AIM: To investigate the clinical value of microRNA(miRNA, miR)-27 expression in patients with diabetic retinopathy(DR).

METHODS: A total of DR 80 patients(DR group)treated between January 2019 and January 2020 were retrospectively reviewed. Meanwhile, 40 patients with simple type 2 diabetes mellitus(T2DM)(T2DM group)and 40 normal healthy persons(control group)were enrolled, and plasma RNA was extracted. Real time fluorescent quantitative reverse transcription polymerase chain reaction(RT-PCR)was adopted to determine plasma miR-27 expression, and enzyme-linked immunosorbent assay was performed to determine the vascular endothelial growth factor(VEGF)level. Plasma miR-27 and serum VEGF expression in different groups and in patients with different severities of DR was comparatively analyzed. Multivariate Logistic regression analysis was performed to screen factors influencing the expression of miR-27 in patients with DR, and Pearson correlation analysis of miR-27, serum VEGF and blood glucose indexes was conducted. Meanwhile, significance of miR-27 in pathogenesis of DR was summarized.

RESULTS: DR group had the highest plasma miR-27 and serum VEGF levels, followed by T2DM group, and then the control group(P<0.05). Proliferative diabetic retinopathy(PDR)patients had higher levels of plasma miR-27, serum VEGF, fasting blood glucose and glycated hemoglobin than those with non-proliferative diabetic retinopathy(NPDR)(P<0.05). It was found that course of disease(OR=3.206), fasting blood glucose(OR=2.570), glycated hemoglobin(OR=2.787), VEGF(OR=3.442)and severity of DR(OR=5.842)were influencing factors of plasma miR-27 expression in DR patients(P<0.05). In DR patients, relative expression of plasma miR-27 was positively correlated with serum VEGF, fasting blood glucose and glycated hemoglobin(r=0.548, 0.398, 0.522, all P<0.05).

CONCLUSION: DR patients have higher plasma miR-27 expression level than those with simple T2DM and normal healthy people. The duration of diabetes, fasting blood glucose, glycated hemoglobin and severity of DR all affect the expression of miR-27. Besides, miR-27 is positively correlated with serum VEGF, glycated hemoglobin and fasting blood glucose. It is speculated that miR-27 may mediate the pathogenesis and progression of DR by regulating glucose metabolism and promoting angiogenesis.