The P12A polymorphism of PPARG has commonly been associated with type 2 diabetes. In order to compare its direct or indirect impact, the progression from impaired glucose tolerance to diabetes was studied. Cox regression analysis was performed, permitting the analysis of multiple risk factors on survival. This, in combination with intervention, was carried out to detect any notable correlation with diabetes. As well genotyping the P12A variant, 5 other variants of this gene were also genotyped to infer the response to troglitazone (as PPARG is a target for troglitazone medications). This then enabled effective analysis of the variants’ effects on insulin sensitivity at 1 year. P/P heterozygotes at the PPARG P12A seemed to be more susceptible in getting diabetes as opposed to alanine carriers. This could be indicative of the type of purine that specifically relates more with diabetes susceptibility. However results showed that there was no significant interaction between genotype and intervention. Neither of the variants genotyped significantly affected the impact of troglitazone on insulin sensitivity at 1 year. Although the proline allele at PPARG P12A showed increase risk for diabetes in those impaired glucose tolerance, which was seen to be an effect modified by body mass index.