Serum exosomal hsa_circRNA_0001842 is the potential biomarker for diagnosing lower limb vascular disease in type 2 diabetes mellitus.

This study aimed to identify the potential circular RNAs (circRNAs) in exosomes isolated from serum as biomarkers of lower limb vascular disease (LLVD) in patients with type 2 diabetes mellitus (T2DM). This research collected circRNAs from exosomes isolated from three T2DM patients and three T2DM patients with LLVD for microarray analysis. Five candidate biomarkers derived from differentially expressed circRNAs were then validated by quantitative real-time polymerase chain reaction in 20 T2DM patients and 20 T2DM patients with LLVD. Finally, expression levels of circRNAs were validated in 160 samples. Significant differences in the expression of 295 circRNAs were found between T2DM controls and T2DM patients with LLVD. Among them, 191 differentially expressed circRNAs were upregulated, and 104 were downregulated in T2DM patients with LLVD. Three upregulated and two downregulated circRNAs were further confirmed in 40 samples. According to the testing of 160 samples, hsa_circ_0001842 showed a noticeable specificity in the T2DM patients with LLVD group (n = 80), with an area under the curve (AUC) of 0.79, a sensitivity of 88.75%, and a specificity of 68.75%. In conclusion, hsa_circ_0001842 was found as a potential diagnostic biomarker for T2DM with LLVD.