Purpose: Nontraditional cardiovascular risk factors such as lipoprotein(a) (Lp(a)), the genetic polymorphisms of apolipoprotein(a), apolipoprotein E (ApoE), and apolipoprotein B (ApoB) increase the prevalence of atherosclerosis in end-stage renal disease (ESRD) through quantitative and qualitative alterations. Given the high burden of cardiovascular fatal events in ESRD, this review aims to gather studies depicting apolipoproteins' changes in ESRD, to describe current evidence and to explore potential lipid-lowering therapies.
Methods: We searched the electronic database of PubMed, SCOPUS, EBSCO, and Cochrane CENTRAL for studies evaluating apolipoproteins in ESRD. Randomized controlled trials, observational studies (including case-control, prospective, or retrospective cohort), and reviews/meta-analysis were included if reference was made to apolipoproteins and cardiovascular consequences in ESRD.
Results: 21 studies met the inclusion criteria. We found a significant correlation between Lp(a) plasma concentrations and atherosclerosis. Lp(a) levels were independent risk factors for atherothrombosis and cardiovascular mortality. LMW apo(a) phenotype proved to be the best predictor for coronary events in ESRD. Single nucleotide polymorphisms in ApoE gene affected the expression and function of the protein, increasing the risk of cardiovascular events. ApoB had a significant correlation with the value of carotid intima-media thickness and vascular stiffness.
Conclusions: The picture of "lipid milieu" in ESRD has not been clearly described. Novel studies show that specific apolipoproteins suffer modifications in uremic patients, being correlated with cardiovascular events. Probably in the next years, the treatment of dyslipidemia in ESRD will not merely target LDL or total cholesterol, but specific isoforms of apolipoproteins which seem to become the central part of the problem.
Keywords: Apo B; Apo E; Apolipoproteins; Dialysis; Dyslipidemia; End-stage renal disease; Lipoprotein (a); Trials.