title: COX-2 gene polymorphisms and risk of chronic periodontitis: a case-control study and meta-analysis.
abstract: OBJECTIVE
  Cyclooxygenase-2 (COX-2) enzyme is a major mediator of inflammation in periodontitis, leading to loss of gingival tissues and alveolar bone supporting the teeth. Previous studies have explored the role of COX-2 polymorphisms with the risk of periodontitis in different ethnic groups; however, findings are inconsistent. So, we aimed to investigate the association of COX-2 polymorphisms (rs20417, rs689466, and rs5275) in susceptibility to chronic periodontitis (CP) in northern Indian population. Meta-analysis was also carried out to precisely estimate the effect of COX-2 polymorphisms in CP.
  
  
  METHODS
  Genotyping of COX-2 polymorphisms was carried out through PCR-RFLP in 200 CP cases and 200 controls. For risk estimation, binary logistic regression was applied using SPSS, version 15.0, while meta-analysis was carried using MIX 2.0 software.
  
  
  RESULTS
  None of the COX-2 polymorphisms independently were associated with the risk of CP. Meta-analysis suggested a significant reduced risk of CP with rs5275+8473 C allele and rs20417 in Chinese population.
  
  
  CONCLUSIONS
  No association was observed in any of the studied COX-2 polymorphisms with CP in North India. But, the study should be replicated in larger sample size to arrive at a definitive conclusion. Meta-analysis suggested a role of rs5275 COX-2 polymorphisms in susceptibility to overall CP, and on ethnic basis, rs20417 showed reduced risk of CP in Chinese population.
authors.affiliation: Department of Medical Genetics, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India.
authors.forename: G
authors.initials: G
authors.lastname: Prakash
authors.forename: M
authors.initials: M
authors.lastname: Umar
authors.forename: S
authors.initials: S
authors.lastname: Ajay
authors.forename: D
authors.initials: D
authors.lastname: Bali
authors.forename: R
authors.initials: R
authors.lastname: Upadhyay
authors.forename: K K
authors.initials: KK
authors.lastname: Gupta
authors.forename: J
authors.initials: J
authors.lastname: Dixit
authors.forename: B
authors.initials: B
authors.lastname: Mittal
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D055113:Chronic Periodontitis / Q000453:epidemiology / Q000235:genetics*; D051546:Cyclooxygenase 2 / Q000235:genetics*; D005260:Female; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D006801:Humans; D007194:India / Q000453:epidemiology; D008297:Male; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D012307:Risk Factors
chemical_list: D051546:Cyclooxygenase 2
keywords: cyclooxygenase-2; meta-analysis; periodontitis; susceptibility