Combined effects of the C161T and Pro12Ala PPARγ2 gene variants with insulin resistance on metabolic syndrome: a case-control study of a central Tunisian population.

We investigated the synergism between variants at the PPARγ locus (C161T and Pro12Ala polymorphisms) with insulin resistance on metabolic syndrome (MS). Five hundred twenty-two subjects were investigated for biochemical and anthropometric measurements. The diagnosis of MS was based on the IDF definition (2009). The HOMA 2 was used to determine HOMA-β, HOMA-S, and HOMA-IR from FPG and FPI concentrations. PCR-RFLP was performed for DNA genotyping. We showed that carriers of the Pro/Pro had a significantly higher FPG, FPI, and HOMA-IR. In addition, Pro/Pro subjects also display reduced HOMA-β and HOMA-S together compared to X/Ala (Pro/Ala and Ala/Ala) subjects. Furthermore, subjects with C/C have a significantly lower FPG, FPI, and HOMA-IR and higher HOMA-S compared to X/T (C/T and T/T) subjects. The C/C genotype carriers with an Ala allele group had significantly reduced FPG, FPI, HOMA-IR, and TG and elevated HOMA-S and HOMA-β than the different genotype combinations. We suggest that the haplotype composed of the C/C genotype carriers with an Ala allele of PPARγ2 group enhances susceptibility to the MS in a central Tunisian population.