Effects of Smoking Cessation on Gastric Emptying in Smokers

Background: Smoking cessation can lead to changes in appetite and weight gain in some patients; thus, smoking cessation may alter gastrointestinal motility. Effects of smoking cessation on gastric emptying in smokers have not been established. Aim: This study sought to determine how smoking cessation affects gastric emptying in smokers. Methods: Participant group comprised 53 habitual smokers and 12 healthy nonsmokers. Habitual smokers were treated for 2 months with transdermal nicotine patches. Gastric emptying was studied using C-13 acetate breath tests at the beginning of the study, and at 1 week and 9 weeks after cessation of patch use. Maximal (CO2)-C-13 excretion time (T-max), (CO2)-C-13 excretion half-life (T-1/2), and parameters beta and kappa, representing initial and subsequent gastric-emptying phases, respectively, were determined using conventional formulae. Results: Before smoking cessation, T-max was reached significantly later in smokers (0.94 +/- 0.3 h, P = 0.014) than in controls (0.89 +/- 0.1 h). At 1 week after the end of treatment, Tmax was significantly decreased (from 1.05 +/- 0.32 h to 0.72 +/- 0.64 h, P= 0.003). T-1/2 also tended to decrease, but not significantly. Although beta was decreased significantly (from 2.46 +/- 0.40 to 2.17 +/- 0.58, P = 0.022), kappa was unchanged. However, by 9 weeks after the end of treatment, T-max (1.28 +/- 0.69 h) had increased to levels seen before treatment. Conclusions: Smoking cessation temporarily accelerates gastric emptying, and decreases in beta suggest that initial-phase gastric emptying accelerates after smoking cessation. The temporary acceleration of gastric emptying after smoking cessation may be involved in the temporary increase in appetite and weight gain seen after smoking cessation.