Plasma vascular endothelial growth factor in Japanese Type 2 diabetic patients with and without nephropathy

To determine whether plasma vascular endothelial growth factor (VEGF) level is elevated in Type 2 diabetic patients with an early stage of diabetic nephropathy.

We studied 71 Japanese Type 2 diabetic patients with normal serum creatinine level (<100 micromol/l) (age 63.0 [60.3-65.6] years old, diabetes duration 15.6 [14.0-17.3] years, HbA1c 7.36% [7.06-7.66%], mean [95% confidence interval, CI]): normoalbuminuric patients (n=36); microalbuminuric patients (n=21); and proteinuric patients (n=14). Plasma VEGF concentration was measured by a quantitative sandwich enzyme immunoassay technique.

Plasma VEGF concentration was not related to the degree of albuminuria: normoalbuminuric patients (25 [13-95] ng/l, median [25th-75th percentile]); microalbuminuric patients (33 [15-120] ng/l); and proteinuric patients (54 [17-107] ng/l). Plasma VEGF level in patients with retinopathy (25 [15-95] ng/l, n=30) was not elevated as compared to those without retinopathy (53 [14-126] ng/l, n=34). Plasma VEGF tended to correlated negatively with diabetes duration (R's=-.217, P=.0690) and HbA1c (R's=-.221, P=.0647), whereas there was no correlation between plasma VEGF level and age, serum creatinine or urinary albumin to creatinine ratio (ACR) of the patients, respectively. Plasma VEGF level in the group of patients with HbA1c equal to or below the median (<7.2%) was significantly higher than that in the group of patients with HbA1c above the median (>7.2%) (P<.05).

The results suggested that Type 2 diabetic patients with microalbuminuria and those with retinopathy are not necessarily associated with an elevation of circulating plasma VEGF concentration. Plausible association between plasma VEGF level and glycemic control remains to be seen.