PPARG and diabetes mellitus: In PPARγ, the frequency of GG genotype in rs2920502 was significantly lower in prediabetes/diabetes subjects (6.85%) than in the normal glucose tolerance subjects (12.69%); logistic regression analysis revealed that subjects with GG genotype of rs2920502 in PPARγ had less risk for prediabetes/diabetes compared to CC genotype (odd ratio (OR): 0.715; 95% confidence interval (CI): 0.527–0.97, P = 0.031).