Interaction of genetic risk factors confers increased risk for metabolic syndrome: the role of peroxisome proliferator-activated receptor γ

The aim of the study was to estimate the influence of interactions between peroxisome proliferator-activated receptor γ (PPARγ) and target genes lipoprotein lipase (LPL), interleukin 6 (IL6), angiotensin converting enzyme (ACE), and angiotensin II type 1 receptor (AT1R) on metabolic syndrome (MetSy) and its traits. The study included 527 participants (263 with MetSy and 264 controls). Genotyping of PPARγ Pro12Ala, LPL PvuII (-/+), IL6 -174G>C, ACE I/D and AT1R 1166A>C was performed using polymerase chain reaction-restriction fragment length polymorphism-based methods. Interaction between PPARγ Pro12Ala and LPL Pvu(-/+) improved prediction of MetSy over and above prediction based on a model containing no interactions (χ(2)=7.22; df=1; p=0.007). In the group of participants with PPARγ Pro12Ala or Ala12Ala genotypes, those with the LPL Pvu (-/+) or (+/+) genotype had greater odds for MetSy (odds ratio OR=5.98; 95% confidence interval CI: 1.46-24.47, p=0.013). Interaction between PPARγ Pro12Ala and IL6 -174G>C improved prediction of high fasting blood glucose (χ(2)=13.99; df=1; p