Background: Chronic Helicobacter pylori infection has been implicated as a risk factor for stroke and other cardiovascular disease. It has been suggested that it acts by promoting atherogenesis. A particular strain of H. pylori, the cytotoxin gene A strain (CagA strain), which has been associated with increased inflammation, has been reported to account for much of this relationship. An early estimate of atherosclerosis can be obtained by ultrasonic imaging of the carotid artery to determine intima-media thickness (IMT). We determined whether H. pylori infection, and particularly the CagA strain, is associated with increased IMT.
Methods: In 983 normal population individuals we measured common carotid artery (CCA) IMT. From serum samples we determined H. pylori and CagA status.
Results: There was no significant association between H. pylori seropositivity and CCA IMT after controlling for age and gender. There were significant relationships between H. pylori seropositivity and a number of conventional cardiovascular risk factors (age, systolic and diastolic blood pressure, body mass index, smoking) and after controlling for these the magnitude of the regression coefficient was reduced by a further half. Amongst H. pylori seropositives the CagA strain was associated with increased IMT after controlling for age and gender (B = 0.0256, 95% CI 0.001-0.050, P = 0.038). The relationship was no longer significant after controlling for other cardiovascular risk factors. (B = 0.0194, 95% CI -0.004-0.042, P = 0.098).
Conclusions: H. pylori and the CagA strain are not major risk factors for early arteriosclerosis as assessed by carotid artery intima-media thickness.