ABSTRACT
In order to study mechanisms in the pathogenesis of hypertriglyceridemia in uremia, maintenance hemodialysis, and post-renal transplantation, plasma post-heparin lipolytic acitivity was measured and the kinetics of triglyceride removal were determined during infusions of triglyceride in patients from each of these groups and in healthy control subjects. In addition, plasma lipolytic activity was measured both during the course of a single hemodialysis treatment and in response to daily hemodialysis over a five-day period. The mean serum triglyceride level was significantly elevated and the mean plasma post-heparin lipolytic activity significantly reduced in all three groups. Post-heparin lipolytic activity in transplant recipients with a normal serum creatinine concentration was not significantly different from that in control subjects. Those transplant recipients with mildly impaired graft function had levels of post-heparin lipolytic activity comparable to those in patients with end-stage renal failure. Triglyceride clearance was significantly reduced in both the transplant recipients and in the uremic patients. During a single hemodialysis treatment with systemic heparinization plasma lipolytic activity decreased after the first hour. With daily hemodialysis, predialysis post-heparin lipolytic activity progressively declined after the second day. It is concluded that reduced post-heparin lipolytic activity and decreased triglyceride clearance contribute to the hypertriglyceridemia seen not only in uremic patients and in patients on maintenance hemodialysis but also in renal allograft recipients. Diminished lipolytic activity in hemodialysis patients may be in part due to heparin-induced depletion.