title: UCP2 -866G/A, Ala55Val and UCP3 -55C/T polymorphisms in association with obesity susceptibility - a meta-analysis study.
abstract: OBJECTIVE
  Variants of UCP2 and UCP3 genes have been reported to be associated with obesity, but the available data on the relationship are inconsistent. A meta-analysis was performed to determine whether there are any associations between the UCP2 -866G/A, Ala55Val, and UCP3 -55C/T polymorphisms and obesity susceptibility.
  
  
  METHODS
  The PubMed, Embase, Web of Science and CNKI, CBMdisc databases were searched for all relevant case-control studies. The fixed or random effect pooled measure was determined on the bias of heterogeneity test among studies. Publication bias was examined by the modified Begg's and Egger's test.
  
  
  RESULTS
  Twenty-two published articles with thirty-two outcomes were included in the meta-analysis: 12 studies with a total of 7,390 cases and 9,860 controls were analyzed for UCP2 -866G/A polymorphism with obesity, 9 studies with 1,483 cases and 2,067 controls for UCP2 Ala55Val and 8 studies with 2,180 cases and 2,514 controls for UCP3 -55C/T polymorphism. Using an additive model, the UCP2 -866G/A polymorphism showed no significant association with obesity risk in Asians (REM OR = 0.81, 95% CI: 0.65-1.01). In contrast, a statistically significant association was observed in subjects of European descent (FEM OR = 1.06, 95% CI: 1.01-1.12). But neither the UCP2 Ala55Val nor the UCP3 -55C/T polymorphism showed any significant association with obesity risk in either subjects of Asian (REM OR = 0.84, 95% CI: 0.67-1.06 for Ala55Val; REM OR = 0.94, 95% CI: 0.55-1.28 for -55C/T) or of European descent (REM OR = 1.04, 95% CI: 0.80-1.36 for Ala55Val; FEM OR = 1.08, 95% CI: 0.97-1.20 for -55C/T).
  
  
  CONCLUSIONS
  Our meta-analysis revealed that the UCP2 -866G/A polymorphism may be a risk factor for susceptibility to obesity in subjects of European descent, but not in individuals of Asian descent. And our results did not support the association between UCP2 Ala55Val, UCP3 -55C/T polymorphisms and obesity in the populations investigated. This conclusion warrants confirmation by further studies.
authors.affiliation: Department of Endocrinology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China.
authors.forename: Li
authors.initials: L
authors.lastname: Qian
authors.forename: Kuanfeng
authors.initials: K
authors.lastname: Xu
authors.forename: Xinyu
authors.initials: X
authors.lastname: Xu
authors.forename: Rong
authors.initials: R
authors.lastname: Gu
authors.forename: Xuan
authors.initials: X
authors.lastname: Liu
authors.forename: Shan
authors.initials: S
authors.lastname: Shan
authors.forename: Tao
authors.initials: T
authors.lastname: Yang
mesh_terms: D019943:Amino Acid Substitution; D044466:Asian People; D016022:Case-Control Studies; D016206:Databases, Bibliographic; D020022:Genetic Predisposition to Disease; D006801:Humans; D007473:Ion Channels / Q000235:genetics*; D024101:Mitochondrial Proteins / Q000235:genetics*; D009765:Obesity / Q000208:ethnology* / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D017594:Publication Bias; D012307:Risk Factors; D000071246:Uncoupling Protein 2; D000071247:Uncoupling Protein 3; D044465:White People
chemical_list: D007473:Ion Channels; D024101:Mitochondrial Proteins; C000604389:UCP2 protein, human; C000604392:UCP3 protein, human; D000071246:Uncoupling Protein 2; D000071247:Uncoupling Protein 3
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