Triglyceride-Rich Lipoprotein Remnants and Cardiovascular Disease

Atherogenic index of plasma and coronary artery disease: a systematic review and meta-analysis of observational studies

BACKGROUND

Atherogenic index of plasma (AIP), a novel logarithmic index that combines fasting triglyceride and high-density lipoprotein cholesterol concentrations, is associated with the burden of atherosclerosis. This study aimed to evaluate the relationship between AIP and coronary artery disease (CAD) risk, severity, and prognosis in populations with and without established CAD.

METHODS

PubMed, Embase, and Web of Science were systematically searched from the inception of each database to August 13, 2024. Cross-sectional studies, case-control studies, and prospective or retrospective cohort studies using multivariate analysis were included. Given that the true effect size may differ across studies, a random-effects model for all analyses was applied.

RESULTS

Fifty-one observational studies were included in this study. Patients with higher AIP were more likely to have CAD (odds ratio (OR): 2.79, 95% CI 1.75-4.45, P < 0.00001). Furthermore, these patients were more likely to have coronary artery calcification (OR: 2.28, 95% CI 1.74-3.00, P < 0.00001), multivessel CAD (OR: 2.04, 95% CI 1.50-2.77, P < 0.00001), and an increased risk of plaque progression (OR: 1.49, 95% CI 1.17-1.91, P = 0.001). In populations without established CAD, higher AIP levels were associated with an increased risk of Major adverse cardiovascular events (MACE) (hazard ratio (HR): 1.28, 95% CI 1.22-1.35, P < 0.00001). Interestingly, this finding was consistent in patients presenting with acute coronary syndrome (HR: 1.59, 95% CI 1.33-1.89, P < 0.00001) and patients with chronic coronary syndrome or stable CAD (HR: 1.65, 95% CI 1.15-2.37, P = 0.007).

CONCLUSIONS

This meta-analysis demonstrates that elevated AIP is strongly associated with increased CAD risk, greater severity, and poorer prognosis in populations with and without established CAD. However, more studies are needed to evaluate the predictive performance and determine the optimal cut-off for AIP in different populations.

Beneficial Effect of Fenofibrate in Combination with Silymarin on Parameters of Hereditary Hypertriglyceridemia-Induced Disorders in an Animal Model of Metabolic Syndrome

Background: Hypertriglyceridemia has serious health risks such as cardiovascular disease, type 2 diabetes mellitus, nephropathy, and others. Fenofibrate is an effective hypolipidemic drug, but its benefits for ameliorating disorders associated with hypertriglyceridemia failed to be proven in clinical trials. Methods: To search for possible causes of this situation and possibilities of their favorable influence, we tested the effect of FF monotherapy and the combination of fenofibrate with silymarin on metabolic disorders in a unique model of hereditary hypertriglyceridemic rats (HHTg). Results: Fenofibrate treatment (100 mg/kg BW/day for four weeks) significantly decreased serum levels of triglyceride, (-77%) and free fatty acids (-29%), the hepatic accumulation of triglycerides, and the expression of genes encoding transcription factors involved in lipid metabolism (Srebf2, Nr1h4. Rxrα, and Slco1a1). In contrast, the hypertriglyceridemia-induced ectopic storage of lipids in muscles, the heart, and kidneys reduced glucose utilization in muscles and was not affected. In addition, fenofibrate reduced the activity of the antioxidant system, including Nrf2 expression (-35%) and increased lipoperoxidation in the liver and, to a lesser extent, in the kidneys and heart. Adding silymarin (micronized form, 600 mg/kg BW/day) to fenofibrate therapy increased the synthesis of glycogen in muscles, (+36%) and reduced hyperinsulinemia (-34%). In the liver, it increased the activity of the antioxidant system, including PON-1 activity and Nrf2 expression, and reduced the formation of lipoperoxides. The beneficial effect of combination therapy on the parameters of oxidative stress and lipoperoxidation was also observed, to a lesser extent, in the heart and kidneys. Conclusions: Our results suggest the potential beneficial use of the combination of FF with SLM in the treatment of hypertriglyceridemia-induced metabolic disorders.

Ratio of remnant cholesterol to high-density lipoprotein cholesterol in relation to gestational diabetes mellitus risk in early pregnancy among Korean women

OBJECTIVE

There is no evidence to suggest that an association exists between the remnant cholesterol (RC) to high-density lipoprotein cholesterol (HDL-C) ratio and gestational diabetes mellitus (GDM). In this study, the RC/HDL-C ratio during the first trimester was examined as a potential indicator of the onset of GDM during the second trimester.

METHODS

This was a secondary analysis of data from a Korea-based prospective cohort study. The study involved 582 women within 14 weeks of pregnancy who were examined between November 2014 and July 2016 at two Korean hospitals. RC was calculated as total cholesterol (TC) minus the sum of low-density lipoprotein cholesterol (LDL-C) and HDL-C. The RC/HDL-C ratio was determined by dividing the RC content by the HDL-C content. The RC/HDL-C ratio and GDM occurrence were investigated utilizing a binary logistic regression model, various sensitivity analyses, and subgroup analyses. Additionally, the RC/HDL-C ratio was evaluated using receiver operating characteristic (ROC) analysis.

RESULTS

The average age of the pregnant women was 32.07 ± 3.78 years, and the RC/HDL-C ratio had a median value of 0.39. The prevalence of GDM was 6.01%. There was a positive association between the RC/HDL-C ratio and the incidence of GDM after adjusting for potential confounding variables (odds ratio: 21.78, 95% confidence interval [CI]: 3.55-133.73, P < 0.001). Furthermore, this association was validated by subgroup and sensitivity analyses. The results indicated that the RC/HDL-C ratio was a robust predictor of GDM, with an area under the ROC curve of 0.795 (95% CI: 0.723-0.868). The optimal threshold value was 0.45, with a sensitivity of 71.4% and a specificity of 75.3%. Compared with traditional lipid markers, including LDL-C, HDL-C, triglycerides, TC, and the emerging marker RC, the RC/HDL-C exhibited higher diagnostic efficacy.

CONCLUSION

There is an increased risk of GDM associated with higher levels of the RC/HDL-C ratio between 12 and 14 weeks of gestation, independent of traditional risk factors. The RC/HDL-C ratio is more effective in diagnosing GDM than traditional lipid markers.

The athero-contour: A novel tool for global and rapid assessment of atherogenic parameters. A use case in saroglitazar treatment of MAFLD patients

BACKGROUND AND AIMS

Comprehensive assessment of pharmacotherapy effects on atherogenic parameters (AP) that influence the risk of cardiovascular disease (CVD) is challenging due to interactions among a large number of parameters that modulate CVD risk.

METHODS

We developed an illustrative tool, athero-contour (AC), which incorporates weighted key lipid, lipo- and glycoprotein parameters, to readily illustrate their overall changes following pharmacotherapy. We demonstrate the applicability of AC to assess changes in AP in response to saroglitazar treatment in patients with metabolic associated fatty liver disease (MAFLD) in the EVIDENCES IV study.

RESULTS

The baseline AC of saroglitazar and placebo groups was worse than the mean of the general population. After 16-week treatment, AC improved significantly in the saroglitazar group due to alterations in very low-density lipoprotein, triglyceride, and glycoproteins.

CONCLUSION

Using AC, we could readily and globally evaluate and visualize changes in AP. AC improved in patients with MAFLD following saroglitazar therapy.

Remnant Cholesterol: Quantification, Concentrations by Sex and Age, and Risk of Ischemic Heart Disease

BACKGROUND

Observational and genetic causal studies have shown an association between high concentrations of remnant cholesterol and increased risk of ischemic heart disease. However, findings from randomized intervention trials that reduced plasma triglycerides, a surrogate marker of remnant cholesterol, have been conflicting. The exact mechanisms by which remnant cholesterol contributes to atherosclerosis and, ultimately, ischemic heart disease remain incompletely understood. Additionally, insight on sex and age differences and the importance of measurement differences of remnant cholesterol in plasma concentrations and risk of ischemic heart disease are sparse.

CONTENT

This review covers current knowledge regarding remnant cholesterol and its role in ischemic heart disease, with particular attention to measurement and sex- and age-specific differences.

SUMMARY

Findings from observational, genetic, and mechanistic studies support the notion that higher remnant cholesterol may be an important cause of ischemic heart disease in both women and men. Concentrations of remnant cholesterol vary by age, with a sharp increase at early adulthood for men and around menopause for women. Remnant cholesterol can be calculated from a standard lipid profile and in addition measured directly using manual ultracentrifugation, automated assays, and nuclear magnetic resonance spectroscopy. Irrespective of the method used to assess plasma concentrations, high concentrations of remnant cholesterol are consistently associated with increased risk of myocardial infarction and ischemic heart disease in observational and genetic causal studies; cholesterol rather than triglycerides in remnants drive this risk. Importantly, results from ongoing randomized clinical trials aiming specifically at lowering remnant cholesterol and ischemic heart disease are eagerly awaited.

The relevance of remnant cholesterol as a guide for lipid management in Indian subjects undergoing coronary revascularization

BACKGROUND

The atherogenic potential of remnant cholesterol, which refers to the cholesterol content of triglyceride-rich, non-low-density lipoprotein (LDL) particles in circulation, has gained increasing attention recently. Unfortunately, very limited information is available regarding remnant cholesterol levels in Indian subjects.

METHODS

This was a retrospective study conducted at a premier, tertiary care center in North India. A total of 3064 consecutive subjects [mean age 61.3 ± 10.3 years, 2550 (83.2%) men] with newly diagnosed coronary artery disease (CAD) undergoing coronary revascularization were included. Enzymatic assays were used for measuring various lipid parameters. Remnant cholesterol was calculated by subtracting LDL cholesterol (LDL-C) and high-density lipoprotein cholesterol from total cholesterol. A value >30 mg/dL was considered elevated.

RESULTS

The mean LDL-C was 79.1 ± 33.1 mg/dL with 46.4% of all subjects having LDL-C <70 mg/dL and only 16.9% having LDL-C <50 mg/dL. The median remnant cholesterol level was 17.0 mg/dL (interquartile range 12.0-24.0 mg/dL) with only 11.9% of subjects having values >30 mg/dL. Only 4.5% of the patients with LDL-C <70 mg/dL and 2.9% of those with LDL-C <50 mg/dL had elevated remnant cholesterol. These proportions were significantly greater in patients with serum triglycerides >200 mg/dL.

CONCLUSION

Our study shows that in a North-Indian population with CAD, elevated remnant cholesterol was present in only a small proportion. The prevalence of elevated remnant cholesterol decreased further as the LDL-C control improved. These findings suggest that elevated remnant cholesterol may not be a clinically relevant therapeutic target in most patients with LDL-C below the currently recommended goals.

Multifaceted Role of Apolipoprotein C3 in Cardiovascular Disease Risk and Metabolic Disorder in Diabetes

Apolipoprotein C3 (APOC3) plays a critical role in regulating triglyceride levels and serves as a key predictor of cardiovascular disease (CVD) risk, particularly in patients with diabetes. While APOC3 is known to inhibit lipoprotein lipase, recent findings reveal its broader influence across lipoprotein metabolism, where it modulates the structure and function of various lipoproteins. Therefore, this review examines the complex metabolic cycle of APOC3, emphasizing the impact of APOC3-containing lipoproteins on human metabolism, particularly in patients with diabetes. Notably, APOC3 affects triglyceride-rich lipoproteins and causes structural changes in high-, very low-, intermediate-, and low-density lipoproteins, thereby increasing CVD risk. Evidence suggests that elevated APOC3 levels-above the proposed safe range of 10-15 mg/dL-correlate with clinically significant CVD outcomes. Recognizing APOC3 as a promising biomarker for CVD, this review underscores the urgent need for high-throughput, clinically feasible methods to further investigate its role in lipoprotein physiology in both animal models and human studies. Additionally, we analyze the relationship between APOC3-related genes and lipoproteins, reinforcing the value of large-population studies to understand the impact of APOC3 on metabolic diseases. Ultimately, this review supports the development of therapeutic strategies targeting APOC3 reduction as a preventive approach for diabetes-related CVD.

One in Five Atherosclerotic Cardiovascular Disease Events in Individuals With Diabetes Attributed to Elevated Remnant Cholesterol

AIMS

Elevated remnant cholesterol (= the cholesterol carried in triglyceride-rich lipoproteins) is a causal risk factor for atherosclerotic cardiovascular disease (ASCVD) and is common in individuals with diabetes. We tested the hypothesis that ASCVD in individuals with diabetes can be partly attributed to elevated remnant cholesterol.

MATERIALS AND METHODS

We included 3806 individuals with diabetes identified among 107,243 individuals from the Copenhagen General Population Study and used multivariable adjusted Poisson regression to estimate the fraction of ASCVD attributable to elevated remnant cholesterol. Elevated remnant cholesterol was defined as levels higher than those observed in individuals with non-high-density lipoprotein (non-HDL) cholesterol < 2.6 mmol/L (100 mg/dL), the European guideline goal. Results were replicated in the UK Biobank.

RESULTS

During 15 years of follow-up, 498 patients were diagnosed with ASCVD, 172 with peripheral artery disease, 185 with myocardial infarction and 195 with ischaemic stroke. In individuals with non-HDL cholesterol < 2.6 mmol/L (100 mg/dL) and in all individuals with diabetes, median remnant cholesterol levels were 0.5 mmol/L (20 mg/dL) and 0.8 mmol/L (31 mg/dL). The fraction of events attributable to elevated remnant cholesterol was 19% (95% confidence interval: 10%-28%) for ASCVD, 21% (5%-37%) for peripheral artery disease, 24% (10%-37%) for myocardial infarction and 17% (1%-31%) for ischaemic stroke; in the UK Biobank, corresponding values were 16% (9%-22%), 25% (12%-36%), 17% (8%-25%) and 7% (0%-19%), respectively.

CONCLUSIONS

One in five ASCVD events in individuals with diabetes can be attributed to elevated remnant cholesterol. It remains to be determined in clinical trials if remnant cholesterol-lowering therapy may prevent ASCVD.

Messenger interference RNA therapies targeting apolipoprotein C-III and angiopoietin-like protein 3 for mixed hyperlipidemia: the future of plozasiran and zodasiran

INTRODUCTION

Mixed hyperlipidemia represents a substantial public health issue and a considerable burden on healthcare systems. Although the introduction of statins and LDL-cholesterol lowering agents have significantly reduced the incidence of atherosclerotic cardiovascular diseases (ASCVD), a significant portion of the population continues to exhibit ASCVD progression due to elevated triglyceride-rich lipoprotein (TRL) levels. This persistent risk has catalyzed the development of novel pharmacological interventions targeting these lipoproteins.

AREAS COVERED

Our special report commenced with a targeted PubMed search using keywords such as 'plozasiran,' 'zodasiran,' and terms related to APOC3 and ANGPTL3. As the review progressed, emergent research questions guided further searches, allowing for the inclusion of additional relevant articles to comprehensively illustrate the linkage between TRLs and cardiovascular disease, discuss the roles of APOC3, ANGPTL3, and the pharmaceutical agents that target these proteins, and provide a comparison on the ARCHES-2 and MUIR trials.

EXPERT OPINION

The ARCHES-2 and MUIR trials demonstrated effective triglyceride reduction by these therapies, yet it is uncertain if this correlates with significant clinical benefits. Advances in antisense oligonucleotide technology, especially the GalNAc delivery platform, show promise for personalized lipid management, though challenges such as cost and safety concerns remain.

Serum Lipoprotein Profiling by NMR Spectroscopy Reveals Alterations in HDL-1 and HDL-2 Apo-A2 Subfractions in Alzheimer's Disease

Identifying biomarkers for Alzheimer's disease (AD) is crucial, due to its complex pathology, which involves dysfunction in lipid transport, contributing to neuroinflammation, synaptic loss, and impaired amyloid-β clearance. Nuclear magnetic resonance (NMR) is able to quantify and stratify lipoproteins. The study investigated lipoproteins in blood from AD patients, aiming to evaluate their diagnostic potential. Serum and plasma were collected from AD patients (n = 25) and healthy individuals (n = 25). We conducted a comprehensive lipoprotein profiling on serum samples using NMR spectroscopy, analysing 112 lipoprotein subfractions. In plasma, we measured unspecific markers of neuronal damage and AD hallmark proteins using single molecule array technology. Additionally, clinical data and cerebrospinal fluid biomarker levels were also collected to enrich our data. Our findings, after adjusting for age and sex differences, highlight significant alterations in two specific lipoproteins; high-density lipoprotein (HDL)-1 Apo-A2 (H1A2) and HDL-2 Apo-A2 (H2A2), both with area under the curve (AUC) values of 0.67, 95% confidence interval (CI) = 0.52-0.82). These results indicate that these lipoprotein subfractions may have potential as indicators of AD-related metabolic changes.

Variance in the composition and number of VLDL and LDL particles with increasing triglyceride or increasing ApoB concentrations

OBJECTIVE

The importance of any enhanced atherogenicity of triglyceride (TG)-rich lipoproteins (TRLs) will depend on the relative abundance of these particles compared with LDL or total apolipoprotein (apo)B. Accordingly, we determined the contribution that TRLs make to total apoB as TG or apoB concentrations increase. We also describe compositional changes in TRLs as TG or apoB increase to assess whether VLDL-C is a valid proxy for VLDL-apoB.

METHODS

We used sequential ultracentrifugation to separate lipoprotein fractions in plasma samples from 1940 dyslipidemic patients not on lipid-lowering medication, and measured apoB, cholesterol and TG in the plasma and in each subfraction. We analyzed this data in quartiles of TG or apoB.

RESULTS

There was wide variance in all parameters in all quartiles of both TG and apoB. Although VLDL-apoB accounted for almost all the increase in total apoB across TG quartiles, LDL-apoB still accounted for 80 % of the total in TG quartile 4. In contrast, LDL-apoB accounted for 90 % of the increase in apoB across apoB quartiles. As TG increases, the increase in VLDL-C is explained more by increased VLDL-C/apoB when TG is moderately elevated, and more by increased VLDL-apoB when TG is very high.

CONCLUSIONS

In conclusion, VLDL-apoB only becomes a substantial component of total apoB with extreme hypertriglyceridemia and VLDL-C is not an appropriate proxy for VLDL-apoB.

Traditional Chinese medicine and plant-derived natural products in regulating triglyceride metabolism: Mechanisms and therapeutic potential

The incidence of cardiometabolic disease is increasing globally, with a trend toward younger age of onset. Among these, atherosclerotic cardiovascular disease is a leading cause of mortality worldwide. Despite the efficacy of traditional lipid-lowering drugs, such as statins, in reducing low-density lipoprotein cholesterol levels, a significant residual risk of cardiovascular events remains, which is closely related to unmet triglyceride (TG) targets. The clinical application of current TG-lowering Western medicines has certain limitations, necessitating alternative or complementary therapeutic strategies. Traditional Chinese medicine (TCM) and plant-derived natural products, known for their safety owing to their natural origins and diverse biological activities, offer promising avenues for TG regulation with potentially fewer side effects. This review systematically summarises the mechanisms of TG metabolism and subsequently reviews the regulatory effects of TCM and plant-derived natural products on TG metabolism, including the inhibition of TG synthesis (via endogenous and exogenous pathways), promotion of TG catabolism, regulation of fatty acid absorption and transport, enhancement of lipophagy, modulation of the gut microbiota, and other mechanisms. In conclusion, through a comprehensive analysis of recent studies, this review consolidates the multifaceted regulatory roles of TCM and plant-derived natural products in TG metabolism and elucidates their potential as safer, multi-target therapeutic agents in managing hypertriglyceridemia and mitigating cardiovascular risk, thereby providing a basis for new drug development.

Mechanisms of Abnormal Lipid Metabolism in the Pathogenesis of Disease

Lipid metabolism is a critical component in preserving homeostasis and health, and lipids are significant chemicals involved in energy metabolism in living things. With the growing interest in lipid metabolism in recent years, an increasing number of studies have demonstrated the close relationship between abnormalities in lipid metabolism and the development of numerous human diseases, including cancer, cardiovascular, neurological, and endocrine system diseases. Thus, understanding how aberrant lipid metabolism contributes to the development of related diseases and how it works offers a theoretical foundation for treating and preventing related human diseases as well as new avenues for the targeted treatment of related diseases. Therefore, we discuss the processes of aberrant lipid metabolism in various human diseases in this review, including diseases of the cardiovascular system, neurodegenerative diseases, endocrine system diseases (such as obesity and type 2 diabetes mellitus), and other diseases including cancer.

Enhanced atherosclerosis in apolipoprotein E knockout rabbits: role of apoB48-rich remnant lipoproteins

Introduction

Apolipoprotein E (apoE) acts as a binding molecule for both the low-density lipoprotein receptor and the lipoprotein receptor-related protein and this function is essential for facilitating the hepatocyte uptake of lipoproteins containing apoB. The absence of apoE leads to increased atherogenicity in both humans and mice, although the precise molecular mechanisms remain incompletely understood.

Objectives

This study aimed to investigate the susceptibility of apoE knockout (KO) rabbits, in comparison with wild-type (WT) rabbits, to diet-induced hyperlipidemia and atherosclerosis.

Methods

ApoE KO rabbits and WT rabbits were fed a diet containing 0.3% cholesterol for 16 weeks. Plasma lipid levels, lipoproteins, and apolipoproteins were analyzed. Atherosclerosis was evaluated at the endpoint of experiments. In addition, we evaluated the oxidizability of those lipoproteins containing apoB to investigate the possible mechanisms of atherosclerosis.

Results

Male apoE KO rabbits showed significantly elevated levels of total cholesterol and triglycerides compared to WT rabbits, while female apoE KO rabbits displayed similar high total cholesterol levels, albeit with significantly higher triglycerides levels than WT controls. Notably, both male (2.1-fold increase) and female (1.6-fold increase) apoE KO rabbits exhibited a significantly augmented aortic lesion area compared to WT controls. Pathological examination showed that the increased intimal lesions in apoE KO rabbits were featured by heightened infiltration of macrophages (2.7-fold increase) and smooth muscle cells (2.5-fold increase). Furthermore, coronary atherosclerotic lesions were also increased by 1.3-fold in apoE KO rabbits. Lipoprotein analysis revealed that apoB48-rich beta-very-low-density lipoproteins were notably abundant in apoE KO rabbits, suggesting that these remnant lipoproteins of intestinal origin serve as the primary atherogenic lipoproteins. Moreover, apoB48-rich remnant lipoproteins isolated from apoE KO rabbits exhibited heightened susceptibility to copper-induced oxidation.

Conclusions

The findings indicate that apoB48-rich remnant lipoproteins, resulting from apoE deficiency, possess greater atherogenic potential than apoB100-rich remnant lipoproteins, regardless of plasma TC levels.

A significant presence in atherosclerotic cardiovascular disease: Remnant cholesterol: A review

The current first-line treatment for atherosclerotic cardiovascular disease (ASCVD) involves the reduction of a patient's low-density lipoprotein cholesterol (LDL-C) levels through the use of lipid-lowering drugs. However, even when other risk factors such as hypertension and diabetes are effectively managed, there remains a residual cardiovascular risk in these patients despite achieving target LDL-C levels with statins and new lipid-lowering medications. This risk was previously believed to be associated with lipid components other than LDL, such as triglycerides. However, recent studies have unveiled the crucial role of remnant cholesterol (RC) in atherosclerosis, not just triglycerides. The metabolized product of triglyceride-rich lipoproteins is referred to as triglyceride-rich remnant lipoprotein particles, and its cholesterol component is known as RC. Numerous pieces of evidence from epidemiological investigations and genetic studies demonstrate that RC plays a significant role in predicting the incidence of ASCVD. As a novel marker for atherosclerosis prediction, when LDL-C is appropriately controlled, RC should be prioritized for attention and intervention among individuals at high risk of ASCVD. Therefore, reducing RC levels through the use of various lipid-lowering drugs may yield long-term benefits. Nevertheless, routine testing of RC in clinical practice remains controversial, necessitating further research on the treatment of elevated RC levels to evaluate the advantages of reducing RC in patients at high risk of ASCVD.

Worldwide Increasing Use of Nonfasting Rather Than Fasting Lipid Profiles

BACKGROUND

Historically, lipids and lipoproteins were measured in the fasting state for cardiovascular risk prediction; however, since 2009 use of nonfasting lipid profiles has increased substantially worldwide. For patients, nonfasting lipid profiles are convenient and avoid any risk of hypoglycemia. For laboratories, blood sampling in the morning and extra visits for patients who have not fasted are avoided. For patients, clinicians, hospitals, and society, nonfasting sampling allows same-day visits with first blood sampling followed by a short wait for test results before clinical consultation. Therefore, nonfasting compared to fasting lipid profiles will save money and time and may improve patient compliance with cardiovascular prevention programs.

CONTENT

We report on the progression of endorsement and implementation of nonfasting lipid profiles for cardiovascular risk prediction worldwide and summarize the recommendations from major medical societies and health authorities in different countries. We also describe practical advantages and disadvantages for using nonfasting lipid profiles. Further, we include a description of why fasting has been the standard historically, the barriers against implementation of nonfasting lipid profiles, and finally we suggest the optimal content of a nonfasting lipid profile.

SUMMARY

Lipid, lipoprotein, and apolipoprotein concentrations vary minimally in response to normal food intake and nonfasting lipid profiles are equal or superior to fasting profiles for cardiovascular risk prediction. Major guidelines and consensus statements in Europe, the United States, Canada, Brazil, Japan, India, and Australia now endorse use of nonfasting lipid profiles in some or all patients; however, there are still gaps in endorsement and implementation of nonfasting lipid profiles worldwide.

Omega-3 fatty acids for cardiovascular event lowering

Low-density lipoprotein cholesterol (LDL-C) is the main target for therapeutics aimed at reducing the risk of atherosclerotic cardiovascular disease (ASCVD) and downstream cardiovascular (CV) events. However, multiple studies have demonstrated that high-risk patient populations harbour residual risk despite effective LDL-C lowering. While data support the causal relationship between triglycerides and ASCVD risk, triglyceride-lowering therapies such as omega-3 fatty acids have shown mixed results in CV outcomes trials. Notably, icosapent ethyl, a purified formulation of eicosapentaenoic acid (EPA), has garnered compelling evidence in lowering residual CV risk in patients with hypertriglyceridaemia and treated with statins. In this review, we summarize studies that have investigated omega-3-fatty acids for CV event lowering and discuss the clinical implementation of these agents based on trial data and guidelines.

Triglyceride-rich lipoproteins and cardiovascular diseases

The global prevalence of cardiovascular diseases (CVD) continues to rise steadily, making it a leading cause of mortality worldwide. Atherosclerosis (AS) serves as a primary driver of these conditions, commencing silently at an early age and culminating in adverse cardiovascular events that severely impact patients' quality of life or lead to fatality. Dyslipidemia, particularly elevated levels of low-density lipoprotein cholesterol (LDL-C), plays a pivotal role in AS pathogenesis as an independent risk factor. Research indicates that abnormal LDL-C accumulation within arterial walls acts as a crucial trigger for atherosclerotic plaque formation. As the disease progresses, plaque accumulation may rupture or dislodge, resulting in thrombus formation and complete blood supply obstruction, ultimately causing myocardial infarction, cerebral infarction, and other common adverse cardiovascular events. Despite adequate pharmacologic therapy targeting LDL-C reduction, patients with cardiometabolic abnormalities remain at high risk for disease recurrence, highlighting the importance of addressing lipid risk factors beyond LDL-C. Recent attention has focused on the causal relationship between triglycerides, triglyceride-rich lipoproteins (TRLs), and their remnants in AS risk. Genetic, epidemiologic, and clinical studies suggest a causal relationship between TRLs and their remnants and the increased risk of AS, and this dyslipidemia may be an independent risk factor for adverse cardiovascular events. Particularly in patients with obesity, metabolic syndrome, diabetes, and chronic kidney disease, disordered TRLs and its remnants levels significantly increase the risk of atherosclerosis and cardiovascular disease development. Accumulation of over-synthesized TRLs in plasma, impaired function of enzymes involved in TRLs lipolysis, and impaired hepatic clearance of cholesterol-rich TRLs remnants can lead to arterial deposition of TRLs and its remnants, promoting foam cell formation and arterial wall inflammation. Therefore, understanding the pathogenesis of TRLs-induced AS and targeting it therapeutically could slow or impede AS progression, thereby reducing cardiovascular disease morbidity and mortality, particularly coronary atherosclerotic heart disease.

Elevated blood remnant cholesterol and triglycerides are causally related to the risks of cardiometabolic multimorbidity

The connection between triglyceride-rich lipoproteins and cardiometabolic multimorbidity, characterized by the concurrence of at least two of type 2 diabetes, ischemic heart disease, and stroke, has not been definitively established. We aim to examine the prospective associations between serum remnant cholesterol, triglycerides, and the risks of progression from first cardiometabolic disease to multimorbidity via multistate modeling in the UK Biobank. We also evaluate the causality of these associations via Mendelian randomization using 13 biologically relevant SNPs as the genetic instruments. Here we show that elevated remnant cholesterol and triglycerides are significantly associated with gradually higher risks of cardiometabolic multimorbidity, particularly the progression of ischemic heart disease to the multimorbidity of ischemic heart disease and type 2 diabetes. These results advocate for effective management of remnant cholesterol and triglycerides as a potential strategy in mitigating the risks of cardiometabolic multimorbidity.

Evinacumab Reduces Triglyceride-Rich Lipoproteins in Patients with Hyperlipidemia: A Post-Hoc Analysis of Three Randomized Clinical Trials

PURPOSE

Natural selection (Mendelian randomization) studies support a causal relationship between elevated triglyceride-rich lipoproteins (TRLs) and atherosclerotic cardiovascular disease (ASCVD). This post-hoc analysis assessed the efficacy of evinacumab in reducing TRLs in patient cohorts from three separate clinical trials with evinacumab.

METHODS

Patients with homozygous familial hypercholesterolemia (HoFH) and low-density lipoprotein cholesterol (LDL-C) ≥ 70 mg/dL were enrolled in a phase III trial (R1500-CL-1629; NCT03399786). Patients diagnosed with refractory hypercholesterolemia, with LDL-C ≥ 70 mg/dL or ≥ 100 mg/dL for those with or without ASCVD, respectively, were enrolled in a phase II trial (R1500-CL-1643; NCT03175367). Patients with severe hypertriglyceridemia (fasting TGs ≥ 500 mg/dL) were enrolled in a phase II trial (R1500-HTG-1522; NCT03452228). Patients received evinacumab intravenously (5 or 15 mg/kg) every 4 weeks, or subcutaneously (300 or 450 mg) every week or every 2 weeks. Efficacy outcomes included change in TRLs (calculated as total cholesterol minus high-density lipoprotein cholesterol minus LDL-C) and other lipid parameters from baseline to 12, 16, or 24 weeks for trial 1522, 1643, and 1629, respectively.

RESULTS

At baseline, TRL levels were higher for patients with severe hypertriglyceridemia entering the 1522 trial vs. other cohorts. Reductions in TRLs were observed across all studies with evinacumab, with > 50% reduction from baseline observed at the highest doses evaluated in patients with HoFH or refractory hypercholesterolemia. Within all three trials, evinacumab was generally well tolerated.

CONCLUSIONS

Despite limitations in direct comparisons between study groups, these data indicate that TRL levels could be a future target for lipid-lowering therapies.

Apolipoprotein E isoforms and their Cys-thiol modifications impact LRP1-mediated metabolism of triglyceride-rich lipoproteins

The low-density lipoprotein (LDL) receptor-related protein (LRP)1 participates in the metabolism of apolipoprotein (apo) E-containing lipoproteins (apoE-LP). We investigated the effects of modifications of cysteine (Cys)-thiol of apoE on LRP1-mediated metabolism. Among the three isoforms, apoE2-LP exhibited the lowest affinity for LRP1 but was significantly catabolized, whereas apoE4-LP was sufficiently bound to LRP1 but showed the lowest catabolic capability. The reduction enhanced the binding and suppressed the catabolism of apoE3-LP, but had no effect on apoE2-LP. The formation of disulfide-linked complexes with apoAII suppressed binding, but enhanced the catabolism of apoE2-LP. Redox modifications of apoE-Cys-thiol may modulate the LRP1-mediated metabolism of apoE2- or apoE3-LP, but not apoE4-LP. The failure of this function may be involved in the pathophysiology of dyslipidemia.

Conditional hepatocyte ablation of PDIA1 uncovers indispensable roles in both APOB and MTTP folding to support VLDL secretion

OBJECTIVES

The assembly and secretion of hepatic very low-density lipoprotein (VLDL) plays pivotal roles in hepatic and plasma lipid homeostasis. Protein disulfide isomerase A1 (PDIA1/P4HB) is a molecular chaperone whose functions are essential for protein folding in the endoplasmic reticulum. Here we investigated the physiological requirement in vivo for PDIA1 in maintaining VLDL assembly and secretion.

METHODS

Pdia1/P4hb was conditionally deleted in adult mouse hepatocytes and the phenotypes characterized. Mechanistic analyses in primary hepatocytes determined how PDIA1 ablation alters MTTP synthesis and degradation as well as altering synthesis and secretion of Apolipoprotein B (APOB), along with complementary expression of intact PDIA1 vs a catalytically inactivated PDIA1 mutant.

RESULTS

Hepatocyte-specific deletion of Pdia1/P4hb inhibited hepatic MTTP expression and dramatically reduced VLDL production, leading to severe hepatic steatosis and hypolipidemia. Pdia1-deletion did not affect mRNA expression or protein stability of MTTP but rather prevented Mttp mRNA translation. We demonstrate an essential role for PDIA1 in MTTP synthesis and function and show that PDIA1 interacts with APOB in an MTTP-independent manner via its molecular chaperone function to support APOB folding and secretion.

CONCLUSIONS

PDIA1 plays indispensable roles in APOB folding, MTTP synthesis and activity to support VLDL assembly. Thus, like APOB and MTTP, PDIA1 is an obligatory component of hepatic VLDL production.

Association between remnant cholesterol and incident atherosclerotic cardiovascular disease, heart failure, and atrial fibrillation

BACKGROUND

It remains unclear if remnant cholesterol is associated with atherosclerotic cardiovascular disease (ASCVD) (myocardial infarction, angina pectoris and stroke), heart failure (HF), and atrial fibrillation (AF) under primary prevention settings.

OBJECTIVE

We aimed to clarify this issue among a general population without a history of ASCVD, HF or AF.

METHODS

Analyses were conducted with a nationwide health claims database collected in the JMDC Claims Database between 2005 and 2022 (n = 1,313,722; median age, 42 years; 54.6% men). We assessed the associations between remnant cholesterol calculated as total cholesterol minus HDL cholesterol minus LDL cholesterol and composite CVD outcomes, including, ASCVD, HF, and AF using Cox proportional hazard model, dividing the individuals into tertiles of remnant cholesterol (T1-T3).

RESULTS

The mean follow-up duration was 3.0 years. In total, 43,755 events were recorded. Remnant cholesterol was significantly associated with composite CVD outcomes after adjustments (T3 vs T1: hazard ratio [HR]; 1.07, 95% confidence interval [CI]: 1.04-1.10, p-trend<0.001). Remnant cholesterol was associated with myocardial infarction (T3 vs T1:HR: 1.20, 95% CI: 1.06-1.34, p-trend=0.002), angina pectoris (T3 vs T1:HR: 1.09, 95% CI: 1.05-1.14, p-trend<0.001), stroke (T3 vs T1:HR: 1.08, 95% CI: 1.02-1.14, p-trend=0.007), and HF (T3 vs T1:HR: 1.08, 95% CI: 1.04-1.12, p-trend<0.001), while we found a marginal inverse association between remnant cholesterol and AF (T3 vs T1:HR: 0.92, 95% CI: 0.86-1.00, p-trend=0.054).

CONCLUSION

Remnant cholesterol was positively associated with ASCVD and HF, while we found a marginal inverse association between remnant cholesterol and AF.

Developing a model to predict the early risk of hypertriglyceridemia based on inhibiting lipoprotein lipase (LPL): a translational study

Hypertriglyceridemia (HTG) is an independent risk factor for atherosclerotic cardiovascular disease (ASCVD). One of the multiple origins of HTG alteration is impaired lipoprotein lipase (LPL) activity, which is an emerging target for HTG treatment. We hypothesised that early, even mild, alterations in LPL activity might result in an identifiable metabolomic signature. The aim of the present study was to assess whether a metabolic signature of altered LPL activity in a preclinical model can be identified in humans. A preclinical LPL-dependent model of HTG was developed using a single intraperitoneal injection of poloxamer 407 (P407) in male Wistar rats. A rat metabolomics signature was identified, which led to a predictive model developed using machine learning techniques. The predictive model was applied to 140 humans classified according to clinical guidelines as (1) normal, less than 1.7 mmol/L; (2) risk of HTG, above 1.7 mmol/L. Injection of P407 in rats induced HTG by effectively inhibiting plasma LPL activity. Significantly responsive metabolites (i.e. specific triacylglycerols, diacylglycerols, phosphatidylcholines, cholesterol esters and lysophospholipids) were used to generate a predictive model. Healthy human volunteers with the impaired predictive LPL signature had statistically higher levels of TG, TC, LDL and APOB than those without the impaired LPL signature. The application of predictive metabolomic models based on mechanistic preclinical research may be considered as a strategy to stratify subjects with HTG of different origins. This approach may be of interest for precision medicine and nutritional approaches.

Cumulative remnant cholesterol predicts cardiovascular outcomes in elderly patients with atherosclerotic cardiovascular disease

AIMS

Remnant cholesterol (RC) reportedly mediates residual cardiovascular risk in atherosclerotic cardiovascular diseases (ASCVD). However, few studies have characterized long-term cumulative RC exposure among elderly people. The study aimed to evaluate the association between cumulative exposure to RC and incident major adverse cardiovascular events (MACE) by analysing a cohort of elderly patients with ASCVD.

METHODS AND RESULTS

This retrospective multicentre cohort study enrolled ASCVD participants aged ≥75 years with baseline visits occurring from 2006 to 2012 followed by four in-person visits. Cumulative RC was estimated as the area under the curve using measurements from the first to fourth visits by using 9-year data. The time-weighted average (TWA) RC was expressed as cumulative exposure to RC averaged by years. All outcomes were follow-up from the fourth visit to the year 2021. Outcomes included a composite of MACE (stroke, unstable angina pectoris, myocardial infarction, and cardiac death). We included 4,680 participants (73.1% male, mean age 79.3 ± 2.5 years). The median follow-up duration was 6.1 years (interquartile range: 3.4-6.6 years). In the multivariable model adjusted for traditional cardiovascular risk factors, low-density lipoprotein cholesterol level, and most recent RC level, the hazard ratios for MACE that compared the high and low tertiles of the RC variables were 1.30 [95% confidence interval (CI), 1.16-1.44] for cumulative RC and 1.36 (95% CI, 1.23-1.52) for TWA RC. Consistent significant associations were observed among most propensity score analyses.

CONCLUSIONS

Long-term cumulative RC was independently associated with incident MACE in elderly participants with ASCVD, suggesting that achieving and maintaining optimal RC levels later in life may still improve cardiovascular outcomes.

Severe hypertriglyceridemia: Existing and emerging therapies

Severe hypertriglyceridemia (sHTG), defined as a triglyceride (TG) concentration ≥ 500 mg/dL (≥ 5.7 mmol/L) is an important risk factor for acute pancreatitis. Although lifestyle, some medications, and certain conditions such as diabetes may lead to HTG, sHTG results from a combination of major and minor genetic defects in proteins that regulate TG lipolysis. Familial chylomicronemia syndrome (FCS) is a rare disorder caused by complete loss of function in lipoprotein lipase (LPL) or LPL activating proteins due to two homozygous recessive traits or compound heterozygous traits. Multifactorial chylomicronemia syndrome (MCS) and sHTG are due to the accumulation of rare heterozygous variants and polygenic defects that predispose individuals to sHTG phenotypes. Until recently, treatment of sHTG focused on lifestyle interventions, control of secondary factors, and nonselective pharmacotherapies that had modest TG-lowering efficacy and no corresponding reductions in atherosclerotic cardiovascular disease events. Genetic discoveries have allowed for the development of novel pathway-specific therapeutics targeting LPL modulating proteins. New targets directed towards inhibition of apolipoprotein C-III (apoC-III), angiopoietin-like protein 3 (ANGPTL3), angiopoietin-like protein 4 (ANGPTL4), and fibroblast growth factor-21 (FGF21) offer far more efficacy in treating the various phenotypes of sHTG and opportunities to reduce the risk of acute pancreatitis and atherosclerotic cardiovascular disease events.

Metabolic-Dysfunction-Associated Steatotic Liver Disease-Its Pathophysiology, Association with Atherosclerosis and Cardiovascular Disease, and Treatments

Metabolic-dysfunction-associated steatotic liver disease (MASLD) is a chronic liver disease that affects more than a quarter of the global population and whose prevalence is increasing worldwide due to the pandemic of obesity. Obesity, impaired glucose metabolism, high blood pressure and atherogenic dyslipidemia are risk factors for MASLD. Therefore, insulin resistance may be closely associated with the development and progression of MASLD. Hepatic entry of increased fatty acids released from adipose tissue, increase in fatty acid synthesis and reduced fatty acid oxidation in the liver and hepatic overproduction of triglyceride-rich lipoproteins may induce the development of MASLD. Since insulin resistance also induces atherosclerosis, the leading cause for death in MASLD patients is cardiovascular disease. Considering that the development of cardiovascular diseases determines the prognosis of MASLD patients, the therapeutic interventions for MASLD should reduce body weight and improve coronary risk factors, in addition to an improving in liver function. Lifestyle modifications, such as improved diet and increased exercise, and surgical interventions, such as bariatric surgery and intragastric balloons, have shown to improve MASLD by reducing body weight. Sodium glucose cotransporter 2 inhibitors (SGLT2i) and glucagon-like peptide-1 receptor agonists (GLP-1RAs) have been shown to improve coronary risk factors and to suppress the occurrence of cardiovascular diseases. Both SGLT2i and GLP-1 have been reported to improve liver enzymes, hepatic steatosis and fibrosis. We recently reported that the selective peroxisome proliferator-activated receptor-alpha (PPARα) modulator pemafibrate improved liver function. PPARα agonists have multiple anti-atherogenic properties. Here, we consider the pathophysiology of MASLD and the mechanisms of action of such drugs and whether such drugs and the combination therapy of such drugs could be the treatments for MASLD.

Intensive Lipid-Lowering Therapy as per the Latest Dyslipidemia Management Guideline in Predicting Favorable Long-Term Clinical Outcomes in Patients Undergoing Coronary Artery Bypass Grafting: A Retrospective Cohort Study

Background There are limited data on low-density lipoprotein cholesterol (LDL-C) goal achievement per the 2019 European Society of Cardiology/European Atherosclerosis Society dyslipidemia management guidelines and its impact on long-term outcomes in patients undergoing coronary artery bypass grafting (CABG). We investigated the association between LDL-C levels attained 1 year after CABG and the long-term outcomes. Methods and Results A total of 2072 patients diagnosed with multivessel coronary artery disease and undergoing CABG between 2011 and 2020 were included. Patients were categorized by lipid levels at 1 year after CABG, and the occurrence of major adverse cardiovascular and cerebrovascular events (MACCEs) was evaluated. The goal of LDL-C <1.40 mmol/L was attained in only 310 patients (14.9%). During a mean follow-up of 4.2 years after the index 1-year assessment, 25.0% of the patients experienced MACCEs. Multivariable-adjusted hazard ratios (95% CIs) for MACCEs, cardiac death, nonfatal myocardial infarction, nonfatal stroke, revascularization, and cardiac rehospitalization were 1.94 (1.41-2.67), 2.27 (1.29-3.99), 2.45 (1.55-3.88), 1.17 (0.63-2.21), 2.47 (1.31-4.66), and 1.87 (1.19-2.95), respectively, in patients with LDL-C ≥2.60 mmol/L, compared with patients with LDL-C <1.40 mmol/L. The LDL-C levels at 1-year post-CABG were independently associated with long-term MACCEs. Conclusions This retrospective analysis demonstrates that lipid goals are not attained in the vast majority of patients at 1 year after CABG, which is independently associated with the increased risk of long-term MACCEs. Further prospective, multicenter studies are warranted to validate if intensive lipid management could improve the outcomes of patients undergoing CABG.

High residual cardiovascular risk after lipid-lowering: prime time for Predictive, Preventive, Personalized, Participatory, and Psycho-cognitive medicine

As time has come to translate trial results into individualized medical diagnosis and therapy, we analyzed how to minimize residual risk of cardiovascular disease (CVD) by reviewing papers on "residual cardiovascular disease risk". During this review process we found 989 papers that started off with residual CVD risk after initiating statin therapy, continued with papers on residual CVD risk after initiating therapy to increase high-density lipoprotein-cholesterol (HDL-C), followed by papers on residual CVD risk after initiating therapy to decrease triglyceride (TG) levels. Later on, papers dealing with elevated levels of lipoprotein remnants and lipoprotein(a) [Lp(a)] reported new risk factors of residual CVD risk. And as new risk factors are being discovered and new therapies are being tested, residual CVD risk will be reduced further. As we move from CVD risk reduction to improvement of patient management, a paradigm shift from a reductionistic approach towards a holistic approach is required. To that purpose, a personalized treatment dependent on the individual's CVD risk factors including lipid profile abnormalities should be configured, along the line of P5 medicine for each individual patient, i.e., with Predictive, Preventive, Personalized, Participatory, and Psycho-cognitive approaches.

Novel and future lipid-modulating therapies for the prevention of cardiovascular disease

Lowering the levels of LDL cholesterol in the plasma has been shown to reduce the risk of atherosclerotic cardiovascular disease (ASCVD). Several other lipoproteins, such as triglyceride-rich lipoproteins, HDL and lipoprotein(a) are associated with atherosclerosis and ASCVD, with strong evidence supporting causality for some. In this Review, we discuss novel and upcoming therapeutic strategies targeting different pathways in lipid metabolism to potentially attenuate the risk of cardiovascular events. Key proteins involved in lipoprotein metabolism, such as PCSK9, angiopoietin-related protein 3, cholesteryl ester transfer protein and apolipoprotein(a), have been identified as viable targets for therapeutic intervention through observational and genetic studies. These proteins can be targeted using a variety of approaches, such as protein inhibition or interference, inhibition of translation at the mRNA level (with the use of antisense oligonucleotides or small interfering RNA), and the introduction of loss-of-function mutations through base editing. These novel and upcoming strategies are complementary to and could work synergistically with existing therapies, or in some cases could potentially replace therapies, offering unprecedented opportunities to prevent ASCVD. Moreover, a major challenge in the prevention and treatment of non-communicable diseases is how to achieve safe, long-lasting reductions in causal exposures. This challenge might be overcome with approaches such as small interfering RNAs or genome editing, which shows how far the field has advanced from when the burden of achieving this goal was placed upon patients through rigorous adherence to daily small-molecule drug regimens.

Dyslipidemia in Patients with Chronic Kidney Disease: An Updated Overview

Dyslipidemia is a potentially modifiable cardiovascular risk factor. Whereas the recommendations for the treatment target of dyslipidemia in the general population are being more and more rigorous, the 2013 Kidney Disease: Improving Global Outcomes clinical practice guideline for lipid management in chronic kidney disease (CKD) presented a relatively conservative approach with respect to the indication of lipid lowering therapy and therapeutic monitoring among the patients with CKD. This may be largely attributed to the lack of high-quality evidence derived from CKD population, among whom the overall feature of dyslipidemia is considerably distinctive to that of general population. In this review article, we cover the characteristic features of dyslipidemia and impact of dyslipidemia on cardiovascular outcomes in patients with CKD. We also review the current evidence on lipid lowering therapy to modify the risk of cardiovascular events in this population. We finally discuss the association between dyslipidemia and CKD progression and the potential strategy to delay the progression of CKD in relation to lipid lowering therapy.

Lipid Levels During Adult Lifetime in Men and Women With and Without a Subsequent Incident Myocardial Infarction: A Longitudinal Analysis of Data From the Tromsø Study 1974 to 2016

Background The atherosclerotic effect of an adverse lipid profile is assumed to accumulate throughout life, leading to increased risk of myocardial infarction (MI). Still, little is known about age at onset and duration of unfavorable lipid levels before MI. Methods and Results Longitudinal data on serum lipid levels for 26 130 individuals (50.5% women, aged 20-89 years) were obtained from 7 population-based health surveys in Tromsø, Norway. Diagnoses of MI were obtained from national registers. A linear mixed model was applied to compare age- and sex-specific mean values of total cholesterol, high-density lipoprotein cholesterol (HDL-C), and triglyceride concentration by MI status (MI versus non-MI). Already from young adulthood, 20 to 35 years before the incident MI, individuals with a subsequent incident MI had on average more adverse lipid levels than individuals of the same age and sex without MI. Analogous to a dose-response relationship, there was a clear trend toward more severe adverse lipid levels the lower the age at incident MI (P<0.001, test for trend through ordered categories <55, 55-74, ≥75 years). This trend was particularly pronounced for high-density lipoprotein cholesterol in percentage of total cholesterol (both sexes) and for the relative relationship between triglyceride, high-density lipoprotein cholesterol, and total cholesterol level (women). The difference in mean lipid level by MI status was just as large in women as in men, but the age pattern differed (P≤0.05, tests of 3-way interaction). Conclusions Compared with general population mean levels, adverse lipid levels were seen 20 to 35 years before the incident MI in both men and women.

Remnant cholesterol, vascular risk, and prevention of atherosclerosis

In patients who have achieved optimal LDL-C control, there remains a residual risk of atherothrombotic cardiovascular disease (ACVD) related to alterations in lipid metabolism, where alterations in triglyceride-rich lipoproteins and the cholesterol they contain, called remnant cholesterol, play a major role. Remnant cholesterol has an association with residual risk of ACVD that is independent of LDL-C and has been demonstrated in epidemiological and Mendelian randomisation studies, and in analyses of clinical trials of lipid-lowering drugs. Remnant triglyceride-rich lipoproteins particles are highly atherogenic, due to their ability to enter and be retained in the arterial wall, their high cholesterol content, and their ability to generate "foam cells" and an inflammatory response. Assessment of remnant cholesterol may provide information on residual risk of ACVD beyond the information provided by LDL-C, Non-HDL-C, and apoB, particularly in individuals with hypertriglyceridaemia, type 2 diabetes, or metabolic syndrome. In the REDUCE-IT study, icosapent ethyl was shown to have a preventive effect against ACVD in very high cardiovascular risk patients with hypertriglyceridaemia treated with statins and target LDL-C. New lipid-lowering drugs will help to define efficacy and criteria in the treatment of excess remnant cholesterol and hypertriglyceridaemia in the prevention of ACVD.

Triglyceride-rich lipoproteins, remnant-cholesterol, and atherosclerotic cardiovascular disease

PURPOSE OF REVIEW

Despite indisputable role of LDL-C lowering, a considerable residual risk for atherosclerotic cardiovascular disease (ASCVD) persists. The precise mechanism(s) underlying this phenomenon remain unclear. Triglyceride-rich lipoproteins (TRL) appear to be one of the main mediators, based on the genetic and epidemiologic data. However, whether this is caused by direct effects of Triglycerides or other components of TRL remains uncertain. The cholesterol component of TRL remnants (Rem-C) has been proposed as a more pertinent mediator of the increased risk associated with high triglycerides.

RECENT FINDINGS

Several long-term observational studies have shown a significant relationship between Rem-C and ASCVD events, compared with other triglyceride-related parameters. Recent trials have shown that lowering of triglyceride levels by various agents, including fibrates and omega-3 fatty acids, in statin-treated subjects, did not explain the reduction in ASCVD events. In a large clinical trial with pemafibrate, a highly selective PPAR-α agonist, in type 2 diabetes and elevated triglycerides, the reduction in triglycerides was accompanied by a significant increase in LDL-C and Apo-B levels, despite a reduction in Rem-C, and no effect on ASCVD events.

SUMMARY

Elevated Rem-C as a risk determinant, with LDL-C at goal, requires additional studies in clinical trials. Standardization and accuracy of Rem-C assays (calculated versus direct method) is also needed.

Clinical Trial Design for Triglyceride-Rich Lipoprotein-Lowering Therapies: JACC Focus Seminar 3/3

Triglyceride-rich lipoproteins (TRLs) are a source of residual risk in patients with atherosclerotic cardiovascular disease, and are indirectly correlated with triglyceride (TG) levels. Previous clinical trials studying TG-lowering therapies have either failed to reduce major adverse cardiovascular events or shown no linkage of TG reduction with event reduction, particularly when these agents were tested on a background of statin therapy. Limitations in trial design may explain this lack of efficacy. With the advent of new RNA-silencing therapies in the TG metabolism pathway, there is renewed focus on reducing TRLs for major adverse cardiovascular event reduction. In this context, the pathophysiology of TRLs, pharmacological effects of TRL-lowering therapies, and optimal design of cardiovascular outcomes trials are major considerations.

The clinical utility of polygenic risk scores for combined hyperlipidemia

PURPOSE OF REVIEW

Combined hyperlipidemia is the most common lipid disorder and is strongly polygenic. Given its prevalence and associated risk for atherosclerotic cardiovascular disease, this review describes the potential for utilizing polygenic risk scores for risk prediction and management of combined hyperlipidemia.

RECENT FINDINGS

Different diagnostic criteria have led to inconsistent prevalence estimates and missed diagnoses. Given that individuals with combined hyperlipidemia have risk estimates for incident coronary artery disease similar to individuals with familial hypercholesterolemia, early identification and therapeutic management of those affected is crucial. With diagnostic criteria including traits such apolipoprotein B, low-density lipoprotein cholesterol, and triglyceride, polygenic risk scores for these traits strongly associate with combined hyperlipidemia and could be used in combination for clinical risk prediction models and developing specific treatment plans for patients.

SUMMARY

Polygenic risk scores are effective tools in risk prediction of combined hyperlipidemia, can provide insight into disease pathophysiology, and may be useful in managing and guiding treatment plans for patients. However, efforts to ensure equitable polygenic risk score performance across different genetic ancestry groups is necessary before clinical implementation in order to prevent the exacerbation of racial disparities in the clinic.

Revealment study on the regulation of lipid metabolism by Lingguizhugan Decoction in heart failure treatment based on integrated lipidomics and proteomics

Lingguizhugan Decoction (LGZGD) is a classical traditional Chinese medicine prescription. Our previous studies found that disorders of lipid metabolism were reversed by LGZGD in heart failure (HF) mice. This study aimed to reveal the regulation of lipid metabolism of LGZGD. A mice model of HF was established by intraperitoneal injection of doxorubicin. The components of LGZGD were identified with the UHPLC-QTOF-MS method. The regulation of lipid metabolism by LGZGD was detected by serum lipidomics and heart tissue proteomics. Molecular docking was further performed to screen active components. A total of 78 compounds in LGZGD were identified. Results of lipidomics showed that 37 lipids illustrated a significant recovery trend to normal after the treatment of LGZGD. Results of proteomics demonstrated that 55 proteins were altered by the administration of LGZGD in HF mice. After enrichment analysis, the Prakg2/Ucp2/Plin1 axis on the Apelin pathway plays a vital role in HF treatment by LGZGD. Nine active components exhibited the outstanding ability of binding to the apelin receptor with MM-GBSA value lower than -60 Kcal/mol. In conclusion, all results combined together revealed that multi-component in the LGZGD had beneficial effects on the HF through ameliorating lipid disorders, which provides a novel insight into the cardioprotective effects of LGZGD and its clinical application.

Prognostic value of remnant cholesterol in patients with coronary heart disease: A systematic review and meta-analysis of cohort studies

Background

The relationship between abnormal lipid levels and atherosclerotic cardiovascular diseases is well established, but the association between remnant cholesterol (RC) and coronary heart disease (CHD) remains uncertain. The aim of this meta-analysis is to systematically evaluate the prognostic value of RC concentration in patients with CHD.

Methods

PubMed, EMBASE, Cochrane, and Web of Science databases were reviewed to identify relevant observational cohort studies published in English up to December 2021. Random-effects meta-analysis compared the highest and lowest RC concentration. The primary outcome was a composite of major adverse cardiovascular events (MACEs) and all-cause mortality in patients with CHD.

Results

A total of 10 studies recruiting 30,605 patients with CHD were selected to be included in this meta-analysis. Patients with CHD with elevated RC concentration had an increased risk of the composite endpoint events (RR = 1.54, 95% CI: 1.26-1.87) and MACEs (RR = 1.70, 95% CI: 1.54-1.88), but the risk of all-cause mortality was not statistically significant (RR = 1.16, 95% CI: 0.79-1.69, P = 0.44). Subgroup analysis showed consistent results.

Conclusion

Our results suggest that elevated concentration RC may independently predict MACEs in patients with CHD. Determination of RC concentration may improve risk stratification of prognosis in patients with CHD. However, more high-quality studies are necessary to confirm this association.

Dyslipidemia and Cardiovascular Disease: Current Knowledge, Existing Challenges, and New Opportunities for Management Strategies

Cardiovascular disease is the leading cause of morbidity and mortality worldwide, and dyslipidemia is one of the major risk factors [...].

Atherogenic Lipoproteins for the Statin Residual Cardiovascular Disease Risk

Randomized controlled trials (RCTs) show that decreases in low-density lipoprotein cholesterol (LDL-C) by the use of statins cause a significant reduction in the development of cardiovascular disease (CVD). However, one of our previous studies showed that, among eight RCTs that investigated the effect of statins vs. a placebo on CVD development, 56–79% of patients had residual CVD risk after the trials. In three RCTs that investigated the effect of a high dose vs. a usual dose of statins on CVD development, 78–87% of patients in the high-dose statin arms still had residual CVD risk. The risk of CVD development remains even when statins are used to strongly reduce LDL-C, and this type of risk is now regarded as statin residual CVD risk. Our study shows that elevated triglyceride (TG) levels, reduced high-density lipoprotein cholesterol (HDL-C), and the existence of obesity/insulin resistance and diabetes may be important metabolic factors that determine statin residual CVD risk. Here, we discuss atherogenic lipoproteins that were not investigated in such RCTs, such as lipoprotein (a) (Lp(a)), remnant lipoproteins, malondialdehyde-modified LDL (MDA-LDL), and small-dense LDL (Sd-LDL). Lp(a) is under strong genetic control by apolipoprotein (a), which is an LPA gene locus. Variations in the LPA gene account for 91% of the variability in the plasma concentration of Lp(a). A meta-analysis showed that genetic variations at the LPA locus are associated with CVD events during statin therapy, independent of the extent of LDL lowering, providing support for exploring strategies targeting circulating concentrations of Lp(a) to reduce CVD events in patients receiving statins. Remnant lipoproteins and small-dense LDL are highly associated with high TG levels, low HDL-C, and obesity/insulin resistance. MDA-LDL is a representative form of oxidized LDL and plays important roles in the formation and development of the primary lesions of atherosclerosis. MDA-LDL levels were higher in CVD patients and diabetic patients than in the control subjects. Furthermore, we demonstrated the atherogenic properties of such lipoproteins and their association with CVD as well as therapeutic approaches.

Leveraging knowledge of HDLs major protein ApoA1: Structure, function, mutations, and potential therapeutics

Apolipoprotein A1 (ApoA1) is a member of the Apolipoprotein family of proteins. It's a vital protein that helps in the production of high-density lipoprotein (HDL) particles, which are crucial for reverse cholesterol transport (RCT). It also has anti-inflammatory, anti-atherogenic, anti-apoptotic, and anti-thrombotic properties. These functions interact to give HDL particles their cardioprotective characteristics. ApoA1 has recently been investigated for its potential role in atherosclerosis, diabetes, neurological diseases, cancer, and certain infectious diseases. Since ApoA1's discovery, numerous mutations have been reported that affect its structural integrity and alter its function. Hence these insights have led to the development of clinically relevant peptides and synthetic reconstituted HDL (rHDL) that mimics the function of ApoA1. As a result, this review has aimed to provide an organized explanation of our understanding of the ApoA1 protein structure and its role in various essential pathways. Furthermore, we have comprehensively reviewed the important ApoA1 mutations (24 mutations) that are reported to be involved in various diseases. Finally, we've focused on the therapeutic potentials of some of the beneficial mutations, small peptides, and synthetic rHDL that are currently being researched or developed, since these will aid in the development of novel therapeutics in the future.

Lipoprotein Assessment in the twenty-first Century

Based on decades of both basic science and epidemiologic research, there is overwhelming evidence for the causal relationship between high levels of cholesterol, especially low-density lipoprotein cholesterol and cardiovascular disease. Risk evaluation and monitoring the response to lipid-lowering therapies are heavily dependent on the accurate assessment of plasma lipoproteins in the clinical laboratory. This article provides an update of lipoprotein metabolism as it relates to atherosclerosis and how diagnostic measures of lipids and lipoproteins can serve as markers of cardiovascular risk, with a focus on recent advances in cardiovascular risk marker testing.

Association of Remnant Cholesterol and Non-High Density Lipoprotein Cholesterol with Risk of Cardiovascular Mortality Among US General Population

Background

There are strong association between remnant cholesterol (RC)/non-high density lipoprotein cholesterol (NHDL-C) and increase cardiovascular (CV) risk. The aim of present study was to investigate the association between target lipid parameters (RC and NHDL-C) and the risk of CV mortality in general population.

Methods

Data set from an open database—National Health and Nutrition Examination Surveys (NHANES) 2003–2014 were extracted (n = 14992). Kaplan-Meier, multivariable COX regression, and restricted cubic spline (RCS) parameters.

Results

Compared to the lowest quartile, RC (adjusted hazard ratio [HR] = 1.63 95%CI 1.05–2.52, P for trend = 0.037) and triglycerides (TG: Model 3: HR = 1.69 95%CI 1.10–2.60, P for trend = 0.049) in the highest quartile were independently associated with the increased cardiovascular mortality, while NHDL-C and apolipoprotein B (ApoB) in adjusted models did not show association (P for trend >0.05). In addition, RCS regression demonstrated that RC (P for nonlinearity = 0.011) and TG (P for nonlinearity = 0.010) levels had a similar J-shape association with CV mortality. Threshold effect analysis showed that when RC ≤ 29.3 mg/dL, the level of RC and CV mortality risk were positively correlated.

Conclusions

Our findings suggest high RC levels are associated with an increased risk of CV mortality, which support that the integration of TG-rich lipoproteins parameters in risk assessment might optimize the identification and management of selected population.

Recent Updates in Hypertriglyceridemia Management for Cardiovascular Disease Prevention

PURPOSE OF REVIEW

Mounting evidence continues to support the causal role of triglyceride-rich lipoproteins (TRL) in the development of atherosclerotic cardiovascular disease (ASCVD). Substantial residual ASCVD risk remains among high-risk patients who have elevated triglycerides despite reduction in low-density lipoprotein cholesterol (LDL-C) with statin therapy. Ongoing research efforts have focused on evaluating triglyceride-lowering therapies among patients with hypertriglyceridemia.

RECENT FINDINGS

The REDUCE-IT trial showed that the addition of icosapent ethyl, a highly purified form of eicosapentaenoic acid (EPA), can reduce vascular events among statin-treated individuals with elevated triglycerides who have either clinical ASCVD or diabetes plus another risk factor. Although additional evidence for EPA has emerged from other trials, conflicting results have been reported by subsequent trials that tested different omega-3 fatty acid formulations. Randomized clinical trials have not demonstrated incremental ASCVD benefit of fibrates on background of statin therapy, but fibrates are used to help prevent pancreatitis in patients with severe hypertriglyceridemia. Selective inhibitors of apolipoprotein C-III (apoC3) and angiopoietin-like protein 3 (ANGPTL3), proteins that are involved in metabolism of TRLs by regulating lipoprotein lipase, have been tested in selected patient populations and showed significant reduction in triglyceride and LDL-C levels. Statin therapy continues to be the cornerstone of pharmacologic reduction of cardiovascular risk. High-dose EPA in the form of icosapent ethyl has been demonstrated to have cardiovascular benefit on top of statins in persons with elevated triglycerides at high ASCVD risk. Ongoing clinical trials are evaluating novel selective therapies such as apoC3 and ANGPTL3 inhibitors.

Management of Mild-to-Moderate Hypertriglyceridemia

OBJECTIVE

Hypertriglyceridemia is highly prevalent globally and its prevalence is rising with international increases in the incidence of obesity and diabetes. This review examines current management and future therapies METHODS: For this review, hypertriglyceridemia is defined as mild-to-moderate triglyceride elevation, a fasting or non-fasting triglyceride level >150 mg/dL and <500 mg/dL. We reviewed scientific studies published over the last 30 years and current professional society recommendations regarding evaluation and treatment of hypertriglyceridemia.

RESULTS

Genetics, lifestyle, and other environmental factors impact triglyceride levels. In adults with mild-to-moderate hypertriglyceridemia, clinicians should routinely assess and treat secondary treatable causes (diet, physical activity, obesity, metabolic syndrome, and reduction or cessation of medications that elevate triglyceride levels). Since atherosclerotic cardiovascular disease (ASCVD) risk is the primary clinical concern, statins are usually first-line treatment. Patients with triglyceride levels between >150 mg/dL and <500 mg/dL whose LDL-C is treated adequately with statins (at "maximally tolerated" doses, per some statements) and have either prior cardiovascular disease or diabetes mellitus plus at least 2 additional cardiovascular disease risk factors should be considered for added icosapent ethyl treatment to further reduce their cardiovascular disease risk. Fibrates, niacin, and other approved agents or agents under development are also reviewed in detail.

CONCLUSION

The treatment paradigm for mild-to-moderate hypertriglyceridemia is changing based on data from recent clinical trials. Recent trials suggest that the addition of icosapent ethyl to background statin therapy may further reduce ASCVD risk in patients with moderate HTG, though a particular TG goal has not been identified.

Remnant Cholesterol Predicts Long-term Mortality of Patients With Metabolic Dysfunction-associated Fatty Liver Disease

CONTEXT

Elevated serum remnant cholesterol independently predicts risks of cardiovascular diseases. However, the association between remnant cholesterol and metabolic dysfunction-associated fatty liver disease (MAFLD) remains unclear.

OBJECTIVE

This study aimed to explore the association of remnant cholesterol with MAFLD and its long-term mortality.

METHODS

We extracted data from the NHANES III, 1988 to1994 and the linked mortality data until December 31, 2015. The association between remnant cholesterol and MAFLD was analyzed by multivariable logistic regression. Cox proportional hazards regression was performed to assess whether elevated remnant cholesterol increased all-cause and cause-specific mortalities in MAFLD patients.

RESULTS

At baseline, 28.6% (1474/5156) of participants had MAFLD. In multivariable logistic regression, the fourth quartile of remnant cholesterol was associated with an increased risk of MAFLD compared with the first quartile (odds ratio [OR]: 1.714; 95% CI, 1.586-1.971; P < .001). In participants with normal levels of triglycerides, low-density lipoprotein and high-density lipoprotein cholesterol, the relationship between remnant cholesterol and MAFLD risk remained significant (OR: 1.346; 95% CI, 1.248-1.761; P < .001). During a median follow-up of 307 months, MAFLD patients with serum remnant cholesterol in the fourth quartile were associated with a higher risk of all-cause mortality (hazard ratio [HR]: 2.183; 95% CI, 1.825-2.407; P < .001), as well as a higher risk of cardiovascular mortality (HR: 2.346; 95% CI, 2.046-2.885; P < .001) and cancer-related mortality (HR: 2.366; 95% CI, 1.864-2.932; P < .001) compared with MAFLD patients in the first quartile.

CONCLUSION

Remnant cholesterol was independently associated with the risk of MAFLD and predicted all-cause, cardiovascular, and cancer-related mortalities in MAFLD patients.

Remnant lipoprotein particles and cardiovascular disease risk

Intravascular catabolism of chylomicrons and very low-density lipoproteins (VLDLs) gives rise to a spectrum of partially lipolyzed remnant particles. Their plasma levels and properties are influenced by lipases, lipid transfer proteins, and content of exchangeable lipoproteins. Particularly important among the latter are apoE, which mediates hepatic binding and uptake of remnants, and apoCIII, which can retard this process. In the course of their plasma transit, remnants can acquire pathologic properties that promote the development of atherosclerotic cardiovascular disease (ASCVD) including increased cholesterol content and transport of thrombogenic and inflammatory mediators. Levels of cholesterol-enriched remnant particles determined by various analytic techniques have been significantly linked to the incidence of ASCVD, most dramatically in dyslipidemic patients homozygous for the apoE2 genetic isoform. Further research is warranted for development of clinical assays that can better capture the pathologic impact of remnant lipoprotein subspecies, and for testing the impact on ASCVD of therapies that reduce their levels.

Sex Differences in Lipid Metabolism: Implications for Systemic Lupus Erythematosus and Cardiovascular Disease Risk

It is known that healthy women during childbearing years have a lower risk of cardiovascular disease (CVD) and coronary heart disease compared to age matched men. Various traditional risk factors have been shown to confer differential CVD susceptibilities by sex. Atherosclerosis is a major cause of CVD and mortality and sex differences in CVD risk could be due to reduced atherogenic low and very low-density lipoproteins (LDL and VLDL) and increased atheroprotective high density lipoproteins (HDLs) in women. In contrast, patients with systemic lupus erythematosus (SLE), a chronic inflammatory disease that predominately affects women, have an increased atherosclerotic and CVD risk. This increased CVD risk is largely associated with dyslipidaemia, the imbalance of atherogenic and atheroprotective lipoproteins, a conventional CVD risk factor. In many women with SLE, dyslipidaemia is characterised by elevated LDL and reduced HDL, eradicating the sex-specific CVD protection observed in healthy women compared to men. This review will explore this paradox, reporting what is known regarding sex differences in lipid metabolism and CVD risk in the healthy population and transgender individuals undergoing cross-sex hormone therapy, and provide evidence for how these differences may be compromised in an autoimmune inflammatory disease setting. This could lead to better understanding of mechanistic changes in lipid metabolism driving the increased CVD risk by sex and in autoimmunity and highlight potential therapeutic targets to help reduce this risk.