Abstract:Objective To investigate the differential expression of miR-9-3p in plasma of type 2 diabetes mellitus (T2DM) patients and T2DM with unstable angina (UA) patients, and furnish evidence for novel diagnostic tool for T2DM with unstable angina. Methods A total of 100 T2DM patients (50 subjects with UA and 50 patients without UA) and 30 healthy volunteers were enrolled from Tangshan Gongren Hospital between January 2012 and June 2013. Total RNA was isolated from plasma using mirVana Paris kit according to manufacture’s instruction.The plasma level of miR-9-3p was determined by qRT-PCR using miR-423-5p as internal control. The receiver operating curve (ROC) was used to evaluate its value in diagnosis of T2DM and T2DM with UA. Results The plasma levels of miR-9-3p in the T2DM group and the T2DM with UA group were significantly increased compared with the control group (P < 0.05). Compared with the T2DM group, the plasma level of miR-9-3p in the T2DM with UA was significantly elevated (P < 0.05). The ROC curves indicated that miR-9-3p had an acceptable value in the diagnosis of T2DM (AUC = 0.723; 95% CI: 0.610, 0.837; P < 0.05) and a high value in the diagnosis of T2DM with UA (AUC = 0.972; 95% CI: 0.963, 0.981; P < 0.05). Conclusions Plasma level of miR-9-3p is elevated in T2DM patients and T2DM with UA patients. Therefore, plasma miR-9-3p may be used as a potential biomarker for early diagnosis of T2DM and T2DM with UA.