ASSOCIATION OF HELICOBACTER-PYLORI AND CHLAMYDIA-PNEUMONIAE INFECTIONS WITH CORONARY HEART-DISEASE AND CARDIOVASCULAR RISK-FACTORS

Objective-To investigate the relation between seropositivity to chronic infections with Helicobacter pylori and Chlamydia pneumoniae and both coronary heart disease and cardiovascular risk factors. Design-Cross sectional study of a population based random sample of men. Coronary heart disease was assessed by electrocardiography, Rose angina questionnaire, and a history of myocardial infarction; serum antibody levels to H pylori and C pneumoniae were measured, risk factor levels determined, and a questionnaire administered. Setting-General practices in Merton, Sutton, and Wandsworth, south London. Subjects-388 white south London men aged 50-69. Main outcome measures-Evidence of coronary risk factors and infection with H pylori or C pneumoniae. Results-47 men (12.1%) had electrocardiographic evidence of ischaemia or infarction. 36 (76.6%) and 18 (38.3%) were seropositive for H pylori and C pneumoniae, respectively, compared with 155 (45.5%) and 62 (18.2%) men with normal electrocardiograms. Odds ratios for abnormal electrocardiograms were 3.82 (95% confidence interval 1.60 to 9.10) and 3.06 (1.33 to 7.01) in men seropositive for H pylori and C pneumoniae, respectively, after adjustment for a range of socioeconomic indicators and risk factors for coronary heart disease. Cardiovascular risk factors that were independently associated with seropositivity to H pylori included fibrinogen concentration and total leucocyte count. Seropositivity to C pneumoniae was independently associated with raised fibrinogen and malondialdehyde concentrations. Conclusions-Both H pylori and C pneumoniae infections are associated with coronary heart disease. These relations are not explained by a wide range of confounding factors. Possible mechanisms include an increase in risk factor levels due to a low grade chronic inflammatory response.