High-density lipoprotein cholesterol and particle concentrations, carotid atherosclerosis, and coronary events: MESA (multi-ethnic study of atherosclerosis)

Causal relationships between four types of lipids and breast cancer risk with potential mediators: evidence from Mendelian randomization study and bioinformatics analysis

BACKGROUND AND PURPOSE

Breast cancer (BC) is the primary cause of cancer-related deaths among women worldwide, with increasing evidence pointing to the effect of metabolic factors, particularly lipid levels, in its pathogenesis. In this research, Mendelian randomization (MR) was employed to explore the causality between four plasma lipid traits-total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C)-and the risk of BC. Additionally, we explored the potential mediating effects of coronary artery disease (CAD), total testosterone (TT) on these associations and possible mechanisms through bioinformatics analyses.

METHODS

Data of genome-wide association study (GWAS) on lipids, CAD, TT and BC were obtained from public sources and websites as part of a genome-wide association research. The inference of causality was primarily assessed through the inverse variance weighting (IVW) approach, with supplementary tests for horizontal pleiotropy and heterogeneity. To verify the directionality of causal relationships, the MR Steiger test was applied. Additionally, reverse causality was evaluated by regarding BC as the exposure. To adjust for confounders, multivariate MR (MVMR) was performed, followed by a two-step mediation analysis to investigate the mediating roles of CAD in the lipid-BC association, and of TT in the CAD-BC relationship. The intersecting SNP (rs11556924) between causal pathways was established through a Venn diagram and its associated gene (Zinc Finger C3HC-Type Containing 1, ZC3HC1) was identified through the g:Profiler database. The expression of ZC3HC1 was further explored using the TIMER, GEPIA2 and HPA database. Finally, enrichment analyses of Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and protein-protein interactions (PPI) network analysis were conducted on ZC3HC1 and its related genes.

RESULTS

The random-effects IVW analysis yielded the following results: HDL-C on CAD (OR = 0.843, 95% CI 0.771-0.921, P < 0.001), CAD on BC (OR = 0.935, 95% CI 0.892-0.980, P = 0.005), HDL-C on BC (OR = 1.127, 95% CI 1.059-1.199, P < 0.001), CAD on TT (OR = 0.987, 95% CI 0.975-0.998, P = 0.020) and TT on BC (OR = 1.354, 95% CI 1.148-1.598, P < 0.001). The MR Steiger test results support the validity of the inferred causal direction (P < 0.001). There were no discernible causal relationships between BC and HDL-C/CAD according to reverse MR analysis (P > 0.05). Following MVMR adjustment, the causal effects of HDL-C, CAD, and TT on BC were still statistically significant (P < 0.05). Besides, the two-step mediation analysis indicated that CAD mediated 7.8% of the causal effect of HDL-C on BC, whereas TT mediated 6.1% of the causal effect between CAD and BC. The expression of ZC3HC1 showed no significant expression difference between normal and BC tissues (P > 0.05), which might indicate a carcinogenic effect independent of expression levels but driven by functional alterations induced by variants (C > T). Functional network analysis suggested that ZC3HC1 was associated with multiple signal pathways in cancers, such as PI3K-Akt and MAPK signal pathways.

CONCLUSIONS

From a genetic perspective, our study reveals that there is causality between HDL-C levels and BC risk, with CAD and TT acting as partial mediators in this relationship. Moreover, our study firstly establishes a potential link between CAD-associated SNP (rs11556924), the corresponding gene (ZC3HC1) functional dysregulation, and the initiation of BC. These findings shed light on the biological links between lipids and BC, potentially contributing to future prevention and treatment strategies.

HDL Cholesterol Is Remarkably Cardioprotective Against Coronary Artery Disease in Native Hawaiians and Pacific Islanders

BACKGROUND

High-density lipoprotein cholesterol (HDL-C) is inversely associated with cardiometabolic risk and exhibits nonlinear effects at extreme levels. Cardiometabolic diseases are a leading cause of death and are particularly prevalent among Native Hawaiian and Pacific Islanders (NHPIs).

OBJECTIVES

This study characterizes HDL-C's association with coronary artery disease (CAD), major adverse cardiovascular events (MACE), and type 2 diabetes (T2D) in NHPIs compared to the general population.

METHODS

Using electronic health record data from the National Institutes of Health All of Us Research Program, we applied Cox proportional hazards models to compare HDL-C's protective effects on CAD, MACE, and T2D between 261 NHPIs and the remaining cohort (n = 188,802). Models were adjusted for key confounders, and restricted cubic splines were used to assess nonlinear risk dynamics.

RESULTS

Tracking individuals across 10,534,661 person-years (mean age 55.7 ± 15.8 years, 38% male), HDL-C was more strongly associated with reduced CAD risk in NHPIs (HR: 0.32; 95% CI: 0.19-0.54) than in the general cohort (HR: 0.57; 95% CI: 0.56-0.58). A marginally stronger association was observed for MACE (NHPI HR: 0.40; 95% CI: 0.23-0.71 vs general HR: = 0.54; 95% CI: 0.53-0.56), while T2D associations were similar. Spline analysis indicated that low HDL-C increases risk for both CAD and T2D in NHPIs.

CONCLUSIONS

HDL-C's protective role against cardiometabolic diseases is more pronounced in NHPIs, particularly for CAD. These findings support further investigation into tailored clinical assessments for this population.

High density lipoprotein particle size and function associate with new cardiovascular events in patients with chronic kidney disease

Chronic Kidney Disease (CKD) is a risk factor for cardiovascular disease (CVD), and patients with CKD have markedly higher CVD mortality compared to healthy controls. However, the relationship between specific lipoprotein profiles and new CV events in patients with advanced CKD and cardiovascular burden is unknown. We profiled the distribution of High density lipoprotein (HDL) size, particle concentration, and cholesterol and triglyceride content of the baseline plasma of 325 subjects with moderate CKD followed for 2.5 years using nuclear magnetic resonance (NMR) spectroscopy. We used Cox regression models controlled for various clinical factors to characterize the role of specific HDL profiles in predicting CV events in this high-risk population. The cholesterol uptake capacity of HDL from peripheral tissues- cholesterol efflux capacity (CEC) and HDL oxidation were also quantified using standardized assays. Patients with new CV events demonstrated increased HDL size, large HDL particle numbers, and CEC. Increased HDL particle size [HR = 2.56, p = 0.002], large HDL particle numbers [HR = 1.41, p = 0.001], HDL-cholesterol levels [HR = 1.03, p = 0.008], and CEC [HR = 1.46, p = 0.03] associated with CV events. Our study demonstrates that higher HDL particle size associated with new CV events in the CKD population with a high cardiovascular burden independent of CEC and HDL cholesterol. Collectively, the data strongly associate altered lipoprotein metabolism, particularly HDL metabolism, and new CV events in patients with established CKD and CVD, allowing us to risk stratify and potentially reduce mortality and morbidity in this high-risk population.

Threshold effect of non-high-density lipoprotein to high-density lipoprotein cholesterol ratio and hypertension in U.S. adults: NHANES 2005-2016

Hypertension is a prevalent chronic non-communicable disease associated with cardiovascular issues, strokes, kidney disorders, and depression. Most hypertensive patients have dyslipidemia and metabolic abnormalities. The non-high-density lipoprotein to high-density lipoprotein cholesterol ratio (NHHR) is a novel index that more accurately assesses the risk of atherosclerotic cardiovascular diseases and metabolic issues like insulin resistance. The association between NHHR and hypertension prevalence is still unclear. The study aims to examine the link between NHHR and hypertension prevalence in American adults. N10,410 adults from the National Health and Nutrition Examination Survey (NHANES) (2005-2016) were included in this cross-sectional analysis. Multivariable logistic regression constructed to analyze the relationship between NHHR and hypertension, with additional analyses including restricted cubic spline regression (RCS), threshold and saturation effect analyses, effect point calculations, subgroup analyses, and sensitivity analyses. Machine learning methods combined with the Boruta algorithm were employed to identify key predictors of hypertension risk. Of the 10,410 participants, 48% were male, with a hypertension prevalence of 37.03%. NHHR was higher in hypertensive patients compared to non-hypertensive individuals (2.74 vs 2.90, P < .001). In models that were completely confounded with factors including general demographic data, BMI, smoking status, alcohol consumption, diabetes, total cholesterol, history of coronary heart disease, LDL, and dietary cholesterol, NHHR showed a significant positive correlation with hypertension prevalence. RCS regression indicated a non-linear relationship, with a saturation effect point at 3.058. Subgroup analyses showed significant interactions by race and education level (P < .05). Machine learning models demonstrated AUCs > 0.8, affirming the importance of NHHR in predicting hypertension. NHHR levels are significantly elevated in hypertensive individuals compared to non-hypertensive adults in the U.S. Furthermore, a non-linear positive correlation exists between NHHR and hypertension risk, suggesting its potential as a predictive biomarker for early hypertension prevention.

Dysfunctional HDL Diagnostic Metrics for Cardiovascular Disease Risk Stratification: Are we Ready to Implement in Clinics?

Epidemiological studies have revealed that patients with higher levels of high-density lipoprotein cholesterol (HDL-C) were more resistant to cardiovascular diseases (CVD), and yet targeting HDL for CVD prevention, risk assessment, and pharmacological management has not proven to be very effective. The mechanistic investigations have demonstrated that HDL exerts anti-atherogenic functions via mediating reverse cholesterol transport, antioxidant action, anti-inflammatory activity, and anti-thrombotic activity. Contrary to expectations, however, adverse cardiovascular events were reported in clinical trials of drugs that raised HDL levels. This has sparked a debate between HDL quantity and quality. Patients with atherosclerotic CVD are associated with dysfunctional HDL, and the degree of HDL dysfunction is correlated with the severity of the disease, independent of HDL-C levels. This growing body of evidence has underscored the need for integrating HDL functional assays in clinical practice for CVD risk management. Because HDL exerts diverse athero-protective functions, there is no single method for capturing HDL functionality. This review critically evaluates the various techniques currently being used for monitoring HDL functionality and discusses key structural changes in HDL indicative of dysfunctional HDL and the technical challenges that need to be addressed to enable the integration of HDL function-based metrics in clinical practice for CVD risk estimation and the development of newer therapies targeting HDL function.

The association of HDL-cholesterol levels with incident major adverse cardiovascular events and mortality in 0.6 million individuals with type 2 diabetes: a population-based retrospective cohort study

BACKGROUND

High levels of high-density lipoprotein cholesterol (HDL-C) are previously considered protective against cardiovascular diseases (CVD), but recent studies suggest an increased risk of adverse events at very high HDL-C levels in the general population. It remains to be elucidated such a relationship in diabetes, a condition with high cardiovascular risks. We examined the association of HDL-C levels with the risk of major adverse cardiovascular events (MACE) and mortality in type 2 diabetes.

METHODS

This retrospective cohort study identified individuals with type 2 diabetes who had HDL-C records (2008-2020) from the electronic health record database of the Hong Kong Hospital Authority. They were classified into three groups based on their first-recorded HDL-C levels following diabetes diagnosis: low (≤ 40 mg/dL), medium (> 40 and ≤ 80 mg/dL) and high HDL-C (> 80 mg/dL) groups. The primary outcome was incident MACE (composite of myocardial infarction, stroke, heart failure, and cardiovascular mortality). Cox regression model and restricted cubic spline analysis were employed to assess the relationship between HDL-C and adverse outcomes.

RESULTS

Among 596,943 individuals with type 2 diabetes included, 168,931 (28.30%), 412,863 (69.16%), and 15,149 (2.54%) were classified as low HDL-C, medium HDL-C, and high HDL-C groups, respectively. Over a median follow-up of 79.5 months, both low and high HDL-C groups had higher risk of incident MACE compared to the medium HDL-C group (HR 1.24, 95% CI 1.23-1.26, P < 0.001; HR 1.09, 95% CI 1.04-1.13, P < 0.001). The spline curves revealed a U-shaped association between HDL-C levels and incident MACE (non-linear p < 0.001). Similar U-shaped relationship was observed for all-cause and non-cardiovascular mortality.

CONCLUSIONS

Our study demonstrated a U-shaped association between HDL-C levels and incident MACEs and all-cause and non-cardiovascular mortality in individuals with type 2 diabetes, highlighting the need for mechanistic studies on the adverse outcomes seen at high HDL-C levels in type 2 diabetes.

Revisiting high-density lipoprotein cholesterol in cardiovascular disease: Is too much of a good thing always a good thing?

Cardiovascular disease (CVD) continues to be a leading cause of global mortality and morbidity. Various established risk factors are linked to CVD, and modifying these risk factors is fundamental in CVD management. Clinical studies underscore the association between dyslipidemia and CVD, and therapeutic interventions that target low-density lipoprotein cholesterol elicit clear benefits. Despite the correlation between low high-density lipoprotein cholesterol (HDLC) and heightened CVD risk, HDL-raising therapies have yet to showcase significant clinical benefits. Furthermore, evidence from epidemiological and genetic studies reveals that not only low HDL-C levels, but also very high levels of HDL-C are linked to increased risk of CVD. In this review, we focus on HDL metabolism and delve into the relationship between HDL and CVD, exploring HDL functions and the observed alterations in its roles in disease. Altogether, the results discussed herein support the conventional wisdom that "too much of a good thing is not always a good thing". Thus, our recommendation is that a careful reconsideration of the impact of high HDL-C levels is warranted, and shall be revisited in future research.

Increasing the complexity of lipoprotein characterization for cardiovascular risk in type 2 diabetes

The burden of cardiovascular disease is particularly high among individuals with diabetes, even when LDL cholesterol is normal or within the therapeutic target. Despite this, cholesterol accumulates in their arteries, in part, due to persistent atherogenic dyslipidaemia characterized by elevated triglycerides, remnant cholesterol, smaller LDL particles and reduced HDL cholesterol. The causal link between dyslipidaemia and atherosclerosis in T2DM is complex, and our contention is that a deeper understanding of lipoprotein composition and functionality, the vehicle that delivers cholesterol to the artery, will provide insight for improving our understanding of the hidden cardiovascular risk of diabetes. This narrative review covers three levels of complexity in lipoprotein characterization: 1-the information provided by routine clinical biochemistry, 2-advanced nuclear magnetic resonance (NMR)-based lipoprotein profiling and 3-the identification of minor components or physical properties of lipoproteins that can help explain arterial accumulation in individuals with normal LDLc levels, which is typically the case in individuals with T2DM. This document highlights the importance of incorporating these three layers of lipoprotein-related information into population-based studies on ASCVD in T2DM. Such an attempt should inevitably run in parallel with biotechnological solutions that allow large-scale determination of these sets of methodologically diverse parameters.

Low HDL-C/ApoA-I index is associated with cardiometabolic risk factors and coronary artery calcium: a sub-analysis of the genetics of atherosclerotic disease (GEA) study

BACKGROUND

The high-density lipoprotein cholesterol to apolipoprotein A-I index (HDL-C/ApoA-I) may be practical and useful in clinical practice as a marker of atherosclerosis. This study aimed to investigate the association between the HDL-C/ApoA-I index with cardiometabolic risk factors and subclinical atherosclerosis.

METHODS

In this cross-sectional sub-analysis of the GEA study, 1,363 individuals, women (51.3%) and men (48.7%) between 20 and 75 years old, without coronary heart disease or diabetes mellitus were included. We defined an adverse cardiometabolic profile as excess adipose tissue metrics, non-alcoholic liver fat measured by non-contrasted tomography, metabolic syndrome, dyslipidemias, and insulin resistance. The population was stratified by quartiles of the HDL-C/Apo-AI index, and its dose-relationship associations were analysed using Tobit regression, binomial, and multinomial logistic regression analysis.

RESULTS

Body mass index, visceral and pericardial fat, metabolic syndrome, fatty liver, high blood pressure, and CAC were inversely associated with the HDL-C/ApoA-I index. The CAC > 0 prevalence was higher in quartile 1 (29.2%) than in the last quartile (22%) of HDL-C/ApoA-I index (p = 0.035). The probability of having CAC > 0 was higher when the HDL-C/ApoA-I index was less than 0.28 (p < 0.001). This association was independent of classical coronary risk factors, visceral and pericardial fat measurements.

CONCLUSION

The HDL-C/ApoA-I index is inversely associated with an adverse cardiometabolic profile and CAC score, making it a potentially useful and practical biomarker of coronary atherosclerosis. Overall, these findings suggest that the HDL-C/ApoA-I index could be useful for evaluating the probability of having higher cardiometabolic risk factors and subclinical atherosclerosis in adults without CAD.

Effect of Reconstituted Human Apolipoprotein A-I on Recurrent Ischemic Events in Survivors of Acute MI

BACKGROUND

The AEGIS-II trial hypothesized that CSL112, an intravenous formulation of human apoA-I, would lower the risk of plaque disruption, decreasing the risk of recurrent events such as myocardial infarction (MI) among high-risk patients with MI.

OBJECTIVES

This exploratory analysis evaluates the effect of CSL112 therapy on the incidence of cardiovascular (CV) death and recurrent MI.

METHODS

The AEGIS-II trial was an international, multicenter, randomized, double-blind, placebo-controlled trial that randomized 18,219 high-risk acute MI patients to 4 weekly infusions of apoA-I (6 g CSL112) or placebo.

RESULTS

The incidence of the composite of CV death and type 1 MI was 11% to 16% lower in the CSL112 group over the study period (HR: 0.84; 95% CI: 0.7-1.0; P = 0.056 at day 90; HR: 0.86; 95% CI: 0.74-0.99; P = 0.048 at day 180; and HR: 0.89; 95% CI: 0.79-1.01; P = 0.07 at day 365). Similarly, the incidence of CV death or any MI was numerically lower in CSL112-treated patients throughout the follow-up period (HR: 0.92; 95% CI: 0.80-1.05 at day 90, HR: 0.89; 95% CI: 0.79-0.996 at day 180, HR: 0.91; 95% CI: 0.83-1.01 at day 365). The effect of CSL112 treatment on MI was predominantly observed for type 1 MI and type 4b (MI due to stent thrombosis).

CONCLUSIONS

Although CSL112 did not significantly reduce the occurrence of the primary study endpoints, patients treated with CSL112 infusions had numerically lower rates of CV death and MI, type-1 MI, and stent thrombosis-related MI compared with placebo. These findings could suggest a role of apoA-I in reducing subsequent plaque disruption events via enhanced cholesterol efflux. Further prospective data would be needed to confirm these observations.

Alcohol Consumption, High-Density Lipoprotein Particles and Subspecies, and Risk of Cardiovascular Disease: Findings from the PREVEND Prospective Study

The associations of HDL particle (HDL-P) and subspecies concentrations with alcohol consumption are unclear. We aimed to evaluate the interplay between alcohol consumption, HDL parameters and cardiovascular disease (CVD) risk. In the PREVEND study of 5151 participants (mean age, 53 years; 47.5% males), self-reported alcohol consumption and HDL-P and subspecies (small, medium, and large) by nuclear magnetic resonance spectroscopy were assessed. Hazard ratios (HRs) with 95% CIs for first CVD events were estimated. In multivariable linear regression analyses, increasing alcohol consumption increased HDL-C, HDL-P, large and medium HDL, HDL size, and HDL subspecies (H3P, H4P, H6 and H7) in a dose-dependent manner. During a median follow-up of 8.3 years, 323 first CVD events were recorded. Compared with abstainers, the multivariable adjusted HRs (95% CIs) of CVD for occasional to light, moderate, and heavy alcohol consumers were 0.72 (0.55-0.94), 0.74 (0.54-1.02), and 0.65 (0.38-1.09), respectively. These associations remained consistent on additional adjustment for each HDL parameter. For CVD, only HDL-C was associated with a statistically significant decreased risk of CVD in a fully adjusted analysis (HR 0.84, 95% CI 0.72-0.97 per 1 SD increment). For coronary heart disease, HDL-C, HDL-P, medium HDL, HDL size, and H4P showed inverse associations, whereas HDL-C and HDL size modestly increased stroke risk. Except for H6P, alcohol consumption did not modify the associations between HDL parameters and CVD risk. The addition of HDL-C, HDL size, or H4P to a CVD risk prediction model containing established risk factors improved risk discrimination. Increasing alcohol consumption is associated with increased HDL-C, HDL-P, large and medium HDL, HDL size, and some HDL subspecies. Associations of alcohol consumption with CVD are largely independent of HDL parameters. The associations of HDL parameters with incident CVD are generally not attenuated or modified by alcohol consumption.

Rethinking HDL-C: An In-Depth Narrative Review of Its Role in Cardiovascular Health

The interplay between HDL-C and LDL levels are closely intertwined with the cardiovascular system. High-Density Lipoprotein Cholesterol (HDL-C) is a well-known biomarker traditionally being interpreted as higher the HDL-C levels, minimal the risk of adverse cardiovascular disease (CVD) outcomes. However, recent research has unveiled a more complex relationship between HDL-C levels and cardiovascular outcomes, including genetic influences and potential risks associated with extremely high HDL-C levels. Intriguingly, extremely high HDL-C levels have been linked to unexpected cardiovascular risks. Up To date research suggests that individuals with genetically linked ultra-high HDL-C levels may depict an increased susceptibility to CVD, challenging the conventional realm that higher HDL-C is always beneficial. The mechanisms underlying this mystery are not fully understood but may involve HDL particle functionality and composition. In a nutshell, the relationship between HDL-C levels and cardiovascular outcomes is multifactorial. While low HDL-C remains a recognized risk factor for CVD, the genetic determinants of HDL-C levels add complexity to this association. Furthermore, extremely high HDL-C levels may not exhibit the expected protective benefits and may even pose unprecedented cardiovascular risks. A comprehensive understanding of these dynamics is essential for advancing our knowledge of CVD risk assessment and developing targeted therapeutic interventions. Further studies are needed to unravel the intricacies of HDL-C's role in cardiovascular health and disease.

Association between exposure to air pollution and blood lipids in the general population of Spain

BACKGROUND AND AIMS

We aimed to assess the associations of exposure to air pollutants and standard and advanced lipoprotein measures, in a nationwide sample representative of the adult population of Spain.

METHODS

We included 4647 adults (>18 years), participants in the national, cross-sectional, population-based di@bet.es study, conducted in 2008-2010. Standard lipid measurements were analysed on an Architect C8000 Analyzer (Abbott Laboratories SA). Lipoprotein analysis was made by an advanced 1 H-NMR lipoprotein test (Liposcale®). Participants were assigned air pollution concentrations for particulate matter <10 μm (PM10 ), <2.5 μm (PM2.5 ) and nitrogen dioxide (NO2 ), corresponding to the health examination year, obtained by modelling combined with measurements taken at air quality stations (CHIMERE chemistry-transport model).

RESULTS

In multivariate linear regression models, each IQR increase in PM10 , PM2.5 and NO2 was associated with 3.3%, 3.3% and 3% lower levels of HDL-c and 1.3%, 1.4% and 1.1% lower HDL particle (HDL-p) concentrations (p < .001 for all associations). In multivariate logistic regression, there was a significant association between PM10 , PM2.5 and NO2 concentrations and the odds of presenting low HDL-c (<40 mg/dL), low HDL-p (

CONCLUSIONS

Our study shows an association between the exposure to air pollutants and blood lipids in the general population of Spain, suggesting a link to atherosclerosis.

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Key Words

• HDL
• air pollution
• cholesterol
• lipids
• lipoprotein
• triglyceride

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MESH Headings

• Male
• Adult
• Humans
• Nitrogen Dioxide/analysis
• Spain/epidemiology
• Cross-Sectional Studies
• Air Pollution/adverse effects
• Air Pollution/analysis
• Air Pollutants/analysis
• Particulate Matter/analysis
• Lipids
• Lipoproteins/analysis
• Environmental Exposure/adverse effects

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Grants

• RC-0006-2016 Consejería de Salud y Bienestar Social, Junta de Andalucía
• CM21/00214 Instituto de Salud Carlos III
• INT21/00037 Instituto de Salud Carlos III
• PI17/02136 Instituto de Salud Carlos III
• PI20/01322 Instituto de Salud Carlos III

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Affiliation(s)

Sergio Valdés Department of Endocrinology and Nutrition, Hospital Regional Universitario de Málaga/Universidad de Málaga, Instituto de Investigación Biomedica de Málaga-IBIMA, Málaga, Spain Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain
Viyey Doulatram-Gamgaram Department of Endocrinology and Nutrition, Hospital Regional Universitario de Málaga/Universidad de Málaga, Instituto de Investigación Biomedica de Málaga-IBIMA, Málaga, Spain
Cristina Maldonado-Araque Department of Endocrinology and Nutrition, Hospital Regional Universitario de Málaga/Universidad de Málaga, Instituto de Investigación Biomedica de Málaga-IBIMA, Málaga, Spain Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain
Eva García-Escobar Department of Endocrinology and Nutrition, Hospital Regional Universitario de Málaga/Universidad de Málaga, Instituto de Investigación Biomedica de Málaga-IBIMA, Málaga, Spain Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain
Sara García-Serrano Department of Endocrinology and Nutrition, Hospital Regional Universitario de Málaga/Universidad de Málaga, Instituto de Investigación Biomedica de Málaga-IBIMA, Málaga, Spain Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain
Wasima Oualla-Bachiri Department of Endocrinology and Nutrition, Hospital Regional Universitario de Málaga/Universidad de Málaga, Instituto de Investigación Biomedica de Málaga-IBIMA, Málaga, Spain Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain
Marta García-Vivanco Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT) - División de Contaminación Atmosférica, Madrid, Spain
Juan Luis Garrido Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT) - División de Contaminación Atmosférica, Madrid, Spain
Victoria Gil Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT) - División de Contaminación Atmosférica, Madrid, Spain
Fernando Martín-Llorente Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT) - División de Contaminación Atmosférica, Madrid, Spain
Alfonso Calle-Pascual Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain Department of Endocrinology and Nutrition and Instituto de Investigación Sanitaria University Hospital S. Carlos (IdISSC), Department Medicine II, Universidad Complutense (UCM), Madrid, Spain
Luis Castaño Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain Hospital Universitario Cruces, BioCruces, UPV/EHU, Barakaldo, Spain Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
Elías Delgado Department of Endocrinology and Nutrition, Hospital Universitario Central de Asturias/University of Oviedo, Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain
Edelmiro Menéndez Department of Endocrinology and Nutrition, Hospital Universitario Central de Asturias/University of Oviedo, Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain
Josep Franch-Nadal Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain EAP Raval Sud, Institut Català de la Salut, Red GEDAPS, Primary Care, Unitat de Suport a la Recerca (IDIAP - Fundació Jordi Gol), Barcelona, Spain
Sonia Gaztambide Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Madrid, Spain Department of Endocrinology and Nutrition, Hospital Universitario Cruces - BioCruces Bizkaia - UPV-EHU, Baracaldo, Barcelona, Spain
Joan Girbés Diabetes Unit, Hospital Arnau de Vilanova, Valencia, Spain
F Javier Chaves Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain Genomic Studies and Genetic Diagnosis Unit, Fundación de Investigación del Hospital Clínico de Valencia - INCLIVA, Valencia, Spain
José L Galán-García Department of Applied Mathematics, University of Málaga, Málaga, Spain
Gabriel Aguilera-Venegas Department of Applied Mathematics, University of Málaga, Málaga, Spain
Joan Carles Vallvé Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain Research Unit on Lipids and Atherosclerosis, Sant Joan University Hospital, Rovira i Virgili University, IISPV, Reus, Spain
Núria Amigó Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain Metabolomics Platform, Universitat Rovira i Virgili, IISRV, Reus, Spain Biosfer Teslab, Reus, Spain
Montse Guardiola Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain Research Unit on Lipids and Atherosclerosis, Sant Joan University Hospital, Rovira i Virgili University, IISPV, Reus, Spain
Josep Ribalta Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain Research Unit on Lipids and Atherosclerosis, Sant Joan University Hospital, Rovira i Virgili University, IISPV, Reus, Spain
Gemma Rojo-Martínez Department of Endocrinology and Nutrition, Hospital Regional Universitario de Málaga/Universidad de Málaga, Instituto de Investigación Biomedica de Málaga-IBIMA, Málaga, Spain Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain

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Association of Lipoprotein(a) Levels With Myocardial Fibrosis in the Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Lipoprotein(a) (Lp[a]) has been identified as an emerging risk factor for adverse cardiovascular (CV) outcomes, including heart failure. However, the connections among Lp(a), myocardial fibrosis (interstitial and replacement), and cardiac remodeling as pathways to CV diseases remains unclear.

OBJECTIVES

This study investigated the relationship between Lp(a) levels and myocardial fibrosis by cardiac magnetic resonance (CMR) T1 mapping and late gadolinium enhancement, as well as cardiac remodeling by cine CMR, in the MESA (Multi-Ethnic Study of Atherosclerosis) cohort.

METHODS

The study included 2,040 participants with baseline Lp(a) measurements and T1 mapping for interstitial myocardial fibrosis (IMF) evaluation in 2010. Lp(a) was analyzed as a continuous variable (per log unit) and using clinical cutoff values of 30 and 50 mg/dL. Multivariate linear and logistic regression were used to assess the associations of Lp(a) with CMR measures of extracellular volume (ECV fraction [ECV%]), native T1 time, and myocardial scar, as well as parameters of cardiac remodeling, in 2,826 participants.

RESULTS

Higher Lp(a) levels were associated with increased ECV% (per log-unit Lp[a]; β = 0.2%; P = 0.007) and native T1 time (per log-unit Lp[a]; β = 4%; P < 0.001). Similar relationships were observed between elevated Lp(a) levels and a higher risk of clinically significant IMF defined by prognostic thresholds per log-unit Lp(a) of ECV% (OR: 1.20; 95% CI: 1.04-1.43) and native T1 (OR: 1.2; 95% CI: 1.1-1.4) equal to 30% and 955 ms, respectively. Clinically used Lp(a) cutoffs (30 and 50 mg/dL) were associated with greater prevalence of myocardial scar (OR: 1.85; 95% CI: 1.1-3.2 and OR: 1.9; 95% CI: 1.1-3.4, respectively). Finally, higher Lp(a) levels were associated with left atrial enlargement and dysfunction.

CONCLUSIONS

Elevated Lp(a) levels are linked to greater subclinical IMF, increased myocardial scar prevalence, and left atrial remodeling.

High-Density Lipoprotein Cholesterol in Atherosclerotic Cardiovascular Disease Risk Assessment: Exploring and Explaining the "U"-Shaped Curve

PURPOSE OF REVIEW

Review updates for the association of HDL-cholesterol with atherosclerotic cardiovascular disease (ASCVD) and discuss the approach to incorporating HDL-cholesterol within risk assessment.

RECENT FINDINGS

There is a U-shaped relationship between HDL-cholesterol and ASCVD. Both low HDL-cholesterol (< 40 mg/dL in men, < 50 mg/dL in women) and very-high HDL-cholesterol (≥ 80 mg/dL in men) are associated with a higher risk of all-cause and ASCVD mortality, independent from traditional risk factors. There has been inconsistency for the association between very-high HDL-cholesterol and mortality outcomes in women. It is uncertain whether HDL-cholesterol is a causal ASCVD risk factor, especially due to mixed results from Mendelian randomization studies and the collinearity of HDL-cholesterol with established risk factors, lifestyle behaviors, and socioeconomic status. HDL-cholesterol is a risk factor or risk enhancer in primary prevention and high-risk condition in secondary prevention when either low (men and women) or very-high (men). The contribution of HDL-cholesterol to ASCVD risk calculators should reflect its observed U-shaped association with all-cause and ASCVD mortality.

Effect of Exercise Training on Lipoprotein Subclass Particle Concentrations and Sizes in Older Women: Results from a Randomized Controlled Trial

BACKGROUND

Evidence suggests that lipoprotein subclass particles are critical markers of cardiovascular disease (CVD) risk. Older women have increased CVD risk related to age. The purpose of this study was to determine whether low and moderate doses of exercise influence lipoprotein subclasses.

METHODS

Women (60-75 years) were randomized into groups for 16 weeks of moderate-intensity exercise training at a low or moderate dose (33.6 and 58.8 kJ/kg body weight weekly, respectively). Lipoprotein subclasses were determined by nuclear magnetic resonance spectroscopy before and after the training.

RESULTS

The average weekly exercise duration was 109 and 164 min, for low- and moderate-dose groups, respectively. In the low-dose group, high-density lipoprotein particle (HDL-P) concentration decreased (Δ = -1.9 ± 3.1 µmol/L, mean ± SD, p = 0.002) and mean HDL-P size increased (Δ = 0.1 ± 0.3 nm, p = 0.028). In the moderate-dose group, mean HDL-P size (Δ = 0.1 ± 0.2 nm; p = 0.024) and low-density lipoprotein particle size increased (Δ = 0.4 ± 3.9 nm; p = 0.007). Baseline body mass index, peak oxygen consumption and age were associated with changes in a few lipoprotein subclasses.

CONCLUSIONS

In this sample of inactive older women, moderate-intensity exercise training at a dose equivalent to or even lower than the minimally recommended level by public health agencies induced changes in lipoprotein subclasses in line with reduced CVD risk. However, higher doses are encouraged for greater health benefits.

Novel Size-Based High-Density Lipoprotein Subspecies and Incident Vascular Events

Background High-density lipoprotein (HDL) particle concentration likely outperforms HDL cholesterol in predicting atherosclerotic cardiovascular events. Whether size-based HDL subspecies explain the atheroprotective associations of HDL particle concentration remains unknown. Our objective was to assess whether levels of specific size-based HDL subspecies associate with atherosclerotic cardiovascular disease in a multiethnic pooled cohort and improve risk prediction beyond traditional atherosclerotic cardiovascular disease risk factors. Methods and Results Seven HDL size-based subspecies were quantified by nuclear magnetic resonance (LP4 algorithm; H1=smallest; H7=largest) among participants without prior atherosclerotic cardiovascular disease in ARIC (Atherosclerosis Risk in Communities), MESA (Multi-Ethnic Study of Atherosclerosis), PREVEND (Prevention of Renal and Vascular Endstage Disease), and DHS (Dallas Heart Study) cohorts (n=15 371 people). Multivariable Cox proportional hazards models were used to evaluate the association between HDL subspecies and incident myocardial infarction (MI) or ischemic stroke at follow-up (average 8-10 years) adjusting for HDL cholesterol and risk factors. Improvement in risk prediction was assessed via discrimination and reclassification analysis. Within the pooled cohort (median age 57 years; female 54%; Black 22%) higher H1 (small) and H4 (medium) concentrations were inversely associated with incident MI (hazard ratio [HR]/SD, H1 0.88 [95% CI, 0.81-0.94]; H4 0.89 [95% CI, 0.82-0.97]). H4 but not H1 improved risk prediction indices for incident MI. Increasing H2 and H4 were inversely associated with improved risk prediction indices for composite end point of stroke, MI, and cardiovascular death (HR/SD, H2 0.94 [95% CI, 0.88-0.99]; H4 0.91 [95% CI, 0.85-0.98]). Levels of the large subspecies (H6 and H7) were not associated with any vascular end point. Conclusions Two of 7 HDL size-based subspecies modestly improved risk prediction for MI and composite vascular end points in a large multiethnic pooled cohort. These findings support assessment of precise HDL subspecies for future studies regarding clinical utility.

Remnant cholesterol predicts cardiovascular mortality beyond low-density lipoprotein cholesterol in patients with peritoneal dialysis

BACKGROUND

Patients undergoing peritoneal dialysis (PD) are prone to dyslipidemia. However, studies concerning remnant cholesterol (RC) in such patients are limited.

OBJECTIVE

We aimed to investigate the association between RC and cardiovascular (CV) mortality in patients on PD.

METHODS

Patients who initiated PD at our center (2006-2018) were retrospectively enrolled. Adjusted Cox models were used to evaluate the independent association between baseline RC levels and CV mortality. We classified patients into 4 concordant/discordant categories according to their baseline lipid profiles. Cox models were then used to determine the association between different low-density lipoprotein cholesterol (LDL-C) and RC levels and CV mortality risk.

RESULTS

The study enrolled 2333 individuals, with a mean RC of 33.4 mg/dL. RC levels were positively associated with CV mortality risk independent of LDL-C in patients on PD (hazard ratio [HR]: 1.05; 95% confidence interval [CI]: 1. 00-1.10). In the concordant/discordant categories, patients with high LDL-C and RC levels had a higher CV mortality risk (HR: 1.52; 95% CI: 1.01-2.28) than those with low LDL-C and RC levels in the entire cohort. Moreover, in older patients, a higher RC level increased CV mortality risk regardless of the LDL-C level (HR: 2.41, 95% CI: 1.22-4.74; HR: 2.15, 95% CI: 1.12-4.14).

CONCLUSIONS

RC levels are elevated in patients on PD and can predict CV mortality beyond LDL-C levels. RC levels should be considered alongside LDL-C levels when assessing prognostic lipid levels in these patients. More attention should be given to RC than to LDL-C in older patients undergoing PD.

Association of apolipoproteins C-I and C-II truncations with coronary heart disease and progression of coronary artery calcium: Multi-Ethnic Study of Atherosclerosis

BACKGROUND AND AIMS

Higher truncated-to-native proteoform ratios of apolipoproteins (apo) C-I (C-I'/C-I) and C-II (C-II'/C-II) are associated with less atherogenic lipid profiles. We examined prospective relationships of C-I'/C-II and C-II'/C-II with coronary heart disease (CHD) and coronary artery calcium (CAC).

METHODS

ApoC-I and apoC-II proteoforms were measured by mass spectrometry immunoassay in 5790 MESA baseline plasma samples. CHD events (myocardial infarction, resuscitated cardiac arrest, fatal CHD, n = 434) were evaluated for up to 17 years. CAC was measured 1-4 times over 10 years for incident CAC (if baseline CAC = 0), and changes (follow-up adjusted for baseline) in CAC score and density (if baseline CAC>0).

RESULTS

C-II'/C-II was inversely associated with CHD (n = 434 events) after adjusting for non-lipid cardiovascular risk factors (Hazard ratio: 0.89 [95% CI: 0.81-0.98] per SD), however, the association was attenuated after further adjustment for HDL levels (0.93 [0.83-1.03]). There was no association between C-I'/C-I and CHD (0.98 [0.88-1.08]). C-II'/C-II was positively associated with changes in CAC score (3.4% [95%CI: 0.6, 6.3]) and density (6.3% [0.3, 4.2]), while C-I'/C-I was inversely associated with incident CAC (Risk ratio: 0.89 [95% CI: 0.81, 0.98]) in fully adjusted models that included plasma lipids. Total apoC-I and apoC-II concentrations were not associated with CHD, incident CAC or change in CAC score.

CONCLUSIONS

Increased apoC-II truncation was associated with reduced CHD, possibly explained by differences in lipid metabolism. Increased apoC-I and apoC-II truncations were also associated with less CAC progression and/or development of denser coronary plaques.

Small High-Density Lipoprotein and Omega-3 Fatty Acid Intake Differentiates Japanese and Japanese-Americans: The INTERLIPID Study

AIM

To identify the most differentiated serum lipids, especially concerning particle size and fractions, between Japanese living in Japan and Japanese-Americans in Hawaii, in the absence of possible genetic confounders, and cross-sectionally examine the associated modifiable lifestyle factors.

METHODS

Overall, 1,241 (aged 40-59 years) Japanese living in Japan and Japanese-Americans in Hawaii were included. We quantified 130 serum lipid profiles (VLDL 1-5, IDL, LDL 1-6, high-density lipoprotein [HDL] 1-4, and their subfractions) using Bruker's 1H-nuclear magnetic resonance spectrometer for the primary outcome. Modifiable lifestyle factors included body mass index (BMI), physical activity, alcohol and smoking habits, and 70 nutrient parameters. We evaluated the different lipids between the groups using partial least squares-discriminant analysis and association between extracted lipids and lifestyle factors using multivariable linear regression analysis.

RESULTS

Concentrations of HDL4, HDL with the smallest particle size, were lower in Japanese than in Japanese-Americans of both sexes. Higher fish-derived omega-3 fatty acid intake and lower alcohol intake were associated with lower HDL4 concentrations. A 1% higher kcal intake of total omega-3 fatty acids was associated with a 9.8-mg/dL lower HDL4. Fish-derived docosapentaenoic acid, eicosapentaenoic acid, and docosahexaenoic acid intake were inversely associated with HDL4 concentration. There was no relationship between country, sex, age, or BMI.

CONCLUSIONS

Japanese and Japanese-Americans can be differentiated based on HDL4 concentration. High fish intake among the Japanese may contribute to their lower HDL4 concentration. Thus, HDL particle size may be an important clinical marker for coronary artery diseases or a fish consumption biomarker.

Triglyceride-rich lipoproteins and insulin resistance in patients with chronic hepatitis C receiving direct-acting antivirals

BACKGROUND & AIMS

Hepatitis C virus (HCV) interferes with carbohydrate and lipid metabolism causing cardiovascular disease and insulin resistance (IR). Direct-acting antivirals (DAAs) are highly effective for the eradication of HCV, with positive effects on metabolic health although paradoxically associated with increased total and LDL-cholesterol. The aims of this study were 1) to characterize dyslipidemia (lipoprotein content, number, and size) in naive HCV-infected individuals and 2) to evaluate the longitudinal association of metabolic changes and lipoparticle characteristics after DAA therapy.

METHODS

We conducted a prospective study with one-year follow-up. 83 naive outpatients treated with DAAs were included. Those co-infected with HBV or HIV were excluded. IR was analyzed using the HOMA index. Lipoproteins were studied by fast-protein liquid chromatography (FPLC) and Nuclear Magnetic Resonance Spectroscopy (NMR).

RESULTS

FPLC analysis showed that lipoprotein-borne HCV was only present in the VLDL region most enriched in APOE. There was a lack of association between HOMA and total cholesterol or cholesterol carried by LDL or HDL at baseline. Alternatively, a positive association was found between HOMA and total circulating triglycerides (TG), as well as with TG transported in VLDL, LDL, and HDL. HCV eradication with DAAs resulted in a strong and significant decrease in HOMA (-22%) and HDL-TG (-18%) after one-year follow-up.

CONCLUSIONS

HCV-dependent lipid abnormalities are associated with IR and DAA therapy can reverse this association. These findings may have potential clinical implications as the HDL-TG trajectory may inform the evolution of glucose tolerance and IR after HCV eradication.

Low concentrations of medium-sized HDL particles predict incident CVD in chronic kidney disease patients

Patients with chronic kidney disease (CKD) are at high risk for CVD. However, traditional CVD risk factors cannot completely explain the increased risk. Altered HDL proteome is linked with incident CVD in CKD patients, but it is unclear whether other HDL metrics are associated with incident CVD in this population. In the current study, we analyzed samples from two independent prospective case-control cohorts of CKD patients, the Clinical Phenotyping and Resource Biobank Core (CPROBE) and the Chronic Renal Insufficiency Cohort (CRIC). We measured HDL particle sizes and concentrations (HDL-P) by calibrated ion mobility analysis and HDL cholesterol efflux capacity (CEC) by cAMP-stimulated J774 macrophages in 92 subjects from the CPROBE cohort (46 CVD and 46 controls) and in 91 subjects from the CRIC cohort (34 CVD and 57 controls). We tested associations of HDL metrics with incident CVD using logistic regression analysis. No significant associations were found for HDL-C or HDL-CEC in either cohort. Total HDL-P was only negatively associated with incident CVD in the CRIC cohort in unadjusted analysis. Among the six sized HDL subspecies, only medium-sized HDL-P was significantly and negatively associated with incident CVD in both cohorts after adjusting for clinical confounders and lipid risk factors with odds ratios (per 1-SD) of 0.45 (0.22-0.93, P = 0.032) and 0.42 (0.20-0.87, P = 0.019) for CPROBE and CRIC cohorts, respectively. Our observations indicate that medium-sized HDL-P-but not other-sized HDL-P or total HDL-P, HDL-C, or HDL-CEC-may be a prognostic cardiovascular risk marker in CKD.

Atherosclerosis Calcification: Focus on Lipoproteins

Atherosclerosis is a chronic inflammatory disease characterized by the accumulation of lipids in the vessel wall, leading to the formation of an atheroma and eventually to the development of vascular calcification (VC). Lipoproteins play a central role in the development of atherosclerosis and VC. Both low- and very low-density lipoproteins (LDL and VLDL) and lipoprotein (a) (Lp(a)) stimulate, while high-density lipoproteins (HDL) reduce VC. Apolipoproteins, the protein component of lipoproteins, influence the development of VC in multiple ways. Apolipoprotein AI (apoAI), the main protein component of HDL, has anti-calcific properties, while apoB and apoCIII, the main protein components of LDL and VLDL, respectively, promote VC. The role of lipoproteins in VC is also related to their metabolism and modifications. Oxidized LDL (OxLDL) are more pro-calcific than native LDL. Oxidation also converts HDL from anti- to pro-calcific. Additionally, enzymes such as autotaxin (ATX) and proprotein convertase subtilisin/kexin type 9 (PCSK9), involved in lipoprotein metabolism, have a stimulatory role in VC. In summary, a better understanding of the mechanisms by which lipoproteins and apolipoproteins contribute to VC will be crucial in the development of effective preventive and therapeutic strategies for VC and its associated cardiovascular disease.

Association of statin therapy with progression of carotid arterial stiffness: the Multi-Ethnic Study of Atherosclerosis (MESA)

Arterial stiffness progresses with age and is a predictor of adverse cardiovascular disease events. Studies examining associations of statin therapy with arterial stiffness have yielded mixed results. Associations between the duration and intensity of statin therapy and arterial stiffness have not been studied in a prospective multiethnic cohort. MESA participants (n = 1242) with statin medication use data at each exam (1-5) and who had undergone B-mode carotid ultrasound at baseline and at Exam 5 after (mean ± [SD]) 9.4 ± 0.5 years were analyzed. Carotid arterial stiffness was measured using the distensibility coefficient (DC) and Young's elastic modulus (YEM). Linear regression models were used to evaluate associations between DC and YEM and statin treatment duration and intensity. At baseline, participants were 66.5 ± 8.1 years old, 41% female, 36% White, 30% African American, 14% Chinese American, and 20% Hispanic. The mean baseline low-density lipoprotein cholesterol (LDL-C) was 149.5 ± 14.5 mg/dL. After adjusting for age, sex, race/ethnicity, and CVD risk factors, the percent changes in DC and YEM were found to not be significantly different in individuals on statin therapy at any combination of visits (1-4) compared to participants never on statin therapy (all p > 0.32). There were also no differences in the percent change in DC and YEM based on statin therapy intensity by quartile (all p > 0.14) over the 10-year follow-up period. Based on the aforementioned results, statin therapy was not associated with changes in carotid artery stiffness over nearly a decade of follow-up regardless of therapy duration or intensity.

Lipoprotein Subclasses Associated With High-Risk Coronary Atherosclerotic Plaque: Insights From the PROMISE Clinical Trial

BACKGROUND More than half of major adverse cardiovascular events (MACE) occur in the absence of obstructive coronary artery disease and are often attributed to the rupture of high-risk coronary atherosclerotic plaque (HRP). Blood-based biomarkers that associate with imaging-defined HRP and predict MACE are lacking. METHODS AND RESULTS Nuclear magnetic resonance-based lipoprotein particle profiling was performed in the biomarker substudy of the PROMISE (Prospective Multicenter Imaging Study for Evaluation of Chest Pain) trial (N=4019) in participants who had stable symptoms suspicious for coronary artery disease. Principal components analysis was used to reduce the number of correlated lipoproteins into uncorrelated lipoprotein factors. The association of lipoprotein factors and individual lipoproteins of significantly associated factors with core laboratory determined coronary computed tomographic angiography features of HRP was determined using logistic regression models. The association of HRP-associated lipoproteins with MACE was assessed in the PROMISE trial and validated in an independent coronary angiography biorepository (CATHGEN [Catheterization Genetics]) using Cox proportional hazards models. Lipoprotein factors composed of high-density lipoprotein (HDL) subclasses were associated with HRP. In these factors, large HDL (odds ratio [OR], 0.70 [95% CI, 0.56-0.85]; P<0.001) and medium HDL (OR, 0.84 [95% CI, 0.72-0.98]; P=0.028) and HDL size (OR, 0.82 [95% CI, 0.69-0.96]; P=0.018) were associated with HRP in multivariable models. Medium HDL was associated with MACE in PROMISE (hazard ratio [HR], 0.76 [95% CI, 0.63-0.92]; P=0.004), which was validated in the CATHGEN biorepository (HR, 0.91 [95% CI, 0.88-0.94]; P<0.001). CONCLUSIONS Large and medium HDL subclasses and HDL size inversely associate with HRP features, and medium HDL subclasses inversely associate with MACE in PROMISE trial participants. These findings may aid in the risk stratification of individuals with chest pain and provide insight into the pathobiology of HRP. REGISTRATION URL: https://clinicaltrials.gov; Unique identifier: NCT01174550.

The benefits of measuring the size and number of lipoprotein particles for cardiovascular risk prediction: A systematic review and meta-analysis

OBJECTIVE

Cardiovascular risk (CVR) is conventionally calculated by measuring the total cholesterol content of high-density lipoproteins (HDL) and low-density lipoproteins (LDL). The purpose of this systematic review was to assess the CVR associated with LDL and HDL particle size and number as determined by nuclear magnetic resonance (NMR) spectroscopy.

MATERIAL AND METHODS

A literature search was performed using the electronic databases MEDLINE and Scopus. All cohort and case-control studies published before January 1, 2019 that met the following inclusion criteria were included: HDL-P, LDL-P, HDL-Z and/or LDL-Z measured by NMR spectroscopy; cardiovascular event as an outcome variable; risk of cardiovascular events expressed as odds ratios or hazard ratios; only adult patients. A meta-analysis was performed for each exposure variable (4 for LDL and 5 for HDL) and for each exposure measure (highest versus lowest quartile and 1-standard deviation increment).

RESULTS

This review included 24 studies. Number of LDL particles was directly associated with CVR: risk increased by 28% with each standard deviation increment. LDL particle size was inversely and significantly associated with CVR: each standard deviation increment corresponded to an 8% risk reduction. CVR increased by 12% with each standard deviation increase in number of small LDL particles. HD, particle number and size were inversely associated with CVR.

CONCLUSION

Larger particle size provided greater protection, although this relationship was inconsistent between studies. Larger number of LDL particles and smaller LDL particle size are associated with increased CVR. Risk decreases with increasing number and size of HDL particles.

Race-Dependent Association of High-Density Lipoprotein Cholesterol Levels With Incident Coronary Artery Disease

BACKGROUND

Plasma lipids are risk factors for coronary heart disease (CHD) in part because of race-specific associations of lipids with CHD.

OBJECTIVES

The purpose of this study was to understand why CHD risk equations underperform in Black adults.

METHODS

Between 2003 and 2007, the REGARDS (REasons for Geographic and Racial Differences in Stroke) cohort recruited 30,239 Black and White individuals aged ≥45 years from the contiguous United States. We used Cox regression models adjusted for clinical and behavioral risk factors to estimate the race-specific hazard of plasma lipid levels with incident CHD (myocardial infarction or CHD death).

RESULTS

Among 23,901 CHD-free participants (57.8% White and 58.4% women, mean age 64 ± 9 years) over a median 10 years of follow-up, 664 and 951 CHD events occurred among Black and White adults, respectively. Low-density lipoprotein cholesterol and triglycerides were associated with increased risk of CHD in both races (P interaction by race >0.10). For sex-specific clinical HDL-C categories: low HDL-C was associated with increased CHD risk in White (HR: 1.22; 95% CI: 1.05-1.43) but not in Black (HR: 0.94; 95% CI: 0.78-1.14) adults (P interaction by race = 0.08); high HDL-C was not associated with decreased CHD events in either race (HR: 0.96; 95% CI: 0.79-1.16 for White participants and HR: 0.91; 95% CI: 0.74-1.12 for Black adults).

CONCLUSIONS

Low-density lipoprotein cholesterol and triglycerides modestly predicted CHD risk in Black and White adults. Low HDL-C was associated with increased CHD risk in White but not Black adults, and high HDL-C was not protective in either group. Current high-density lipoprotein cholesterol-based risk calculations could lead to inaccurate risk assessment in Black adults.

High-density lipoprotein revisited: biological functions and clinical relevance

Previous interest in high-density lipoproteins (HDLs) focused on their possible protective role in atherosclerotic cardiovascular disease (ASCVD). Evidence from genetic studies and randomized trials, however, questioned that the inverse association of HDL-cholesterol (HDL-C) is causal. This review aims to provide an update on the role of HDL in health and disease, also beyond ASCVD. Through evolution from invertebrates, HDLs are the principal lipoproteins, while apolipoprotein B-containing lipoproteins first developed in vertebrates. HDLs transport cholesterol and other lipids between different cells like a reusable ferry, but serve many other functions including communication with cells and the inactivation of biohazards like bacterial lipopolysaccharides. These functions are exerted by entire HDL particles or distinct proteins or lipids carried by HDL rather than by its cholesterol cargo measured as HDL-C. Neither does HDL-C measurement reflect the efficiency of reverse cholesterol transport. Recent studies indicate that functional measures of HDL, notably cholesterol efflux capacity, numbers of HDL particles, or distinct HDL proteins are better predictors of ASCVD events than HDL-C. Low HDL-C levels are related observationally, but also genetically, to increased risks of infectious diseases, death during sepsis, diabetes mellitus, and chronic kidney disease. Additional, but only observational, data indicate associations of low HDL-C with various autoimmune diseases, and cancers, as well as all-cause mortality. Conversely, extremely high HDL-C levels are associated with an increased risk of age-related macular degeneration (also genetically), infectious disease, and all-cause mortality. HDL encompasses dynamic multimolecular and multifunctional lipoproteins that likely emerged during evolution to serve several physiological roles and prevent or heal pathologies beyond ASCVD. For any clinical exploitation of HDL, the indirect marker HDL-C must be replaced by direct biomarkers reflecting the causal role of HDL in the respective disease.

High-Density Lipoprotein and Long-Term Incidence and Progression of Aortic Valve Calcification: The Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Aortic valve calcification (AVC) shares pathological features with atherosclerosis. Lipoprotein components have been detected in aortic valve tissue, including HDL (high-density lipoprotein). HDL measures have inverse associations with cardiovascular disease, but relationships with long-term AVC progression are unclear. We investigated associations of HDL cholesterol, HDL-particle number and size, apoC3-defined HDL subtypes, and, secondarily, CETP (cholesteryl ester transfer protein) mass and activity, with long-term incidence and progression of AVC.

METHODS

We used linear mixed-effects models to evaluate the associations of baseline HDL indices with AVC. AVC was quantified by Agatston scoring of up to 3 serial computed tomography scans over a median of 8.9 (maximum 11.2) years of follow-up in the Multi-Ethnic Study of Atherosclerosis (n=6784).

RESULTS

After adjustment, higher concentrations of HDL-C (high-density lipoprotein cholesterol), HDL-P (HDL particles), large HDL-P, and apoC3-lacking HDL-C were significantly associated with lower incidence/progression of AVC. Neither small or medium HDL-P nor apoC3-containing HDL-C was significantly associated with AVC incidence/progression. When included together, a significant association was observed only for HDL-C, but not for HDL-P. Secondary analyses showed an inverse relationship between CETP mass, but not activity, and AVC incidence/progression. In exploratory assessments, inverse associations for HDL-C, HDL-P, large HDL-P, and apoC3-lacking HDL with AVC incidence/progression were more pronounced for older, male, and White participants. ApoC3-containing HDL-C only showed a positive association with AVC in these subgroups.

CONCLUSIONS

In a multiethnic population, HDL-C, HDL-P, large HDL-P, and apoC3-lacking HDL-C were inversely associated with long-term incidence and progression of AVC. Further investigation of HDL composition and mechanisms could be useful in understanding pathways that slow AVC.

Lipoprotein Profile in Immunological Non-Responders PLHIV after Antiretroviral Therapy Initiation

Nuclear magnetic resonance (NMR)-based advanced lipoprotein tests have demonstrated that LDL and HDL particle numbers (LDL-P and HDL-P) are more powerful cardiovascular (CV) risk biomarkers than conventional cholesterol markers. Of interest, in people living with HIV (PLHIV), predictors of preclinical atherosclerosis and vascular dysfunction may be associated with impaired immune function. We previously stated that immunological non-responders (INR) were at higher CV risk than immunological responders (IR) before starting antiretroviral therapy (ART). Using Liposcale® tests, we characterized the lipoprotein profile from the same cohort of PLHIV at month 12 and month 36 after starting ART, intending to explore what happened with these indicators of CV risk during viral suppression. ART initiation dissipates the differences in lipoprotein-based CV risk markers between INR and IR, and only an increase in the number of HDL-P was found in INR + IR when compared to controls (p = 0.047). Interestingly, CD4+ T-cell counts negatively correlated with medium HDL-P concentrations at month 12 in all individuals (ρ = −0.335, p = 0.003). Longitudinal analyses showed an important increase in LDL-P and HDL-P at month 36 when compared to baseline values in both IR and INR. A proper balance between a proatherogenic and atherogenic environment may be related to the reconstitution of CD4+ T-cell count in PLHIV.

Effect of the ABCA1 agonist CS-6253 on amyloid-β and lipoprotein metabolism in cynomolgus monkeys

BACKGROUND

Inducing brain ATP-binding cassette 1 (ABCA1) activity in Alzheimer's disease (AD) mouse models is associated with improvement in AD pathology. The purpose of this study was to investigate the effects of the ABCA1 agonist peptide CS-6253 on amyloid-β peptides (Aβ) and lipoproteins in plasma and cerebrospinal fluid (CSF) of cynomolgus monkeys, a species with amyloid and lipoprotein metabolism similar to humans.

METHODS

CS-6253 peptide was injected intravenously into cynomolgus monkeys at various doses in three different studies. Plasma and CSF samples were collected at several time points before and after treatment. Levels of cholesterol, triglyceride (TG), lipoprotein particles, apolipoproteins, and Aβ were measured using ELISA, ion-mobility analysis, and asymmetric-flow field-flow fractionation (AF4). The relationship between the change in levels of these biomarkers was analyzed using multiple linear regression models and linear mixed-effects models.

RESULTS

Following CS-6253 intravenous injection, within minutes, small plasma high-density lipoprotein (HDL) particles were increased. In two independent experiments, plasma TG, apolipoprotein E (apoE), and Aβ42/40 ratio were transiently increased following CS-6253 intravenous injection. This change was associated with a non-significant decrease in CSF Aβ42. Both plasma total cholesterol and HDL-cholesterol levels were reduced following treatment. AF4 fractionation revealed that CS-6253 treatment displaced apoE from HDL to intermediate-density- and low density-lipoprotein (IDL/LDL)-sized particles in plasma. In contrast to plasma, CS-6253 had no effect on the assessed CSF apolipoproteins or lipids.

CONCLUSIONS

Treatment with the ABCA1 agonist CS-6253 appears to favor Aβ clearance from the brain.

Lipids and lipoproteins in cardiovascular diseases: a classification

Lipids and lipoproteins, their metabolism, and their transport are essential contributing factors of cardiovascular disease (CVD) as they regulate plasma cholesterol concentration, enhancing cholesterol uptake by macrophages, leading to foam cell formation and ultimately resulting in plaque formation and inflammation. However, lipids and lipoproteins have cardioprotective functions as well, such as preventing oxidation of proatherogenic molecules and downregulating inflammatory proteins.

The Role of High-Density Lipoprotein Cholesterol in 2022

PURPOSE OF THE REVIEW

High-density lipoproteins (HDL) are responsible for the transport in plasma of a large fraction of circulating lipids, in part from tissue mobilization. The evaluation of HDL-associated cholesterol (HDL-C) has provided a standard method for assessing cardiovascular (CV) risk, as supported by many contributions on the mechanism of this arterial benefit. The present review article will attempt to investigate novel findings on the role and mechanism of HDL in CV risk determination.

RECENT FINDINGS

The most recent research has been aimed to the understanding of how a raised functional capacity of HDL, rather than elevated levels per se, may be responsible for the postulated CV protection. Markedly elevated HDL-C levels appear instead to be associated to a raised coronary risk, indicative of a U-shaped relationship. While HDL-C reduction is definitely related to a raised CV risk, HDL-C elevations may be linked to non-vascular diseases, such as age-related macular disease. The description of anti-inflammatory, anti-oxidative and anti-infectious properties has indicated potential newer areas for diagnostic and therapeutic approaches. In the last two decades inconclusive data have arisen from clinical trials attempting to increase HDL-C pharmacologically or by way of recombinant protein infusions (most frequently with the mutant A-I Milano); prevention of stent occlusion or heart failure treatment have shown instead significant promise. Targeted clinical studies are still ongoing.

HDL particle subclasses in statin treated patients with peripheral artery disease predict long-term survival

Low-density lipoprotein-cholesterol (LDL-C) reduction showed a strong reduction of cardiovascular (CV) event rates in CV disease. However, the residual risk of future CV events remains high, which especially extends to peripheral arterial disease (PAD). Nuclear magnetic resonance (NMR)-spectroscopy offers a novel method for analyses of the lipoprotein spectrum. This study investigates lipoprotein subclasses using NMR-spectroscopy and assesses implications for long-term survival in PAD. NMR-spectroscopy was performed by Nightingale Inc. in 319 patients with stable PAD and well-controlled CV risk factors. Patients were followed-up for ten years. During that period 123 patients (38.5%) died, of those 68 (21.3%) were defined as CV-deaths. Outcome data were analyzed by the Kaplan-Meier method and multivariable Cox regression for lipoprotein particles. Small and medium high-density lipoprotein-particles (S-HDL-P and M-HDL-P) showed a significant inverse association with all-cause mortality in Cox-regression analyses after multivariable adjustment (S-HDL-P hazard ratio 0.71, 95% confidence interval 0.57-0.88; M-HDL-P 0.72, 0.58-0.90) for each increase of 1 standard deviation. In contrast, cholesterol-rich x-large HDL-particles (XL-HDL-P) showed a positive association with all-cause mortality (1.51, 1.20-1.89). Only the association between XL-HDL-P and CV-death sustained multivariable adjustment (1.49, 1.10-2.02), whereas associations for S-HDL-P and M-HDL-P were attenuated (0.76, 0.57-1.01; 0.80, 0.60-1.06). This study shows a novel association for a beneficial role of S-HDL-P and M-HDL-P but a negative association with higher cholesterol-rich XL-HDL-P for long-term outcome in well-treated patients with PAD. Thus, these results provide evidence that NMR-measured HDL particles identify patients at high CV residual risk beyond adequate lipid-lowering therapy.

Moderate alcohol consumption and lipoprotein subfractions: a systematic review of intervention and observational studies

CONTEXT

Moderate alcohol consumption is associated with decreased risk of cardiovascular disease (CVD) and improvement in cardiovascular risk markers, including lipoproteins and lipoprotein subfractions.

OBJECTIVE

To systematically review the relationship between moderate alcohol intake, lipoprotein subfractions, and related mechanisms.

DATA SOURCES

Following PRISMA, all human and ex vivo studies with an alcohol intake up to 60 g/d were included from 8 databases.

DATA EXTRACTION

A total of 17 478 studies were screened, and data were extracted from 37 intervention and 77 observational studies.

RESULTS

Alcohol intake was positively associated with all HDL subfractions. A few studies found lower levels of small LDLs, increased average LDL particle size, and nonlinear relationships to apolipoprotein B-containing lipoproteins. Cholesterol efflux capacity and paraoxonase activity were consistently increased. Several studies had unclear or high risk of bias, and heterogeneous laboratory methods restricted comparability between studies.

CONCLUSIONS

Up to 60 g/d alcohol can cause changes in lipoprotein subfractions and related mechanisms that could influence cardiovascular health.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. 98955.

Relationship between Apolipoprotein E Genotype and Lipoprotein Profile in Patients with Coronary Heart Disease

(1) Background: Apolipoprotein E(ApoE) plays a critical role in lipid transport. The specific allele of APOE being expressed is associated with the development of coronary heart disease (CHD), however the specific mechanisms by which ApoE drives disease are unclear. In this study, we investigated the relationship between APOE allele, lipoprotein metabolome, and CHD severity to provide evidence for the efficacy of clinical cholesterol-lowering therapy; (2) Methods: Blood samples were collected from 360 patients with CHD that were actively being treated with statins. The lipoprotein profile, including particle numbers, particle size, and lipoprotein composition concentrates, was measured by nuclear magnetic resonance (NMR) spectroscopy. The severity of CHD was determined by quantifying coronary angiography results using the Gensini scoring system; (3) Results: We found there was no significant difference in low-density lipoprotein cholesterol (LDL-C) levels among ε2+ (ε2 allele carriers, consisting of ε2/ε2 and ε2/ε3 genotypes), ε3 (consisting of ε3/ε3 and ε2/ε4 genotypes), and ε4+ (ε4 allele carriers, consisting of ε3/ε4 and ε4/ε4 genotypes) participants receiving statin treatment. Compared with the ε3 group, patients with the ε2+ genotype showed lower concentrations of total low-density lipoprotein (LDL), small-LDL, and middle-LDL particles, as well as a larger LDL size, higher very low-density lipoprotein (VLDL) composition concentrates, and higher intermediate density lipoprotein (IDL) composition concentrates. The ε4+ group showed higher concentrations of total LDL, small LDL particles, and LDL compositions with smaller LDL size. The higher level of small LDL concentration was associated with a high Gensini score (B = 0.058, p = 0.024). Compared with the ε3 group, the risk of increased branch lesions in the ε2+ group was lower (OR = 0.416, p = 0.027); (4) Conclusions: The specific allele of APOE being expressed can affect the severity of CHD by altering components of the lipoprotein profile, such as the concentration of small LDL and LDL size.

Associations of Endogenous Hormones With HDL Novel Metrics Across the Menopause Transition: The SWAN HDL Study

CONTEXT

Novel metrics of high-density lipoprotein (HDL) (subclasses, lipid content, and function) may improve characterization of the anti-atherogenic features of HDL. In midlife women, changes in these metrics vary by time relative to the final menstrual period (FMP), supporting a contribution of estradiol (E2) and follicle-stimulating hormone (FSH).

OBJECTIVE

We tested associations of endogenous E2 and FSH with novel HDL metrics and assessed whether these associations varied by time relative to FMP.

METHODS

This study was a longitudinal analysis from the Study of Women's Health Across the Nation (SWAN) HDL study, using a community-based cohort of 463 women, baseline mean age 50.2 (2.7) years. The main outcome measures were HDL cholesterol efflux capacity (HDL-CEC), HDL phospholipids (HDL-PL), HDL triglycerides (HDL-Tg), HDL particles (HDL-P), HDL size, and HDL cholesterol (HDL-C).

RESULTS

In multivariable analyses, E2 was positively associated with HDL size, large HDL-P, HDL-CEC, and HDL-Tg, but negatively with medium HDL-P (P values < 0.05). The positive association between E2 and HDL-Tg was stronger 2 years post-FMP than before, (interaction P = 0.031). FSH was positively related to total and medium HDL-P, but negatively to HDL size, large HDL-P, and HDL-CEC per particle (P values < 0.05). Associations of higher FSH with greater total HDL-P and smaller HDL size were only evident at/after menopause (interaction P values < 0.05).

CONCLUSION

Some of the associations linking E2 and FSH with novel HDL metrics were vulnerable to time relative to menopause onset. Whether a late initiation of hormone therapy relative to menopause could have a detrimental effect on lipid content of HDL particles should be tested in the future.

Association of Carotid Intima Media Thickness With Metabolic Syndrome Among Low-Income Middle-Aged and Elderly Chinese: A Population-Based Cross-Sectional Study

Background: We aimed to evaluate the relationship between metabolic syndrome (MetS) including its components and carotid intima media thickness (CIMT) in a low-income Chinese population aged ≥45 years.

Methods: The participants underwent a general health screening and B-mode carotid ultrasonography that measured CIMT. The diagnosis of MetS and its components was based on the modified International Diabetes Federation Criteria for the Asian Population. The univariate and multivariable linear regression analyses were used to evaluate the relationship between MetS and CIMT.

Results: A total of 3,583 participants (mean age, 60 years) was included in the analyses (41.4% male and 58.6% female); more than 50% of the participants were diagnosed with MetS. In the multivariable linear regression analysis, the mean CIMT was 0.009 mm greater in the participants with MetS than in those without MetS (β = 0.009; 95% CI, 0.003–0.014; P < 0.05). Moreover, a high number of MetS components was associated with greater CIMT values; for example, CIMT increased by 0.007 and 0.015 mm for the individuals diagnosed with 3–4 and 5 MetS components, respectively. Among the MetS components, elevated blood pressure (β = 0.022; 95% CI, 0.015–0.029; P < 0.001) and abdominal obesity (β = 0.008; 95% CI, 0.001–0.015; P < 0.001) were positively correlated with CIMT. However, the increased triglyceride levels were negatively associated with CIMT (β = −0.008; 95% CI: −0.015 to −0.002; P = 0.012), especially among the elderly population.

Conclusions: The risk of carotid atherosclerosis increased in the presence of multiple MetS components in a low-income, middle-aged, and elderly population. Accordingly, more detailed management strategies are essential for the early prevention and intervention of atherosclerosis in this low-income population with MetS, in China.

Meta-analysis of epigenome-wide association studies of carotid intima-media thickness

Common carotid intima-media thickness (cIMT) is an index of subclinical atherosclerosis that is associated with ischemic stroke and coronary artery disease (CAD). We undertook a cross-sectional epigenome-wide association study (EWAS) of measures of cIMT in 6400 individuals. Mendelian randomization analysis was applied to investigate the potential causal role of DNA methylation in the link between atherosclerotic cardiovascular risk factors and cIMT or clinical cardiovascular disease. The CpG site cg05575921 was associated with cIMT (beta = -0.0264, p value = 3.5 × 10^-8) in the discovery panel and was replicated in replication panel (beta = -0.07, p value = 0.005). This CpG is located at chr5:81649347 in the intron 3 of the aryl hydrocarbon receptor repressor gene (AHRR). Our results indicate that DNA methylation at cg05575921 might be in the pathway between smoking, cIMT and stroke. Moreover, in a region-based analysis, 34 differentially methylated regions (DMRs) were identified of which a DMR upstream of ALOX12 showed the strongest association with cIMT (p value = 1.4 × 10^-13). In conclusion, our study suggests that DNA methylation may play a role in the link between cardiovascular risk factors, cIMT and clinical cardiovascular disease.

Altered HDL Proteome Predicts Incident CVD in Chronic Kidney Disease Patients

Patients with chronic kidney disease (CKD) are at high risk for CVD. However, traditional lipid risk factors, including low HDL levels, cannot completely explain the increased risk. Altered HDL proteome is linked with both CVD and CKD, but the role of HDL proteins in incident CVD events in patients with CKD is unknown. In this prospective case-control study, we used targeted proteomics to quantify 31 HDL proteins in 92 subjects (46 incident new CVD and 46 one-to-one matched controls) at various stages of CKD. We tested associations of HDL proteins with incident CVD using matched logistic regression analysis. In the model fully adjusted for clinical confounders, lipid levels, C-reactive protein, and proteinuria, no significant associations were found for HDL-C, but we observed inverse associations between levels of HDL proteins paraoxonase/arylesterase 1 (PON1), paraoxonase/arylesterase 3 (PON3), and LCAT and incident CVD. Odds ratios (per 1 SD) were 0.38 (0.18–0.97, P = 0.042), 0.42 (0.20–0.92, P = 0.031), and 0.30 (0.11–0.83, P = 0.020) for PON1, PON3, and LCAT, respectively. Apolipoprotein A-IV remained associated with incident CVD in CKD patients in models adjusted for clinical confounders and lipid levels but lost significance with the addition of C-reactive protein and proteinuria to the model. In conclusion, levels of four HDL proteins, PON1, PON3, LCAT, and apolipoprotein A-IV, were found to be inversely associated with incident CVD events in CKD patients. Our observations indicate that HDLs' protein cargo, but not HDL-C levels, can serve as a marker—and perhaps mediator—for elevated CVD risk in CKD patients.

Clinical lipidomics: realizing the potential of lipid profiling

Dysregulation of lipid metabolism plays a major role in the etiology and sequelae of inflammatory disorders, cardiometabolic and neurological diseases, and several forms of cancer. Recent advances in lipidomic methodology allow comprehensive lipidomic profiling of clinically relevant biological samples, enabling researchers to associate lipid species and metabolic pathways with disease onset and progression. The resulting data serve not only to advance our fundamental knowledge of the underlying disease process but also to develop risk assessment models to assist in the diagnosis and management of disease. Currently, clinical applications of in-depth lipidomic profiling are largely limited to the use of research-based protocols in the analysis of population or clinical sample sets. However, we foresee the development of purpose-built clinical platforms designed for continuous operation and clinical integration-assisting health care providers with disease risk assessment, diagnosis, and monitoring. Herein, we review the current state of clinical lipidomics, including the use of research-based techniques and platforms in the analysis of clinical samples as well as assays already available to clinicians. With a primary focus on MS-based strategies, we examine instrumentation, analysis techniques, statistical models, prospective design of clinical platforms, and the possible pathways toward implementation of clinical lipidomics.

High Density Lipoproteins: Is There a Comeback as a Therapeutic Target?

Low plasma levels of High Density Lipoprotein (HDL) cholesterol (HDL-C) are associated with increased risks of atherosclerotic cardiovascular disease (ASCVD). In cell culture and animal models, HDL particles exert multiple potentially anti-atherogenic effects. However, drugs increasing HDL-C have failed to prevent cardiovascular endpoints. Mendelian Randomization studies neither found any genetic causality for the associations of HDL-C levels with differences in cardiovascular risk. Therefore, the causal role and, hence, utility as a therapeutic target of HDL has been questioned. However, the biomarker "HDL-C" as well as the interpretation of previous data has several important limitations: First, the inverse relationship of HDL-C with risk of ASCVD is neither linear nor continuous. Hence, neither the-higher-the-better strategies of previous drug developments nor previous linear cause-effect relationships assuming Mendelian randomization approaches appear appropriate. Second, most of the drugs previously tested do not target HDL metabolism specifically so that the futile trials question the clinical utility of the investigated drugs rather than the causal role of HDL in ASCVD. Third, the cholesterol of HDL measured as HDL-C neither exerts nor reports any HDL function. Comprehensive knowledge of structure-function-disease relationships of HDL particles and associated molecules will be a pre-requisite, to test them for their physiological and pathogenic relevance and exploit them for the diagnostic and therapeutic management of individuals at HDL-associated risk of ASCVD but also other diseases, for example diabetes, chronic kidney disease, infections, autoimmune and neurodegenerative diseases.

Is a High HDL-Cholesterol Level Always Beneficial?

The specific interest concerning HDL cholesterol (HDL-C) is related to its ability to uptake and return surplus cholesterol from peripheral tissues back to the liver and, therefore, to its role in the prevention of cardiovascular diseases, such as atherosclerosis and myocardial infarction, but also transient ischemic attack and stroke. Previous epidemiological studies have indicated that HDL-C concentration is inversely associated with the risk of cardiovascular disease and that it can be used for risk prediction. Some genetic disorders are characterized by markedly elevated levels of HDL-C; however, they do not translate into diminished cardiovascular risk. The search of the potential causative relationship between HDL-C and adverse events has shifted the attention of researchers towards the composition and function of the HDL molecule/subfractions. HDL possesses various cardioprotective properties. However, currently, it appears that higher HDL-C is not necessarily protective against cardiovascular disease, but it can even be harmful in extremely high quantities.

Biomarker Discovery in Atherosclerotic Diseases Using Quantitative Nuclear Magnetic Resonance Metabolomics

Despite great progress in the management of atherosclerosis (AS), its subsequent cardiovascular disease (CVD) remains the leading cause of morbidity and mortality. This is probably due to insufficient risk detection using routine lipid testing; thus, there is a need for more effective approaches relying on new biomarkers. Quantitative nuclear magnetic resonance (qNMR) metabolomics is able to phenotype holistic metabolic changes, with a unique advantage in regard to quantifying lipid-protein complexes. The rapidly increasing literature has indicated that qNMR-based lipoprotein particle number, particle size, lipid components, and some molecular metabolites can provide deeper insight into atherogenic diseases and could serve as novel promising determinants. Therefore, this article aims to offer an updated review of the qNMR biomarkers of AS and CVD found in epidemiological studies, with a special emphasis on lipoprotein-related parameters. As more researches are performed, we can envision more qNMR metabolite biomarkers being successfully translated into daily clinical practice to enhance the prevention, detection and intervention of atherosclerotic diseases.

HDL in Atherosclerotic Cardiovascular Disease: In Search of a Role

For a long time, high-density lipoprotein cholesterol (HDL-C) has been regarded as a cardiovascular disease (CVD) protective factor. Recently, several epidemiological studies, while confirming low plasma levels of HDL-C as an established predictive biomarker for atherosclerotic CVD, indicated that not only people at the lowest levels but also those with high HDL-C levels are at increased risk of cardiovascular (CV) mortality. This “U-shaped” association has further fueled the discussion on the pathophysiological role of HDL in CVD. In fact, genetic studies, Mendelian randomization approaches, and clinical trials have challenged the notion of HDL-C levels being causally linked to CVD protection, independent of the cholesterol content in low-density lipoproteins (LDL-C). These findings have prompted a reconsideration of the biological functions of HDL that can be summarized with the word “HDL functionality”, a term that embraces the many reported biological activities beyond the so-called reverse cholesterol transport, to explain this lack of correlation between HDL levels and CVD. All these aspects are summarized and critically discussed in this review, in an attempt to provide a background scenario for the “HDL story”, a lipoprotein still in search of a role.

Environmental Factors Modifying HDL Functionality

BACKGROUND

Currently, it has been recognized that High-Density Lipoproteins (HDL) functionality plays a much more essential role in protection from atherosclerosis than circulating HDL-cholesterol (HDL-C) levels per se. Cholesterol efflux from macrophages to HDL, cholesterol efflux capacity (CEC) has been shown to be a key metric of HDL functionality. Thus, quantitative assessment of CEC may be an important tool for the evaluation of HDL functionality, as improvement of HDL function may lead to a reduction of the risk for Cardiovascular disease (CVD).

INTRODUCTION

Although the cardioprotective action of HDLs is exerted mainly through their involvement in the reverse cholesterol transport (RCT) pathway, HDLs also have important anti-inflammatory, antioxidant, antiaggregatory and anticoagulant properties that contribute to their favorable cardiovascular effects. Certain genetic, pathophysiologic, disease states and environmental conditions may influence the cardioprotective effects of HDL either by inducing modifications in lipidome and/or protein composition or in the enzymes responsible for HDL metabolism. On the other hand, certain healthy habits or pharmacologic interventions may actually favorably affect HDL functionality.

METHOD

The present review discusses the effects of environmental factors, including obesity, smoking, alcohol consumption, dietary habits, various pharmacologic interventions, as well as aerobic exercise, on HDL functionality.

RESULT

Experimental and clinical studies or pharmacological interventions support the impact of these environmental factors in the modification of HDL functionality, although the mechanisms that are mediated are poorly understood.

CONCLUSION

Further research should be conducted to unreal the underlying mechanisms of these environmental factors and to identify new pharmacologic interventions, capable of enhancing CEC, improving HDL functionality and potentially improving cardiovascular risk.

Familial Hypercholesterolemia: Do HDL Play a Role?

Cardiovascular disease (CVD) in heterozygous familial hypercholesterolemia (HeFH), the most frequent monogenic disorder of human metabolism, is largely driven by low-density lipoprotein (LDL) cholesterol concentrations. Since the CVD rate differs considerably in this population, beyond the lifetime LDL cholesterol vascular accumulation, other classical risk factors are involved in the high cardiovascular risk of HeFH. Among other lipoprotein disturbances, alterations in the phenotype and functionality of high-density lipoproteins (HDL) have been described in HeFH patients, contributing to the presence and severity of CVD. In fact, HDL are the first defensive barrier against the burden of high LDL cholesterol levels owing to their contribution to reverse cholesterol transport as well as their antioxidant and anti-inflammatory properties, among others. In this context, the present narrative review aimed to focus on quantitative and qualitative abnormalities in HDL particles in HeFH, encompassing metabolic, genetic and epigenetic aspects.