When DN was set as the dependent variable and bilirubin concentrations, duration of diabetes, BMI, SBP, DBP, WHR, HbA1c, GA, CRP, Fasting C peptide, FPG, CRP, HDL-C, TG, TC, LDL-C, Albumin, Haemoglobin were set as covariates, bilirubin concentrations were identified as an independent protective factor for DN (OR = 0.05, 95% confidence interval [CI]: 0.01–0.66), while duration of diabetes (OR =1.15, 95% CI: 1.07–1.22) and SBP (OR = 1.05, 95% CI: 1.02–1.08) were identified as independent risk factors for DN (all P < 0.01, Table 4). The gene discussed is CRP; the disease is diabetes mellitus.