Chronic infection with Helicobacter pylori, Chlamydia pneumoniae, or cytomegalovirus: population based study of coronary heart disease

Objective-To study possible associations between coronary heart disease and serological evidence of persistent infection with Helicobacter pylori, Chl amydia pneumoniae, or cytomegalovirus. Design-Population based, case-control study, nested within a randomised tri al. Setting-Five general practices in Bedfordshire, UK. Individuals-288 patients with incident or prevalent coronary heart disease and 704 age and sex matched controls. Results-High concentrations of serum IgG antibodies to H pylori were presen t in 54% of cases v 46% of controls, with corresponding results for C pneum oniae seropositivity (33% v 33%), and cytomegalovirus seropositivity (40% v 31%). After adjustments for age, sex, smoking, indicators of socioeconomic status, and standard risk factors, the odds ratios (95% confidence interva ls) for coronary heart disease of seropositivity to these agents were: 1.28 (0.93 to 1.75) for H pylori, 0.95 (0.66 to 1.36) for C pneumoniae, and 1.4 0 (0.96 to 2.05) for cytomegalovirus. Conclusions-There is no good evidence of strong associations between corona ry heart disease and serological markers of persistent infection with H pyl ori, C pneumoniae, or cytomegalovirus. To determine the existence of modera te associations between these agents and disease, however, larger scale stu dies will be needed that can keep residual confounders to a minimum.