AIM: To investigate the changes in serum levels of trefoil factor 1(Tff1)and bone morphogenetic protein 4(BMP4)in patients with diabetic retinopathy, and to evaluate their diagnostic value for diabetic retinopathy.METHODS: From January 2022 to January 2024, 186 patients with type 2 diabetes were selected as the study group and divided into a retinopathy subgroup(52 cases)and a non-retinopathy subgroup(134 cases)based on the presence of retinopathy. Another 186 healthy volunteers who underwent physical examinations during the same period were chosen as the control group. Serum Tff1 and BMP4 levels were measured using the enzyme-linked immunosorbent assay(ELISA). Pearson analysis was used to assess the correlation between serum Tff1, BMP4 levels, and clinical data. Multivariate Logistic regression analysis was performed to identify factors influencing the development of retinopathy in type 2 diabetic patients. Receiver operating characteristic(ROC)curve analysis was conducted to evaluate the diagnostic value of serum Tff1 and BMP4 levels for retinopathy in type 2 diabetic patients.RESULTS: Compared to the control group, serum Tff1 levels were lower and BMP4 levels were higher in both retinopathy and non-retinopathy subgroups(all P<0.05). Specifically, serum Tff1 levels were lower and BMP4 levels were higher in the retinopathy subgroup than in the non-retinopathy subgroup(all P<0.05). Pearson analysis revealed that Tff1 levels in type 2 diabetes patients were negatively correlated with disease duration, glycated hemoglobin levels, and triglyceride levels, while BMP4 levels were positively correlated(all P<0.05). Multivariate Logistic regression analysis identified type 2 diabetes duration, glycated hemoglobin, triglycerides, Tff1, and BMP4 as influencing factors for retinopathy development in type 2 diabetes patients(all P<0.05). ROC curve analysis showed that the combined diagnosis of serum Tff1 and BMP4 had an area under the curve(AUC)of 0.901, which was significantly higher than that of Tff1 alone(Z=2.069, P=0.039)and BMP4 alone(Z=2.072, P=0.038).CONCLUSION: Serum Tff1 levels are decreased and BMP4 levels are increased in patients with diabetic retinopathy, and the combined detection of these two markers offers high diagnostic value for diabetic retinopathy.