Prevalence of ischemic stroke and Helicobacter pylori infection

Abstract

Dear Sir, We appreciated the paper by Shindler‐Itskovitch et al,1 who ob‐ served an association between Helicobacter pylori infection and oc‐ currence of ischemic stroke. Their results are in contrast with the conclusion of the metanalysis carried out by Yu et al,2 who stated no association whatsoever. Previous metanalyses, on the contrary, found a positive association.3 We offer an explanation for such ap‐ parent disagreement: The metanalysis by Yu et al is based on the selection of papers to be analyzed and on the lack of differentiation between cardioembolic vs non‐cardioembolic stroke.1 We hypothe‐ sized that only patients with this latter type of stroke and younger than 65 years should be considered at risk for an infectious origin of vascular ischemia, particularly if the agent of infection is H pylori. Indeed, this was what we observed in Turin, Italy.4 Moreover, our 80 consecutive patients with ischemic stroke were diagnosed by means of a positive 13C‐urea breath test (UBT), as did Shindler‐ Itskovitch et al,1 not solely on the basis of the presence of total IgG antibodies against H pylori, as in most other studies. Another intrigu‐ ing finding in Turin was the stronger correlation of the association for females, 86.3% of whom were 13C‐UBT–positive in contrast to 77.5% of males. H pylori infection was not differently associated with current smoking, serum total cholesterol, glucose levels, fibrinogen value in plasma, and hypertension, when compared to the H pylori‐ negative status.4 Even more interesting was the previous finding by Bornstein et al5 in Israel in a nationwide study of an apparently pro‐ tective effects by cigarette smoking; 16% of stroke patients were smokers, as compared to 26.5% of controls; and hyperlipemia was present in 8.2% of patients and in 27.5% of controls.5 Even though the findings of local studies are important, they also indicate that the observations originated in different settings should not be general‐ ized tout court. In this regard, childhood stroke was reported to be of infectious origin by famous neurologists such as Pierre Marie and Sigmund Freud; they wrote that there are no single infective agents, but rather many infectious diseases, that are associated with acute cerebrovascular accidents (reported in 6, refs 10,11). The association between the concept of “total burden of infections” and the risk of ischemic stroke was reiterated by Grau et al,6 and it was observed also in the Northern Manhattan Study. Since stroke incidence and its ominous consequences are on the rise, the prudent physician should evaluate in his local setting all risk factors, including H pylori infection. CONFLIC T OF INTERE S T