Abstract: Objective To explore the related markers of diabetic retinopathy (DR) and analyze the expression and clinical value of circulating miR-3197 and miR-2116-5p in patients with type 2 diabetic retinopathy with blood glucose control. Methods 72 patients with type 2 diabetes (T2DM) who were diagnosed with diabetic retinopathy (DR) in our hospital from July 2018 to March 2020 were selected as the research objects, and 72 patients with T2DM who did not suffer from DR during the same period were selected as control group. To compare the general information of the two groups of patients, the μParaflo™ MicroRNA microarray method was used to detect the miRNA expression levels of the two groups of patients, and verified by transcription quantitative PCR (RT-qPCR) technology. Spearman method and Pearson method were used to analyze the correlation between miR-3197 and miR-2116-5p in the serum of DR patients with DR and various biochemical indicators, and to analyze the circulating microRNAs by receiver operating characteristic curve (ROC). The diagnostic sensitivity and specificity of miR-3197 and miR-2116-5p single test and two combined tests for DR, to evaluate the diagnostic value. Results The GA, FPG, UACR, and HbA1c indicators of the DR group were higher than those of the non-DR group, and the difference was statistically significant (P<0.05). There was no significant difference between the groups in age, BMI, diabetes course, TC, Cr, HDL, LDL, TG and BUN (P>0.05). A total of 73 miRNAs were differentially expressed in DR cases through μParaflo™ MicroRNA microarray. Among them, the levels of miR-3197 and miR-2116-5p in DR patients were significantly higher than those in non-DR patients, and the results were verified by RT-qPCR analysis. The serum levels of miR-3197 and miR-2116-5p in the DR group were positively correlated with DR, GA, FPG, UACR, and HbA1c, respectively (all P<0.001). ROC curve analysis was used to evaluate circulating miR-3197 and miR-2116--5p. The AUCs of miR-3197 and miR-2116-5p were 0.903 and 0.875, respectively, and the AUC of miR-3197 and miR-2116-5p combined detection was 0.976, which was significantly greater than the single detection. Conclusion Circulating miR-3197 and miR-2116-5p are significantly up-regulated in DR patients, which are closely related to the severity of DR and a variety of DR related indicators, and may participate in the occurrence and development of DR. the combined detection of them has higher diagnostic value for DR and has a very promising application prospect in clinical treatment.

Key words: Type 2 diabetes, Diabetic retinopathy, Diagnostic value, Gene expression