The CRP/HDL-C ratio had the best diagnostic performance AUC = 0.752 (95% CI: 0.711 ~ 0.794), followed by diabetes duration AUC = 0.672(95% CI: 0.626 ~ 0.719), HbA1c AUC = 0.653 (95% CI: 0.605 ~ 0.701), FPG AUC = 0.636 (95% CI: 0.580 ~ 0.692) and age AUC = 0.557 (95% CI: 0.500 ~ 0.613). The gene discussed is CRP; the disease is diabetes mellitus.