title: Association between Chlamydophila pneumoniae infection and risk of coronary heart disease for Japanese: the JPHC study.
abstract: BACKGROUND
  Chlamydophila pneumoniae infection is considered a risk factor for atherosclerosis and coronary heart disease in western countries. However, evidence of it being a risk for Japanese is very limited because of a lower risk of coronary heart disease than for western people. The aim of this study was to examine further the association between C. pneumoniae infection and risk of coronary heart disease in Japanese.
  
  
  METHODS
  We conducted a nested case-control study of 49,011 Japanese men and women who participated in The Japan Public Health Center (JPHC) study. By the end of 2004, 196 cases of coronary heart disease and 155 cases of myocardial infarction had been documented among the participants. Two controls were selected for each case. For these subjects, we examined the association between serum anti C. pneumoniae IgA and IgG on the one hand and risk of coronary heart disease on the other.
  
  
  RESULTS
  Concentration of C. pneumoniae IgA antibody was positively associated with risk of coronary heart disease and more specifically myocardial infarction. Subjects with the highest quartile of IgA antibody showed 2.29 (95%CI, 1.21-4.33) times higher risk of coronary heart disease and 2.58 (95%CI, 1.29-5.19) times higher risk of myocardial infarction than those with lowest quartile. However, no such association was detected for IgG antibody.
  
  
  CONCLUSIONS
  C. pneumoniae infection was found to be positively associated with risk of coronary heart disease.
authors: Center for Medical Sciences, School of Health Sciences, Ibaraki Prefectural University of Health Sciences, Ami, Ibaraki, Japan.
authors: Naomi
authors: N
authors: Sakurai-Komada
authors: Public Health, Department of Social and Environmental Medicine, Osaka University Graduate School of Medicine, Suita, Osaka-fu 565-0871, Japan. Electronic address: iso@pbhel.med.osaka-u.ac.jp.
authors: Hiroyasu
authors: H
authors: Iso
authors: Center for Medical Sciences, School of Health Sciences, Ibaraki Prefectural University of Health Sciences, Ami, Ibaraki, Japan; School of Health Sciences, Uekusagakuen University, Chiba, Japan.
authors: Kazuko A
authors: KA
authors: Koike
authors: Epidemiology and Prevention Division, Research Center for Cancer Prevention and Screening, National Cancer Center, Tokyo, Japan.
authors: Ai
authors: A
authors: Ikeda
authors: Center for Medical Sciences, School of Health Sciences, Ibaraki Prefectural University of Health Sciences, Ami, Ibaraki, Japan; Department of Public Health, Dokkyo Medical University, School of Medicine, Mibu, Tochigi, Japan.
authors: Mitsumasa
authors: M
authors: Umesawa
authors: Public Health, Department of Social and Environmental Medicine, Osaka University Graduate School of Medicine, Suita, Osaka-fu 565-0871, Japan.
authors: Satoyo
authors: S
authors: Ikehara
authors: Epidemiology and Prevention Division, Research Center for Cancer Prevention and Screening, National Cancer Center, Tokyo, Japan; Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors: Manami
authors: M
authors: Inoue
authors: Epidemiology and Prevention Division, Research Center for Cancer Prevention and Screening, National Cancer Center, Tokyo, Japan.
authors: Shoichiro
authors: S
authors: Tsugane
mesh_terms: D000328:Adult; D000907:Antibodies, Bacterial / Q000097:blood*; D016022:Case-Control Studies; D023521:Chlamydophila Infections / Q000097:blood / Q000453:epidemiology*; D016993:Chlamydophila pneumoniae / Q000276:immunology; D003327:Coronary Disease / Q000097:blood / Q000453:epidemiology*; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood*; D007074:Immunoglobulin G / Q000097:blood*; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000453:epidemiology; D011446:Prospective Studies; D012307:Risk Factors; D016037:Single-Blind Method; D011795:Surveys and Questionnaires
chemical_list: D000907:Antibodies, Bacterial; D007070:Immunoglobulin A; D007074:Immunoglobulin G
keywords: Chlamydophila pneumoniae; Coronary heart disease; JPHC study; Nested case–control study; Risk factor