title: Correlation of hyperhomocysteinaemia and Chlamydia pneumoniae IgG seropositivity with coronary artery disease in a general population.
abstract: BACKGROUND
  Both Chlamydia pneumoniae infection and hyperhomocysteinaemia have been assumed to increase the atherosclerotic risk independently of each other and independently of the classic risk factors. The correlation between hyperhomocysteinaemia, C. pneumoniae infection and coronary artery disease (CAD) have not been investigated in the general population.
  
  
  METHODS
  In an ancillary study to the Persian Gulf Healthy Heart Study, a cohort study of men and women aged >or=25 years, a random sample of 1699 (48.9% males, 51.1% females) subjects were evaluated. Total homocysteine, high sensitivity C-reactive protein (CRP) and IgG antibodies to C. pneumoniae were determined by ELISA. Minnesota coding criteria of a 12-lead resting electrocardiogram was used for evaluation of CAD.
  
  
  RESULTS
  A total of 12.4% of the subjects had electrocardiogram-defined (Minnesota-coding criteria) coronary artery disease. Hyperhomocysteinaemia (>14 micromol/l) and IgG seropositivity were found in 50.8% and 37.7%, respectively. Neither of hyperhomocysteinaemia nor C. pneumoniae IgG seropositivity showed a significant association with CAD after adjusting of sex and age. Concurrent elevated CRP level (>8.2mg/l) and C. pneumoniae seropositivity (chronic C. pneumoniae infection) had a significant association with CAD [OR=1.73, CI (1.09-2.75); p=0.01] after adjusting for age, sex, systolic and diastolic blood pressures, BMI, and serum levels of LDL-cholesterol, fasting blood sugar and triglyceride as covariates in a logistic regression model. This odds ratio increased to 2.11, CI (1.18-4.12; p=0.02) when concurrent hyperhomocysteinaemia and chronic C. pneumoniae infection, as a single covariate entity; was adjusted for multiple risk factors in another logistic regression model.
  
  
  CONCLUSIONS
  Concurrent hyperhomocysteinaemia and chronic C. pneumoniae infection, as a single entity, was independently associated with coronary artery disease in the general population. This synergism may have important implications for risk-stratification and intervention trials.
authors.affiliation: Professor Haghighi Section of Tropical Medicine, The Persian Gulf Health Research Center, Bushehr University of Medical Science, Bushehr, Islamic Republic of Iran. nabipourpg@bpums.ac.ir
authors.forename: Iraj
authors.initials: I
authors.lastname: Nabipour
authors.forename: Katayon
authors.initials: K
authors.lastname: Vahdat
authors.forename: Seyed Mojtaba
authors.initials: SM
authors.lastname: Jafari
authors.forename: Mohammad
authors.initials: M
authors.lastname: Amiri
authors.forename: Ebrahim
authors.initials: E
authors.lastname: Shafeiae
authors.forename: Ahmad
authors.initials: A
authors.lastname: Riazi
authors.forename: Abdol-Latif
authors.initials: AL
authors.lastname: Amini
authors.forename: Raha
authors.initials: R
authors.lastname: Pazoki
authors.forename: Zahra
authors.initials: Z
authors.lastname: Sanjdideh
mesh_terms: D000328:Adult; D000368:Aged; D000907:Antibodies, Bacterial / Q000276:immunology; D002097:C-Reactive Protein / Q000378:metabolism; D016022:Case-Control Studies; D023521:Chlamydophila Infections / Q000150:complications* / Q000453:epidemiology / Q000276:immunology; D016993:Chlamydophila pneumoniae / Q000276:immunology; D015331:Cohort Studies; D003324:Coronary Artery Disease / Q000150:complications* / Q000453:epidemiology; D004562:Electrocardiography; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006710:Homocysteine / Q000097:blood; D006801:Humans; D020138:Hyperhomocysteinemia / Q000150:complications* / Q000453:epidemiology; D007074:Immunoglobulin G / Q000276:immunology; D007256:Information Systems / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged
chemical_list: D000907:Antibodies, Bacterial; D007074:Immunoglobulin G; D006710:Homocysteine; D002097:C-Reactive Protein