The GG genotype of rs2920502 in PPARγ was associated with decreased risk of impaired glucose tolerance (G allele: OR: 0.818, 95%CI: 0.526–0.969, P = 0.042; GG: OR: 0.715, 95%CI: 0.527–0.97, P = 0.031). The gene discussed is PPARG; the disease is Impaired glucose tolerance.