title: The association between the peroxisome proliferator-activated receptor-gamma2 (PPARG2) Pro12Ala gene variant and type 2 diabetes mellitus: a HuGE review and meta-analysis.
abstract: The peroxisome proliferator-activated receptor-gamma gene (PPARG) has been implicated in the etiology of type 2 diabetes mellitus and has been investigated in numerous epidemiologic studies. In this Human Genome Epidemiology review, the authors assessed this relation in an updated meta-analysis of 60 association studies. Electronic literature searches were conducted on September 14, 2009. Population-based cohort, case-control, cross-sectional, or genome-wide association studies reporting associations between the PPARG Pro12Ala gene variant (rs1801282) and type 2 diabetes were included. An updated literature-based meta-analysis involving 32,849 type 2 diabetes cases and 47,456 controls in relation to the PPARG Pro12Ala variant was conducted. The combined overall odds ratio, calculated by per-allele genetic model random-effects meta-analysis for type 2 diabetes and the Pro12Ala polymorphism, was 0.86 (95% confidence interval: 0.81, 0.90). The analysis indicated a moderate level of heterogeneity attributable to genuine variation in gene effect size (I(2) = 37%). This may reflect the variation observed between ethnic populations and/or differences in body mass index. Work on PPARG Pro12Ala should now focus on the observed heterogeneity in the magnitude of the association between populations. Further investigations into gene-gene and gene-environment interactions may prove enlightening.
authors.affiliation: Department of Public Health and Primary Care, University ofCambridge, Cambridge CB2 0SR, UK. hng20@medschl.cam.ac.uk
authors.forename: Hebe N
authors.initials: HN
authors.lastname: Gouda
authors.forename: Gurdeep S
authors.initials: GS
authors.lastname: Sagoo
authors.forename: Anne-Helen
authors.initials: AH
authors.lastname: Harding
authors.forename: Jan
authors.initials: J
authors.lastname: Yates
authors.forename: Manjinder S
authors.initials: MS
authors.lastname: Sandhu
authors.forename: Julian P T
authors.initials: JP
authors.lastname: Higgins
mesh_terms: D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology / Q000235:genetics*; D005787:Gene Frequency; D018740:Genetic Heterogeneity; D020022:Genetic Predisposition to Disease / Q000453:epidemiology / Q000235:genetics*; D006801:Humans; D047495:PPAR gamma / Q000235:genetics*; D011110:Polymorphism, Genetic; D012044:Regression Analysis
chemical_list: D047495:PPAR gamma