Sitagliptin reduces transforming growth factor-β1 and Platelet derived growth factor-BB in regulation of UAER in type 2 diabetic nephropathy stage III patients

Background: Sitagliptin has been used as oral hypoglycemic agents and widely used for treatment of type 2 diabetes mellitus (T2DM). Objectives: The study aimed to explore the correlation of transforming growth factor-β1 (TGF-β1) and Platelet derived growth factor-BB (PDGF-BB) in regulation of urinary albumin excretion rate (UAER). Material and method: 164 patients with type 2 diabetic nephropathy (DN) at stage III admitted in our hospital from June to December 2015 and 160 healthy individuals for physical examination were selected in our study. All patients were treated with metformin before admission and given metformin plus sitagliptin treatment in our hospital. Related clinical parameters, such as, fasting blood glucose (FPG), postprandial blood glucose (PBG), homeostasis model assessment for insulin resistance (HOMAIR), homeostasis model assessment for insulin secretion index (HOMA-IS), glycosylated hemoglobin (HbA1c), urinary albumin excretion rate (UAER), urinary TGF-β1 and PDGF-BB were measured. Linear regression analysis was carried out among the parameters. Results: Type 2 DN patients showed poor health status with most parameters significantly higher than in healthy individuals (P<0.01). Sitagliptin application significantly reduced the levels of FPG, PBG, Insulin, HbA1C, HOMA-IR, SBP and TG (P<0.01), and promoted the level of HOMA-IS (P<0.01). Linear regression analysis illustrated that UAER closely correlated with TGF-β1 (r=0.774, P<0.001) and PDGF-BB (r=0.758, P<0.001), which all showed significantly decreased levels after sitagliptin application (P<0.01). TGF-β1 positively correlated with PDGF-BB (r=0.787, P<0.001), as well. Conclusions: This study provides a preliminary evidence for the management of T2DM. Our findings suggest that sitagliptin may change UAER by regulation of urinary PDGF-BB and TGF-β1 in type 2 DN stage III patients.