Objective: Chronic infection by Helicobacter pylori is regarded as an etiological factor for vascular diseases. However, there are conflicting results on the relevance of chronic infection by Helicobacter pylori as a risk factor for ischemic stroke. The aim of our study was to investigate the association between Helicobacter pylori infection and ischemic stroke subtypes in Chinese.

Method: A total of 150 patients with ischemic stroke were enrolled in the patient group. Analyses were stratified for etiologic stroke subtypes according to 2007 modified Trial of Org 10172 in Acute Stroke Treatment criteria: 119 patients with atherothrombosis, 15 patients with cardioembolism, and 12 patients with small artery disease. One hundred and thirty-one control subjects without clinical and instrumental evidence of atherosclerotic diseases were randomly selected from health check-up center. The potential risk factors for Helicobacter pylori infection and traditional risk factors for ischemic stroke of all subjects were analyzed. The serum specific antibody IgG of Helicobacter pylori was detected by enzyme-linked immunosorbent assay. Conditional logistic regression was used to analyze the data.

Results: The Helicobacter pylori/IgG-positive rate in the patient group was higher than that in the healthy control group, but the difference was not statistically significant [67.3% versus 61.8%; odds ratio (OR) = 1.272; P = 0.336]. This result remained non-significant after adjustment for other established risk factors [OR = 1.222; 95% confidence interval (CI): 0.688-2.171; P = 0.494]. Subgroup analysis using univariate and multivariate analyses yielded similar results in all etiologic stroke subtypes (univariate analysis, atherothrombosis: OR = 1.368, 95%CI: 0.810-2.311, P = 0.241; cardioembolism: OR = 0.926, 95%CI:0.311-2.758, P = 0.890; small artery disease: OR = 1.852, 95%CI: 0.478-7.167, P = 0.366; multivariate analysis, atherothrombosis: OR = 1.385, 95%CI: 0.726-2.639, P = 0.323; cardioembolism: OR = 0.832, 95%CI: 0.236-2.932, P = 0.775; small artery disease: OR = 1.836, 95%CI: 0.396-8.503, P = 0.437).

Conclusions: This case-control study does not reveal any strong association between chronic Helicobacter pylori infection and ischemic stroke. Large case-control prospective studies are required for further investigation of the potential association between Helicobacter pylori infection and ischemic stroke risk, particularly in certain subgroups.