Objective: Adipocyte fatty acid-binding protein (AFABP) was recently introduced as an adipocyte-expressed factor, serum levels of which independently correlate with the development of the metabolic syndrome and cardiovascular disease in humans. In the current study, we investigated renal elimination of this protein by comparing circulating AFABP levels in patients on chronic haemodialysis (CD) with controls. We hypothesized that if renal filtration is a significant route of elimination of AFABP, it would accumulate in CD patients.
Patients and measurements: AFABP 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.
Results: Median serum AFABP levels were more than 10-fold higher in CD patients (510.9 +/- 294.7 microg/l) as compared to controls (44.3 +/- 35.2 microg/l). Furthermore, CD independently predicted AFABP concentrations in multiple regression analysis. In addition, body mass index and free fatty acids were independently associated with circulating AFABP.
Conclusions: Renal filtration appears as an important route of elimination of AFABP. Future studies should elucidate whether this adipocyte-expressed factor contributes to the increased risk of cardiovascular disease found in end-stage renal disease.