Changes in Serum Nampt Levels and Its Significances in Diabetic Nephropathy Patients-The Potential Role of Nampt in T2DM with Diabetic Nephropathy

Background: Nicotinamide phosphoribosyltransferase(Nampt) has a variety of biological effects, which can participate in the development of inflammatory diseases, metabolism diseases and chronic kidney disease, et al. However, the role of Nampt in T2DM and DN is still controversial. Objective: The study aimed to investigate changes in serum Nampt levels and its significance in diabetic nephropathy (DN). Method: A total of 321 type 2 diabetes (T2DM) were divided into normal albuminuria group (NA, n=110), microalbuminuria group (MA, n=106) and large amount of albuminuria group (LA, n=105). 105 healthy persons were selected forming the control group (NC, n=105).; 118 T2DM without insulin therapy were screened out as the non–insulin therapy group (NIT.; n=116). Serum Nampt and interleukin (IL)-1β were measured by enzyme-linked immunosorbent assay. The relationships among the variables were analyzed by Pearson correlation analysis and Stepwise multiple regression analysis. Results: Serum Nampt and IL-1β in the LA group were significantly higher than other groups, and they were higher in MA than in the NA group (P<0.05). Serum Nampt was positively correlated with IL-1β and urinary albumin-to-creatinine ratio (UACR) (P <0.01), and IL-1β and UACR were independent relevant factors affecting Nampt. Serum Nampt was positively correlated with insulin resistance (HOMA-IR) but negatively correlated with the quantitative insulin sensitivity check index (QUICKI) (P <0.01) in the NIT group. Conclusion: We indicated that serum Nampt and IL-1β were increased accompanied by the increased UACR and the association between Nampt and insulin resistance and β-cell function in T2DM with different UACRs.