Abstract: Objective To investigate the diagnostic value of triglyceride/cystatin C (TG/Cys-C) ratio combined with malondialdehyde (MDA) level in patients with type 2 diabetes mellitus (T2DM). 
Methods The clinical data of 300 patients with T2DM were collected, and the patients were divided into T2DM group and diabetic kidney disease (DKD) group according to complication of kidney disease. The influencing factors of DKD in T2DM patients were analyzed, and the levels of triglycerides (TG), cystatin C (Cys-C), and MDA were detected. The diagnostic value of the levels of TG/Cys-C and MDA alone and in combination for the diagnosis of DKD in T2DM patients was analyzed by receiver operating characteristic (ROC) curve. 
Results The TG/Cys C ratio in the T2DM and DKD group was lower than that in the T2DM group, while the levels of MDA, ACR, and SCR were higher than those in the T2DM group, with statistical significance (P＜0.05). Logistic regression analysis showed that the TG/Cys C ratio and MDA level were independent risk factors for T2DM and DKD patients (P＜0.05). The area under the ROC curve (AUC) values of TG/Cys C ratio and MDA level for the diagnosis of T2DM patients with nephropathy were 0.809 and 0.837 respectively (95%CI: 0.760-0.852, 0.791-0.877, respectively). The AUC value for the combined diagnosis of the two was 0.915 (95%CI: 0.877-0.944). 
Conclusion Both TG/Cys-C ratio and MDA levels have certain reference value for the diagnosis of DKD in T2DM patients, and the combination of TG/ CyS-C ratio and MDA level is of higher value for the diagnosis of DKD in T2DM patients. 

Key words: diabetes mellitus, type 2, diabetic nephropathy, influencing factors