Prospective Study of the Association Between the Proline to Alanine Codon 12 Polymorphism in the <i>PPAR</i>γ Gene and Type 2 Diabetes

OBJECTIVE—To determine whether the Pro12Ala polymorphism in the PPARγ gene was associated with risk of type 2 diabetes in the Nurses’ Health Study. RESEARCH DESIGN AND METHODS—The study was a nested case-control study of 387 incident cases of type 2 diabetes and 771 matching control subjects nested within the Nurses’ Health Study, a prospective cohort study. Association between PPARγ genotype and incident type 2 diabetes was estimated using logistic regression. RESULTS—Carriers of the PPARγ variant 12Ala allele had reduced risk of type 2 diabetes compared with noncarriers. Unadjusted and adjusted odds ratios of type 2 diabetes were 0.74 (95% CI 0.55–1.00) and 0.72 (0.52–0.99), respectively. CONCLUSIONS—The results of this study provide further support for an inverse association between the PPARγ variant 12Ala allele and risk of type 2 diabetes.