Serum levels of the adipokine zinc-α2-glycoprotein are increased in chronic hemodialysis

Zinc-α2-glycoprotein (ZAG) has recently been proposed as a new adipokine involved in body weight control. In the current study, we investigated renal elimination of this adipokine by comparing circulating ZAG levels in patients on chronic hemodialysis (CD) with controls. Sixty CD patients and 60 controls with a glomerular filtration rate greater than 50 mL/min were included. Serum concentrations of ZAG were determined by enzyme-linked immunosorbent assay; and its relationship with renal function, glucose and lipid metabolism, as well as inflammation was studied in both groups. Median ZAG serum levels were almost 2-fold higher in CD patients (94.4 ± 29.4 mg/L) as compared with controls (48.3 ± 23.5 mg/L) (P < .001). Furthermore, circulating ZAG was negatively correlated with fasting insulin, homeostasis model assessment of insulin resistance, and leptin in controls in univariate analysis. Moreover, CD independently predicted ZAG concentrations in multiple regression analysis. Renal filtration appears to be an important route of ZAG elimination, and markers of renal function should be included in studies on ZAG physiology.