Obejctive　To determine the level of serum superoxide dismutase (SOD), neutrophil gelatinase-related lipocalin (NGAL) and Kindney Injury Molecule 1 (KIM-1)in patients with type 2 diabetes, and to analyze its diagnostic value.

A total of 212 patients with type 2 diabetes were selected and divided into a negative group (n = 163) and a positive group (n = 49) according to urine microalbumin / urine creatinine ratio (ACR), and 118 healthy people who underwent health examinations at the same time were selected as health control. Serum SOD, NGAL and KIM-1 levels were measured, and statistical analysis was performed to calculate the diagnostic value of SOD and NGAL alone or in combination for early renal injury in diabetes.

The SOD level in the negative group was significantly higher than that in control group [218(176~234)] U/mL vs [233(192~276)] U/mL, P＜0.001, and the SOD level in the positive group was signally lower than that in the negative group [172(142~215)] U/mL vs [218(176~234)] U/mL, P＜0.01; There was no significant difference in the NGAL level between the negative group and control group [46.2(22.3~68.1)] mg/L vs [39.4(19.8~47.3)] mg/L, P＞0.05, The NGAL level in the positive group was notably lower than that in the negative group [98.6(56.4~130.0)] mg/L vs [46.2(22.3~68.1)] mg/L, P＜0.001; the KIM-1 level in the negative group was markedly higher than that in the control group [43.0(35.9~51.4)] ng/L vs [33.2(28.1~37.9)] ng/L, P＜0.05, the KIM-1 level in the positive group was prominently lower than that in the negative group [77.6(54.2~93.8)] ng/L vs [43.0(35.9~51.4)] ng/L, P＜0.001. The detection rate of SOD, NGAL and KIM-1 for early diabetic kidney injury was 73.47%, 85.71% and 87.76% respectively, and the area under the ROC curve was 0.737, 0.816 and 0.876, respectively. The positive detection rate was 95.92% after the three were applied in combination, where the area under the ROC curve is 0.957.

With the decrease of serum SOD level and the increase of NGAL and KIM-1 level, the combined detection of these three levels is helpful for the detection and early intervention of renal injury in early diabetic stage.