Relationship Between Helicobacter pylori Infection and Serum Interleukin‐18 in Patients with Carotid Atherosclerosis

BACKGROUND: Helicobacter pylori (H. pylori) infection stimulates the production of proinflammatory cytokines associated with the development of atherosclerosis. Levels of circulating interleukin-18 (IL-18) have been positively correlated with carotid intima-media thickness (IMT) and coronary plaque area and have identified IL-18 levels as important predictors of coronary events and cardiovascular mortality. This study aimed to examine the relationship between serum IL-18 and H. pylori-IgG antibody as a sign of H. pylori infection in patients with carotid atherosclerosis. METHODS: The carotid IMT, traditional atherosclerotic risk factors, levels of serum H. pylori-IgG and IL-18 were measured in 573 health checkup examinees. RESULTS: Serum IL-18 and H. pylori-IgG levels were significantly increased in subjects with increased IMT in comparison with those with normal IMT. In subjects with increased IMT, serum H. pylori-IgG was positively correlated with serum IL-18 (r = .402, p = .002), and the association was independent of traditional atherosclerotic risk factors (β = 0.310, p < .001). CONCLUSIONS: In health checkup examinees with increased IMT, serum IL-18 and H. pylori-IgG were independently correlated and were significantly higher than in subjects with normal IMT.