title: Association of adiponectin gene (ADIPOQ) rs2241766 polymorphism with obesity in adults: a meta-analysis.
abstract: BACKGROUND
  Adiponectin plays an important role in regulating glucose levels and fatty acid oxidation. Multiple studies have assessed the association between rs2241766 polymorphism in the adiponectin (ADIPOQ) gene and obesity susceptibility. However, the results are inconsistent and inconclusive. The aim of this meta-analysis was to investigate this association in adults.
  
  
  METHODS
  Several electronic databases were searched for relevant literature published up to November 2013. Statistical analyses were performed using software Review Manager (Version 5.02) and STATA (Version 10.0). The pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated with a random-effects model or a fixed-effect model depending on heterogeneity among studies. Q tests and Egger's tests were performed to assess heterogeneity and publication bias. Sensitivity analysis was conducted to confirm the reliability and stability of the meta-analysis.
  
  
  RESULTS
  A total of 2,819 obese and 3,024 controls in 18 case-control studies were included in the meta-analysis. The results indicated that compared with TT genotype, the ADIPOQ-rs2241766 GG genotype was associated with an increased risk for obesity (OR = 1.39, 95% CI: 1.11-1.73, P for heterogeneity = 0.520, I2 = 0%) in overall studies. Whereas, GT genotype was associated with a borderland increased risk for obesity (OR = 1.13, 95% CI: 0.94-1.36, P for heterogeneity = 0.006, I2 = 51%). The susceptibility of obesity was increased based on genotypes of TT<GT<GG (P for trend = 0.011). Subgroup analysis of different regions revealed that the ADIPOQ-rs2241766 GG genotype increased obesity risk in the Chinese studies (OR = 1.54, 95% CI: 1.19-2.00) but not in the non-Chinese studies (OR = 1.02, 95% CI: 0.66-1.58). Similar results were observed in allelic, recessive, and dominant genetic models. There was no significant evidence of publication bias in the overall, Chinese, and non-Chinese studies (P = 0.426, P = 0.935, and P = 0.390, respectively).
  
  
  CONCLUSIONS
  The results of this meta-analysis suggest that the ADIPOQ-rs2241766 G/T polymorphism might be associated with obesity in Chinese studies but not in non-Chinese studies in adults. Better-designed studies that consider confounding factors and assess larger sample sizes with a focus on ADIPOQ-rs2241766G/T polymorphisms and obesity are required in the future.
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Capital Medical University, Beijing, China; Beijing Municipal Key Laboratory of Clinical Epidemiology, Beijing, China.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Wu
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Capital Medical University, Beijing, China; Beijing Municipal Key Laboratory of Clinical Epidemiology, Beijing, China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Department of Hospital Management, School of Health Administration and Education, Capital Medical University, Beijing, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Meng
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Capital Medical University, Beijing, China; Beijing Municipal Key Laboratory of Clinical Epidemiology, Beijing, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Zhang
mesh_terms: D052242:Adiponectin / Q000235:genetics*; D000328:Adult; D044466:Asian People; D016022:Case-Control Studies; D005260:Female; D020022:Genetic Predisposition to Disease; D055106:Genome-Wide Association Study; D006801:Humans; D008297:Male; D008957:Models, Genetic; D009765:Obesity / Q000208:ethnology / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D016017:Odds Ratio; D020641:Polymorphism, Single Nucleotide; D012307:Risk Factors; D044465:White People
chemical_list: C499918:ADIPOQ protein, human; D052242:Adiponectin
references.citation: Metab Syndr Relat Disord. 2011 Dec;9(6):419-26
references.pmid: 21870907
references.citation: Nature. 2006 Dec 14;444(7121):875-80
references.pmid: 17167476
references.citation: J Mol Med (Berl). 2003 Jul;81(7):428-34
references.pmid: 12750819
references.citation: J Biochem. 1996 Oct;120(4):803-12
references.pmid: 8947845
references.citation: Nature. 2003 Jun 12;423(6941):762-9
references.pmid: 12802337
references.citation: Hum Mol Genet. 2002 Oct 1;11(21):2607-14
references.pmid: 12354786
references.citation: Obes Res. 2005 May;13(5):807-12
references.pmid: 15919831
references.citation: BMJ. 1997 Sep 13;315(7109):629-34
references.pmid: 9310563
references.citation: Curr Diab Rep. 2003 Apr;3(2):151-8
references.pmid: 12728641
references.citation: Diabetes. 2008 Dec;57(12):3353-9
references.pmid: 18776141
references.citation: Curr Opin Investig Drugs. 2005 Oct;6(10):988-93
references.pmid: 16259219
references.citation: PLoS One. 2013 Apr 04;8(4):e58412
references.pmid: 23593121
references.citation: Pancreas. 2009 Nov;38(8):907-12
references.pmid: 19696691
references.citation: Biochem Biophys Res Commun. 1996 Apr 16;221(2):286-9
references.pmid: 8619847
references.citation: J Biol Chem. 1996 May 3;271(18):10697-703
references.pmid: 8631877
references.citation: Nat Med. 2002 Jul;8(7):731-7
references.pmid: 12068289
references.citation: BMJ. 2003 Sep 6;327(7414):557-60
references.pmid: 12958120
references.citation: Obesity (Silver Spring). 2009 Apr;17(4):737-44
references.pmid: 19165155
references.citation: Biochem Biophys Res Commun. 1999 Apr 2;257(1):79-83
references.pmid: 10092513
references.citation: Diabetes. 1998 May;47(5):821-30
references.pmid: 9588456
references.citation: Diabetes Metab Syndr Obes. 2012;5:369-78
references.pmid: 23118546
references.citation: Mol Biol Rep. 2013 Feb;40(2):1819-26
references.pmid: 23108996
references.citation: Diabetes. 2006 Feb;55(2):545-50
references.pmid: 16443793
references.citation: Metabolism. 2003 Jul;52(7):881-4
references.pmid: 12870165
references.citation: PLoS Genet. 2012;8(3):e1002607
references.pmid: 22479202
references.citation: Biomed Environ Sci. 2006 Jun;19(3):179-84
references.pmid: 16944773
references.citation: Diabetes Care. 2010 Apr;33(4):908-13
references.pmid: 20067957
references.citation: Mol Biol Rep. 2013 Feb;40(2):1135-44
references.pmid: 23065236
references.citation: J Biol Chem. 1995 Nov 10;270(45):26746-9
references.pmid: 7592907
references.citation: Atherosclerosis. 2010 Feb;208(2):412-20
references.pmid: 20018283
references.citation: Ann Hum Genet. 2009 Sep;73(Pt 5):492-501
references.pmid: 19573164
references.citation: Proc Natl Acad Sci U S A. 2002 Dec 10;99(25):16309-13
references.pmid: 12456889
references.citation: Arterioscler Thromb Vasc Biol. 2000 Jun;20(6):1595-9
references.pmid: 10845877