Peripheral blood microRNA-15a is a potential biomarker for type 2 diabetes mellitus and pre-diabetes

MicroRNAs (miRNAs) are small non-coding RNAs that function as crucial regulators of gene expression. Recently, dysregulation of miRNA expression in the blood has been demonstrated to be associated with various diseases, including type 2 diabetes mellitus (T2D), suggesting a potential for their use as biomarkers of disease prognosis. The present study examined the expression levels of T2D-associated miR-15a in peripheral whole blood samples from patients with T2D, pre-diabetes individuals exhibiting impaired fasting glucose (IFG) and impaired glucose tolerance (IGT), as well as healthy control subjects, in order to investigate the potential of peripheral blood miR-15a as a biomarker for the prediction of T2D and pre-diabetes. The present study included 24 patients with T2D, 22 IFG/IGT individuals and 24 healthy controls. The expression levels of miR-15a were analyzed by reverse transcription-quantitative polymerase chain reaction. The results indicated that the peripheral blood miR-15a expression levels were significantly decreased in patients with T2D and IFG/IGT individuals, compared with healthy control subjects (P<0.05). As determined by multivariate logistic regression analysis, lower miR-15a expression was significantly associated with T2D (odds ratio [OR], 0.51; 95% confidence interval [CI], 0.16-0.73; P<0.05) and pre-diabetes (OR, 0.56; 95% CI, 0.23-0.79; P<0.05). This association remained statistically significant following adjustment for age, body mass index and hypertension, as well as other biochemical indicators. Furthermore, a receiver operating characteristic analysis revealed that blood miR-15a distinguished patients with T2D and IFG/IGT individuals from healthy controls (area under the curves; 95% CI: 0.864; 0.751-0.977 and 95% CI: 0.852; 0.752-0.953, respectively). These results demonstrated that peripheral blood miR-15a expression levels were significantly lower in patients with T2D and IFG/IGT individuals, compared with healthy individuals. Thus, miR-15a in peripheral whole blood may serve as a potential biomarker for T2D and pre-diabetes.