Abstract： Objective To investigate the relationship between serum neutrophil extracellular trapps(NETs)levels and carotid intima-media thickness(CIMT)in patients with type 2 diabetes mellitus(T2DM).Methods A total of 112 newly diagnosed T2DM patients were selected from September 2022 to May 2023.Patients were divided into the T2DM group(T2DM,n=35),T2DM+the intima-media thickening group(CIMT,n=39)and T2DM+the atheromatous plaque group(PLA,n=38)according to the CIMT.And 50 cases of healthy people were selected as the normal control(NC)group in the same period.Results Compared with the NC group,the BMI,SBP,FPG,2 hPG,TC,and NETs increased in the T2DM group(P<0.05);The BMI,SBP,HbA1c,2 hPG,TG,CIMT,HOMA-IR,and NETs were higher in the CIMT group than in the T2DM group(P<0.05),while FPG,TC,and LDL-C were higher in the CIMT group than in the NC group(P<0.05).The SBP,HbA1c,2 hPG,LDL-C,CIMT,and NETs were higher in the PLA group than in the CIMT group(P<0.05),while BMI,FPG,TG,and HOMA-IR were higher in the PLA group than in the T2DM group(P<0.05).Spearman correlation analysis showed that CIMT in T2DM patients was positively correlated with NETs,smoking,BMI,SBP,FPG,2 hPG,HbA1c,LDL-C,TC,TG,UACR and HOMA-IR(P<0.05).Multiple linear regression analysis showed that NETs,HbA1c,LDL-C and TG were independent risk factors for CIMT in the T2DM patients.The analysis of the working characteristic curve of the subjects showed that the area under the curve of serum NETs for diagnosing T2DM combined with AS was 0.960,with sensitivity of 97.4%and specificity of 84.7%.Conclusion Serum NETs are associated with atherosclerosis in T2DM patients.