To investigate whether serum PSAP and EPDR1 levels were associated with insulin resistance, we performed analysis of the correlation between PSAP and EPDR1 and indicators of FBG levels (r = 0.5004; P< 0.0001), PSAP and HAb1c (r = 0.4688; P< 0.0001), PSAP and C-peptide (r = 0.3981; P = 0.0003), PSAP and TyG (r = 0.2362; P< 0.0001), PSAP and HOMA-IR (r = 0.3314; P = 0.0035), PSAP and HOMA-CR (r = 0.5486; P< 0.0001), EPDR1 and insulin (r = 0.2291; P = 0.045), EPDR1 and HOMA-IR (r = 0.2462; P = 0.0309) in both T2DM and normal control groups. The gene discussed is EPDR1; the disease is type 2 diabetes mellitus.