Serum sirtuin 1 protein as a potential biomarker for type 2 diabetes: Increased expression of sirtuin 1 and the correlation with microRNAs.

Background: Type 2 diabetes (T2DM) is characterized by hyperglycemia and insulin deficiency. Sirtuin 1 (SIRT1), serving as a deacetylase, is critical in the regulation of glucose and lipid metabolism. Recently, a number of studies have been conducted to investigate the role of SIRT1 in the pathogenesis of T2DM. However, there are no sufficient data about the relationship between SIRT1 and T2DM. The aim of this study was to analyze the expressions of microRNAs (miRNAs) (miR-34a, miR-9, miR-132, and miR-181a) involved in SIRT1 regulation and SIRT1 protein in the serum of T2DM patients and controls. Materials and Methods: miRNA expressions were determined by real-time polymerase chain reaction, and enzyme-linked immunosorbent assay was used to measure the SIRT1 protein levels in 25 T2DM patients and 25 controls. Results: Fasting blood glucose and glycated hemoglobin levels were significantly higher in patients when compared with controls (P < 0.001). There was no difference for miRNA expressions between the groups (P > 0.05). SIRT1 protein level was significantly increased in patients as compared to controls (P = 0.044). Moreover, SIRT1 was negatively correlated with miR-181a (r = -0.558, P = 0.005) and miR-132 (r = -0.435, P = 0.034) in patients. Conclusion: Obtained results indicate that serum SIRT1 may be a potentially new biomarker for T2DM and also miR-181a and miR-132 may be involved in the development of T2DM by targeting SIRT1. This is the first study reporting on the effects of SIRT1 and related miRNAs in Turkish T2DM patients.