Serum levels of angiopoietin-related growth factor in diabetes mellitus and chronic hemodialysis

Angiopoietin-related growth factor (AGF) was recently introduced as a novel liver-derived protein that antagonizes obesity and insulin resistance. In the current study, we investigated circulating AGF levels in relation to renal function and type 2 diabetes mellitus (T2DM). Angiopoictin-related growth factor was determined by enzyme-linked immunosorbent assay in subjects with a glomerular filtration rate greater than 50 mL/min (n = 60, 30 diabetic and 30 nondiabetic) and in patients on chronic hemodialysis (CD; n = 60, 32 diabetic and 28 nondiabetic), Furthermore, AGF was correlated to clinical and biochemical measures of renal function, glucose and lipid metabolism, as well as inflammation. Median serum AGF levels were significantly lower in CD patients (125.9 +/- 96.3 mu g/L) as compared with subjects with a glomerular filtration rate greater than 50 mL/min (164.0 +/- 95.4 mu g/L) (P < .05). Furthermore, AGF serum levels were significantly increased in diabetic patients (161.7 +/- 114.2 mu g/L) as compared with nondiabetic subjects (123.0 +/- 88.2 mu g/L) (P < .01). Moreover, CD negatively and T2DM positively predicted AGF concentrations in multiple regression analysis. In addition, fasting serum glucose was independently and positively correlated with circulating AGF in all patients and controls. Our results suggest that renal dysfunction is negatively and T2DM is positively associated with AGF serum levels. Further studies are needed to better elucidate the physiologic significance of circulating AGF in human disease. (C) 2009 Elsevier Inc. All rights reserved.