title: A cohort study on the association between periodontal disease and the development of metabolic syndrome.
abstract: BACKGROUND
  An association between periodontal disease and metabolic syndrome based on cross-sectional and case-control studies was recently reported, but their causal relationship has not been fully clarified. The objective of this cohort study is to investigate the association between periodontal disease and changes in metabolic-syndrome components to accumulate evidence of the causal relationship between the two conditions.
  
  
  METHODS
  The study subjects consisted of 1,023 adult employees (727 males and 296 females; mean age: 37.3 years) who underwent medical and dental checkups between 2002 and 2006 and in whom all metabolic-syndrome components were within the standard values in 2002. The association between the presence of periodontal pockets and the positive conversion of metabolic-syndrome components was investigated using multiple logistic-regression analysis, odds ratios (ORs), and 95% confidence intervals (CIs).
  
  
  RESULTS
  The presence of periodontal pockets was associated with a positive conversion of one or more metabolic components during the 4-year observation period (OR: 1.6; 95% CI: 1.1 to 2.2). The ORs for a positive conversion of one component and two or more components were 1.4 (95% CI: 1.0 to 2.1) and 2.2 (95% CI: 1.1 to 4.1), respectively, and the difference was significant for two or more positive components. Of the metabolic-syndrome components, positive conversions of blood pressure and the blood-lipid index were significantly associated with the presence of periodontal pockets.
  
  
  CONCLUSIONS
  The presence of periodontal pockets was associated with a positive conversion of metabolic-syndrome components, suggesting that preventing periodontal disease may prevent metabolic syndrome.
authors.affiliation: Department of Oral Health Sciences, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan.
authors.forename: Toyoko
authors.initials: T
authors.lastname: Morita
authors.forename: Yoji
authors.initials: Y
authors.lastname: Yamazaki
authors.forename: Ayae
authors.initials: A
authors.lastname: Mita
authors.forename: Koji
authors.initials: K
authors.lastname: Takada
authors.forename: Misae
authors.initials: M
authors.lastname: Seto
authors.forename: Norihide
authors.initials: N
authors.lastname: Nishinoue
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Sasaki
authors.forename: Masafumi
authors.initials: M
authors.lastname: Motohashi
authors.forename: Masao
authors.initials: M
authors.lastname: Maeno
mesh_terms: D000328:Adult; D001421:Bacteria, Anaerobic / Q000302:isolation & purification; D015331:Cohort Studies; D016001:Confidence Intervals; D005260:Female; D006090:Gram-Negative Bacteria / Q000302:isolation & purification; D006801:Humans; D007564:Japan; D016015:Logistic Models; D008297:Male; D024821:Metabolic Syndrome / Q000209:etiology*; D008875:Middle Aged; D016017:Odds Ratio; D010510:Periodontal Diseases / Q000150:complications*; D010514:Periodontal Pocket / Q000382:microbiology / Q000473:pathology; D055815:Young Adult