Abstract

BACKGROUND
VEGF(vascular endothelial growth factor) has been implicated in the pathogenesis of neovascularization and endothelial dysfunction in diabetes mellitus. However, its precise role in diabetic nephropathy is still unknown. Our aims were to determine whether alterations of plasma and urinary VEGF levels were related to diabetic microvascular complications, especially nephropathy in type 2 diabetic patients. METHODS: 107 type 2 diabetic patients, without non-diabetic kidney diseases, and 47 healthy control subjects were studied. The urinary albumin excretion was defined as the albumin-to-creatinine ratio(ACR) in 24 hour urine samples. The study subjects were divided into four groups: a nondiabetic healthy control group(n=47), a normoalbuminuric diabetic group(ACR <30mug/mg, n=37), a microalbuminuric diabetic group(ACR 30~299mug/mg, n=37) and an overt proteinuric diabetic group(ACR=300mug/mg, n=33). The plasma and urinary VEGF levels were measured in these subjects by enzyme-linked immunosorbent assays. RESULTS: 1) The urinary VEGF concentrations were significantly higher in the diabetic groups than in the controls, even in the normoalbuminuric stage(log VEGF/Cr, normoalbuminuria; 4.33+/-1.06 vs. control; 3.53+/-0.79, p=0.009). The levels of urinary VEGF excretions increased with advancing diabetic nephropathy stage. 2) The plasma and urinary VEGF levels were higher in the hypertensive diabetic than the normotensive diabetic patients. 3) In the diabetic patients, the level of plasma VEGF was positively correlated with the BUN(r=0.398, p=0.039) and urinary ACR (r=0.251, p=0.044). The level of urinary VEGF was positively correlated with the urinary ACR(r=0.645, p<0.001), and creatinine(r=0.336, p=0.009), but negatively correlated with the level of serum albumin(r=-0.557, p<0.001). Both the levels of urinary VEGF and serum creatinine were independently correlated with the urinary ACR. CONCLUSIONS: The excretion of urinary VEGF increased at a relatively earlier stage in diabetic nephropathy and was significantly correlated with the excretion of urinary albumin. These results suggested the possibility of urinary VEGF as a sensitive marker or the detection of diabetic nephropathy and in predicting disease progression.

• Keywords: DM nephropathy;VEGF;Type 2 diabetes mellitus;Proteinuria;