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

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. 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. 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. 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.