Serum Lipoprotein (a) Levels in Patients with Chronic Renal Failure – Evolution after Renal Transplantation and Relationship with Other Parameters of Lipoprotein Metabolism: A Prospective Study

Abstract

In order to analyze the relationship between lipoprotein (a) [Lp (a)] and other lipoproteins during chronic renal failure and once renal function is restored after kidney transplantation, we determined the serum levels of total lipoprotein, high-density lipoprotein, low-density lipoprotein, and very-low-density lipoprotein cholesterols, total and very-low-density lipoprotein triglycerides, apohpoproteins A-I, B, C-II, C-III, and E, and E, and Lp (a) in 30 patients with chronic renal failure before and 12 months after renal transplantation. During the 1st year after transplantation, all patients were treated only with ciclosporin and prednisone and had serum creatinine levels < 1.6 mg/dl (140 μmol/l) and proteinuria < 500 mg/day. No patients had chronic hepatic disease. To determine reference values we studied a control group of 60 healthy volunteers. Before renal transplantation, the study group showed higher concentrations of triglycerides, very-low-density triglycerides, very-low density lipoprotein cholesterol, apohpoproteins, C-II and C-III, and Lp(a) than the control group. There was no correlation between Lp(a) and any of the studied variables. After renal transplantation, the serum levels of total lipoprotein, high-density lipoprotein, and low-density lipoprotein and apohpoproteins A-I and B increased significantly. Apohpoproteins C-II and C-III and Lp(a) decreased and normalized. After these changes had taken place, there was no relationship between Lp(a) and other parameters of lipoprotein metabolism. We conclude that the increase in Lp(a) during the chronic renal failure phase is basically related to the loss of renal function and does not depend on the resultant alterations which are produced in other lipoprotein variables.

Arterial function after successful renal transplantation

“…There is frequently a reduction in blood pressure posttransplantation mirroring the central blood pressure regulatory role of the kidney, but also contributing is the increased use of vasoactive agents. Improvement in lipid parameters also follows restoration of normal renal function post-transplantation; lipoprotein(a) is reduced [20], and hypercholesterolemia is easier to control [21]. Such changes were confirmed in our population: one year after transplantation there was a general improvement in cardiovascular risk factors including brachial blood pressure, lipids, and homocyst(e)ine levels.…”

Lipoprotein (a): impact by ethnicity and environmental and medical conditions

“…In contrast, mixed results regarding Lp(a) have been reported from cross sectional studies (163,169,174,185,(194)(195)(196)(197)(198)(199)(200)(201)(202)(203)(204). Notably, the decrease of Lp(a) in renal transplant patients was in dependent of the modality of immunosuppressive therapy (169,(184)(185)(186)(187)(188)(189)(190)(191), arguing against a contribution by an in flammatory component.…”

“…The influence of renal transplantation on Lp(a) con centrations has also been investigated and prospective studies generally demonstrate a decrease of Lp(a) levels following kidney transplantation (169,(184)(185)(186)(187)(188)(189)(190)(191)(192)(193), although the followup period has been limited. In contrast, mixed results regarding Lp(a) have been reported from cross sectional studies (163,169,174,185,(194)(195)(196)(197)(198)(199)(200)(201)(202)(203)(204).…”

Apo(a) Phenotypes and Lp(a) Concentrations in Renal Transplant Patients

“…Concerning Lp(a), prospective studies have shown that its concentration falls rapidly during the first weeks [9, 15, 16]and maintained normal values at 6 months [15, 16]and 1 year [17]following renal transplantation.…”