Six SNPs (GCKR rs1260326; SLC30A8 rs11558471; CDKN2A/B rs10811661; and MTNR1B rs1387153, rs2166706, and rs10830963) were prominently associated with prediabetes and T2DM after adjusting for age, sex, and BMI, and rs10811661 in CDKN2A/B exhibited the most powerful association with increased prediabetes and T2DM (OR = 1.346, 95% CI = 1.143–1.585). The gene discussed is MTNR1B; the disease is type 2 diabetes mellitus.