Effect of smoking on gastric acid secretion in patients with duodenal ulcer.

The effect of smoking on gastric secretion was studied in 15 consecutive patients with duodenal ulcer--six normosecretors (basal acid output less than or equal to 3 mEq/h), and nine hypersecretors (basal acid output greater than 3 mEq/h). The volume, acid output, acid concentration, and pH of the gastric juice measured before, during and after 1 h of smoking did not show any significant difference in these patients taken as a single group, or when the normosecretors and hypersecretors were analysed as separate groups (P greater than 0.05 for each parameter in each group). The higher acid output before and during smoking in hypersecretors than in normosecretors was due to the higher acid concentration in the gastric juice (P less than 0.01). Study of the pH curves of the gastric juice after acute smoking showed that hypersecretors had a lower pH for a longer duration compared with normosecretors. This could make the hypersecretors with a history of chronic smoking more prone to developing duodenal ulcer.