Diagnostic significance of serum PP4R1 and its predictive value for the development of chronic complications in patients with type 2 diabetes mellitus.

BACKGROUND: Protein phosphatase 4 regulatory subunit 1 (PP4R1) is one of the regulatory subunits of PP4. It has been determined to be involved in the regulation of TNF-α-induced hepatic insulin resistance and gluconeogenesis. Considering the important role of PP4R1 in hepatic insulin resistance, the current study explored the expression and diagnostic value of PP4R1 in type 2 diabetes mellitus (T2DM) patients and further investigated its predictive value for the development of chronic complications.
METHOD: Hundred and five patients with T2DM and 97 healthy controls were collected. qRT-PCR was used for the measurement of serum PP4R1 mRNA level in both T2DM and control groups. The diagnostic value of PP4R1 in T2DM patients was evaluated using receiver operating characteristic (ROC) curve. Kaplan-Meier methods and Cox regression analysis were used to evaluate the predictive value of PP4R1 for the development of chronic complications in T2DM patients.
RESULTS: PP4R1 was determined to be elevated in the serum of T2DM patients compared with healthy controls. Serum PP4R1 had the potential to distinguish T2DM patients from healthy controls with a sensitivity of 81.9% and specificity of 82.5%. Patients with high PP4R1 expression experienced more chronic complications events. The multivariate Cox analysis results suggested that serum PP4R1 expression was an independent factor for the occurrence of chronic complications for T2DM patients. 
CONCLUSION: PP4R1 is elevated in the serum of T2DM patients, had the potential to distinguish T2DM patients from healthy controls. PP4R1 serves as a promising biomarker for predicting the risk of future chronic complications in T2DM patients.