Helicobacter pylori infection increases subsequent ischemic stroke risk: a nationwide population-based retrospective cohort study.
BACKGROUND AND PURPOSE
The association of Helicobacter pylori infection (HP-I) with ischemic stroke (IS) incidence has been studied, but conflicting results have been reported. The purpose of this study was to investigate the association between chronic HP-I and the risk of acute IS by using data from the Taiwan National Health Insurance Research Database.


METHODS
We identified17 332 patients with HP-I and 69 328 randomly selected age- and gender-matched controls from 1 January 2000 to 31 December 2010. Both cohorts were followed up until the occurrence of IS or until censored. The Cox proportional hazards model was used for assessing the association of HP-I with IS.


RESULTS
Compared with the control cohort, patients diagnosed with HP-I exhibited a higher incidence rate of IS (14.8 vs. 8.45 per 1000 person years) and a hazard ratio (HR) of 1.52 (95% confidence interval [CI] = 1.40-1.65). The HRs for IS were 1.49 (1.37-1.62) in patients diagnosed with HP-I who had one admission, increasing to 2.26 (1.71-1.98) for those who had two or more admissions when adjusted for age, sex and comorbidities (P for trend < 0.0001). In addition, we observed a significantly positive association between nonembolic IS and increased admissions (P for trend < 0.0001) but negative association with embolic IS.


CONCLUSION
Chronic HP-I is significantly associated with an increased risk of IS, particularly nonembolic IS. Anti-HP therapy may be beneficial to IS prevention.