Smoking and male gender rather than CagA protein are associated with increased risk for duodenal ulcer in Helicobacter pylori-infected patients in Taiwan.

The aim of this study was to examine the seroprevalence of antibody to CagA antigen, as well as other major H. pylori antigens by Western blot in H. pylori-infected subjects with endoscopically normal mucosa (N = 54) and duodenal ulcer (N = 51). The role of the host and environmental factors was also evaluated. There was no significant difference in the prevalence of antibodies against the major H. pylori antigens between the two groups. A high prevalence of antibody to CagA was detected in patients with normal mucosa (93%) and duodenal ulcer (86%). Multivariate analysis shows that male gender (odds ratio = 4.94, 95% CI = 1.39-17.77, P = 0.014) and smoking (odds ratio = 8.89, 95% CI = 2.17-36.48, P = 0.002) were associated with duodenal ulcer disease. This study suggests that smoking and male gender rather than CagA protein are associated with increased risk for duodenal ulcer in H. pylori-infected patients in Taiwan.