Brief communication: smoking and duodenal blood flow.

Smoking promotes an increase in both the incidence and the recurrence of duodenal ulcers, but the mechanisms responsible for its adverse effects on the duodenal mucosa are still poorly understood. The aim of the present study was to investigate the effect of chronic cigarette smoking on duodenal blood flow. In 20 dyspeptic patients (10 non-smokers and 10 smokers) with endoscopically normal duodenum, mucosal blood flow was measured in the duodenal bulb by laser Doppler flowmetry during endoscopy. Basal bulbar perfusion was found to be significantly lower (P < 0.05) in smokers. Our results suggest that duodenal blood flow is reduced in heavy smokers. This may promote duodenal damage because of both local ischaemia and the reduced secretion of protective bicarbonate.