Lipoprotein(a) hyperlipidemia as cardiovascular risk factor: pathophysiological aspects

Association Between Lipoprotein(a) and Dilatation of Different Aortic Segments in Hypertensive Patients

PURPOSE

There are limited reports on the potential link between Lp(a) and ARDM. Thus, we examined the relationship between Lp(a) and ARDM among hypertensive patients.

METHODS

We used echocardiography to measure ARDM in 513 consecutively hospitalized patients. namely, the aortic valve annulus (Ava), sinuses of Valsalva (SV), sinotubular junction (STJ), and ascending aorta (AA) in 513 consecutive inpatients. We also examined the Lp(a), and other laboratory profiles of all participants.

RESULTS

Lp(a) exhibited a positive and independent relationship with the SV diameter (coefficient [β] = 0.330, p = 0.002) and STJ (coefficient [β] = 0.253, p = 0.023), regardless of age, sex, height, or other clinical factors among hypertensive, but not nonhypertensive patients. We also demonstrated that a marked rise in Lp(a) levels was independently associated with SV dilatation (SVD) (OR: 1.006, 95% CI: 1.002-1.009, p = 0.002) and AA dilatation (AAD) (OR: 1.006, 95% CI: 1.000-1.011, p = 0.035) in patients with hypertension. In the subgroup analysis, elevated Lp(a) levels were significantly associated with SV dilatation in all subgroups, and with AAD in males and patients aged 65 years or younger (p < 0.05). The restricted cubic spline analysis indicated a linear association between Lp(a) levels and the risk of both SV and AAD (p < 0.05).

CONCLUSIONS

Herein, we were the first to report that among hypertensive patients, elevated Lp(a) concentrations were intricately linked to the ARDMs at SV and STJ. Moreover, we revealed that the Lp(a) level was a stand-alone indicator of SVD and AAD.

Atherosclerosis and Its Related Laboratory Biomarkers

Atherosclerosis constitutes a persistent inflammatory ailment, serving as the predominant underlying condition for coronary artery disease (CAD), peripheral artery disease (PAD), and cerebrovascular disease. The progressive buildup of plaques within the walls of medium- and large-caliber arteries characterizes the atherosclerotic process. This accumulation results in significant narrowing that impedes blood flow, leading to critical tissue oxygen deficiency. Spontaneous blockage of thrombotic vessels can precipitate stroke and myocardial infarction, which are complications representing the primary global causes of mortality. Present-day models for predicting cardiovascular risk incorporate conventional risk factors to gauge the likelihood of cardiovascular events over a ten-year span. In recent times, researchers have identified serum biomarkers associated with an elevated risk of atherosclerotic events. Many of these biomarkers, whether used individually or in combination, have been integrated into risk prediction models to assess whether their inclusion enhances predictive accuracy. In this review, we have conducted a comprehensive analysis of the most recently published literature concerning serum biomarkers associated with atherosclerosis. We have explored the potential utility of incorporating these markers in guiding clinical decisions.

Familial Hyperlipidemia Caused by Apolipoprotein B Mutation in the Pediatric Amish Population: A Mini Review

Familial Hypercholesterolemia (FH) is an autosomal dominant genetic disorder that causes increased low density lipoprotein cholesterol (LDL-C) levels and a higher risk of premature atherosclerosis and cardiovascular disease (CVD). Common causes of FH include inherited genetic mutations in the LDLR, APOB, and PCSK9 genes. LDLR, APOB, and PCSK9 mutations account for 79%, 5%, and <1% of cases of FH respectively. Apolipoprotein B (ApoB) is the necessary atherogenic lipoprotein which can serve as a determinant of cardiovascular disease including hypercholesterolemia. A founder variant in Apolipoprotein B (APOB p.R3527Q) causes FH and is found in 12% of the Pennsylvania Amish population. This article provides an overview of ApoB metabolism and clinical manifestations associated with APOB mutations. An understanding of the clinical manifestations caused by APOB p.R3527Q can be beneficial for the clinical diagnosis and treatment of FH in the Amish. Based on previous studies, changes in LDL cholesterol (LDL-C), LDL particles (LDL-P), small dense LDL particles, and ApoB levels can be seen among these patients putting them at an increased risk for atherosclerotic issues, vascular hardening, and changes in endothelial function, particularly among homozygous individuals.

Lipoprotein(a) induces caspase-1 activation and IL-1 signaling in human macrophages

Introduction

Lipoprotein(a) (Lp(a)) is an LDL-like particle with an additional apolipoprotein (apo)(a) covalently attached. Elevated levels of circulating Lp(a) are a risk factor for atherosclerosis. A proinflammatory role for Lp(a) has been proposed, but its molecular details are incompletely defined.

Methods and results

To explore the effect of Lp(a) on human macrophages we performed RNA sequencing on THP-1 macrophages treated with Lp(a) or recombinant apo(a), which showed that especially Lp(a) induces potent inflammatory responses. Thus, we stimulated THP-1 macrophages with serum containing various Lp(a) levels to investigate their correlations with cytokines highlighted by the RNAseq, showing significant correlations with caspase-1 activity and secretion of IL-1β and IL-18. We further isolated both Lp(a) and LDL particles from three donors and then compared their atheroinflammatory potentials together with recombinant apo(a) in primary and THP-1 derived macrophages. Compared with LDL, Lp(a) induced a robust and dose-dependent caspase-1 activation and release of IL-1β and IL-18 in both macrophage types. Recombinant apo(a) strongly induced caspase-1 activation and IL-1β release in THP-1 macrophages but yielded weak responses in primary macrophages. Structural analysis of these particles revealed that the Lp(a) proteome was enriched in proteins associated with complement activation and coagulation, and its lipidome was relatively deficient in polyunsaturated fatty acids and had a high n-6/n-3 ratio promoting inflammation.

Discussion

Our data show that Lp(a) particles induce the expression of inflammatory genes, and Lp(a) and to a lesser extent apo(a) induce caspase-1 activation and IL-1 signaling. Major differences in the molecular profiles between Lp(a) and LDL contribute to Lp(a) being more atheroinflammatory.

Lipoprotein(a) in Atherosclerotic Diseases: From Pathophysiology to Diagnosis and Treatment

Lipoprotein(a) (Lp(a)) is a low-density lipoprotein (LDL) cholesterol-like particle bound to apolipoprotein(a). Increased Lp(a) levels are an independent, heritable causal risk factor for atherosclerotic cardiovascular disease (ASCVD) as they are largely determined by variations in the Lp(a) gene (LPA) locus encoding apo(a). Lp(a) is the preferential lipoprotein carrier for oxidized phospholipids (OxPL), and its role adversely affects vascular inflammation, atherosclerotic lesions, endothelial function and thrombogenicity, which pathophysiologically leads to cardiovascular (CV) events. Despite this crucial role of Lp(a), its measurement lacks a globally unified method, and, between different laboratories, results need standardization. Standard antilipidemic therapies, such as statins, fibrates and ezetimibe, have a mediocre effect on Lp(a) levels, although it is not yet clear whether such treatments can affect CV events and prognosis. This narrative review aims to summarize knowledge regarding the mechanisms mediating the effect of Lp(a) on inflammation, atherosclerosis and thrombosis and discuss current diagnostic and therapeutic potentials.

Insights into the pivotal role of statins and its nanoformulations in hyperlipidemia

Hyperlipidemia is the primary cause of heart disorders and has been manifested as the condition with remarkable higher levels of very-low-density lipoproteins, low-density lipoproteins, intermediate-density lipoprotein, triglycerides, and cholesterol in blood circulation. Genetic causes or systemic metabolic illnesses like diabetes mellitus, increased alcohol consumption, hypothyroidism, and primary biliary cirrhosis are several reasons behind development of hyperlipidemia. Higher levels of lipids and lipoproteins in plasma are responsible for various health disorders in human body like occlusion of blood vessels, acute pancreatitis, and reduced artery lumen elasticity. Both primary and secondary prophylaxis of heart disease can be achieved through combination of pharmacologic therapy with therapeutic lifestyle adjustments. Statins which belongs to HMG-CoA reductase inhibitors are preferred for primary prevention of hyperlipidemia particularly for individuals at higher risk of development of heart disease. This review discusses the recent advancements and outcomes of nanoparticle drug carriers for statins in the therapy of hyperlipidemia.

Relationship between lipoprotein(a) and revascularization after percutaneous coronary intervention in type 2 diabetes mellitus patients with acute coronary syndrome

BACKGROUND

As a residual risk factor for coronary heart disease, lipoprotein(a) [Lp(a)] is associated with the occurrence of cardiovascular events after percutaneous coronary intervention (PCI). The revascularization rate after PCI is high among diabetic patients. However, the relationship between Lp(a) and revascularization after PCI in type 2 diabetes mellitus (T2DM) patients with acute coronary syndrome (ACS) remains unclear.

METHODS

The investigation was a single-center, observational, retrospective cohort study. Patients with T2DM who were first diagnosed with ACS and underwent PCI were included in the study. As a result, 362 patients were enrolled and divided into three groups according to tertiles on basis of Lp(a) levels (11.48 mg/dL and 21.70 mg/dL). The incidence of major adverse cardiac events (MACEs), including cardiac death, revascularization due to myocardial ischemia, readmission due to angina, and nonfatal stroke, was evaluated. Subgroups were established according to the low-density lipoprotein cholesterol (LDL-C) level (70 mg/dL).

RESULTS

During follow-up (median: 2.0 years), 69 MACEs occurred, and 76.81% of these patients underwent revascularization. The Lp(a) level in the MACE group was significantly higher than that in the non-MACE group (22.90 mg/dL vs. 14.10 mg/dL, p < .001). Kaplan-Meier analysis revealed that the incidence of adverse cardiovascular events was significantly higher in the high Lp(a) groups than in the low Lp(a) groups (p = .001), mainly because of the increased occurrence of revascularization irrespective of LDL-C level (<70 mg/dL; ≥70 mg/dL, both p < .05) rather than death, nonfatal stroke, or hospital readmission due to angina (both p > .05). The receiver operating characteristic (ROC) curve showed that the area under the curve (AUC) for Lp(a) in predicting the occurrence of MACE and revascularization were 0.664 and 0.668 respectively, both p < .05. Furthermore, multivariate Cox regression models indicated that Lp(a) was independently associated with revascularization [medium Lp(a) category: HR (95% CI): 2.988 (1.164-7.671), p = .023; high Lp(a) category: HR (95% CI): 4.937 (2.023-12.052), p < .001].

CONCLUSION

Lp(a) was an independent predictor of revascularization in patients with ACS complicated with T2DM, regardless of LDL-C levels. This suggests that Lp(a) measurement may help identify high-risk diabetic patients with ACS.

Synthesis, Molecular Docking, and Preclinical Evaluation of a New Succinimide Derivative for Cardioprotective, Hepatoprotective and Lipid-Lowering Effects

Cardiac and hepatotoxicities are major concerns in the development of new drugs. Better alternatives to other treatments are being sought to protect these vital organs from the toxicities of these pharmaceuticals. In this regard, a preclinical study is designed to investigate the histopathological effects of a new succinimide derivative (Comp-1) on myocardial and liver tissues, and the biochemical effects on selected cardiac biomarkers, hepatic enzymes, and lipid profiles. For this, an initially lethal/toxic dose was determined, followed by a grouping of selected albino rats into five groups (each group had n = 6). The control group received daily oral saline for 8 days. The 5-FU (5-Fluorouracil) group received oral saline daily for 8 days, added with the administration of a single dose of 5-FU (150 mg/kg I.P.) on day 5 of the study. The atenolol group received oral atenolol (20 mg/kg) for 8 days and 5-FU (150 mg/kg I.P.) on day 5 of the protocol. Similarly, two groups of rats treated with test compound (Comp-1) were administered with 5 mg/kg I.P. and 10 mg/kg I.P. for 8 days, followed by 5-FU (150 mg/kg I.P.) on day 5. Toxicity induced by 5-FU was manifested by increases in the serum creatinine kinase myocardial band (CK-MB), troponin I (cTnI) and lactate dehydrogenase (LDH), lipid profile, and selected liver enzymes, including ALP (alkaline phosphatase), ALT (alanine transaminase), AST (aspartate aminotransferase), BT (bilirubin total), and BD (direct bilirubin). These biomarkers were highly significantly decreased after the administration of the mentioned doses of the test compound (5 mg/kg and 10 mg/kg). Similarly, histological examination revealed cardiac and hepatic tissue toxicity by 5-FU. However, those toxic effects were also significantly recovered/improved after the administration of Comp-1 at the said doses. This derivative showed dose-dependent effects and was most effective at a dose of 10 mg/kg body weight. Binding energy data computed via docking simulations revealed that our compound interacts toward the human beta2-adrenergic G protein-coupled receptor (S = −7.89 kcal/mol) with a slight stronger affinity than the calcium channel T-type (S = −7.07 kcal/mol). In conclusion, the histological and biochemical results showed that the test compound (Comp-1) had prominent cardioprotective, hepatoprotective, and lipolytic effects against 5-FU-induced toxicity in the subjected animal model.

Lipid and Haematologic Profiling of Regular Blood Donors Revealed Health Benefits

Background

Objective

Materials and Methods

Results

Conclusion

Clinical characterization of familial hypercholesterolemia due to an amish founder mutation in Apolipoprotein B

Background

Familial hypercholesterolemia (FH) due to a founder variant in Apolipoprotein B (ApoB^R3500Q) is reported in 12% of the Pennsylvania Amish community. By studying a cohort of ApoB^R3500Q heterozygotes and homozygotes, we aimed to characterize the biochemical and cardiac imaging features in children and young adults with a common genetic background and similar lifestyle.

Methods

We employed advanced lipid profile testing, carotid intima media thickness (CIMT), pulse wave velocity (PWV), and peripheral artery tonometry (PAT) to assess atherosclerosis in a cohort of Amish ApoB^R3500Q heterozygotes (n = 13), homozygotes (n = 3), and their unaffected, age-matched siblings (n = 9). ApoB^R3500Q homozygotes were not included in statistical comparisons.

Results

LDL cholesterol (LDL-C) was significantly elevated among ApoB^R3500Q heterozygotes compared to sibling controls, though several ApoB^R3500Q heterozygotes had LDL-C levels in the normal range. LDL particles (LDL-P), small, dense LDL particles, and ApoB were also significantly elevated among subjects with ApoB^R3500Q. Despite these differences in serum lipids and particles, CIMT and PWV were not significantly different between ApoB^R3500Q heterozygotes and controls in age-adjusted analysis.

Conclusions

We provide a detailed description of the serum lipids, atherosclerotic plaque burden, vascular stiffness, and endothelial function among children and young adults with FH due to heterozygous ApoB^R3500Q. Fasting LDL-C was lower than what is seen with other forms of FH, and even normal in several ApoB^R3500Q heterozygotes, emphasizing the importance of cascade genetic testing among related individuals for diagnosis. We found increased number of LDL particles among ApoB^R3500Q heterozygotes but an absence of detectable atherosclerosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02539-3.

Efficacy and safety of Qushi Huayu granule for hyperlipidemia: study protocol for a randomized, double-blind, placebo-controlled trial

Background

Hyperlipidemia has become a common chronic disease worldwide in recent years. Studies have shown that hyperlipidemia patients, especially those with a high level of serum low-density lipoprotein cholesterol (LDL-C), have a significantly higher prevalence of atherosclerosis, leading to coronary heart disease. Previous basic experiments and clinical studies have shown that Qushi Huayu granules (QSHY) reduce blood lipids in patients with non-alcoholic fatty liver disease (NAFLD) accompanied by hyperlipidemia. However, the clinical efficacy of QSHY in patients with hyperlipidemia is still lacking. This study aims to investigate the effect and safety of QSHY for hyperlipidemia.

Methods

This is a randomized, double-blind, placebo-controlled trial. A total of 210 participants will be enrolled and randomized into the QSHY or placebo granules groups in equal proportions, who will receive treatment for 24 weeks. The primary outcome will be the change in LDL-C from baseline to week 12. Secondary outcomes will be changes in other serum lipids markers, life quality measuring health surveys, and traditional Chinese medicine (TCM) pattern scale. All related tests will be measured at baseline, week 12, and week 24 after enrollment. Adverse events and the safety of intervention will be monitored and evaluated.

Discussion

We designed a clinical trial of hyperlipidemia management with QSHY, a TCM prescription. The results of this trial will present the efficacy and safety of QSHY in patients with hyperlipidemia.

Trial registration

Chinese Clinical Trial Registry ChiCTR2000034125. Registered on June 25, 2019

Moxibustion for treating patients with hyperlipidemia: A systematic review and meta-analysis protocol

BACKGROUND

Hyperlipidemia has been a root cause of atherosclerosis, which leads to a high risk to serious cardio-cerebrovascular disease. Many trials have reported that moxibustion therapy is effective in lowering blood lipid levels when treating hyperlipidemia. The aim of this systematic review is to assess the effectiveness and safety of moxibustion therapy for hyperlipidemia.

METHODS

Two reviewers will electronically search the following databases: the Cochrane Central Register of Controlled Trials (CENTRAL); PubMed; EMBASE; China National Knowledge Infrastructure (CNKI); Chinese Biomedical Literature Database (CBM); Chinese Scientific Journal Database (VIP database); and Wan-Fang Database from the inception, without restriction of publication status and languages. Additional searching including researches in progress, the reference lists and the citation lists of identified publications. Study selection, data extraction, and assessment of study quality will be performed independently by 2 reviewers. Changes of blood lipid levels from baseline to the end of the treatment, including low-density lipoprotein cholesterol (LDL-C) level, total cholesterol (TC) level, triglycerides (TG) level and high-density lipoprotein cholesterol (HDL-C) level will be assessed as the primary outcomes. Quality of life, long-term effect and safety will be evaluated as secondary outcomes. If it is appropriate for a meta-analysis, RevMan 5.3 statistical software will be used; otherwise, a descriptive analysis will be conducted. Data will be synthesized by either the fixed-effects or random-effects model according to a heterogeneity test. The results will be presented as risk ratio (RR) with 95% confidence intervals (CIs) for dichotomous data and weight mean difference (WMD) or standard mean difference (SMD) 95% CIs for continuous data.

RESULTS

This study will provide a comprehensive review of the available evidence for the treatment of moxibustion with hyperlipidemia.

CONCLUSIONS

The conclusions of our study will provide an evidence to judge whether moxibustion is an effective and safe intervention for patients with hyperlipidemia.

ETHICS AND DISSEMINATION

This systematic review will be disseminated in a peer-reviewed journal or presented at relevant conferences. It is not necessary for a formal ethical approval because the data are not individualized.

TRIAL REGISTRATION NUMBER

PROSPERO CRD42019130545.

PCSK9 positively correlates with plasma sdLDL in community-dwelling population but not in diabetic participants after confounder adjustment

This study aimed to investigate the relationship between plasma proprotein convertase subtilisin kexin 9 (PCSK9) and small dense low-density lipoprptein (sdLDL) in diabetic and non-diabetic participants in a community-dwelling cohort.The plasma levels of PCSK9 and sdLDL were detected in 1766 participants (median age: 61.40 years; 733 males vs 1033 females; 383 diabetic vs 1383 non-diabetic patients) from the Pingguoyuan community of Beijing, China.Results showed that Pearson correlation analysis revealed a positive correlation between PCSK9 and sdLDL (r = 0.263, P < .001). Multiple linear regression analysis showed a significant positive correlation between plasma PCSK9 and sdLDL in the whole population study. sdLDL was used as the dependent variable, and the potential cofounders were adjusted. However, any independent relationship was not observed between circulating PCSK9 and sdLDL in the diabetic subpopulation (r = 0.269, P < .05, β = 9.591, P > .05).Thus, there is a positive correlation between plasma PCSK9 and sdLDL in a community-dwelling cohort, but not in type 2 diabetic subpopulation, after confounder adjustment.

Effect of 405 nm low intensity irradiation on the absorption spectrum of in-vitro hyperlipidemia blood

BACKGROUND:

Laser therapy is reported to be clinically effective for improving microcirculation, rheological properties and blood lipid profiles despite the lack of certainty on the mechanism.

OBJECTIVE:

This study intends to provide methods to drop blood lipid level of hyperlipidemia samples by low-intensity laser irradiation therapy and provide reasoning of mechanism.

METHODS:

Twenty whole blood samples of high level of lipids profile are irradiated by 405 nm low-intensity laser at 12 J/cm2 twice a day for 3 days and compared with normal lipids profile group. Then whole blood sample are centrifuged to obtain result of erythrocyte for further interpretation. Multi-scan spectrum microplate reader is used to measure absorption spectrum and data is analyzed by software SPSS 14.0.

RESULTS:

Results show that after 405 nm low-intensity laser irradiation, whole blood samples of high lipid level statistically have higher absorbance peak value than normal samples while erythrocyte samples have lower absorbance peak value.

CONCLUSIONS:

From the divergence of absorption peak value change after low-intensity laser irradiation for whole blood sample and erythrocyte, we suspect that low level laser irradiation affects the enzymes activity of lipid metabolism, improves the cholesterol balance of plasma and cytoplasm in erythrocyte, and decreases aggregation of the erythrocyte.

Reduced incidence of cardiovascular events in hyper-Lp(a) patients on lipoprotein apheresis. The G.I.L.A. (Gruppo Interdisciplinare Aferesi Lipoproteica) pilot study

BACKGROUND

Lipoprotein apheresis (LA) is the elective therapy for homozygous and other forms of Familial Hypercholesterolemia, Familial Combined Hypercholesterolemia, resistant/intolerant to lipid lowering drugs, and hyper-lipoproteinemia(a). Lipoprotein(a) [Lp(a)] has been classified as the most prevalent genetic risk factor for coronary artery disease and aortic valve stenosis.

AIM

Our multicenter retrospective study has the aim to analyze the incidence of adverse cardiovascular events (ACVE) before and during the LA treatment, in subjects with elevated level of Lp(a) (>60 mg/dL) [hyper-Lp(a)] and chronic ischemic heart disease.

METHODS

We collected data of 23 patients (mean age 63 ± 9 years, male 77%; from hospital of Pisa 11/23, Pistoia 7/23, Verona 2/23, Padova 2/23 and Ferrara 1/23), with hyper-Lp(a), pre-apheresis LDL-cholesterol <100 mg/dL, cardiovascular disease, on maximally tolerated lipid lowering therapy and LA treatment (median 7 years, interquartile range 3-9 years). The LA treatment was performed by heparin-induced LDL precipitation apheresis (16/23), dextran-sulphate (4/23), cascade filtration (2/23) and immunoadsorption (1/23). The time lapse between first cardiovascular event and beginning of apheresis was 6 years (interquartile range 1-12 years).

RESULTS

The recorded ACVE, before and after the LA treatment inception, were 40 and 10 respectively (p < 0.05), notably, the AVCE rates/year were 0.43 and 0.11 respectively (p < 0.05) with a 74% reduction of event occurrence.

CONCLUSIONS

Our data confirm long-term efficacy and positive impact of LA on morbidity in patients with hyper-Lp(a) and chronic ischemic heart disease on maximally tolerated lipid lowering therapy.

Reverse Cholesterol Transport: Molecular Mechanisms and the Non-medical Approach to Enhance HDL Cholesterol

Dyslipidemia (high concentrations of LDL-c and low concentrations of HDL-c) is a major cause of cardiovascular events, which are the leading cause of death in the world. On the other hand, nutrition and regular exercise can be an interesting strategy to modulate lipid profile, acting as prevention or treatment, inhibiting the risk of diseases due to its anti-inflammatory and anti-atherogenic characteristics. Additionally, the possibility of controlling different training variables, such as type, intensity and recovery interval, can be used to maximize the benefits of exercise in promoting cardiovascular health. However, the mechanisms by which exercise and nutrients act in the regulation of cholesterol and its fractions, such as reverse cholesterol transport, receptors and transcription factors involved, such as PPARs and their role related to exercise, deserve further discussion. Therefore, the objective of this review is to debate about non-medical approaches to increase HDL-c, such as nutritional and training strategies, and to discuss the central mechanisms involved in the modulation of lipid profile during exercise, as well as that can be controlled by physical trainers or sports specialists in attempt to maximize the benefits promoted by exercise. The search for papers was performed in the databases: Medline (Pubmed), Science Direct, Scopus, Sport Discus, Web of Science, Scielo and Lilacs until February 2016.

Association between lipoprotein (a) and proprotein convertase substilisin/kexin type 9 in patients with heterozygous familial hypercholesterolemia: A case-control study

BACKGROUND

Recent data have suggested an important role of lipoprotein (a) [Lp(a)] and proprotein convertase substilisin/kexin type 9 (PCSK9) in the development of atherosclerotic cardiovascular disease (ASCVD) in both general population and family hypercholesterolemia (FH), while the relation of Lp(a) to PCSK9 has not been examined.

OBJECTIVE

The aim of the present study was to investigate the association between plasma PCSK9 and Lp(a)in patients with heterozygous FH (HeFH).

METHODS

Two hundred and fifty-five molecularly confirmed patients with HeFH were compared to 255 age- and gender-matched non-FH controls. Plasma PCSK9 and Lp(a) concentrations were measured using ELISA and immunoturbidimetric method respectively, and finally their association was assessed.

RESULTS

Both plasma PCSK9 and Lp(a) levels were significantly higher in patients with HeFH compared to control group (p<0.001). Besides, the Lp(a) concentration and percentage of Lp(a)≥300mg/L were increased by PCSK9 tertiles in HeFH group (both p<0.05) while not in control group. In partial correlation analysis, Lp(a) was associated with PCSK9 (r=0.254, p<0.001) in HeFH group but not in control, which were further confirmed by multivariable linear regression analysis. Furthermore, significant associations between Lp(a) and PCSK9 were also found in subgroups of HeFH group irrespective of definite or probable FH, with and without coronary artery disease (CAD), and with statin or not.

CONCLUSIONS

Plasma Lp(a) level was associated with PCSK9 in patients with HeFH alone, suggesting that much about the interaction of PCSK9 with Lp(a) in FH need further explorations.

Hypolipidemic activity of P-methoxycinnamic diester (PCO-C) isolated from Copernicia prunífera against Triton WR-1339 and hyperlipidemic diet in mice

Carnauba wax is extracted from the leaves of the Copernicia prunífera and contains approximately 80% of esters in its composition. The purpose of the present study was evaluate the hypolipidemic effect of p-methoxycinnamic diesters (PCO-C) extracted from Copernicia prunífera in a model of acute and chronic dyslipidemia in mice. The levels of total cholesterol and triglycerides were significantly reduced plasma levels in PCO-C at the dose of 100mg/kg in a model of acute and chronic dyslipidemia. Histological studies showed that PCO-C has no hepatotoxic effect and reduces hepatic steatosis in animals that consumed hyperlipidemic ration. Thus, it was concluded that PCO-C isolated from Copernicia Prunifera was effective in reducing total cholesterol and triglyceride levels in both dyslipidemia induction models. The finding indicates that PCO-C might be beneficial in treatment of hyperlipidemia and atherosclerosis.

Association of matrix γ-carboxyglutamic acid protein levels with insulin resistance and Lp(a) in diabetes: A cross-sectional study

AIMS

The risk of cardiovascular disease (CVD) and mortality is increased in patients with chronic kidney disease (CKD), with a background role of vascular calcification in the development of CVD also reported. Studies have demonstrated that high lipoprotein(a) (Lp(a)) levels accelerate the development of atherosclerolsis and are potentially involved in the vascular calcification. Matrix Gla Protein (MGP) seems to play an important role in vascular calcification. The aim of the study was to examine the potential association of MGP concentrations with Lp(a) and insulin resistance.

METHODS

The study involved 100patients divided in four groups: 25 with both CKD stage 4 and Type2 Diabetes (DM) (Group-A), 25 with CKD4 without DM (Group-B), 25 non uremic patients with DM (Group-C) and 25 healthy subjects (Group-D). Serum glucose, Lp(a), MGP, plasma HBA1c and insulin were measured in all patients. Insulin resistance was estimated by the homeostasis model assessment equation (HOMA-IR).

RESULTS

A significant positive linear association between MGP and Lp(a) levels (r=0.272, p=0.006) was noted, as well as between MGP and HOMA-IR levels (r=0.308, p=0.002). However, no significant linear association between Lp(a) and HOMA-IR levels was recorded. A similar positive association between MGP and insulin levels (r=0.204, p=0.042) was also found.

CONCLUSION

This study concluded that diabetes coexisting with renal disease leads to extreme vascular calcification expressed by elevated MGP levels, resulting in higher frequency of cardiovascular disease in comparison to CKD patients without diabetes. The detected Lp(a) and MGP association in CKD4 patients may also represent the key to the complicated mechanism of their coexisting accelerated atherosclerosis and vascular calcification.

Small Dense Low-Density Lipoprotein as Biomarker for Atherosclerotic Diseases

Low-density lipoprotein (LDL) plays a key role in the development and progression of atherosclerosis and cardiovascular disease. LDL consists of several subclasses of particles with different sizes and densities, including large buoyant (lb) and intermediate and small dense (sd) LDLs. It has been well documented that sdLDL has a greater atherogenic potential than that of other LDL subfractions and that sdLDL cholesterol (sdLDL-C) proportion is a better marker for prediction of cardiovascular disease than that of total LDL-C. Circulating sdLDL readily undergoes multiple atherogenic modifications in blood plasma, such as desialylation, glycation, and oxidation, that further increase its atherogenicity. Modified sdLDL is a potent inductor of inflammatory processes associated with cardiovascular disease. Several laboratory methods have been developed for separation of LDL subclasses, and the results obtained by different methods can not be directly compared in most cases. Recently, the development of homogeneous assays facilitated the LDL subfraction analysis making possible large clinical studies evaluating the significance of sdLDL in the development of cardiovascular disease. Further studies are needed to establish guidelines for sdLDL evaluation and correction in clinical practice.

Lipoprotein(a) and its role in inflammation, atherosclerosis and malignancies

Lipoprotein (a) (Lp(a)) is a modified low-density lipoprotein (LDL) particle with an additional specific apolipoprotein (a), covalently attached to apolipoprotein B‑100 of LDL by a single thioester bond. Increased plasma Lp(a) level is a genetically determined, independent, causal risk factor for cardiovascular disease.

The precise quantification of Lp(a) in plasma is still hampered by mass-sensitive assays, large particle variation, poor standardization and lack of assay comparability.

The physiological functions of Lp(a) include wound healing, promoting tissue repair and vascular remodeling. Similarly to other lipoproteins, Lp(a) is also susceptible for oxidative modifications, leading to extensive formation of pro-inflammatory and pro-atherogenic oxidized phospholipids, oxysterols, oxidized lipid-protein adducts in Lp(a) particles, that perpetuate atherosclerotic lesion progression and intima-media thickening through induction of M1-macrophages, inflammation, autoimmunity and apoptosis. The oxidation-specific epitopes of modified lipoproteins are major targets of pre-immune, natural IgM antibodies, that may attenuate the pro-inflammatory and pro-atherogenic effects of Lp(a).

Although the data are still insufficient, recent studies suggest a potential anti-neoplastic role of Lp(a).

Lipoprotein(a) Levels in Patients With Abdominal Aortic Aneurysm

Circulating markers relevant to the development of abdominal aortic aneurysm (AAA) are currently required. Lipoprotein(a), Lp(a), is considered a candidate marker associated with the presence of AAA. The present meta-analysis aimed to evaluate the association between circulating Lp(a) levels and the presence of AAA. The PubMed-based search was conducted up to April 30, 2015, to identify the studies focusing on Lp(a) levels in patients with AAA and controls. Quantitative data synthesis was performed using a random effects model, with standardized mean difference (SMD) and 95% confidence interval (CI) as summary statistics. Overall, 9 studies were identified. After a combined analysis, patients with AAA were found to have a significantly higher level of Lp(a) compared to the controls (SMD: 0.87, 95% CI: 0.41-1.33, P < .001). This result remained robust in the sensitivity analysis, and its significance was not influenced after omitting each of the included studies from the meta-analysis. The present meta-analysis confirmed a higher level of circulating Lp(a) in patients with AAA compared to controls. High Lp(a) levels can be associated with the presence of AAA, and Lp(a) may be a marker in screening for AAA. Further studies are needed to establish the clinical utility of measuring Lp(a) in the prevention and management of AAA.

Efficacy and safety of Yinchenwuling powder for hyperlipidemia: a systematic review and Meta-analysis

OBJECTIVE

To assess the clinical effectiveness and adverse effects of Yinchenwuling powder (YCWLP) in the treatment of hyperlipidemia using Meta-analysis.

METHODS

Seven electronic databases were searched for randomized controlled trials designed to evaluate the clinical effectiveness of YCWLP for hyperlipidemia published in any language prior to February 2015. Two reviewers independently identified articles, extracted data, assessed quality, and cross-checked the results. Revman 5.3 was used to analyze the data.

RESULTS

Only five randomized controlled trials with poor methodology were included in the analysis. The five trials compared YCWLP with conventional lipid-lowering drugs. Meta-analysis indicated that YCWLP was more effective at the levels of total cholesterol and triglycerides, while increasing the level of high-density lipoprotein cholesterol without serious adverse effects. However, it was not more effective than lipid-lowering drugs in reducing low-density lipoprotein cholesterol and improving hemorheology.

CONCLUSION

YCWLP appeared to improve lipid levels. However, given the high risk of bias among the trials, we could not conclude that YCWLP was beneficial to patients with hyperlipidemia. More rigorous trials are required to provide stronger evidence for the conclusion.

Phosphocholine-containing ligands direct CRP induction of M2 macrophage polarization independent of T cell polarization: Implication for chronic inflammatory states

INTRODUCTION

We studied monocyte transendothelial migration and subsequent polarization into M1/M2 macrophages in response to C-reactive protein (CRP) with two disease-related ligands: (1) phosphocholine (PC) and (2) multilamellar liposomes containing both unoxidized and oxidized forms of the lipid, phosphatidylcholine. These ligands differ in biological origin: PC is present on bacterial cell walls while oxidized lipids are present in atherogenic lipids.

METHODS

We used an in vitro model of human monocyte transendothelial migration and assessed the polarization of monocytes and T cells and signaling through Fcγ receptors in monocytes.

RESULTS

CRP without ligands did not promote M2 macrophage differentiation over background levels. However, when paired with either ligand, it increased M2 numbers. M2 differentiation was dependent on IL-13, and in the case of CRP with PC, was associated with a Th2 response. Paradoxically, while CRP with PC initiated a Th2 response, the combination of liposomes with CRP resulted in a Th1 response without any change in Th2 numbers despite association with M2 macrophage polarization. To resolve the conundrum of an anti-inflammatory macrophage response coexisting with a proinflammatory T cell response, we investigated signaling of CRP and its ligands through Fcγ receptors, which leads to macrophage activation independent of T cell signaling. We found that CRP plus PC acted via FcγRI, whereas CRP with liposomes bound to FcγRII. Both were activating signals as evidenced by SYK phosphorylation.

CONCLUSION

We conclude that CRP with ligands can promote M2 macrophage differentiation to fibroblasts through FcγR activation, and this may result in an anti-inflammatory influence despite a proinflammatory T cell environment caused by oxidized lipids. The potential relationship of this mechanism to chronic inflammatory disease is discussed.

Lipoprotein apheresis for the treatment of elevated circulating levels of lipoprotein(a): a critical literature review

Lipoprotein(a), which consists of a low-density lipoprotein (LDL) particle linked to an apolipoprotein(a) moiety, is currently considered an independent risk factor for cardiovascular disease due to its atherogenic (LDL-like) and prothrombotic (plasminogen-like) properties. The aim of this review is to provide an overview of the current and newer therapies for lowering increased lipoprotein(a) levels, focusing on lipoprotein apheresis. After a systematic literature search, we identified ten studies which, overall, documented that lipoprotein apheresis is effective in reducing increased lipoprotein(a) levels and cardiovascular events.

The relationship between Lp(a) and CVD outcomes: a systematic review

Robust associations between lipoprotein(a) [Lp(a)] and CVD outcomes among general populations have been published in previous studies. However, associations in high risk primary prevention and secondary prevention populations are less well defined. In order to investigate this further, a systematic review was performed including prospective studies, which assessed the relationship between Lp(a) and CVD outcomes using multivariable analyses. Additional information was gathered on Lp(a) assays, multivariable modelling and population characteristics. Literature searches from inception up to December 2015 retrieved 2850 records. From these 60 studies were included. Across 39 primary prevention studies in the general population (hazard ratios ranged from 1.16 to 2.97) and seven high risk primary prevention studies (hazard ratios ranged from 1.01 to 3.7), there was evidence of a statistically significant relationship between increased Lp(a) and an increased risk of future CVD. Results in 14 studies of secondary prevention populations were also suggestive of a modest statistically significant relationship (hazard ratios ranged from 0.75 to 3.7).Therefore current evidence would suggest that increased Lp(a) levels are associated with modest increases in the risk of future CVD events in both general and higher risk populations. However, further studies are required to confirm these findings.

PCSK9 inhibitors and their role in high-risk patients in reducing LDL cholesterol levels: evolocumab

Patients with familial hypercholesterolemia or statin intolerance are especially challenging to manage since LDL cholesterol levels often remain considerably elevated despite clinicians’ best efforts. With statins regarded as first-line pharmacologic therapy by the current American College of Cardiology/American Heart Association guidelines to reduce LDL cholesterol and cardiovascular risk, there is now a critical need to determine when other agents will play a role beyond maximally tolerated statin therapy and lifestyle changes. In this review, we take a closer look at evolocumab (Repatha®), one of the new injectable human monoclonal antibodies to PCSK9 and its efficacy and safety properties from the results of various trials.

The role of C-reactive protein in innate and acquired inflammation: new perspectives

The participation of C-reactive protein (CRP) in host defense against microorganisms has been well described. More controversial has been its role in chronic conditions such as cardiovascular disease. Our recent publications explain the reasons for some of the confusion concerning CRP as a risk factor for disease and whether it is pro-inflammatory or anti-inflammatory. We found that two isoforms of CRP, pentameric (pCRP) and monomeric (mCRP), on microparticles (MPs), were not measureable by standard clinical assays. When we investigated MPs by imaging cytometry in plasma from controls versus patients with peripheral artery disease, we found that MPs from endothelial cells bearing mCRP were elevated. This elevation did not correlate with the soluble pCRP measured by high-sensitivity CRP assays. The data suggest that detection of mCRP on MPs may be a more specific marker in diagnosis, measurement of progression, and risk sensitivity in chronic disease. In an in vitro model of vascular inflammation, pCRP was anti-inflammatory and mCRP was pro-inflammatory for macrophage and T cell polarization. When we further investigated pCRP under defined conditions, we found that pCRP in the absence of a phosphocholine ligand had no inflammatory consequences. When combined with phosphocholine ligands, pCRP signaled through two Fcγ receptors (FcγRI and FcγRII) via phosphorylation of spleen tyrosine kinase (pSYK) to activate monocytes. Phosphocholine itself, when bound to pCRP, induced a congruent M2 macrophage and Th2 response. Phosphocholine is also the head group on the lipid phosphatidylcholine, which can become oxidized. Liposomes bearing oxidized phosphatidylcholine without pCRP promoted a uniform M1 macrophage and Th1 pro-inflammatory response. When oxidized liposomes were bound to pCRP, there was a disjunction in the macrophage and T cell response: monocytes matured into M2 macrophages, but the T cells polarized into a Th1 phenotype. The CRP-bound liposomes signaled monocytes via FcγRII to promote an anti-inflammatory M2 macrophage state, whereas the lack of FcγR on T cells allowed their liposome-induced polarization to a pro-inflammatory Th1 phenotype unopposed by the contribution of the pCRP/FcγR interaction. Different isoforms of CRP and its binding to complex ligands may determine its biological activities and their contribution to inflammatory states.