The increase in paraoxonase-1 is associated with a decrease in left ventricular volume in kidney transplant recipients.

Background: Patients on dialysis have impaired cardiac function, in part due to increased fluid volume and ventricular stress. Restored kidney function through transplantation reduces left ventricular volume in both systole and diastole. Paraoxonase 1 (PON1) is reduced in patients on dialysis, which may be related to their impaired cardiac function. We tested the hypothesis that change in PON1 is associated with changes in left ventricular (LV) end-volume and LV mass after kidney transplantation. Methods: Patients were studied before and 12 months after kidney transplantation. The control group was patients on dialysis not expected to receive a transplant in the next 12 months. Cardiac magnetic resonance imaging was used to measure LV end-diastolic and end-systolic volume and LV mass. PON1 was measured by arylesterase activity and by mass. Results: PON1 mass and activity were not different between the groups at baseline. Both PON1 mass and activity were increased post-kidney transplantation (p<0.0001 for change). The change in PON1 mass (p=0.0062) and PON1 arylesterase activity (p=0.0254) were inversely correlated with the change in NT-proBNP for patients receiving a kidney transplant. However, only the change in the PON1 mass, but not the change in PON1 arylesterase, was inversely correlated with the change in left ventricular volume (ml/m2.7) (p=0.0146 and 0.0114 for diastolic and systolic, respectively) and with the change in hemoglobin (p=0.0042). Conclusions: PON1 mass and activity increase after kidney transplantation. The increase in PON1 mass is consistent with a novel relationship to the increase in hemoglobin and the decrease in LV end-systolic and end-diastolic volume.