicotine- and placebo-treated animals. Blood pressure (in mm Hg) increased throughout a 3-week treatment period in nicotine-treated animals and was significantly higher [P < .05 by two-way ANOVA] than in placebo-treated rats. Blood pressure returned to normal within 1 week following exhaustion of the pellets. Oral glucose tolerance tests performed 2.5 weeks after pellet placement showed similar glucose, insulin, and free fatty acid (FFA) profiles by two-way ANOVA. In summary, smokeless nicotine exposure leads to sustained but reversible hypertension without deterioration in glucose tolerance or insulin action when weight gain is controlled. We conclude that in rats smokeless nicotine adversely affects the coronary risk profile by increasing blood pressure.