Urinary angiopoietin-2 is associated with albuminuria in patients with type 2 diabetes mellitus

Abstract

Aims. To evaluate the levels of angiopoietin-1 (Ang-1), Ang-2, and vascular endothelial growth factor (VEGF) in serum and urine, and their association with albuminuria in patients with type 2 diabetes mellitus. Methods. In 113 type 2 diabetic patients with normoalbuminuria, microalbuminuria, and macroalbuminuria and 30 healthy controls, the levels of Ang-1, Ang-2, and VEGF in serum and urine were measured by enzyme-linked immunosorbent assay (ELISA). Results. Urinary and serum levels of Ang-2 were significantly higher in diabetic patients with normoalbuminuria than in healthy controls. Increased urinary Ang-2 level was positively associated with the degree of albuminuria. Urinary Ang-1 levels were significantly higher in normoalbuminuria patients and lower in macroalbuminuria patients than in controls. The levels of urinary VEGF increased in the albuminuria subgroup, though serum levels of Ang-1 and VEGF did not change. Urinary Ang-2 levels were correlated positively with albuminuria and negatively with glomerular filtration rate (GFR). Stepwise multiple regression analysis identified albuminuria (P < 0.001) and GFR (P = 0.001) as significant predictors of urinary Ang-2. Conclusions. Our data suggest that urinary Ang-2 is stepwise increased with renal damage in patients with type 2 diabetes mellitus and is associated with albuminuria.