Results of a large population-based study support the hypothesis that estrogen promotes duodenal bicarbonate secretion, which lowers the risk for ulcers.

Studies have shown that women are less likely than men to develop duodenal ulcers (DUs). Other studies have suggested that estrogen stimulates duodenal bicarbonate secretion, which could be a biological mechanism for the lower incidence of DUs among women. To investigate this possible link, researchers in China conducted an epidemiologic study involving 64,385 patients who underwent endoscopy for dyspepsia.


The prevalence of DUs was lower in women than men: Women aged 20 to 49 were 4 to 5 times less likely to have DUs than men of the same age; in contrast, women aged 60 to 69 were only 1.3 times less likely to have DUs than men of the same age. Basal and acid-stimulated duodenal bicarbonate secretion levels were higher among women aged 20 to 29 than men of that age group, but this was not true for patients aged 60 to 69.

Among a cohort of eight volunteers, bicarbonate secretion increased with estrogen levels during the physiologic menstrual cycle. In other subanalyses, exogenous 17-? estradiol stimulated duodenal bicarbonate secretion in both sexes and both age groups, and estrogen receptors were found on the plasma membranes and in the cytosol of duodenal epithelial cells of both sexes.

The authors conclude that estrogen regulates human duodenal bicarbonate secretion, which might reduce the risk for DUs in women.


Citation(s):

Tuo B et al. Estrogen regulation of duodenal bicarbonate secretion and sex-specific protection of human duodenum. Gastroenterology 2011 Sep; 141:854.