Urinary platelet-derived growth factor-BB as an early marker of nephropathy in patients with type 2 diabetes: an Egyptian study.

Background: Diabetic nephropathy (DN) is one of the most serious complications of diabetes worldwide. Strong evidence suggests that several growth factors may contribute to the initiation and progressive fibrosis of DN. Recently, there is an overexpression of platelet-derived growth factor (PDGF) in renal biopsies from patients with DN. This study aimed to investigate the clinical significance of urinary PDGF-BB level in type 2 diabetic patients with and without nephropathy and to evaluate its relationship with various clinical and laboratory parameters.

Methods: Urinary levels of PDGF-BB were measured in 60 Egyptian type 2 diabetic patients categorized into three equal groups (normo-, micro-, and macroalbuminuria), according to urinary albumin level. In addition, 20 healthy subjects were selected to serve as controls.

Results: The urinary PDGF-BB levels were significantly increased in type 2 diabetic patients as compared to controls (p < 0.001). Moreover, diabetics with micro- and macroalbuminuria had significantly higher levels than in those with normoalbuminuria (p < 0.001). Urinary PDGF-BB correlated positively with disease duration, low-density lipoprotein (LDL)-cholesterol, and urinary albumin and negatively with creatinine clearance in diabetic patients. In a multiple regression model, urinary PDGF-BB was strongly and independently associated with nephropathy in diabetic patients (β = -0.03, p < 0.001).

Conclusions: PDGF-BB may play an important role in the initiation and progression of DN. It is considered as a good predictor for early deterioration of renal function in DN. Thus, measurement of urinary PDGF-BB in type 2 diabetic patients could be used for early detection of diabetic renal disease.