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.