Lipoprotein metabolism in renal replacement therapy: a review

Lipoprotein disorders are considered an important cause for the high cardiovascular morbidity and mortality in patients with end-stage renal disease and following renal transplantation. This article reviews the disease-associated changes of lipids and lipoproteins in these patients and, where known, the underlying causes and mechanisms. Further, we discuss the perturbed lipoprotein system in relation to the cardiovascular risk of patients on renal replacement therapy. Patients treated by hemodialysis are often hypertriglyceridemic with increased very low density lipoprotein (VLDL) levels and a type IV Frederickson pattern of hyperlipidemia. Total and LDL cholesterol concentrations are usually normal or subnormal. Treatment of end-stage renal disease by peritoneal dialysis results in increased total, VLDL and LDL cholesterol concentrations. Both treatment modalities are accompanied by a decrease of high density lipoprotein (HDL) cholesterol and apolipoprotein AI, whereas lipoprotein(a) [Lp(a)] concentrations are significantly elevated in both groups. Following renal transplantation a high incidence of hypercholesterolemia and hypertrigylceridemia is observed, which is attributed, at least in part, to the immunosuppressive therapy. Most patients normalize HDL cholesterol values and Lp(a) decreases to pre-disease plasma concentrations. Several studies have described elevated levels of cholesterol, triglycerides and Lp(a) in patients with cardiovascular complications during different phases of renal replacement therapy, which indicates a predictive (causative) role of these parameters for atherosclerotic diseases.