Treat-to-Target or High-Intensity Statin in Patients With Coronary Artery Disease: A Randomized Clinical Trial

Importance

In patients with coronary artery disease, some guidelines recommend initial statin treatment with high-intensity statins to achieve at least a 50% reduction in low-density lipoprotein cholesterol (LDL-C). An alternative approach is to begin with moderate-intensity statins and titrate to a specific LDL-C goal. These alternatives have not been compared head-to-head in a clinical trial involving patients with known coronary artery disease.

Objective

To assess whether a treat-to-target strategy is noninferior to a strategy of high-intensity statins for long-term clinical outcomes in patients with coronary artery disease.

Design, Setting, and Participants

A randomized, multicenter, noninferiority trial in patients with a coronary disease diagnosis treated at 12 centers in South Korea (enrollment: September 9, 2016, through November 27, 2019; final follow-up: October 26, 2022).

Interventions

Patients were randomly assigned to receive either the LDL-C target strategy, with an LDL-C level between 50 and 70 mg/dL as the target, or high-intensity statin treatment, which consisted of rosuvastatin, 20 mg, or atorvastatin, 40 mg.

Main Outcomes and Measures

Primary end point was a 3-year composite of death, myocardial infarction, stroke, or coronary revascularization with a noninferiority margin of 3.0 percentage points.

Results

Among 4400 patients, 4341 patients (98.7%) completed the trial (mean [SD] age, 65.1 [9.9] years; 1228 females [27.9%]). In the treat-to-target group (n = 2200), which had 6449 person-years of follow-up, moderate-intensity and high-intensity dosing were used in 43% and 54%, respectively. The mean (SD) LDL-C level for 3 years was 69.1 (17.8) mg/dL in the treat-to-target group and 68.4 (20.1) mg/dL in the high-intensity statin group (n = 2200) (P = .21, compared with the treat-to-target group). The primary end point occurred in 177 patients (8.1%) in the treat-to-target group and 190 patients (8.7%) in the high-intensity statin group (absolute difference, -0.6 percentage points [upper boundary of the 1-sided 97.5% CI, 1.1 percentage points]; P < .001 for noninferiority).

Conclusions and Relevance

Among patients with coronary artery disease, a treat-to-target LDL-C strategy of 50 to 70 mg/dL as the goal was noninferior to a high-intensity statin therapy for the 3-year composite of death, myocardial infarction, stroke, or coronary revascularization. These findings provide additional evidence supporting the suitability of a treat-to-target strategy that may allow a tailored approach with consideration for individual variability in drug response to statin therapy.

Trial Registration

ClinicalTrials.gov Identifier: NCT02579499.

Single Ascending Dose Study of a Short Interfering RNA Targeting Lipoprotein(a) Production in Individuals With Elevated Plasma Lipoprotein(a) Levels

IMPORTANCE

Lipoprotein(a) (Lp[a]) is an important risk factor for atherothrombotic cardiovascular disease and aortic stenosis, for which there are no treatments approved by regulatory authorities.

OBJECTIVES

To assess adverse events and tolerability of a short interfering RNA (siRNA) designed to reduce hepatic production of apolipoprotein(a) and to assess associated changes in plasma concentrations of Lp(a) at different doses.

DESIGN, SETTING, AND PARTICIPANTS

A single ascending dose study of SLN360, an siRNA targeting apolipoprotein(a) synthesis conducted at 5 clinical research unit sites located in the US, United Kingdom, and Australia. The study enrolled adults with Lp(a) plasma concentrations of 150 nmol/L or greater at screening and no known clinically overt cardiovascular disease. Participants were enrolled between November 18, 2020, and July 21, 2021, with last follow-up on December 29, 2021.

INTERVENTIONS

Participants were randomized to receive placebo (n = 8) or single doses of SLN360 at 30 mg (n = 6), 100 mg (n = 6), 300 mg (n = 6), or 600 mg (n = 6), administered subcutaneously.

MAIN OUTCOMES AND MEASURES

The primary outcome was evaluation of safety and tolerability. Secondary outcomes included change in plasma concentrations of Lp(a) to a maximum follow-up of 150 days.

RESULTS

Among 32 participants who were randomized and received the study intervention (mean age, 50 [SD, 13.5] years; 17 women [53%]), 32 (100%) completed the trial. One participant experienced 2 serious adverse event episodes: admission to the hospital for headache following SARS-CoV-2 vaccination and later for complications of cholecystitis, both of which were judged to be unrelated to study drug. Median baseline Lp(a) concentrations were as follows: placebo, 238 (IQR, 203-308) nmol/L; 30-mg SLN360, 171 (IQR, 142-219) nmol/L; 100-mg SLN360, 217 (IQR, 202-274) nmol/L; 300-mg SLN360, 285 (IQR, 195-338) nmol/L; and 600-mg SLN360, 231 (IQR, 179-276) nmol/L. Maximal median changes in Lp(a) were -20 (IQR, -61 to 3) nmol/L, -89 (IQR, -119 to -61) nmol/L, -185 (IQR, -226 to -163) nmol/L, -268 (IQR, -292 to -189) nmol/L, and -227 (IQR, -270 to -174) nmol/L, with maximal median percentage changes of -10% (IQR, -16% to 1%), -46% (IQR, -64% to -40%), -86% (IQR, -92% to -82%), -96% (IQR, -98% to -89%), and -98% (IQR, -98% to -97%), for the placebo group and the 30-mg, 100-mg, 300-mg, and 600-mg SLN360 groups, respectively. The duration of Lp(a) lowering was dose dependent, persisting for at least 150 days after administration.

CONCLUSIONS AND RELEVANCE

In this phase 1 study of 32 participants with elevated Lp(a) levels and no known cardiovascular disease, the siRNA SLN360 was well tolerated, and a dose-dependent lowering of plasma Lp(a) concentrations was observed. The findings support further study to determine the safety and efficacy of this siRNA.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04606602; EudraCT Identifier: 2020-002471-35.

Expert position statements: comparison of recommendations for the care of adults and youth with elevated lipoprotein(a)

PURPOSE OF REVIEW

Summarize recent recommendations on clinical management of adults and youth with elevated lipoprotein(a) [Lp(a)] who are at-risk of or affected by cardiovascular disease (CVD).

RECENT FINDINGS

There is ample evidence to support elevated Lp(a) levels, present in approximately 20% of the general population, as a causal, independent risk factor for CVD and its role as a significant risk enhancer. Several guidelines and position statements have been published to assist in the identification, treatment and follow-up of adults with elevated levels of Lp(a). There is growing interest in Lp(a) screening and strategies to improve health behaviors starting in youth, although published recommendations for this population are limited. In addition to the well established increased risk of myocardial infarction, stroke and valvular aortic stenosis, data from the coronavirus pandemic suggest adults with elevated Lp(a) may have a particularly high-risk of cardiovascular complications. Lp(a)-specific-lowering therapies are currently in development. Despite their inability to lower Lp(a), use of statins have been shown to improve outcomes in primary and secondary prevention.

SUMMARY

Considerable differences exist amongst published guidelines for adults on the use of Lp(a) in clinical practice, and recommendations for youth are limited. With increasing knowledge of Lp(a)'s role in CVD, including recent observations of COVID-19-related risk of cardiovascular complications, more harmonized and comprehensive guidelines for Lp(a) in clinical practice are required. This will facilitate clinical decision-making and help define best practices for identification and management of elevated Lp(a) in adults and youth.

Lipoprotein(a)-hyperlipoproteinemia as cause of chronic spinal cord ischemia resulting in progressive myelopathy - successful treatment with lipoprotein apheresis

High concentrations of lipoprotein(a) (Lp(a)) represent an important independent and causal risk factor associated with adverse outcome in atherosclerotic cardiovascular disease (CVD). Effective Lp(a) lowering drug treatment is not available. Lipoprotein apheresis (LA) has been proven to prevent cardiovascular events in patients with Lp(a)-hyperlipoproteinemia (Lp(a)-HLP) and progressive CVD. Here we present the course of a male patient with established peripheral arterial occlusive disease (PAOD) at the early age of 41 and coronary artery disease (CAD), who during follow-up developed over 2 years a progressive syndrome of cerebellar and spinal cord deficits against the background of multifactorial cardiovascular risk including positive family history of CVD. Spastic tetraplegia and dependency on wheel chair and nursing care represented the nadir of neurological deficits. All conventional risk factors including LDL-cholesterol had already been treated and after exclusion of other causes, genetically determined Lp(a)-HLP was considered as the major underlying etiologic factor of ischemic vascular disease in this patient including spinal cord ischemia with vascular myelopathy. Treatment with an intensive regimen of chronic LA over 4.5 years now was successful to stabilize PAOD and CAD and led to very impressive neurologic and overall physical rehabilitation and improvement of quality of life.

Measurement of Lp(a) concentration must be recommended to assess individual cardiovascular risk. Extracorporeal clearance of Lp(a) by LA should be considered as treatment option for select patients with progressive Lp(a)-associated ischemic syndromes.

The Levels of Soluble Adhesion Molecules in Diabetic and Nondiabetic Patients with Combined Hyperlipoproteinemia and the Effect of Ciprofibrate Therapy

Cell adhesion molecules are thought to play a role in atherosclerosis. Several clinical trials have shown that fibrate treatment leads to a reduction in coronary events, although the mechanisms are not fully understood. Soluble vascular cell adhesion molecule-1 (sVCAM-1), soluble intercellular adhesion molecule-1 (sICAM-1) and soluble E-selectin plasma concentrations were measured in 10 obese dyslipidemic men (group A), in 10 obese dyslipidemic type 2 diabetic men without coronary artery disease (CAD) (group B), and in 10 dyslipidemic type 2 diabetic men with angiographically documented CAD (group C) before and after 12 weeks of treatment with ciprofibrate. Compared with nondiabetic dyslipidemic men, diabetic patients with CAD or without documented CAD had significantly increased levels of sVCAM-1 (512 ±39 versus 750 ±139 ng/mL; p<0.0001 and 566 ±78 ng/mL; p<0.01, respectively) and sE-selectin (54.8 ±6.9 versus 65.9 ±8.8 ng/mL; p<0.001 and 62.6 ±9.4 ng/mL; p=0.056, respectively). The levels of sICAM-1 were similar in all 3 groups. Multivariate analyses showed that the higher sCAM levels in patients occurred independently of lipoprotein levels. Waist circumference as a marker of abdominal adiposity was the only independent predictor of elevated concentrations of all 3 cell adhesion molecules in multivariate analyses. sE-selectin was associated with HbA1C levels (p<0.01) in diabetic men at baseline. After 12 weeks of ciprofibrate therapy, sVCAM-1 levels were reduced by 13.5 ±2.1%, sICAM-1 levels by 11.8 ±2.2%, and sE-selectin levels by 17.1 ±3.5% (p<0.01 for all) with the greatest sE-selectin reduction in the diabetic subgroups (p<0.001). There was no correlation between the lowering of soluble adhesion molecules and the magnitude of lipid-lowering effect. An increased level of circulating adhesion molecules may be a mechanism by which dyslipidemia and/or diabetes mellitus promotes atherogenesis, and treatment with ciprofibrate may alter vascular cell activation.

Lipoprotein apheresis results in plaque stabilization and prevention of cardiovascular events: comments on the prospective Pro(a)LiFe study

Elevated lipoprotein(a) (Lp(a)) has emerged as an important independent cardiovascular risk factor, and causal association has been accepted with adverse outcome in atherosclerotic disease. Lipoprotein apheresis (LA) can lower low-density lipoprotein (LDL)-cholesterol and Lp(a) by 60–70 % and is the final escalating therapeutic option in patients with hyperlipoproteinemias (HLP) involving LDL or Lp(a) particles. Major therapeutic effect of LA is preventing cardiovascular events. Stabilizing plaque morphology might be an important underlying mechanism of action. In Germany, since 2008, a reimbursement guideline has been implemented to establish the indication for LA not only for familial or severe forms of hypercholesterolemia but also for Lp(a)-HLP associated with a progressive course of cardiovascular disease, that persists despite effective treatment of other concomitant cardiovascular risk factors, i.e. isolated Lp(a)-HLP. The Pro(a)LiFe-study confirmed with a prospective multicenter design that LA can effectively reduce Lp(a) plasma levels and prevent cardiovascular events.

Clinical benefit of long-term lipoprotein apheresis in patients with severe hypercholesterolemia or Lp(a)-hyperlipoproteinemia with progressive cardiovascular disease

Low-density lipoprotein cholesterol (LDL-C) and lipoprotein(a) (Lp(a)) are established causal risk factors for cardiovascular disease (CVD). Efficacy, safety, and tolerability of lipoprotein apheresis (LA) were investigated in 118 patients with CVD covering a period with 36,745 LA treatments in a retrospective, monocentric study. Indications for LA were severe hypercholesterolemia (n = 83) or isolated Lp(a) hyperlipoproteinemia (Lp(a)-HLP) (n = 35). In patients with hypercholesterolemia, initial pre-LA LDL-C was 176.4 ± 67.0 mg/dL. In patients with isolated Lp(a)-HLP, initial pre-LA Lp(a) was 127.2 ± 67.3 mg/dL. Mean reduction rates of LA were 67 % for both LDL-C and Lp(a). During chronic LA, the average annual rate of major adverse cardiac events of all patients declined by 79.7 % (p < 0.0001). Subgroup analysis showed decline by 73.7 % (p < 0.0001) in patients with severe hypercholesterolemia, and by 90.4 % (p < 0.0001) in patients with isolated Lp(a)-HLP. Adverse events occurred in 1.1 % of treatments. LA treatment of patients with a high risk for CVD due to hypercholesterolemia and/or Lp(a)-HLP demonstrated clinical benefit and was safe and well tolerated.

[The alternative view on diagnostic of hyperlipoproteinemia, cholesterol lipoproteins of low density and effect of statins: a lecture]

The effect of statins occur in several stages: 1) inhibition in hepatocytes of synthesis of functionally specific pool of spirit cholesterol, polar mono-layer of lipoproteins of very low density; 2) activation of hydrolysis of triglycerides in lipoproteins of very low density, formation of apoE/B-100-ligand and absorption of lipoproteins of very low density by insulin-depended cells; 3) decreasing of content of and spirit cholesterol-lipoproteins of very low density in blood plasma; 4) activation of hydrolysis of triglycerides in lipoproteins of low density, formation of apoB-100-ligand and absorption of lipoproteins of low density by insulin-independent cells; 5) decreasing of level of and increasing of content of lipoproteins of high density. During first weeks of effect of statins occurs decreasing of concentration of triglycerides and unesterified spirit cholesterol-lipoproteins of very low density in blood plasma. Then, slower and more durational decreasing of level of spirit cholesterol-lipoproteins of low density occurs. The value of spirit cholesterol-lipoproteins of low density is primarily determined by content of palmitic saturated fatty acid in food, its endogenous synthesis from glucose and concentration of palmitic triglycerides and lipoproteins of very low density of the same name in blood plasma. The effect of preparations is biologically valid and corresponds to alternative hypolipidemic preparations. All these preparations have an effect following a common algorithm: they activate, using different mechanisms, receptor absorption of lipoproteins of very low density or lipoproteins of low density by cells. The level of spirit cholesterol-lipoproteins of low density in full measure depends on content of triglycerides in blood. The concentration of spirit cholesterol in blood plasma has a reliable diagnostic significance only under physiological content of triglycerides. The main criterion of diagnostic and control of hypolipidemic therapy biologically is content of triglycerides. The comprehension of differences in effect of hypolipidemic preparations within framework of common algorithm permits rationally combine them under treatment of both primary inheritable phenotypes of glucolipoproteins and secondary symptomatic types of glucolipoproteins under obligatory observation of strict dietary treatment.

Changes in low-density lipoprotein cholesterol levels after discharge for acute myocardial infarction in a real-world patient population

Aggressively managing low-density lipoprotein cholesterol (LDL-C) after myocardial infarction (MI) is a cornerstone of secondary prevention. The changes in LDL-C after MI and the factors associated with LDL-C levels are unknown. Therefore, we directly measured fasting LDL-C levels in 797 MI patients from 24 US hospitals from 2005 to 2008. Mean LDL-C levels at discharge, 1 month, and 6 months were 95.1, 81.9, and 87.1 mg/dL, respectively. In a hierarchical, multivariable, repeated measures model, older age, male sex, and hypertension were associated with lower LDL-C levels, whereas self-reported avoidance of health care because of cost was associated with higher LDL-C. Both the presence and intensity of statin therapy at discharge were strongly associated with LDL-C levels, with adjusted mean 6-month changes of -3.4 mg/dL (95% confidence interval (CI): -12.1, 5.3) for no statins; 1.7 mg/dL (95% CI: -4.7, 8.1) for low statins; -10.2 mg/dL (95% CI: -14.5, -6.0) for moderate statins; and -13.9 mg/dL (95% CI: -19.7, -8.0) for intensive statins (P < 0.001). In conclusion, we found that greater reductions in LDL-C levels after MI were strongly associated with the presence and intensity of statin therapy, older age, male sex, hypertension, and better socioeconomic status. These findings support the use of intensive statin therapy in post-MI patients and provide estimates of the expected LDL-C changes after MI in a real-world population.

[Pathogenic mechanisms of proatherogenic changes in pregnant women with concomitant obesity]

The concentration of insulin, high sensitivity C-reactive protein (CRP) and indices of lipid metabolism (concentrations of triacylglycerols, total cholesterol, cholesterol of low density lipoproteins and cholesterol of very low density lipoproteins) in women with concomitant obesity in the second trimester of pregnancy were studied. Changes of the lipid profile in the pregnant women with concomitant obesity indicate development of type IV hyperlipoproteinemia. Concentrations of insulin and CRP in the blood serum of the pregnant women with obesity were respectively 92.1% and 62.5% higher than in the control group. On the basis of literature data and our own research it was concluded that the complex of the metabolic changes (insulin resistance, dislipidemia, endothelial dysfunction, systemic inflammation) in pregnant women with obesity promotes development of proatherogenic changes.

Hyperlipoproteinemia(a): clinical significance and treatment options

Recent epidemiologic and Mendelian randomization studies together have provided evidence that lipoprotein(a) (Lp(a)) plays a causal role in the pathogenesis of atherosclerosis and cardiovascular disease (CVD). The risk association with CVD is weak but seems continuous in shape and without an obvious threshold for Lp(a) levels. A plasma concentration of 60 mg/dl compared to usual levels is associated with an odds ratio for coronary heart disease of about 1.5 after adjustment for other cardiovascular risk factors. Niacin (nicotinic acid) is the pharmacologic means of choice for decreasing elevated Lp(a) levels but the drug is often poorly tolerated due to adverse reactions. Dietary measures, exercise and other lipid-lowering drugs, especially statins, fibrates and ezetimibe, are without effect. In patients with severe progressive cardiovascular disease and very high Lp(a) levels, lipoprotein apheresis may be used to effectively decrease Lp(a) concentrations. The method is expensive and impractical for most patients and its feasibility depends by and large on the healthcare reimbursement system of the respective country. No established treatment, however, selectively reduces Lp(a) without influencing other lipoproteins. Moreover, despite the clear association of hyperlipoproteinemia(a) with cardiovascular risk, no rigorously designed study to date has demonstrated that lowering Lp(a) concentrations has beneficial effects on cardiovascular endpoints. Randomized trials to this effect are urgently needed.

Cognitive impairment and polidistrectual atherosclerotic disease in chylomicronemia syndrome: a case report

A case of chylomicronemia syndrome is reported in a 72-year-old male with distinctive features of chronic pancreatic damage, severe hypertriglyceridemia, polidistrectual atherosclerosis and premature cognitive impairment. Although the patient had a positive history for recurrent episodes of pancreatitis the characteristic lesions of the hyperchylomicronemia syndrome, such as eruptive xanthomas and lipemia retinalis, were not present and splenomegaly could not be documented due to a previous post-traumatic splenectomy. Based on clinical phenotype, an apolipoprotein C-II deficiency was excluded by a fresh plasma infusion test, in which clarification of the patient plasma was not obtained. The absence of changes in the lipoprotein electrophoretic plasma after heparin infusion can be secondary to a lipoprotein lipase deficiency, a rare genetic disorder with an incidence of one per million. In relation to the resistance to diet and drugs, plasma exchange therapy was performed. After 3 years of this treatment there was no significant progression of atherosclerosis.

Study of changes in antioxidant enzymes status in diabetic post menopausal group of women suffering from cardiovascular complications

BACKGROUND

In type 2 diabetic patients, persistence of hyperglycemia has been reported as a cause of increased production of oxygen free radicals (FR), which leads to oxidative stress (OS) and becomes the main factor for predisposition to the cardiovascular complications in diabetes. Diabetic postmenopausal women are prone to cardiovascular disease due to reduced production of estrogen which is a potent antioxidant and prevents oxidative stress (OS) in body. The study is being aimed to find out the status of antioxidant enzymes (AOEs) and malondialdehyde (MDA) in post-menopausal diabetic women.

METHODS

The study was conducted with a total of 70 cases, which included 35 Type 2 diabetic post-menopausal females (45 - 60 years) with diabetic CVD complication as the study group and 35 age matched type 2 diabetic postmenopausal females without CVD complication.

RESULTS

All diabetic post menopausal females with CVD had significantly higher levels of fasting plasma glucose (FPG), postprandial plasma glucose (PPPG), total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-C), very low density lipoprotein cholesterol (VLDL-C), catalase (CAT), and malondialdehyde (MDA) and significantly lower levels of HDL-C, reduced glutathione (GSH), glutathione reductase (GR), glutathione peroxidase (GPx), and superoxide dismutase (SOD) as compared to the levels of control subjects.

CONCLUSIONS

During menopause, reduced production of estrogen causes hypertriglyceridemia, hypercholesterolemia, and hyperlipoproteinemia whose oxidation causes the accumulation of FR in the cell, which precipitates OS. Also, type 2 diabetic subjects with CVD poor glycemic control and impaired AOEs result in increased oxidative injury by failure of protective mechanisms, which further leads to oxidative stress.

Adiponectin and risk of coronary heart disease in apparently healthy men and women (from the EPIC-Norfolk Prospective Population Study)

The objective of the present study was to evaluate the association between adiponectin levels and incidence of coronary heart disease (CHD). We performed a prospective case-control analysis nested in the EPIC-Norfolk cohort. Participants were apparently healthy men and women 45 to 79 years of age who developed fatal or nonfatal CHD during an average follow-up period of 7.7 ± 1.1 years. In total 1,035 participants with incident CHD were matched for age, gender, and enrollment time to 1,920 controls who remained free of CHD over the study follow-up. Baseline nonfasting plasma adiponectin concentrations were determined by enzyme-linked immunosorbent assay. Adiponectin levels were lower in participants with CHD than in matched controls (men 8.74 vs 9.13 μg/ml, p = 0.01; women 12.6 vs 13.4 μg/ml, p = 0.03). A 1-μg/ml increment in adiponectin was associated with decreased CHD risk (odds ratio 0.78, 95% confidence interval 0.63 to 0.96, p = 0.02, in men; odds ratio 0.73, 95% confidence interval 0.55 to 0.96, p = 0.03, in women). However, this association was no longer significant after adjustment for established cardiovascular risk factors. Stratification of participants according to metabolic syndrome status showed that men and women with metabolic syndrome had a higher CHD risk, irrespective of their adiponectin levels. In conclusion, although a low adiponectin concentration is associated with an increased CHD risk, findings of the present study do not suggest that its measurement is useful to refine CHD risk assessment once traditional risk factors and clinical features of the metabolic syndrome have been considered.

Hyper-betalipoproteinemia LDL 1,2: a newly identified nonatherogenic hypercholesterolemia in a group of hypercholesterolemic subjects

OBJECTIVE

The identification of a non-atherogenic and an atherogenic lipoprotein profile, non-athero phenotype A vs. athero phenotype B, in a group of hypercholesterolemic subjects reveals newly discovered non-atherogenic hypercholesterolemia. Individuals with this type of hypercholesterolemia, or hyper-betalipoproteinemia LDL1,2, are probably not at increased risk to develop a premature atherothrombosis or a sudden cardiovascular event. Examined individuals with hyper-betalipoproteinemia LDL1,2 were divided into two subgroups: individuals under 40 years of age, and older individuals between 46 and 71 years of age. Subjects in the under 40 years of age group did not have any apparent clinical or laboratory-proven impairment of the cardiovascular system. The older subjects with hyper-betalipoproteinemia and a non-atherogenic lipoprotein profile had only mild signs of clinically irrelevant aortic valve sclerosis.

METHODS

A quantitative analysis of the lipoprotein spectrum in plasma in a group of hypercholesterolemic subjects was performed. An innovative electrophoresis method on polyacrylamide gel (PAG) was used for the analysis of plasma lipoproteins and for the identification of atherogenic vs. non-atherogenic lipoproteins in plasma. With regard to lipids, total cholesterol and triglycerides in plasma were analyzed with an enzymatic CHOD PAP method (Roche Diagnostics, FRG). A new parameter, the score for anti-atherogenic Risk (SAAR), was calculated as the ratio between non-atherogenic to atherogenic plasma lipoproteins in the examined subjects.

RESULTS

There was a high concentration of LDL1, and LDL2 subfractions (p<0.0001), and an extremely low concentration of LDL3-7 (p<0.0001) in the non-atherogenic lipoprotein profile of hyper-betalipoproteinemia LDL1,2 compared to the control group. Higher concentrations (p<0.0001) of lipids and lipoproteins in the non-atherogenic hypercholesterolemia, compared to the control group, were also found. The hyper-betalipoproteinemia LDL1,2 was also characterized by high SAAR values. There was found a higher concentration of HDL large and HDL intermediate subfractions in hypercholesterolemic subjects.

CONCLUSIONS

The advantages of this new diagnostic method include: (i) identification of the existence of a non-atherogenic hyper-betalipoproteinemia LDL1,2 in examined hypercholesterolemic subjects with untreated hypercholesterolemia (ii) introduction of a new risk measure, the score for anti-atherogenic risk (SAAR), for the estimation of atherogenic/anti-atherogenic risk. (iii) the presence of small dense LDL in plasma is decisive for the declaration of an atherogenic lipoprotein profile. It is valid for hyperlipidemia and for normolipidemia as well.

[Hyperlipoproteinaemia and dyslipoproteinaemia I. Classification, diagnostics, cardiovascular, cardiometabolic and residual risk]

Cardiovascular diseases remain the most important cause of death worldwide. The situation in the Czech Republic is one of the best when compared to the other countries of the former socialist block; on the other hand, we significantly lack behind when the comparison is made to south and southwest European countries. The concept of risk factors (RF) and multifactorial character of atherosclerosis as the main cause of cardiovascular diseases (CVD) is fully accepted at present. Hyperlipoproteinaemia (HLP) and dyslipidemia (DLP) are a group of high incidence metabolic diseases characterised by increased levels of lipids and lipoproteins in plasma or, in case of DLP, by unsuitable, atherogenic composition of lipids and lipoproteins in plasma. HLP and DLP are among the most important RF for the development of CVD. Mainly LDL-cholesterol (LDL-C) is perceived as a very important risk factor; successful reduction of LDL-C is linked to a reduction in cardiovascular risk. Even when LDL-C is decreased and the so-called "target values" achieved, patients are still at risk ofa CV event. This remnant risk is the so called "residual risk". The most important "rival" to LDL-cholesterol among the risk factors is the metabolic syndrome, or rather the DLP associated with the metabolic syndrome, characterised from the perspective of DLP by low levels of HDL-cholesterol and increased triglycerides with concurrent occurrence of "small dense LDL". The issue of heterogeneity and atherogenicity oflipoprotein particles in general then becomes topical. Lipoprotein (a)--Lp(a) is another important lipid risk factor that is getting a significant attention.

Comparison of four direct homogeneous methods for the measurement of low-density lipoprotein cholesterol

BACKGROUND

The primary lipoprotein risk factor is low-density lipoprotein cholesterol (LDL-C), and medication is targeted at lowering LDL-C values. To clarify the usefulness of direct homogeneous assays for LDL-C measurement, we compared the values obtained by various reagents to those obtained by the Friedewald equation and analyzed different reactivity to IDL/VLDL and LDL.

METHODS

Serum samples were collected from 55 patients with hypercholesterolemia. The LDL-C concentrations were determined by four direct homogeneous assays using reagent A (Kyowa Medex), B (Sekisui Medical), C (Denka Seiken), and D (Sysmex), which are commercially available.

RESULTS

Significant correlation was observed in LDL-C values obtained by the homogeneous assays and the Friedewald equation. However, there were two discrepancies in reagents B and C, respectively. These assays showed 40% and 55% lower LDL-C values than those calculated by the Friedewald equation, respectively. Reactivity to the IDL fraction in reagents B and C was lower than in reagents A and D.

CONCLUSIONS

Direct homogeneous assays for LDL-C are suitable for routine laboratory examination. However, it was shown that attention should be given to the different reactivity to IDL and LDL among reagents in some clinical samples.

A polygenic basis for four classical Fredrickson hyperlipoproteinemia phenotypes that are characterized by hypertriglyceridemia

Numerous single nucleotide polymorphisms (SNPs) have been found in recent genome wide association studies (GWAS) to be associated with subtle plasma triglyceride (TG) variation in normolipidemic subjects. However, since these GWAS did not specifically evaluate patients with rare disorders of lipoprotein metabolism--'hyperlipoproteinemia' (HLP)--it remains largely unresolved whether any of these SNP determinants of modest physiological changes in TG are necessarily also determinants of most HLP phenotypes. To address this question, we evaluated 28 TG-associated SNPs from GWAS in 386 unrelated adult patients with one of five Fredrickson phenotypes (HLP types 2A, 2B, 3, 4 and 5) and 242 matched normolipidemic controls. We found that several SNPs associated with TG in normolipidemic samples, including APOA5 p.S19W and -1131T>C, TRIB1 rs17321515, TBL2 rs17145738, GCKR rs780094, GALNT2 rs4846914 and ANGPTL3 rs12130333, were significantly associated with HLP types 2B, 3, 4 and 5. The findings indicate that: (i) the TG-associated Fredrickson HLP types 2B, 3, 4 and 5 are polygenic traits; (ii) these Fredrickson HLP types share numerous genetic determinants among themselves; and (iii) genetic determinants of modest TG variation in normolipidemic population samples also underlie--to an apparently even greater degree--susceptibility to these rare HLP phenotypes. Thus, the TG-associated Fredrickson HLP types 2B, 3, 4 and 5, although historically considered to be distinct are actually complex traits sharing among them several common genetic determinants seen in GWAS of normolipidemic population samples.

Restriction enzyme analysis of the apolipoprotein A-I gene in fish eye disease and Tangier disease

Restriction enzyme analysis of the apolipoprotein A-I (apo A-I) gene was performed in two patients with fish eye disease and one with Tangier disease. Despite the marked deficiency of high density lipoprotein and concomitantly of apo A-I in these two conditions, no evidence was found for major deletions or insertions in the apo A-I gene.

Distribution of apolipoprotein E isoforms between very low and high density lipoproteins of normal subjects and hyperlipidemic patients with special reference to type III hyperlipidemia

Serum very low (VLDL) and high density lipoproteins (HDL) from 17 hyperlipidemic patients and 10 normal subjects have been isolated by preparative ultracentrifugation, and the electrophoretic patterns of apolipoprotein E (apo E) isoforms in the lipoproteins have been examined by isoelectric focusing. Type III hyperlipidemia (dyslipoproteinemia) has been suggested to be a disease caused by an abnormal mutant of the apo E-3 isoform. In accordance with this, all patients with type III hyperlipidemia in the present study showed lack of apo E-3 in VLDL. However, all these patients demonstrated a protein zone corresponding to apo E-3 in their HDL fraction. Patients with other types of hyperlipidemia or normal subjects who showed an apo E-4 variant in VLDL had an HDL that lacked apo E-4. The results support the hypothesis that type III hyperlipidemia is due to an abnormal composition of the VLDL particles rather than a result of an abnormal mutant of apo E-3.

Scavenger receptor class B type I protein as an independent predictor of high-density lipoprotein cholesterol levels in subjects with hyperalphalipoproteinemia

CONTEXT

In mice, scavenger receptor class B, type I (SR-BI) receptor protein deficiency is associated with elevated high-density lipoprotein (HDL)-cholesterol (HDL-C) levels.

OBJECTIVE

Our objective was to determine the relationship between SR-BI protein and HDL-C levels in humans.

DESIGN

This was a prospective study of adults with hyperalphalipoproteinemia. Fasting blood was obtained for lipid and lipoprotein measurement, genomic DNA, and monocyte-derived macrophages. SR-BI protein levels were measured by Western blots, and SR-BI activity was measured by cholesteryl ester (CE) uptake of each donor's radiolabeled HDL with their monocyte-derived macrophages, or by degradation and specific cell association of dual-labeled HDL in vitro.

SETTING

The study was performed in a tertiary university teaching hospital.

RESULTS

The mean age was 57.2 +/- 10.9 yr (n = 65). SR-BI protein levels were inversely associated with HDL-C levels (P < 0.002), HDL particle size (P < 0.05), and positively associated with CE uptake (P < 0.004); there was no association with plasma apolipoprotein levels. SR-BI protein levels (P = 0.01) were independent predictors of HDL-C levels. Subjects who were carriers of the A allele for the rs4238001 (glycine to serine at position 2) polymorphism [single nucleotide polymorphism (SNP)] had lower SR-BI protein levels (P = 0.01), whereas carriers of the C allele for the rs2278986 SNP also had lower SR-BI protein levels (P = 0.02). Body mass index (P = 0.05), rs4238001 (P = 0.01), and rs2278986 (P = 0.01) SNPs were independent predictors of SR-BI protein levels. In vitro studies of murine macrophages stably expressing the glycine to serine at position 2 SNP showed less degradation (P < 0.0004) and specific cell association (P < 0.0004) of [(125)I, (3)H]-CE-labeled HDL.

CONCLUSIONS

SR-BI protein has an independent effect on HDL-C levels in women with hyperalphalipoproteinemia. Two SNPs were significantly associated with lower SR-BI protein levels.

Genetic variation in phospholipid transfer protein modulates lipoprotein profiles in hyperalphalipoproteinemia

We previously demonstrated the role of a phospholipid transfer protein (PLTP) gene variation (rs2294213) in determining levels of high-density lipoprotein cholesterol (HDL-C) in hypoalphalipoproteinemia (HypoA). We have now explored the role of PLTP in hyperalphalipoproteinemia (HyperA). The human PLTP gene was screened for sequence anomalies by DNA melting in 107 subjects with HyperA. The association with plasma lipoprotein levels was evaluated. We detected 7 sequence variations: 1 previously reported variation (rs2294213) and 5 novel mutations including 1 missense mutation (L106F). The PLTP activity was unchanged in the p.L106F mutation. The frequency of the rs2294213 minor allele was markedly increased in the HyperA group (7.0%) in comparison with a control group (4.3%) and the hypoalphalipoproteinemia group (2.2%). Moreover, rs2294213 was strongly associated with HDL-C levels. Linear regression models predict that possession of the rs2294213 minor allele increases HDL-C independent of triglycerides. These findings extend the association of rs2294213 with HDL-C levels into the extremes of the HDL distribution.

Influence of xantinole nicotinic acid on cutaneous microcirculation in patients with coronary artery disease and hyperlipoproteinemia

Xantinole nicotinic acid (NA) dose dependently lowers plasma levels of atherogenic lipoproteins and increases blood flow through vasodilation. The aim of this study was to evaluate the effect of NA on cutaneous microcirculation in patients with coronary artery disease and hyperlipidemia. In this open pilot study, five men and three women (74.2+/-9.1 yrs; 81.4+/-7.9 kg; 171.6+/-7.0 cm) with angiographically proven coronary artery disease and hyperlipidemia were included. Nailfold capillary microscopy was used for measurements of erythrocyte velocities at rest and after three minutes of ischemia, before and one hour after intake of 1000 mg of NA. The blood pressure (120+/-12/73+/-8 mmHg vs. 113+/-10/72+/-5 mmHg; p=0.19/0.83) and the heart rate (72+/-8/min vs. 70+/-7/min; p=0.38) remained unchanged. The mean capillary red blood cell velocity at rest (v(RBC); 0.27+/-0.23 mm/s vs. 0.32+/-0.18 mm/s; p=0.089) and the time to maximal post ischemia erythrocyte velocity (t(peak); 21.0+/-7.9 s vs. 24.3+/-15.5 s; p=0.49) did not change. The maximal post ischemic erythrocyte velocity (v(maxRBC); 0.93+/-0.33 mm/s vs. 1.19+/-0.19 mm/s; p=0.0096) raised slightly but significantly, the duration of post-ischemia hyperemia (DpH; 101+/-16 s vs. 127+/-15 s; p=0.0005) increased markedly. One patient reported about flush in the whole body. The administration of 1000 mg of NA resulted in a significant improvement of the cutaneous microcirculation in patients with coronary artery disease and hyperlipidemia.

Non-HDL cholesterol and apoB in dyslipidaemia

On the basis of a high correlation, non-HDL-C (non-high-density lipoprotein cholesterol) and apoB (apolipoprotein B) have been suggested to be of equivalent value for clinical practice; however, the strength of this relationship has not been examined in detail in patients with dyslipidaemia. The present study examines the variance of non-HDL-C compared with apoB in 1771 consecutive patients evaluated in a lipid clinic. These patients were divided into normolipidaemic subjects (n=407), type I hyperlipoproteinaemia (n=16), type IIa (n=736) and IIb (n=231) hyperlipoproteinaemia, type III hyperlipoproteinaemia (n=38), type IV hyperlipoproteinaemia (n=509) and type V hyperlipoproteinaemia (n=101). The relationship between non-HDL-C and apoB was examined both in terms of correlation and concordance. Correlation was high, but concordance was only moderate in the normolipidaemic subjects and in those with type IIa and type IIb hyperlipoproteinaemia. Correlation and concordance were both low in the subgroups with type III and type V hyperlipoproteinaemia. In those with type IV hyper-lipoproteinaemia, correlation was moderately high (r=0.74), but concordance was only fair. In conclusion, our results indicate that there is substantial variance of apoB for given values of non-HDL-C in many dyslipidaemic subjects. It follows that correlation is not adequate as a sole judge of equivalence of laboratory parameters.

Triglyceride-rich lipoproteins as agents of innate immunity

Bacterial endotoxin (i.e., lipopolysaccharide [LPS]) elicits dramatic responses in the host, including elevated plasma lipid levels due to increased synthesis and secretion of triglyceride-rich lipoproteins by the liver and inhibition of lipoprotein lipase. This cytokine-induced hyperlipoproteinemia, clinically termed the "lipemia of sepsis," was customarily thought to involve the mobilization of lipid stores to fuel the host response to infection. However, because lipoproteins can also bind and neutralize LPS, we have long postulated that triglyceride-rich lipoproteins (very-low-density lipoproteins and chylomicrons) are also components of an innate, nonadaptive host immune response to infection. Recent research demonstrates the capacity of lipoproteins to bind LPS, protect against LPS-induced toxicity, and modulate the overall host response to this bacterial toxin.

Low-density lipoprotein cholesterol estimation by a new formula — Confirmation

Our result supports the reliability of new Anandaraja's formula for low-density lipoprotein estimation in Brazil population.

Cholesteryl ester transfer protein and hyperalphalipoproteinemia in Caucasians

It is unclear whether cholesteryl ester transfer protein (CETP) contributes to high density lipoprotein cholesterol (HDL-C) levels in hyperalphalipoproteinemia (HALP) in Caucasians. Moreover, even less is known about the effects of hereditary CETP deficiency in non-Japanese. We studied 95 unrelated Caucasian individuals with HALP. No correlations between CETP concentration or activity and HDL-C were identified. Screening for CETP gene defects led to the identification of heterozygosity for a novel splice site mutation in one individual. Twenty-five heterozygotes for this mutation showed reduced CETP concentration (-40%) and activity (-50%) and a 35% increase of HDL-C compared with family controls. The heterozygotes presented with an isolated high HDL-C, whereas the remaining subjects exhibited a typical high HDL-C/low-triglyceride phenotype. The increase of HDL-C in the CETP-deficient heterozygotes was primarily attributable to increased high density lipoprotein containing apolipoprotein A-I and A-II (LpAI:AII) levels, contrasting with an increase in both high density lipoprotein containing apolipoprotein A-I only and LpAI:AII in the other group. This study suggests the absence of a relationship between CETP and HDL-C levels in Caucasians with HALP. The data furthermore indicate that genetic CETP deficiency is rare among Caucasians and that this disorder presents with a phenotype that is different from that of subjects with HALP who have no mutation in the CETP gene.

The Influence of Hyperlipoproteinemia on in Vitro Distribution of Amiodarone and Desethylamiodarone in Human and Rat Plasma

PURPOSE

To study the effect of hyperlipoproteinemia on in vitro distribution of amiodarone (AM) and its prevalent metabolite desethylamiodarone (DEA) in human and rat plasma.

MATERIALS AND METHODS

Human and rat normolipidemic (NL) and hyperlipidemic (HL) plasma were spiked with AM and DEA. The fractions (high and low density lipoproteins, triglyceride rich lipoproteins and lipoprotein deficient plasma) were separated using ultracentrifugation.

RESULTS

Human and rat displayed similar patterns in terms of association of AM and DEA in NL plasma, in which the highest and lowest associations were observed in lipoprotein deficient (LPDP) and triglyceride (TRL) rich plasma fractions, respectively. In HL a substantial shift was observed in partitioning of AM and DEA mostly to TRL. The shift of AM and DEA into TRL fraction of HL plasma was more drastic for rat than human. In HL, association of AM with rat LPDP and HDL fractions were 10 and 26-fold lower than in the corresponding human fractions, respectively. The DEA:AM ratio in rat, but not human, was significantly affected by HL.

CONCLUSION

HL caused a major shift of AM and DEA to TRL fraction in both species. The findings were consistent with the higher AM concentrations previously noted in HL rats given the drug.

Safety and Tolerability of Long Lasting LDL-apheresis in Familial Hyperlipoproteinemia

The aim of this work is to arbitrate the incidence of side effects and tolerability of long lasting LDL-apheresis in familial hyperlipoproteinemia. 1200 procedures were performed and the last 463 of them were evaluated. An immunoadsorption method of LDL-apheresis was used (continuous blood cell separator Cobe Spectra; secondary device: automated adsorption-desorption ADA, Medicap; absorption columns: Lipopak). As a whole, 6.26% adverse events were found and subsequently resolved by standard symptomatic therapy. Vaso-vagal reactions (symptoms of neurovegetative lability) were the most common adverse effects, presented as malaise, weakness, slight and short-term drop in blood pressure or other general signs. They were all well controlled by symptomatic therapy. We conclude that LDL-apheresis in the hands of experienced personnel is a safe procedure. An acceptable procedure duration limit, balancing the possibility to achieve a targeted cholesterol level while still maintaining an acceptable patient tolerance, was confirmed to be 4 hours.

Polyacrylamide gradient gel electrophoresis of lipoprotein subclasses

High-density (HDL), low-density (LDL), and very-low-density (VLDL) lipoproteins are heterogeneous cholesterol-containing particles that differ in their metabolism, environmental interactions, and association with disease. Several protocols use polyacrylamide gradient gel electrophoresis (GGE) to separate these major lipoproteins into known subclasses. This article provides a brief history of the discovery of lipoprotein heterogeneity and an overview of relevant lipoprotein metabolism, highlighting the importance of the subclasses in the context of their metabolic origins, fates, and clinical implications. Various techniques using polyacrylamide GGE to assess HDL and LDL heterogeneity are described, and how the genetic and environmental determinations of HDL and LDL affect lipoprotein size heterogeneity and the implications for cardiovascular disease are outlined.

Lipoprotein particle analysis by nuclear magnetic resonance spectroscopy

Laboratory measurements of plasma lipids (principally cholesterol and triglycerides) and lipoprotein lipids (principally low-density lipoprotein [LDL] and low-density lipoprotein [HDL] cholesterol) are the cornerstone of the clinical assessment and management of atherosclerotic cardiovascular disease (CVD) risk. LDL particles, and to a lesser extent very-low-density lipoprotein [VLDL] particles, cause atherosclerosis, whereas HDL particles prevent or reverse this process through reverse cholesterol transport. The overall risk for CVD depends on the balance between the "bad" LDL (and VLDL) and "good" HDL particles. Direct assessment of lipoprotein particle numbers us now possible through nuclear magnetic resonance spectroscopic analysis.

Impact of thiazolidenediones on serum lipoprotein levels

The thiazolidinediones, acting through peroxisome proliferator-activated receptor chi (PPARchi), affect multiple areas of metabolism. Of increasing importance is the recognition that these agents affect lipoprotein metabolism and cause changes in serum lipid and lipoprotein levels. All three thiazolidinediones, including troglitazone (which was withdrawn in the year 2000), rosiglitazone, and pioglitazone, tend to increase high-density lipoprotein (HDL) cholesterol, increase the size/decrease the density of low-density lipoprotein (LDL) particles, and raise the level of lipoprotein(a). In addition, troglitazone and pioglitazone, but not rosiglitazone, lower triglyceride levels modestly, thereby further contributing to increases in LDL and HDL size. The mechanism for these effects is still being clarified, but may involve enhancement of triglyceride clearance (in the case of pioglitazone), alteration of apolipoprotein C-III levels, reduction of hepatic lipase, and increase in ATP binding cassette A1 (ABCA1) activity. The clinical implications of these effects need further exploration.

Diminished macrophage cholesterol removal rate by the altered HDL metabolism in the Nagase analbuminemic rat

Dyslipoproteinemia of the Nagase analbuminemic rat (NAR) is characterized by elevated concentrations of VLDL and LDL attributed to increased rates of liver lipoprotein synthesis. Increased lysophosphatidylcholine (LPC) in NAR HDL has been attributed to high plasma LCAT activity. We show here that, as compared with Sprague-Dawley rats (SDR), NAR plasma triacylglycerol (TAG), total cholesterol (TC), HDL TAG, protein, total phospholipids (PL), LPC, and PS are increased. These alterations rendered the NAR HDL particle more susceptible to the activity of the enzyme hepatic lipoprotein lipase (HL), which otherwise was unaltered in our study. Fractional catabolic rates in blood of the autologous 125I-apoHDL (median and lower quartile values), were, respectively, 0.231 and 1.645 (n = 10) in NAR as compared with 0.140 and 0.109 (n = 10) in SDR (P = 0.012), corresponding to synthesis rates of HDL protein of 89.8 +/- 33.7 mg/d in NAR and 17.4 +/- 6.5 mg/d in SDR (P = 0.0122). Furthermore, Swiss mouse macrophage free-cholesterol (FC) efflux rates, measured as the percent [14C]-cholesterol efflux/6 h, were 8.2 +/- 2.3 (n = 9) in NAR HDL and 11.2 +/- 3.2 (n = 10) in SDR HDL (P = 0.03). Therefore, in NAR the modification of the HDL composition slows down the cell FC efflux rate, and together with the increased rate of plasma HDL metabolism influences the reverse cholesterol transport system.

Effects of bezafibrate on HDL2/HDL3 ratio in postmenopausal hypertriglyceridemic women

The short-term effects of bezafibrate on high-density lipoprotein cholesterol quality and triglyceride-rich lipoprotein metabolism in 186 postmenopausal hypertriglyceridemic women were investigated. Patients were randomized to an untreated group and to bezafibrate (400 mg/d) for 6 months. Fasting lipid concentrations, high-density lipoprotein 2, and high-density lipoprotein 3 levels were measured at baseline and after 3 and 6 months. At 3 months, bezafibrate had significantly decreased mean serum triglycerides and remnant-like particle cholesterol levels (105.7 +/- 43.4 mg/dL and 5.33 +/- 2.1 mg/dL, P < .001, respectively) from baseline values (232.5 +/- 63.9 mg/dL and 9.69 +/- 3.8 mg/dL, respectively). It also maintained lower total cholesterol, low-density lipoprotein cholesterol, triglycerides, and remnant-like particle cholesterol concentrations to 6 months. After 3 months, it significantly increased mean serum high-density lipoprotein cholesterol (55.1 +/- 14.7 vs 64.8 +/- 12.1 mg/dL; P < .0001) and maintained higher high-density lipoprotein cholesterol at 6 months. The high-density lipoprotein 2-high-density lipoprotein 3 ratio was decreased after 3 months of therapy with bezafibrate (2.13 +/- 0.68) from the baseline (2.42 +/- 0.71) (P < .01).

The two novel CETP mutations Gln87X and Gln165X in a compound heterozygous state are associated with marked hyperalphalipoproteinemia and absence of significant coronary artery disease

High levels of high-density lipoprotein cholesterol (HDL-C) occur with cholesteryl ester transfer protein (CETP) deficiency. However, the extent to which CETP deficiency states may be associated with protection against coronary artery disease (CAD) has been controversial. We evaluated a Greek pedigree with high levels of HDL-C and no history of premature CAD. The proband, a 45-year-old male with an HDL-C of 194 mg/dl with absent CETP activity, was heterozygous for two novel CETP mutations (Q87X and Q165X). A 64-slice multidetector CT scan revealed minimal (<10%) narrowing of the proximal left anterior descending artery without any other evidence of coronary atherosclerosis. In contrast to previous studies, these data suggest that complete CETP deficiency does not promote premature atherosclerosis. However, it remains unclear as to whether the relative lack of coronary atherosclerosis was the direct consequence of CETP deficiency and/or the lack of traditional CAD risk factors.

Lipoprotein(a) and atherosclerosis: new perspectives on the mechanism of action of an enigmatic lipoprotein

Although elevated plasma concentrations of lipoprotein(a) (Lp(a)) have been identified as a risk factor for coronary heart disease, the pathophysiologic and physiologic roles of Lp(a) continue to elude basic researchers and clinicians alike. Lp(a) is a challenging lipoprotein to study because it has a complex structure consisting of a low-density lipoprotein-like moiety to which is covalently attached the unique glycoprotein apolipoprotein(a) (apo(a)). Apo(a) contains multiply repeated kringle domains that are similar to a sequence found in the fibrinolytic proenzyme plasminogen; differing numbers of kringle sequences in apo(a) give rise to Lp(a) isoform size heterogeneity. In addition to elevated plasma concentrations of Lp(a), apo(a) isoform size has been identified as a risk factor for coronary heart disease, although studies addressing this relationship have been limited. The similarity of Lp(a) to low-density lipoprotein and plasminogen provides an enticing link between the processes of atherosclerosis and thrombosis, although a clear demonstration of this association in vivo has not been provided. Clearly, Lp(a) is a risk factor for both atherothrombotic and purely thrombotic events; a plethora of mechanisms to explain these clinical findings has been provided by both in vitro studies as well as animal models for Lp(a).

[The influence of a diet with including amaranth oil on antioxidant and immune status in patients with ischemic heart disease and hyperlipoproteidemia]

It was investigated the influence of a diet supplemented with amaranth oil on dynamic of antioxidant and immune status in 125 patients with ischemic heart disease and hyper-lipoproteidemia. The efficacy of diets with different contents of squalene (100, 200, 400, 600 mg per day) was compared. It was shown that antiatherosclerotic diet with inclusion 600 mg squalene has promoted the most positive changes of immune status. The consumption of 200-400 mg of squalene per day produced the more significant antioxidant effect.

[Lipids abnormalities in children with refractory nephrotic proteinuria]

The aim of the study is to evaluate the lipids disorders in children with refractory proteinuria in acute phase and remission of the disease. The study group consist of 39 children, mean age 8.2 +/- 3.9 years with refractory nephrotic syndrome (RNS)/nephrotic proteinuria (RNP), wchich were divided in 3 groups according to RNS/RNP frequency: group A--17 children up to 3 times, group B--13 children 4-9 times, group C--9 children > or = 10 times. Total number of relapses was 53. In all children at the start and every 3 months, the total cholesterol concentration (TC), LDL, HDL cholesterol, triglicerydes (TG), apolipoprotein A1(apoA1), apoliporotein B100 (apoB100 ) were measured. The duration of the study was 12 months.

RESULTS

Children with NS/NP in the acute phase of the disease show high levels of TC, TG, LDL-C and apolipoproteins: apo AI, apo B100, The level of HDL-C was normal. In the groups A, B, C a normalization of average levels of apo B100, was recorded after 3 month, apo AI after 3 to 6 months. With the increasing amount of relapses the time to normalization of average levels of TC and LDL-C was prolonged. Normal average levels of LDL-C were recorded in the group A after 3 months, in the group B after 9 months, in the group C was still high. TC normalization was recorded after 6 months only in the group A, in the groups B and C the level was high; TG was high during 12 months of observation in all groups.

CONCLUSION

The persistance of high TC, LDL-C and TG levels during the remission phase in children with higher numbers of NS/NP relapses is a risk factor of atherosclerosis developement.