Serum Levels of the Adipokine Fasting-induced Adipose Factor/Angiopoietin-like Protein 4 Depend on Renal Function

Fasting-induced adipose factor/angiopoietin-like protein 4 (FIAF/Angptl4) was recently introduced as a novel adipokine influencing glucose and lipid homeostasis. In the current study, we quantified circulating FIAF/Angtl4 levels in patients on chronic hemodialysis (CD) as compared to controls with a glomerular filtration rate above 50 ml/min. FIAF/Angptl4 was determined by ELISA in control (n=60) and CD (n=60) patients and correlated to clinical and biochemical measures of renal function, glucose and lipid metabolism, as well as inflammation, in both groups. Median serum FIAF/Angptl4 levels were more than 5-fold higher in CD patients (48.3 μg/l) as compared to control subjects (8.4 μg/l) (p<0.001). Furthermore, serum creatinine independently predicted FIAF/Angptl4 concentrations in multiple regression analyses in control subjects (p<0.01). In CD patients, C-reactive protein was independently and positively associated with circulating FIAF/Angptl4 (p<0.01). Taken together, we show that serum FIAF/Angptl4 levels are significantly increased in end-stage renal disease and independently associated with markers of renal function in control subjects.