Abstract: Objective To investigate the expression of serum thioredoxin-interacting protein (TXNIP) in patients with type 2 diabetic retinopathy (DR) and its relationship with oxidative stress. Methods According to the severity of the disease, 82 DR patients (the DR group) were divided into the PDR group (42 cases) and the NPDR group (40 cases). In addition, 50 healthy volunteers (the control group) and 50 patients with simple type 2 diabetes (the diabetes group) were selected. General data of all subjects were collected. The levels of superoxide dismutase (SOD), reduced glutathione (GSH), malondialdehyde (MDA) and TXNIP were detected by xanthine oxidase method, dithio Dinitrobenzoic acid colorimetry, thiobarbital method and enzyme-linked immunosorbent assay. Glycated hemoglobin (HbA1c), fasting blood glucose (FPG), triglyceride (TG) and total cholesterol (TC) were determined by automatic biochemical analyzer. Results Compared with the control group, TG and TC increased significantly in the diabetes group and the DR group (P＜0.05), but there was no significant difference between the diabetes group and the DR group. HbA1c, FPG, MDA and TXNIP increased sequentially in the control group, the diabetes group and the DR group, while SOD and GSH decreased sequentially (all P＜0.05). Compared with the PDR group, MDA and TXNIP in the NPDR group decreased, while SOD and GSH increased (P＜0.05). There were no significant differences in HbA1c, FPG, TG and TC between the two groups. Higher levels of MDA and TXNIP were all risk factors for PDR in DR patients, higher levels of SOD and GSH were protective factors (P＜0.05). The area under ROC curve of serum TXNIP in the diagnosis of DR was 0.803 (95%CI: 0.730-0.875). When the cutoff value was 3.01 μg/L, the sensitivity, specificity and Youden index were 53.66%, 94.00% and 0.477, respectively. Conclusion TXNIP is abnormally high expressed in the serum of DR patients, and it may promote the occurrence and development of the disease by regulating oxidative stress response. High serum TXNIP level is a risk factor for PDR in DR patients, and serum TXNIP has certain auxiliary value in clinical diagnosis of DR.

Key words: diabetic retinopathy, diabetes mellitus, type 2, oxidative stress, thioredoxins, Logistic models, ROC curve, thioredoxin-interacting protein