Abstract
BACKGROUND: Helicobacter pylori infection and interleukin-1 polymorphisms are associated with an increased risk of gastric cancer. We examined the prevalence of Helicobacter pylori seropositivity and interleukin-1 polymorphisms between ST-segment elevation myocardial infarction and non-ST-segment elevation acute coronary syndrome patients. METHODS: We recruited consecutive acute coronary syndrome patients, and 101 non-ST-segment elevation acute coronary syndrome patients and 103 ST-segment elevation myocardial infarction patients were enrolled. Interleukin-1 polymorphism analyses were performed for single nucleotide polymorphism in interleukin-1 beta-511 and the variable number of tandem repeats polymorphism in the interleukin-1 receptor antagonist by polymerase chain reaction. Immunoglobulin G antibodies against Helicobacter pylori and high sensitivity C-reactive protein were also measured. RESULTS: The rates of the simultaneous presence of interleukin-1 polymorphisms and Helicobacter pylori-seropositivity between non-ST-segment elevation acute coronary syndrome and ST-segment elevation myocardial infarction groups were 25.7% and 42.7%, respectively (P = 0.012). Helicobacter pylori-seropositive subjects with interleukin-1 polymorphisms showed significantly higher levels of high sensitivity C-reactive protein (0.04-0.12 vs. 0.02-0.05; P<0.001). Multivariate logistic regression analysis revealed that the carriage of Helicobacter pylori-seropositivity and interleukin-1 polymorphisms was significantly associated with ST-segment elevation myocardial infarction (odds ratio, 2.32; 95% confidence interval, 1.23-4.37; P = 0.009). The C-statistic of conventional risk factors was 0.68 (P<0.001) and that including Helicobacter pylori-seropositivity and interleukin-1 polymorphisms was 0.70 (P<0.001); continuous net reclassification improvement was 34% (P = 0.0094) and integrated discrimination improvement was 3.0% (P = 0.014). CONCLUSIONS: The coincidence of Helicobacter pylori-seropositivity and interleukin-1 polymorphisms was significantly associated with higher levels of high sensitivity C-reactive protein and the increased risk of ST-segment elevation myocardial infarction.