title: The association of seropositivity to Helicobacter pylori, Chlamydia pneumoniae, and cytomegalovirus with risk of cardiovascular disease: a prospective study.
abstract: OBJECTIVE
  We sought to determine whether seropositivity to Helicobacter pylori, Chlamydia pneumoniae, and cytomegalovirus (CMV) is an independent predictor of incident cardiovascular disease.
  
  
  BACKGROUND
  Recent reports have suggested that infections may contribute to risk of cardiovascular disease. However, prospective studies of these associations in a free-living population are lacking.
  
  
  METHODS
  We measured serum H. pylori IgG, C. pneumoniae IgG and IgA, and CMV IgG levels in Framingham Heart Study cohort participants. Blood samples were drawn during the 16th biennial examination cycle (1979 to 1982) from 1,187 participants free of cardiovascular disease (mean age 69 years) and stored at -20 degrees C. A pooled primary end point of myocardial infarction, atherothrombotic stroke, and coronary heart disease deaths was studied in relation to serology. Using a Cox model, hazard ratios (HR) and 95% confidence intervals (CI) were calculated, adjusting for age, gender, and established risk factors.
  
  
  RESULTS
  Seropositivity to H. pylori IgG, C. pneumoniae IgG, C. pneumoniae IgA, and CMV IgG was 60%, 45%, 11%, and 69%, respectively. During 10 years of follow-up, incident cardiovascular disease occurred in 199 participants (16.8%). In age- and gender-adjusted models, H. pylori IgG (HR 1.09, 95% CI 0.81 to 1.46), C. pneumoniae IgG (HR 0.91, 95% CI 0.68 to 1.20), C. pneumoniae IgA (HR 0.65, 95% CI 0.39 to 1.07), and CMV IgG (HR 0.84, 95% CI 0.62 to 1.12) were not associated with incident cardiovascular disease. These associations were further attenuated after adjustment for risk factors including body mass index, total and high-density lipoprotein cholesterol, diabetes mellitus, smoking, and hypertension. These estimates did not change for the individual components of cardiovascular disease, and seropositivity to more than one organism did not alter these risk estimates substantially.
  
  
  CONCLUSIONS
  In this elderly cohort, chronic H. pylori, C. pneumoniae, and CMV infections, as evidenced by seropositivity, were not associated with increased risk for cardiovascular disease. Additional studies are needed to determine the relations of chronic infections to cardiovascular disease risk in younger persons.
authors.affiliation: National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, Massachusetts 01702, USA.
authors.forename: Agha W
authors.initials: AW
authors.lastname: Haider
authors.forename: Peter W F
authors.initials: PW
authors.lastname: Wilson
authors.forename: Martin G
authors.initials: MG
authors.lastname: Larson
authors.forename: Jane C
authors.initials: JC
authors.lastname: Evans
authors.forename: Eric L
authors.initials: EL
authors.lastname: Michelson
authors.forename: Philip A
authors.initials: PA
authors.lastname: Wolf
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: O'Donnell
authors.forename: Daniel
authors.initials: D
authors.lastname: Levy
mesh_terms: D000368:Aged; D002318:Cardiovascular Diseases / Q000453:epidemiology* / Q000382:microbiology; D023521:Chlamydophila Infections / Q000453:epidemiology*; D016993:Chlamydophila pneumoniae; D015331:Cohort Studies; D015897:Comorbidity; D003586:Cytomegalovirus Infections / Q000453:epidemiology*; D005260:Female; D016481:Helicobacter Infections / Q000453:epidemiology*; D016480:Helicobacter pylori; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D016036:Seroepidemiologic Studies