Background: Oral ethanol intake results in lower blood ethanol concentrations than intravenous administration of the same dose of ethanol. This first-pass metabolism is thought to be due to gastric metabolism of ethanol via alcohol dehydrogenase and also to hepatic first-pass metabolism.
Methods: Since a loss of gastric mucosa may decrease first-pass metabolism of ethanol, this metabolism was studied in 10 elderly subjects (6 women and 4 men) with atrophic gastritis and bacterial overgrowth and in 17 control subjects with normal gastric secretory function. Atrophic gastritis was verified by means of the serum pepsinogen I to pepsinogen II ratio and the hypochlorhydria occurring after pentagastrin stimulation. Bacterial overgrowth was assessed by bacteria. In addition, gastric emptying rates of ethanol solution with technetium-99m sulfur colloid were calculated from scintigraphic images. Furthermore, gastric biopsy specimens were taken from 12 female patients with atrophic gastritis and from 12 controls for determination of alcohol dehydrogenase activity.
Results: Neither gender (female versus male, 28 +/- 5% versus 42 +/- 5%), atrophic gastritis (normal versus atrophic gastritis, 35 +/- 4% versus 32 +/- 6%), nor tetracycline treatment in atrophic gastritis subjects (before versus after, 32 +/- 6% versus 41 +/- 5%) had a statistically significant effect on the first-pass metabolism of ethanol in the elderly. Gastric alcohol dehydrogenase activity was significantly lower in atrophic gastritis subjects than in controls (p < 0.01). A significant correlation was found between the first-pass metabolism of ethanol in healthy controls and gastric half-emptying time (p = 0.032).
Conclusions: We conclude from these data that the rate of gastric emptying modulates first-pass metabolism of ethanol in elderly individuals.