title: Coronary heart disease and chronic periodontitis: is polymorphism of interleukin-6 gene the common risk factor in a Chinese population?
abstract: OBJECTIVE
  Coronary heart disease (CHD) and chronic periodontitis (CP) both are multifactorial chronic diseases and related to inflammation. Interleukin-6 (IL-6) plays an important role in the pathogenesis of inflammatory diseases. The purpose of the study was to investigate the association among IL-6 gene polymorphisms, CP and CHD susceptibility in a Chinese population.
  
  
  METHODS
  The investigation was conducted as a case-control study involving 505 individuals: 113 patients with CHD and CP, 84 patients with CHD, 178 patients with CP and 130 control individuals. The polymorphisms of IL-6 gene were analyzed by polymerase chain reaction-restriction fragment length polymorphism. Relationships between the distributions of the genotypes and risk factors were also assessed.
  
  
  RESULTS
  Mutations at the loci -174 G/C, -597 G/A of IL-6 were rare in a Chinese population. No significant difference for IL-6-572C/G polymorphism was detected among moderate CP group, severe CP group and control (P = 0.312 and 0.481), significant differences were found between CHD groups and non-CHD groups (P ≤ 0.001). After adjustment for CHD risk factors, the G allele resulted in an increased risk (OR = 1.676-1.856), the GG/CG genotype was nearly two times higher risk compared to CC genotype (OR = 2.010-2.136).
  
  
  CONCLUSIONS
  IL-6-572C/G polymorphism did not correlate with CP susceptibility, but might be a potential risk factor for CHD in a Chinese population.
authors.affiliation: Department of Periodontology, Guangdong Provincial Stomatological Hospital, Southern Medical University, Guangzhou, China.
authors.forename: W H
authors.initials: WH
authors.lastname: Fan
authors.forename: D L
authors.initials: DL
authors.lastname: Liu
authors.forename: L M
authors.initials: LM
authors.lastname: Xiao
authors.forename: C J
authors.initials: CJ
authors.lastname: Xie
authors.forename: S Y
authors.initials: SY
authors.lastname: Sun
authors.forename: J C
authors.initials: JC
authors.lastname: Zhang
mesh_terms: D000225:Adenine; D000328:Adult; D000368:Aged; D000428:Alcohol Drinking / Q000009:adverse effects; D016022:Case-Control Studies; D002681:China; D002874:Chromosome Mapping; D055113:Chronic Periodontitis / Q000276:immunology*; D003327:Coronary Disease / Q000276:immunology*; D003596:Cytosine; D005260:Female; D005787:Gene Frequency / Q000235:genetics; D020022:Genetic Predisposition to Disease / Q000235:genetics; D005838:Genotype; D006147:Guanine; D006801:Humans; D006949:Hyperlipidemias / Q000150:complications; D006973:Hypertension / Q000150:complications; D015850:Interleukin-6 / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics; D009765:Obesity / Q000150:complications; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length / Q000235:genetics*; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects
chemical_list: D015850:Interleukin-6; D006147:Guanine; D003596:Cytosine; D000225:Adenine