title: The Pro12Ala polymorphism in the peroxisome proliferator-activated receptor gamma-2 gene (PPARγ2) is associated with increased risk of coronary artery disease: a meta-analysis.
abstract: BACKGROUND
  Contradictory results have been reported regarding the association between Pro12Ala polymorphism of PPARγ2 and coronary artery disease (CAD). We sought to estimate the inconsistent results by performing a comprehensive meta-analysis.
  
  
  METHODS
  Studies in English or Chinese publications were identified by screening MEDLINE, Embase, CNKI, Wanfang and CBM. 22 studies including 8948 cases and 14427 controls were selected. A random-effects model was applied to combine the divergent outcomes of the individual studies, while addressing between-study heterogeneity and publication bias.
  
  
  RESULTS
  The Pro12Ala polymorphism of control population followed Hardy-Weinberg equilibrium for all studies (P>0.05). Overall, a marginal increased risk of CAD under the recessive genetic model (AlaAla vs ProAla+ProPro: P = 0.04, OR = 1.31, 95%CI 1.01-1.69, P(heterogeneity) = 0.67, I(2) = 0%) and the homozygote comparison (AlaAla vs ProPro: P = 0.04,OR = 1.30, 95%CI 1.01-1.68, P(heterogeneity) = 0.68, I(2) = 0%) was observed. In the subgroup analysis by ethnicity, carriers of AlaAla homozygotes had a significant increased risk for CAD among Caucasians (AlaAla vs ProAla+ProPro: P = 0.01, OR = 1.45, 95%CI 1.08-1.96, P(heterogeneity) = 0.48, I(2) = 0%; AlaAla vs ProPro: P = 0.02,OR = 1.44, 95%CI 1.07-1.93, P(heterogeneity) = 0.46, I(2) = 0%). After dividing into population source, the CAD risk magnitude of hospital-based studies was distinctly strengthened under the recessive model (P = 0.03,OR = 1.85,95%CI 1.07-3.19, P(heterogeneity) = 0.87,I(2) = 0%) and the homozygote comparison (P = 0.03,OR = 1.83, 95%CI 1.06-3.16, P(heterogeneity) = 0.88, I(2) = 0%). There was no observable publication bias as reflected by funnel plot and Egger's linear regression test (t = -0.12, P = 0.91).
  
  
  CONCLUSIONS
  Our results demonstrated that the PPARγ2 Pro12Ala polymorphism might be risk-conferring locus for the progression of CAD among Caucasians, but not among Asians.
authors.affiliation: Department of Cardiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Zhijun
authors.initials: Z
authors.lastname: Wu
authors.forename: Yuqing
authors.initials: Y
authors.lastname: Lou
authors.forename: Wei
authors.initials: W
authors.lastname: Jin
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
authors.forename: Lin
authors.initials: L
authors.lastname: Lu
authors.forename: Guoping
authors.initials: G
authors.lastname: Lu
mesh_terms: D044466:Asian People / Q000235:genetics; D003324:Coronary Artery Disease / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D047495:PPAR gamma / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D012306:Risk; D044465:White People / Q000235:genetics
chemical_list: D047495:PPAR gamma