Objective To analyze the values of serum Delta-like protein 4 (DLL4) and cAMP response element-binding protein (CREB) levels in predicting microvascular injury of patients with different stages of diabetic retinopathy (DR).

Methods Eighty diabetic patients from February 2020 to February 2023 were selected as research objects, and they were divided into no DR group (n=37), non-proliferative DR group (n=19) and proliferative DR group (n=24) according to different stages of DR; serum DLL4 and CREB levels in the blood were detected, and the FACS Count flow cytometry was used to detect levels of endothelial progenitor cells (EPC), circulating endothelial cells (CEC) and circulating progenitor cells (CPC) in patients.

Results The levels of DLL4 and CREB in the blood of proliferative DR group were the highest, while the levels of DLL4 and CREB in the no DR group were the lowest, and the differences were statistically significant (P < 0.05); different stages of DR were significantly positively correlated with the levels of DLL4 and CREB (P < 0.05); the high levels of DLL4 and CREB in the blood of diabetic patients were the independent risk factors affecting staging of DR (P < 0.05). The levels of EPC and CPC in the blood of proliferative DR group were the lowest, while the level of CEC was the highest; in the no DR group, the levels of EPC and CPC were the highest, while the level of CEC was the lowest, and the differences were statistically significant (P < 0.05); the levels of DLL4 and CREB were significantly negatively correlated with EPC and CPC levels (P < 0.05), while the levels of DLL4 and CREB were significantly positively correlated with CEC level (P < 0.05); the area under the curve (AUC) of both DLL4 and CREB in predicting microvascular injury in DR patients was greater than 0.85.

Conclusion As the staging of DR increases, the levels of serum DLL4 and CREB show a significant upward trend, and DLL4 and CREB have higher predictive values for microvascular injury.