Apolipoprotein(a) phenotypes predict the risk for carotid atherosclerosis in patients with end-stage renal disease.

Abstract

Several studies have demonstrated that atherosclerotic complications are the major cause of morbidity and mortality in hemodialysis patients. High lipoprotein(a) [Lp(a)] plasma concentrations are an independent fisk factor for atherosclerosis. Patients with end-stage renal disease (ESRD) have elevated plasma concentrations of Lp(a), which are not explained by size variation at the apolipoprotein(a) [apo(a)] gene locus. The aim of our study was to investigate whether Lp(a) concentrations and/or apo(a) phenotypes are predictive of the degree of atherosclerosis in the extracranial carotid arteries in ESRD patients. Of 167 patients, 108 showed atherosclerotic plaques (65%). Univariate analysis showed that the plaque-affected group was significantly older and had a higher frequency of angina pectoris, previous myocardial infarction, or cerebrovascular accident. Furthermore, this group included significantly more patients with low-molecularweight apo(a) isoforms (26.9% versus 8.5%, P<.005) and had P atients with terminal renal insufficiency suffer from an increased morbidity and mortality related to atherosclerotic diseases. 12 Although there undoubtedly are many contributory factors, several lipoprotein abnormalities have been suggested as a major cause of these diseases (for review, see Reference 3).Recently, increased plasma concentrations of lipoprotein(a) [Lp(a)] have been described in end-stage renal disease (ESRD) patients. 412 The distribution of Lp(a) plasma concentrations in the Caucasian population is highly skewed and extremely broad (range, <0.1 to >100 mg/dL), 13 with mean and median concentrations of approximately 15 and 8 mg/dL, respectively.

Lipoprotein Metabolism and Lipid Management in Chronic Kidney Disease

“…This inconsistency might have been due, at least in part, to the nonstandardized assay method for Lp(a) in the past. When apo(a) phenotyping was performed in conjunction with plasma Lp(a) concentrations, however, an association between the apo(a) K-IV repeat polymorphism and CV complications was consistently observed (3,35,85,(97)(98)(99)(100)(101)(102)(103)(104) (Table 3). A cross-sectional study in 607 HD patients showed an association between low molecular weight apo(a) phenotype with history of coronary events (35).…”

Associations Among Serum Lipoprotein(a) Levels, Apolipoprotein(a) Phenotypes, and Myocardial Infarction in Patients With Extremely Low and High Levels of Serum Lipoprotein(a)

“…Japanese Circulation Journal Vol.63, September 1999 patients with end-stage renal disease, 20 hypertension (HT) 21 or diabetes mellitus (DM), 12 those undergoing coronary bypass surgery, 22 and hemodialysis patients with or without DM. 13 However, the relation between apo(a) isoform size polymorphism and MI has rarely been studied, 23 and it would be interesting to determine whether, and how much, apo(a) isoform size polymorphism contributes to the increased serum Lp(a) levels in MI, because an inverse relation does exist between plasma Lp(a) levels and apo(a) size.…”

Is apolipoprotein(a) a susceptibility gene for Type I diabetes mellitus and related to long-term survival?

“…Since phenotypes with 11±16 or more than 34 K±IV repeats in the smaller apo(a) isoform were underrepresented, we formed one group by combining 11±19 and one by combining more than 31 K±IV repeats. In a further step, we divided apo(a) phenotypes in two subgroups according to the molecular weight of the smaller apo(a) iso-forms, as done in all of our and some of others previous works [3,4,8,30,32,33]. The low molecular weight group (LMW) included all subjects with at least one apo(a) isoform with 11 to 22 K±IV repeats [29]; the high molecular weight (HMW) group comprised all subjects who had only isoforms with more than 22 K±IV repeats.…”

“…The low molecular weight group (LMW) included all subjects with at least one apo(a) isoform with 11 to 22 K±IV repeats [29]; the high molecular weight (HMW) group comprised all subjects who had only isoforms with more than 22 K±IV repeats. In case two apo(a) isoforms were detectable, we used only the smaller apo(a) isoform for categorization [3,4,8,30,32,33].…”