Associations Between High-Density Lipoprotein Particles and Ischemic Events by Vascular Domain, Sex, and Ethnicity: A Pooled Cohort Analysis

Dyslipidemias in multiple sclerosis

PURPOSE

To investigate the frequency of dyslipidemia phenotypes in multiple sclerosis and to assess the associations with lipoprotein particle size distributions.

METHODS

This cross-sectional study included 203 healthy controls (HC), 221 relapsing-remitting MS (RRMS), and 126 progressive MS (PMS). A lipid profile with total cholesterol, high-density lipoprotein cholesterol (HDL-C), triglycerides, and apolipoprotein B levels were measured. Low density lipoprotein cholesterol (LDL-C), very low-density lipoprotein cholesterol, large buoyant LDL-C and small dense LDL-C were calculated using the Sampson-NIH equations method. Dyslipidemia phenotypes were categorized by their nonHDL-C and triglyceride values. The diameters and concentrations of triglyceride-rich lipoprotein particles (TRLP), LDL particles (LDLP), and HDL particles (HDLP) were measured with proton NMR lipoprotein profiling. Serum proprotein convertase subtilisin/kexin type 9 (PCSK9) levels were obtained using immunoassay.

RESULTS

The frequencies of normolipidemia, and various dyslipidemia phenotypes were similar in HC, RRMS, and PMS. The size of the TRLP, very large TRLP, large TRLP, and small LDLP concentrations had a decreasing pattern of HC>RR>PMS. The lowest tertile of EDSS was associated with higher concentrations of HDLP and small HDLP in PMS. PCSK9 was associated with concentration of HDL particles, primarily via its effects on the concentration of small HDL particles.

CONCLUSIONS

There were no differences in the frequency of dyslipidemias in MS compared to healthy controls. Higher HDLP concentrations are associated with lower disability in PMS.

Differences in HDL-related coronary heart disease risk between individuals with and without diabetes

BACKGROUND AND AIMS

High-density lipoprotein (HDL) might lose atheroprotective functions in the presence of diabetes. We sought to examine associations of HDL cholesterol (HDL-C) and HDL particle (HDL-P) subclasses with risk of coronary heart disease (CHD) stratified by diabetes.

METHODS

We included 393,516 participants (20,691 diabetics and 372,825 nondiabetics) from the UK Biobank. Restricted cubic splines cooperated with Cox model were used to estimate associations of HDL with CHD.

RESULTS

During a median follow-up of 13.0 years, 3398 (16.4 %) and 24,772 (6.6 %) incident CHD events occurred among diabetics and nondiabetics, respectively. HDL-C showed inverse associations with CHD among nondiabetics, whereas U-shaped associations among diabetics. Compared to individuals with normal HDL-C (40th - 60th percentile, 1.32-1.51 mmol/L), those in the top percentile (95th, >2.16 mmol/L) had lower CHD risks among nondiabetics (Hazard Ratio, 0.79; 95 % confidence interval, 0.73-0.86), but higher risks among diabetics (1.38, 1.02-1.88). As for HDL-P, there were inverted U-shaped associations of very large HDL-P and linearly negative associations of large HDL-P with CHD among nondiabetics; however, linearly positive associations of very large HDL-P and null associations of large HDL were observed among diabetics. L-shaped associations of medium and small HDL-P were found both in diabetics and nondiabetics.

CONCLUSIONS

Very high HDL-C levels were associated with lower CHD risks in nondiabetics, but higher risks in diabetics. Smaller HDL-P was negatively, whereas very large HDL-P was positively associated with CHD risk in diabetics. These data advance our knowledge about the interactions between HDL and diabetes.

Quantification of high-density lipoprotein particle number by proton nuclear magnetic resonance: don't believe the numbers

PURPOSE OF REVIEW

Proton nuclear magnetic resonance (NMR) can rapidly assess lipoprotein concentrations and sizes in biological samples. It may be especially useful for quantifying high-density lipoprotein (HDL), which exhibits diverse particle sizes and concentrations. We provide a critical review of the strengths and limitations of NMR for quantifying HDL subclasses.

RECENT FINDINGS

Recent studies using NMR have shed light on HDL's role in various disorders, ranging from residual cardiovascular risk to host susceptibility to infection. However, accurately quantifying HDL particle number, size, and concentration (HDL-P) remains a challenge. Discrepancies exist between NMR and other methods such as gel electrophoresis, ion mobility analysis and size-exclusion chromatography in estimating the abundance of HDL species and the ratio of apolipoprotein A-I (APOA1) to HDL particles.

SUMMARY

NMR is a low-cost method for quantifying HDL-P that is readily applicable to clinical and translational studies. However, inconsistencies between the results of NMR quantification of HDL-P and other independent methods hinder the interpretation of NMR results. Because proton NMR apparently fails to accurately quantify the sizes and concentrations of HDL, the relevance of such studies to HDL biology poses challenges. This limits our understanding of pathophysiological implications of HDL-P as determined by NMR, particularly in determining cardiovascular disease (CVD) risk.

Nuclear-Magnetic-Resonance-Spectroscopy-Derived Serum Biomarkers of Metabolic Vulnerability Are Associated with Disability and Neurodegeneration in Multiple Sclerosis

PURPOSE

Metabolic vulnerabilities can exacerbate inflammatory injury and inhibit repair in multiple sclerosis (MS). The purpose was to evaluate whether blood biomarkers of inflammatory and metabolic vulnerability are associated with MS disability and neurodegeneration.

METHODS

Proton nuclear magnetic resonance spectra were obtained from serum samples from 153 healthy controls, 187 relapsing-remitting, and 91 progressive MS patients. The spectra were analyzed to obtain concentrations of lipoprotein sub-classes, glycated acute-phase proteins, and small-molecule metabolites, including leucine, valine, isoleucine, alanine, and citrate. Composite indices for inflammatory vulnerability, metabolic malnutrition, and metabolic vulnerability were computed. MS disability was measured on the Expanded Disability Status Scale. MRI measures of lesions and whole-brain and tissue-specific volumes were acquired.

RESULTS

Valine, leucine, isoleucine, alanine, the Inflammatory Vulnerability Index, the Metabolic Malnutrition Index, and the Metabolic Vulnerability Index differed between healthy control and MS groups in regression analyses adjusted for age, sex, and body mass index. The Expanded Disability Status Scale was associated with small HDL particle levels, inflammatory vulnerability, and metabolic vulnerability. Timed ambulation was associated with inflammatory vulnerability and metabolic vulnerability. Greater metabolic vulnerability and inflammatory vulnerability were associated with lower gray matter, deep gray matter volumes, and greater lateral ventricle volume.

CONCLUSIONS

Serum-biomarker-derived indices of inflammatory and metabolic vulnerability are associated with disability and neurodegeneration in MS.

New perspectives on the high-density lipoprotein system and its role in the prevention and treatment of atherosclerotic cardiovascular disease

PURPOSE OF REVIEW

The causal role of high-density lipoprotein (HDL) in atherosclerotic cardiovascular disease (CVD) remains debated. Considering recent evidence, the purpose of this review is to a provide a focused update and new perspectives on HDL and CVD.

RECENT FINDINGS

A Mendelian randomization study demonstrated an increased risk of CVD when HDL-cholesterol was predominantly transported in larger HDL particles and a decreased risk of CVD when HDL-cholesterol was predominantly transported in smaller HDL particles. Moreover, another Mendelian randomization study demonstrated that concentration and content of medium HDL particles is associated with CVD. A Mendelian randomization study that utilized stratified analyses demonstrated that individuals with HDL-cholesterol 50 mg/dl or less were at increased risk of CVD. Lastly, the AEGIS-II trial demonstrated that CSL112, a human apolipoprotein A-I that increases cholesterol efflux, did not significantly reduce cardiovascular events in patients at very high risk. Exploratory analyses showed that patients treated with CSL112 had numerically lower rates of cardiovascular events.

SUMMARY

Qualitative markers of HDL may be causally related to CVD. There is a need for ongoing research into HDL therapeutics that promote the biological properties of HDL. The optimal cohort or disease state that will benefit from these therapies needs to be identified.

Association of High-Density Lipoprotein Parameters and Risk of Heart Failure: A Multicohort Analysis

BACKGROUND

High-density lipoprotein (HDL) is commonly characterized by its cholesterol concentration (HDL-C) and inverse association with atherosclerotic cardiovascular disease.

OBJECTIVES

The authors sought to evaluate the association of HDL particle concentration (HDL-P), HDL particle size (HDL-size), HDL-C, and cholesterol content per particle (HDL-C/HDL-P) with risk of overall heart failure (HF) and subtypes.

METHODS

Participants from the Atherosclerosis Risk In Communities Study, Dallas Heart Study, Multi-Ethnic Study of Atherosclerosis, and Prevention of Renal and Vascular End-stage Disease studies without HF history were included. Associations of HDL-P, HDL-size, HDL-C, and HDL-C/HDL-P with risk of overall HF, HF with reduced and preserved ejection fraction were assessed using adjusted Cox models.

RESULTS

Among 16,925 participants (53.5% women; 21.8% Black), there were 612 incident HF events (3.6%) (HF with reduced ejection fraction, 309 [50.5%]; HF preserved ejection fraction, 303 [49.5%]) over median follow-up of 11.4 years. In adjusted models, higher HDL-P was significantly associated with lower HF risk (HR of highest vs lowest tertile of HDL-P: 0.76 [95% CI: 0.62-0.93]). Larger HDL-size was significantly associated with higher overall HF risk (HR of largest vs smallest tertile of HDL-size: 1.27 [95% CI: 1.03-1.58]). HF risk associated with HDL-P and HDL-size was similar for HF subtypes. In adjusted analyses, there was no significant association between HDL-C and HF risk. Higher HDL-C/HDL-P was significantly associated with higher overall HF risk (HR of highest vs lowest tertile of HDL-C/HDL-P: 1.29 [95% CI: 1.04-1.60]).

CONCLUSIONS

Higher HDL-P was associated with a lower risk of HF. In contrast, larger HDL-size was associated with higher risk of HF and there was no significant association observed between HDL-C and HF risk after accounting for cardiovascular risk factors.

The high-density lipoprotein cholesterol (HDL-C)-concentration-dependent association between anti-inflammatory capacity and sepsis: A single-center cross-sectional study

INTRODUCTION

Known to have pleiotropic functions, high-density lipoprotein (HDL) helps to regulate systemic inflammation during sepsis. As preserving HDL-C level is a promising therapeutic strategy for sepsis, the interaction between HDL and sepsis worth further investigation. This study aimed to determine the impact of sepsis on HDL's anti-inflammatory capacity and explore its correlations with disease severity and laboratory parameters.

METHODS AND MATERIALS

We enrolled 80 septic subjects admitted to the intensive care unit and 50 controls admitted for scheduled coronary angiography in this cross-sectional study. We used apolipoprotein-B depleted (apoB-depleted) plasma to measure the anti-inflammatory capacity of HDL-C. ApoB-depleted plasma's anti-inflammatory capacity is defined as its ability to suppress tumor necrosis factor-α-induced vascular cell adhesion molecule-1 (VCAM-1) expression in human umbilical-vein endothelial cells. A subgroup analysis was conducted to investigate in septic subjects according to disease severity.

RESULTS

ApoB-depleted plasma's anti-inflammatory capacity was reduced in septic subjects relative to controls (VCAM-1 mRNA fold change: 50.1% vs. 35.5%; p < 0.0001). The impairment was more pronounced in septic subjects with than in those without septic shock (55.8% vs. 45.3%, p = 0.0022). Both associations were rendered non-significant with the adjustment for the HDL-C level. In sepsis patients, VCAM-1 mRNA fold change correlated with the SOFA score (Spearman's r = 0.231, p = 0.039), lactate level (r = 0.297, p = 0.0074), HDL-C level (r = -0.370, p = 0.0007), and inflammatory markers (C-reactive protein level: r = 0.441, p <0.0001; white blood cell: r = 0.353, p = 0.0013).

CONCLUSION

ApoB-depleted plasma's anti-inflammatory capacity is reduced in sepsis patients and this association depends of HDL-C concentration. In sepsis patients, this capacity correlates with disease severity and inflammatory markers. These findings explain the prognostic role of the HDL-C level in sepsis and indirectly support the rationale for targeting HDL-C as sepsis treatment.

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.

A higher non-HDL-C/HDL-C ratio was associated with an increased risk of progression of nonculprit coronary lesion in patients with acute coronary syndrome undergoing percutaneous coronary intervention

BACKGROUND

The ratio of nonhigh-density lipoprotein cholesterol (non-HDL-C) to high-density lipoprotein cholesterol (HDL-C) has been shown associated with various metabolic diseases and atherosclerosis in primary prevention. However, there is limited evidence on the relationship between the non-HDL-C/HDL-C ratio and progression of nonculprit coronary lesion (NCCL) after percutaneous coronary intervention (PCI).

HYPOTHESIS

Our study aimed to investigate the potential association between the non-HDL-C/HDL-C ratio and NCCL progression in patients with acute coronary syndrome (ACS) undergoing PCI.

METHODS

We conducted a retrospective analysis of ACS patients who underwent coronary angiography twice at a single center from 2016 to 2022. Lipid measurements, demographic, clinical, and other laboratory data were collected from electronic medical records. NCCLs were evaluated using quantitative coronary angiography. The primary outcome was the progression of NCCL. Patients were categorized based on NCCL progression and tertiles of the non-HDL-C/HDL-C ratio. Associations were analyzed using univariate and multivariate logistic regression analysis.

RESULTS

The study included 329 ACS patients who underwent PCI, with a median follow-up angiography of 1.09 years. We found NCCL progression in 95 (28.9%) patients with acceptable low-density lipoprotein cholesterol control (median: 1.81 mmol/L). Patients in the top tertile of the non-HDL-C/HDL-C ratio had a higher risk of NCCL progression. After adjusting for potential confounding factors, the non-HDL-C/HDL-C ratio remained a significant predictor for NCCL progression (adjusted odds ratio: 1.45; 95% confidence interval: 1.14-1.86; p < 0.05).

CONCLUSIONS

The non-HDL-C/HDL-C ratio predicts NCCL progression in ACS patients following PCI, providing a valuable tool for risk assessment and enhancing secondary prevention of atherosclerotic cardiovascular disease.

High-density lipoprotein functionality, cardiovascular health, and patterns of alcohol consumption: new insights and future perspectives

PURPOSE OF REVIEW

Cardiovascular diseases (CVD) pose a significant public health challenge, contributing to 422 million disability-adjusted life years in 2021. The role of high-density lipoproteins (HDL) and alcohol consumption, one of their major modifiable determinants, remains controversial. The objective of this review is to provide a comprehensive narrative overview of HDL functionality and its predictive value for CVD in relation to patterns of alcohol consumption.

RECENT FINDINGS

HDL phenotypes beyond HDL-cholesterol (HDL-c) such as distribution of HDL subspecies, HDL particle abundance, and reverse cholesterol transport capacity are promising indicators of atherosclerotic CVD risk. Low-to-moderate alcohol consumption seems to improve HDL functionality and reduce the incidence of CVD among primarily middle-aged men and postmenopausal women. Advancements in our understanding of HDL biogenesis, structure, and function hold promise for improving HDL-related measures and their predictive value for cardiovascular health.

SUMMARY

Low-to-moderate alcohol consumption appears to not only increase HDL-c concentration found in the HDL fraction of plasma but also enhance HDL functionality, providing insights into the underlying mechanisms linking alcohol exposure and cardiovascular health benefits. However, rigorous, well designed intervention trials of alcohol consumption on hard cardiovascular outcomes are needed to identify robust causal associations of HDL phenotypes and alcohol consumption with cardiovascular risk.

High-Density Lipoprotein Particles and Torque Teno Virus in Stable Outpatient Kidney Transplant Recipients

Torque teno virus (TTV) is emerging as a potential marker for monitoring immune status. In transplant recipients who are immunosuppressed, higher TTV DNA loads are observed than in healthy individuals. TTV load measurement may aid in optimizing immunosuppressive medication dosing in solid organ transplant recipients. Additionally, there is a growing interest in the role of HDL particles in immune function; therefore, assessment of both HDL concentrations and TTV load may be of interest in transplant recipients. The objective of this study was to analyze TTV loads and HDL parameters in serum samples collected at least one year post-transplantation from 656 stable outpatient kidney transplant recipients (KTRs), enrolled in the TransplantLines Food and Nutrition Cohort (Groningen, the Netherlands). Plasma HDL particles and subfractions were measured using nuclear magnetic resonance spectroscopy. Serum TTV load was measured using a quantitative real-time polymerase chain reaction. Associations between HDL parameters and TTV load were examined using univariable and multivariable linear regression. The median age was 54.6 [IQR: 44.6 to 63.1] years, 43.3% were female, the mean eGFR was 52.5 (±20.6) mL/min/1.73 m2 and the median allograft vintage was 5.4 [IQR: 2.0 to 12.0] years. A total of 539 participants (82.2%) had a detectable TTV load with a mean TTV load of 3.04 (±1.53) log10 copies/mL, the mean total HDL particle concentration was 19.7 (±3.4) μmol/L, and the mean HDL size was 9.1 (±0.5) nm. The univariable linear regression revealed a negative association between total HDL particle concentration and TTV load (st.β = -0.17, 95% CI st.β: -0.26 to -0.09, p < 0.001). An effect modification of smoking behavior influencing the association between HDL particle concentration and TTV load was observed (Pinteraction = 0.024). After adjustment for age, sex, alcohol intake, hemoglobin, eGFR, donor age, allograft vintage and the use of calcineurin inhibitors, the negative association between HDL particle concentration and TTV load remained statistically significant in the non-smoking population (st.β = -0.14, 95% CI st.β: -0.23 to -0.04, p = 0.006). Furthermore, an association between small HDL particle concentration and TTV load was found (st.β = -0.12, 95% CI st.β: -0.22 to -0.02, p = 0.017). Higher HDL particle concentrations were associated with a lower TTV load in kidney transplant recipients, potentially indicative of a higher immune function. Interventional studies are needed to provide causal evidence on the effects of HDL on the immune system.

Triglyceride/HDL cholesterol ratio and lipoprotein insulin resistance Score: Associations with subclinical atherosclerosis and incident cardiovascular disease

BACKGROUND

The triglyceride/HDL cholesterol (TG/HDL-C) ratio and the Lipoprotein Insulin Resistance (LP-IR) score are lipid markers of insulin resistance. Their associations with carotid intima media thickness (cIMT; subclinical atherosclerosis) and incident cardiovascular disease (CVD) have not been thoroughly investigated.

METHODS

In a cross-sectional cohort (89 subjects without type 2 diabetes (T2D) and 81 subjects with T2D we determined cIMT (ultrasound), homeostasis model assessment of insulin resistance (HOMA-IR) and the TG/HDL-C ratio. The LP-IR score, based on 6 lipoprotein characteristics determined by nuclear magnetic resonance spectroscopy, was measured in 123 participants. A prospective study was carried out among 6232 participants (Prevention of REnal and Vascular ENd-stage Disease study).

RESULTS

Cross-sectionally, the adjusted associations of HOMA-IR, the TG/HDL-C ratio and the LP-IR score with cIMT were approximately similar (standardized β = 0.34 (95 % CI 0.19-0.48), 0.24 (95 % CI 0.09-039) and 0.41 (95 % CI 0.23--0.59), respectively). Prospectively, 507 new cases of CVD were observed after a median follow-up of 8.2 (interquartile range 7.5-8.8) years. HOMA-IR, the TG/HDL-C ratio and LP-IR were each associated with incident CVD independent of potential confounders (HR 1.12, 95 % CI 1.02-1.24;1.22, 95 % CI 1.11-1.35 and 1.15. 95 % CI 1.01-1.31, respectively). The association of the TG/HDL-C ratio with incident CVD was somewhat stronger than that of HOMA-IR.

CONCLUSION

Lipoprotein-based markers of insulin resistance are at least as strongly associated with subclinical atherosclerosis and clinical atherosclerosis development as HOMA-IR, obviating the need to measure insulin to determine the impact of insulin resistance. For practical purposes, the easily obtainable TG/HDL-C ratio may suffice.

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.

The lipidomic correlates of epigenetic aging across the adult lifespan: A population-based study

Lipid signaling is involved in longevity regulation, but which specific lipid molecular species affect human biological aging remains largely unknown. We investigated the relation between complex lipids and DNA methylation-based metrics of biological aging among 4181 participants (mean age 55.1 years (range 30.0-95.0)) from the Rhineland Study, an ongoing population-based cohort study in Bonn, Germany. The absolute concentration of 14 lipid classes, covering 964 molecular species and 267 fatty acid composites, was measured by Metabolon Complex Lipid Panel. DNA methylation-based metrics of biological aging (AgeAccelPheno and AgeAccelGrim) were calculated based on published algorithms. Epigenome-wide association analyses (EWAS) of biological aging-associated lipids and pathway analysis were performed to gain biological insights into the mechanisms underlying the effects of lipidomics on biological aging. We found that higher levels of molecular species belonging to neutral lipids, phosphatidylethanolamines, phosphatidylinositols, and dihydroceramides were associated with faster biological aging, whereas higher levels of lysophosphatidylcholine, hexosylceramide, and lactosylceramide species were associated with slower biological aging. Ceramide, phosphatidylcholine, and lysophosphatidylethanolamine species with odd-numbered fatty acid tail lengths were associated with slower biological aging, whereas those with even-numbered chain lengths were associated with faster biological aging. EWAS combined with functional pathway analysis revealed several complex lipids associated with biological aging as important regulators of known longevity and aging-related pathways.

Associations of healthful and unhealthful plant-based diets with plasma markers of cardiometabolic risk

PURPOSE

Plant-based diets, particularly when rich in healthy plant foods, have been associated with a lower risk of type 2 diabetes and cardiovascular disease. However, the impact of plant-based diets that distinguish between healthy and unhealthy plant foods on cardiometabolic biomarkers remains unclear.

METHODS

Dietary information was collected by two 24-h recalls among 34,785 adults from a nationwide cross-sectional study. Plasma levels of insulin, C-peptide, glucose, C-reactive protein (CRP), white blood cell (WBC) count, triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) were measured. Linear regression was used to evaluate the percentage difference in plasma marker concentrations by three plant-based diet indices, namely the overall plant-based diet index (PDI), the healthful PDI (hPDI), and the unhealthful PDI (uPDI).

RESULTS

Greater hPDI-adherence scores (comparing extreme quartiles) were associated with lower levels of insulin, Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), TG/HDL-C ratio, CRP, WBC count, and TG, and higher levels of HDL-C, with the percentage differences of  - 14.55,  - 15.72,  - 11.57,  - 14.95,  - 5.26,  - 7.10, and 5.01, respectively (all Ptrend ≤ 0.001). Conversely, uPDI was associated with higher levels of insulin, C-peptide, HOMA-IR, TG/HDL-C ratio, CRP, WBC count, and TG, but lower HDL-C, with the percentage differences of 13.71, 14.00, 14.10, 10.43, 3.32, 8.00, and  - 4.98 (all Ptrend ≤ 0.001), respectively. Overall PDI was only associated with lower levels of CRP and WBC count (all Ptrend ≤ 0.001).

CONCLUSION

Our findings suggest that hPDI may have positive, whereas uPDI may have negative impacts on multiple cardiometabolic risk markers, and underscore the need to consider the quality of plant foods in future PDI studies.

High density lipoprotein: When to rethink too much of a good thing

High density lipoprotein cholesterol (HDL-C) is a known contributor to atherosclerotic cardiovascular disease (ASCVD) risk when HDL-C <40 mg/dL in men and <50 mg/dL in women. There has been much interest in the potential cardioprotective properties of HDL-C, as it removes cholesterol from the periphery to the liver for exertion and holds inherent anti-thrombotic and anti-inflammatory properties. However, clinical trials raising HDL-C pharmacologically have not shown to improve cardiovascular outcomes. In fact, observational studies have demonstrated an increased risk of non-cardiovascular mortality and infection when HDL-C >90 mg/dL and >70 mg/dL in women and men, respectively. The ability for the HDL particle to effectively transport cholesterol from the periphery for excretion in bile is more complex than illustrated on a standard cholesterol panel. There is variability in its function, size, density, subclass, reverse cholesterol transport, and cholesterol efflux capacity, which impact the particles ability to effectively reduce cardiovascular disease (CVD) risk. Research has shown that HDL particles are prone to have a reduction in its efficacy in response to infection, auto-immune disease, menopause and cardiometabolic conditions during pregnancy. Additionally, recent studies have shown that low HDL-C may not adequately influence ASCVD risk in Black adults. The purpose of this contemporary review is to highlight the utility of using HDL-C in assessing CVD risk.

A First-in-Human Study of AMG 986, a Novel Apelin Receptor Agonist, in Healthy Subjects and Heart Failure Patients

PURPOSE

AMG 986 is a novel apelin receptor (APJ) agonist that improves cardiac contractility in animal models without adversely impacting hemodynamics. This phase 1b study evaluated the safety/tolerability, pharmacokinetics, and pharmacodynamics of AMG 986 in healthy subjects and patients with heart failure (HF).

METHODS

Healthy adults (Parts A/B) and HF patients (Part C) aged 18-85 years were randomized 3:1 to single-dose oral/IV AMG 986 or placebo (Part A); multiple-dose oral/IV AMG 986 or placebo (Part B); or escalating-dose oral AMG 986 or placebo (Part C).

PRIMARY ENDPOINT

treatment-emergent adverse events, laboratory values/vital signs/ECGs; others included AMG 986 pharmacokinetics, left ventricular (LV) function.

RESULTS

Overall, 182 subjects were randomized (AMG 986/healthy: n = 116, placebo, n = 38; AMG 986/HF: n = 20, placebo, n = 8). AMG 986 had acceptable safety profile; no clinically significant dose-related impact on safety parameters up to 650 mg/day was observed. AMG 986 exposures increased nonlinearly with increasing doses; minimal accumulation was observed. In HF with reduced ejection fraction patients, there were numerical increases in percent changes from baseline in LV ejection fraction and stroke volume by volumetric assessment with AMG 986 vs placebo (stroke volume increase not recapitulated by Doppler).

CONCLUSIONS

In healthy subjects and HF patients, short-term AMG 986 treatment was well tolerated. Consistent with this observation, clinically meaningful pharmacodynamic effects in HF patients were not observed. Changes in ejection fraction and stroke volume in HF patients suggest additional studies may be needed to better define the clinical utility and optimal dosing for this molecule.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov NCT03276728.

DATE OF REGISTRATION

September 8, 2017.

Differences in HDL-related mortality risk between individuals with and without hypertension: a prospective cohort study in UK Biobank

BACKGROUND AND AIMS

Very high levels of high-density lipoprotein cholesterol (HDL-C) have been paradoxically linked to increased mortality risk. The present study aimed to examine associations of HDL-C and varied sizes of the HDL particle (HDL-P) with mortality risk stratified by hypertension.

METHODS AND RESULTS

This prospective cohort study included 429 792 participants (244 866 with hypertension and 184 926 without hypertension) from the UK Biobank. During a median follow-up of 12.7 years, 23 993 (9.8%) and 8142 (4.4%) deaths occurred among individuals with and without hypertension, respectively. A U-shaped association of HDL-C with all-cause mortality was observed in individuals with hypertension after multivariable adjustment, whereas an L-shape was observed in individuals without hypertension. Compared with individuals with normal HDL-C of 50-70 mg/dL, those with very high HDL-C levels (>90 mg/dL) had a significantly higher risk of all-cause mortality among individuals with hypertension (hazard ratio, 1.47; 95% confidence interval, 1.35-1.61), but not among those without hypertension (1.05, 0.91-1.22). As for HDL-P, among individuals with hypertension, a larger size of HDL-P was positively whereas smaller HDL-P was negatively associated with all-cause mortality. After additional adjustment for larger HDL-P in the model, the U-shaped association between HDL-C and mortality risk was altered to an L-shape among individuals with hypertension.

CONCLUSIONS

The increased risk of mortality associated with very high HDL-C existed only in individuals with hypertension, but not in those without hypertension. Moreover, the increased risk at high HDL-C levels in hypertension was likely driven by larger HDL-P.

Both LDL and HDL particle concentrations associate positively with an increased risk of developing microvascular complications in patients with type 2 diabetes: lost protection by HDL (Zodiac-63)

BACKGROUND

Triglyceride-rich lipoproteins (TRL) and low-density lipoproteins (LDL) are associated positively whereas high-density lipoproteins (HDL) are associated inversely with the development of new-onset type 2 diabetes (T2D). Here we studied potential associations between these lipoprotein particle concentrations and the risk of developing microvascular complications in patients with established T2D.

METHODS

Lipoprotein particle concentrations (TRLP, LDLP, and HDLP) were determined in 278 patients with T2D participating in a primary care-based longitudinal cohort study (Zwolle Outpatient Diabetes project Integrating Available Care [ZODIAC] study) leveraging the Vantera nuclear magnetic resonance (NMR) platform using the LP4 algorithm. Associations between lipoprotein particles and incident microvascular complications (nephropathy, neuropathy, and retinopathy) were assessed using Cox proportional hazards regression models.

RESULTS

In total, 136 patients had microvascular complications at baseline. During a median follow-up of 3.2 years, 49 (34.5%) of 142 patients without microvascular complications at baseline developed new-onset microvascular complications. In multivariable Cox proportional hazards regression analyses, both total LDLP and HDLP concentrations, but not total TRLP concentrations, were positively associated with an increased risk of developing any microvascular complications after adjustment for potential confounding factors, including age, sex, disease duration, HbA1c levels, history of macrovascular complications, and statin use (adjusted hazard ratio [HR] per 1 SD increment: 1.70 [95% CI 1.24-2.34], P < 0.001 and 1.63 [95% CI 1.19-2.23], P = 0.002, respectively). When analyzing each microvascular complication individually, total LDLP concentrations were positively associated with retinopathy (adjusted HR 3.35, 95% CI 1.35-8.30, P = 0.009) and nephropathy (adjusted HR 2.13, 95% CI 1.27-3.35, P = 0.004), and total HDLP concentrations with neuropathy (adjusted HR 1.77, 95% CI 1.15-2.70, P = 0.009). No significant associations were observed for lipoprotein particle subfractions.

CONCLUSIONS

Total lipoprotein particle concentrations of both LDL and HDL associate positively with an increased risk of developing microvascular complications in T2D. We propose that the protective role of HDL on the development of microvascular complications may be lost in established T2D.

The association between platelet reactivity and lipoprotein levels in Framingham Heart Study participants

BACKGROUND

Hypertriglyceridemia is an independent risk factor for major adverse cardiovascular events, though the mechanisms linking triglycerides and platelet function with thrombosis, remain elusive. The aim of this study was to assess the association between platelet function and triglyceride levels.

METHODS

We included participants from the Framingham Heart Study Third Generation cohort, OMNI, and New Offspring Spouse cohort who attended the third examination cycle (2016-2019). Eligible participants were categorized into four triglyceride subgroups.

RESULTS

The study comprised a total of 1897 (55.53 %) participants with normal TG levels; 883 (25.85 %) participants with high-normal TGs; 378 (11.07 %) with borderline high TGs; and 258 (7.55 %) participants with hypertriglyceridemia. After adjusting for age, sex, alcohol consumption, aspirin, statin and P2Y₁₂ inhibitors, the levels of ADP-induced platelet aggregation were inversely associated with total cholesterol levels (P < 0.0001). Platelet disaggregation was associated with low-density lipoprotein and high-density lipoprotein cholesterol levels (P < 0.0001). Lastly, in a shear-stress chamber assay mimicking arterial flow velocities, TG levels in the normal-high group were associated with increased levels of collagen-dependent thrombogenicity (β = 24.16, SE = 6.65, P < 0.0001).

CONCLUSION

Triglyceride levels are associated with altered platelet activation and aggregation. Furthermore, increased platelet-driven thrombogenicity is directly associated with triglyceride levels after adjusting for medications and other covariates.

The Relationship of Alcohol Consumption and HDL Metabolism in the Multiethnic Dallas Heart Study

BACKGROUND

Small studies have suggested that moderate alcohol consumption increases HDL cholesterol (HDL-C) levels and cholesterol efflux capacity (CEC), a main anti-atherosclerotic HDL function.

OBJECTIVES

This study aimed to understand the degree to which alcohol intake is associated with various HDL markers in a large, multiethnic population cohort, the Dallas Heart Study (DHS), and whether alcohol modifies the link between HDL markers and atherosclerotic cardiovascular disease (ASCVD).

METHODS

Participants of the DHS were included if they had self-reported alcohol intake and CEC measurements (N=2,919). Alcohol intake was analyzed continuously (grams/week) and as an ordered categorical variable (never, past, light, moderate, heavy, and binge drinkers). HDL-C, CEC, HDL particle number (HDL-P), HDL particle size (HDL-size), and ApoA-I were the primary HDL measures.

RESULTS

After adjustment for confounding variables, increasing continuous measure of alcohol intake was associated with increased levels of all HDL markers. Moreover, as compared to moderate drinkers, light drinkers had decreased levels of the HDL markers.

CONCLUSION

In a large, multiethnic cohort, increased alcohol intake was associated with increased levels of multiple markers of HDL metabolism. However, the association of HDL markers with ASCVD risk as modified by alcohol consumption is unable to be determined in this low-risk cohort.

High-density lipoprotein subclasses and cardiovascular disease and mortality in type 2 diabetes: analysis from the Hong Kong Diabetes Biobank

OBJECTIVE

High-density lipoproteins (HDL) comprise particles of different size, density and composition and their vasoprotective functions may differ. Diabetes modifies the composition and function of HDL. We assessed associations of HDL size-based subclasses with incident cardiovascular disease (CVD) and mortality and their prognostic utility.

RESEARCH DESIGN AND METHODS

HDL subclasses by nuclear magnetic resonance spectroscopy were determined in sera from 1991 fasted adults with type 2 diabetes (T2D) consecutively recruited from March 2014 to February 2015 in Hong Kong. HDL was divided into small, medium, large and very large subclasses. Associations (per SD increment) with outcomes were evaluated using multivariate Cox proportional hazards models. C-statistic, integrated discrimination index (IDI), and categorial and continuous net reclassification improvement (NRI) were used to assess predictive value.

RESULTS

Over median (IQR) 5.2 (5.0-5.4) years, 125 participants developed incident CVD and 90 participants died. Small HDL particles (HDL-P) were inversely associated with incident CVD [hazard ratio (HR) 0.65 (95% CI 0.52, 0.81)] and all-cause mortality [0.47 (0.38, 0.59)] (false discovery rate < 0.05). Very large HDL-P were positively associated with all-cause mortality [1.75 (1.19, 2.58)]. Small HDL-P improved prediction of mortality [C-statistic 0.034 (0.013, 0.055), IDI 0.052 (0.014, 0.103), categorical NRI 0.156 (0.006, 0.252), and continuous NRI 0.571 (0.246, 0.851)] and CVD [IDI 0.017 (0.003, 0.038) and continuous NRI 0.282 (0.088, 0.486)] over the RECODe model.

CONCLUSION

Small HDL-P were inversely associated with incident CVD and all-cause mortality and improved risk stratification for adverse outcomes in people with T2D. HDL-P may be used as markers for residual risk in people with T2D.

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 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.

Nut consumption is associated with a shift of the NMR lipoprotein subfraction profile to a less atherogenic pattern among older individuals at high CVD risk

BACKGROUND

Scientific evidence has accumulated on the beneficial effects of nut consumption on cardiovascular risk and cholesterol reduction, but few studies have examined the effects of nuts on advanced measures of lipoprotein atherogenicity determined by nuclear magnetic resonance (NMR) spectroscopy. We analyzed associations between the amount and type of of nuts consumed and advanced measures of lipoprotein atherogenity and insulin resistance in older individuals at high cardiovascular risk.

METHODS

The present observational study was carried out within the framework of the Prevención con Dieta Mediterránea (PREDIMED) trial. Cross-sectional and longitudinal analyses after 1-year of follow-up were conducted in 196 men and women recruited in the PREDIMED-Reus (Spain) center. Dietary intake was assessed using a validated semi-quantitative food questionnaire. Baseline and 1-year fasting plasma lipoprotein and metabolite profiling were performed in plasma using NMR spectra Vantera^® Clinical Analyzer. Associations by tertiles of nut consumption between baseline and 1-year changes and advanced measures of lipoprotein atherogenicity, branched chain amminoacids, and measures of insulin resistance were tested by multivariable-adjusted ANCOVA models.

RESULTS

Compared to paticipants in the bottom tertile, those in the top tertile of total nut consumption showed higher levels of large HDL particles and HDL-cholesterol, lower levels of branched-chain amino acids (BCAA) and GlycA, and reduced lipoprotein insulin resistance and diabetes risk index. Participants in the top tertile of walnut consumption disclosed lower levels of very large VLDL, total LDL particles, LDL-cholesterol, and GlycA. Participants in the top tertile of non-walnut nut consumption displayed higher levels of total HDL particles, HDL-cholesterol and apoliporotein A1, lower BCAA and GlycA, and reduced lipoprotein insulin resistance. Participants in the top tertile of 1-year changes in walnut consumption showed increases in medium-sized HDL particles in comparison to the bottom tertile.

CONCLUSIONS

In older individuals at high cardiovascular risk, increasing nut consumption was associated with a shift of the NMR lipoprotein subfraction profile to a less atherogenic pattern, as well as lower circulating concentrations of BCAA and decreased insulin resistance. These results provide novel mechanistic insight into the cardiovascular benefit of nut consumption. Trial registration ISRCTN35739639; registration date: 05/10/2005; recruitment start date 01/10/2003.

GlycA, hsCRP differentially associated with MI, ischemic stroke: In the Dallas Heart Study and Multi-Ethnic Study of Atherosclerosis: GlycA, hsCRP Differentially Associated MI, Stroke

Objective

Inflammatory markers are associated with cardiovascular disease (CVD); however, the ability to specifically predict myocardial infarction (MI) as well as ischemic stroke remains unknown. There has not been a direct comparison of the associations between GlycA and hsCRP and MI and ischemic stroke in a multi-ethnic pooled cohort.

Methods

Multi-center, multi-ethnic, population-based community prospective pooled cohort of the Dallas Heart Study (DHS) and Multi-Ethnic Study of Atherosclerosis (MESA). 9,785 participants without baseline CVD enrolled with median follow-up of 13.4 years. Fatal/nonfatal MI and fatal/nonfatal ischemic stroke were assessed separately and then combined.

Results

GlycA was moderately associated with hsCRP (R=0.58 in DHS and R=0.55 in MESA). In adjusted Cox proportional hazards models with competing risk adjusted for both inflammatory markers, GlycA was directly associated with MI (HR Q4 vs. Q1 1.90, 95% CI 1.39 to 2.58), whereas hsCRP was not (HR Q4 vs. Q1 0.92, 95% CI 0.70 to 1.21). Conversely, hsCRP was directly associated with ischemic stroke (HR Q4 vs. Q1 1.73, 95% CI 1.15 to 2.59), but GlycA was not (HR Q4 vs. Q1 1.21, 95% CI 0.77 to 1.90). GlycA improved net reclassification for MI and hsCRP did so for ischemic stroke.

Conclusions

Although both GlycA and hsCRP were associated with incident CVD, GlycA more strongly predicted incident MI, and hsCRP more strongly predicted ischemic stroke.

Reduction of A-to-I RNA editing in the failing human heart regulates formation of circular RNAs

Alterations of RNA editing that affect the secondary structure of RNAs can cause human diseases. We therefore studied RNA editing in failing human hearts. Transcriptome sequencing showed that adenosine-to-inosine (A-to-I) RNA editing was responsible for 80% of the editing events in the myocardium. Failing human hearts were characterized by reduced RNA editing. This was primarily attributable to Alu elements in introns of protein-coding genes. In the failing left ventricle, 166 circRNAs were upregulated and 7 circRNAs were downregulated compared to non-failing controls. Most of the upregulated circRNAs were associated with reduced RNA editing in the host gene. ADAR2, which binds to RNA regions that are edited from A-to-I, was decreased in failing human hearts. In vitro, reduction of ADAR2 increased circRNA levels suggesting a causal effect of reduced ADAR2 levels on increased circRNAs in the failing human heart. To gain mechanistic insight, one of the identified upregulated circRNAs with a high reduction of editing in heart failure, AKAP13, was further characterized. ADAR2 reduced the formation of double-stranded structures in AKAP13 pre-mRNA, thereby reducing the stability of Alu elements and the circularization of the resulting circRNA. Overexpression of circAKAP13 impaired the sarcomere regularity of human induced pluripotent stem cell-derived cardiomyocytes. These data show that ADAR2 mediates A-to-I RNA editing in the human heart. A-to-I RNA editing represses the formation of dsRNA structures of Alu elements favoring canonical linear mRNA splicing and inhibiting the formation of circRNAs. The findings are relevant to diseases with reduced RNA editing and increased circRNA levels and provide insights into the human-specific regulation of circRNA formation.

Vectorcardiography-derived index allows a robust quantification of ventricular electrical synchrony

Alteration of muscle activation sequence is a key mechanism in heart failure with reduced ejection fraction. Successful cardiac resynchronization therapy (CRT), which has become standard therapy in these patients, is limited by the lack of precise dyssynchrony quantification. We implemented a computational pipeline that allows assessment of ventricular dyssynchrony by vectorcardiogram reconstruction from the patient’s electrocardiogram. We defined a ventricular dyssynchrony index as the distance between the voltage and speed time integrals of an individual observation and the linear fit of these variables obtained from a healthy population. The pipeline was tested in a 1914-patient population. The dyssynchrony index showed minimum values in heathy controls and maximum values in patients with left bundle branch block (LBBB) or with a pacemaker (PM). We established a critical dyssynchrony index value that discriminates electrical dyssynchronous patterns (LBBB and PM) from ventricular synchrony. In 10 patients with PM or CRT devices, dyssynchrony indexes above the critical value were associated with high time to peak strain standard deviation, an echocardiographic measure of mechanical dyssynchrony. Our index proves to be a promising tool to evaluate ventricular activation dyssynchrony, potentially enhancing the selection of candidates for CRT, device configuration during implantation, and post-implant optimization.

Ischemic stroke and intestinal flora: an insight into brain-gut axis

Stroke is a type of cerebrovascular disease that significantly endangers human health and lowers quality of life. This understandably places a heavy burden on society and families. In recent years, intestinal flora has attracted increasing attention from scholars worldwide, and its association with ischemic stroke is becoming a hot topic of research amongst researchers in field of stroke. After suffering from a stroke, intestinal microbial dysbiosis leads to increased intestinal permeability and activation of the intestinal immune system, which in turn leads to ectopic intestinal bacteria and pro-inflammatory cells that enter brain tissue through the damaged blood-brain barrier. This exacerbates ischemia-reperfusion injury. Interestingly, after a stroke, some metabolites produced by the intestinal flora attenuate ischemia-reperfusion injury by suppressing the post-stroke inflammatory response and promotes the repair of neurological function. Here we elucidate the changes in gut flora after occurrence of a stroke and highlight the immunomodulatory processes of the post-stroke gut flora.

Higher Free Triiodothyronine Is Associated With Higher HDL Particle Concentration and Smaller HDL Particle Size

CONTEXT

Thyroid function status has effects on the development of atherosclerotic cardiovascular disease by affecting lipid metabolism, but associations of high-density lipoprotein (HDL) particle concentrations and subfractions with thyroid hormone levels within the reference range remain elusive.

OBJECTIVE

The aim of the present study was to determine the associations of free triiodothyronine (FT3), free thyroxine (FT4) and thyroid-stimulating hormone (TSH) levels with HDL particle characteristics in euthyroid individuals.

METHODS

This cross-sectional study on the associations of thyroid hormones with HDL particle concentrations, HDL subfractions, and HDL particle size included 5844 euthyroid individuals (FT3, FT4, and TSH levels within the reference range and no medication use affecting thyroid function), participating in the Prevention of REnal and Vascular ENd-stage Disease (PREVEND) study. HDL particles and subfractions were measured by nuclear magnetic resonance using an optimized version of the NMR LipoProfile Test (LP4).

RESULTS

In multivariable linear regression analyses, FT3 was positively associated with total HDL particle concentration (std.β = 0.14; P < 0.001) and with small (std.β = 0.13; P < 0.001) and medium-sized HDL particles (std.β = 0.05; P = 0.001). Conversely, FT3 was inversely associated with large HDL particles (std.β = -0.07; P < 0.001) and with HDL particle size (std.β = -0.08; P < 0.001). Such associations with FT4 or reciprocally with TSH were less pronounced or nonsignificant.

CONCLUSION

In euthyroid individuals, higher FT3 is cross-sectionally associated with higher total HDL particle concentration and with lower HDL particle size. These associations may be relevant to better understand the role of HDL in thyroid function-associated atherosclerotic cardiovascular disease.

Profoundly Disturbed Lipoproteins in Cirrhotic Patients: Role of Lipoprotein-Z, a Hepatotoxic LDL-like Lipoprotein

Detailed information regarding lipoprotein concentrations and subfractions in cirrhotic patients before and after orthotopic liver transplantation (OLT) is lacking. Lipoprotein-Z (LP-Z) is a recently characterised abnormal, hepatotoxic free cholesterol-rich low-density lipoprotein (LDL)-like lipoprotein. We determined the lipoprotein profiles, including LP-Z, in cirrhotic patients and OLT recipients and assessed the prognostic significance of LP-Z on the OLT waiting list. We performed analyses in cirrhotic transplant candidates and non-cirrhotic OLT recipients. A population-based cohort was used as reference. The setting was a University hospital. Lipoprotein particle concentrations and subfractions were measured by nuclear magnetic resonance spectroscopy. In the cirrhotic patients (N = 130), most measures of triglyceride-rich lipoproteins (TRL), LDL, and high-density lipoproteins (HDL) were much lower compared to the OLT recipients (N = 372) and controls (N = 6027) (p < 0.01). In the OLT recipients, many lipoprotein variables were modestly lower, but HDL-cholesterol, triglycerides, and TRL and HDL size were greater vs. the control population. LP-Z was measurable in 40 cirrhotic patients and 3 OLT recipients (30.8% vs. 0.8%, p < 0.001). The cirrhotic patients with measurable LP-Z levels had profoundly lower HDL-cholesterol and particle concentrations (p < 0.001), and worse Child Pugh Turcotte classifications and MELD scores. The presence of LP-Z (adjusted for age, sex, and MELD score) predicted worse survival in cirrhotic patients (HR per 1 LnSD increment: 1.11, 95%CI 1.03−1.19, p = 0.003). In conclusion, cirrhotic patients have considerably lower plasma concentrations of all major lipoprotein classes with changes in lipoprotein subfraction distribution. After OLT, these lipoprotein abnormalities are in part reversed. LP-Z is associated with cirrhosis. Its presence may translate in disturbed HDL metabolism and worse survival.

U-Shaped Relationship of High-Density Lipoprotein Cholesterol and Incidence of Total, Ischemic and Hemorrhagic Stroke: A Prospective Cohort Study

BACKGROUND

We aimed to investigate the association between serially measured HDL-C (high-density lipoprotein cholesterol) levels and stroke risk in a prospective cohort study.

METHODS

We included 96 258 individuals (79.6% men, mean age 51.5 years) without a history of stroke, myocardial infarction, or cancer at baseline from the Kailuan Study, with repeated measurements of HDL-C in 2006, 2008, 2010, 2012, 2014, and 2016. Cumulatively, averaged HDL-C concentrations were calculated using all available HDL-C measurements before incidence stroke or end of follow-up (December 31, 2017). Incident stroke cases were confirmed by review of medical records and further subclassified into ischemic or hemorrhagic stroke. Cox proportional hazards regression and restricted cubic splines were used to examine these associations.

RESULTS

During a median follow-up of 10.7 years, 5012 incident stroke cases occurred. Restricted cubic splines analysis suggested a U-shaped association between concentrations of cumulatively averaged HDL-C and risk of stroke (P_nonlinearity <0.001), with the nadir of risk at 1.29 mmol/L. After adjustment for cardiovascular risk factors, individuals with cumulatively averaged HDL-C ≤1.06 mmol/L or ≥2.05 mmol/L had hazard ratios for total stroke of 1.31 (95% CI, 1.15-1.49) and 1.85 (1.63-2.09) compared with those with HDL-C of 1.26 to 1.39 mmol/L. Corresponding hazard ratios were 1.29 (1.11-1.48) and 1.84 (1.60-2.11) for ischemic stroke and 1.54 (1.12-2.12) and 2.29 (1.73-3.04) for hemorrhagic stroke, respectively.

CONCLUSIONS

Both low and high cumulatively averaged HDL-C were associated with an increased risk of ischemic and hemorrhagic strokes.

HDL Is Not Dead Yet

High-density lipoprotein cholesterol (HDL-C) levels are inversely correlated with coronary heart disease (CHD) in multiple epidemiological studies, but whether HDL is causal or merely associated with CHD is unclear. Recent trials for HDL-raising drugs were either not effective in reducing CHD events or, if beneficial in reducing CHD events, were not conclusive as the findings could be attributed to the drugs’ LDL-reducing activity. Furthermore, the first large Mendelian randomization study did not causally relate HDL-C levels to decreased CHD. Thus, the hypothesis that HDL is protective against CHD has been rightfully challenged. However, subsequent Mendelian randomization studies found HDL characteristics that are causally related to decreased CHD. Many aspects of HDL structure and function, especially in reverse cholesterol transport, may be better indicators of HDL’s protective activity than simply measuring HDL-C. Cholesterol efflux capacity is associated with lower levels of prevalent and incident CHD, even after adjustment for HDL-C and apolipoprotein A-1 levels. Also, subjects with very high levels of HDL-C, including those with rare mutations that disrupt hepatic HDL uptake and reverse cholesterol transport, may be at higher risk for CHD than those with moderate levels. We describe here several cell-based and cell-free in vitro assays of HDL structure and function that may be used in clinical studies to determine which of HDL’s functions are best associated with protection against CHD. We conclude that the HDL hypothesis may need revision based on studies of HDL structure and function, but that the HDL hypothesis is not dead yet.

Serum bilirubin levels are associated with poor functional outcomes in patients with acute ischemic stroke or transient ischemic attack

BACKGROUND

The prognostic value of serum bilirubin in stroke is controversial, since bilirubin has both neuroprotective and neurotoxic properties. We aimed to investigate the association between serum bilirubin, including total bilirubin (TBIL), direct bilirubin (DBIL) and indirect bilirubin (IBIL) and poor functional outcomes in patients with acute ischemic stroke (AIS) or transient ischemic attack (TIA).

METHODS

All patients with AIS or TIA were recruited from the Third China National Stroke Registry. The poor functional outcomes included modified Rankin Scale (mRS) score 2-6 and 3-6 at 3 months and 1 year. Multivariable logistic regression was used to investigate the associations of TBIL, DBIL, and IBIL with poor functional outcomes.

RESULTS

Among 11,121 enrolled patients, the median (interquartile range) of TBIL, DBIL, and IBIL was 13.30 (9.90-17.70), 3.80 (2.70-5.30), and 9.30 (6.70-12.80) µmol/L. After adjustment for conventional confounding factors, patients in the highest TBIL quartile had the highest proportion of mRS score 2-6 at 3 months (odds ratio [OR], 1.37; 95 % confidence interval [CI], 1.19-1.59) and 1 year (OR, 1.31; 95 % CI, 1.13-1.52), and mRS score 3-6 at 3 months (OR, 1.33; 95 % CI, 1.11-1.59) and 1 year (OR, 1.28; 95 % CI, 1.07-1.53), when compared to patients in the lowest TBIL quartile. Similar results were observed for DBIL and IBIL. We also found J-shaped associations between serum bilirubin levels and each outcome.

CONCLUSIONS

Elevated levels of serum bilirubin were significantly associated with poor functional outcomes in patients with AIS or TIA at 3 months and 1 year.

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.

Cholesterol efflux pathways, inflammation, and atherosclerosis

Plasma levels of high-density lipoprotein (HDL) inversely correlate with the incidence of cardiovascular diseases (CVD). The causal relationship between plasma HDL-cholesterol levels and CVD has been called into question by Mendelian randomization studies and the majority of clinical trials not showing any benefit of plasma HDL-cholesterol raising drugs on CVD. Nonetheless, recent Mendelian randomization studies including an increased number of CVD cases compared to earlier studies have confirmed that HDL-cholesterol levels and CVD are causally linked. Moreover, several studies in large population cohorts have shown that the cholesterol efflux capacity of HDL inversely correlates with CVD. Cholesterol efflux pathways exert anti-inflammatory and anti-atherogenic effects by suppressing proliferation of hematopoietic stem and progenitor cells, and inflammation and inflammasome activation in macrophages. Cholesterol efflux pathways also suppress the accumulation of cholesteryl esters in macrophages, i.e. macrophage foam cell formation. Recent single-cell RNASeq studies on atherosclerotic plaques have suggested that macrophage foam cells have lower expression of inflammatory genes than non-foam cells, probably reflecting liver X receptor activation, upregulation of ATP Binding Cassette A1 and G1 cholesterol transporters and suppression of inflammation. However, when these pathways are defective lesional foam cells may become pro-inflammatory.

The triumvirate: why hypertension, obesity, and diabetes are risk factors for adverse effects in patients with COVID-19

The outbreak of coronavirus disease 2019 (COVID-19) caused by a novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a pandemic. The cellular receptor for SARS-CoV-2 entry is the angiotensin-converting enzyme 2, a membrane-bound homolog of angiotensin-converting enzyme. Henceforth, this has brought the attention of the scientific community to study the interaction between COVID-19 and the renin-angiotensin system (RAS), as well as RAS inhibitors. However, these inhibitors are commonly used to treat hypertension, chronic kidney disorder, and diabetes. Obesity is a known risk factor for heart disease, diabetes, and hypertension, whereas diabetes and hypertension may be indirectly related to each other through the effects of obesity. Furthermore, people with hypertension, obesity, diabetes, and other related complications like cardiovascular and kidney diseases have a higher risk of severe COVID-19 infection than the general population and usually exhibit poor prognosis. This severity could be due to systemic inflammation and compromised immune response and RAS associated with these comorbid conditions. Therefore, there is an urgent need to develop evidence-based treatment methods that do not affect the severity of COVID-19 infection and effectively manage these chronic diseases in people with COVID-19.

HDL in the 21st Century: A Multifunctional Roadmap for Future HDL Research

Low high-density lipoprotein cholesterol (HDL-C) characterizes an atherogenic dyslipidemia that reflects adverse lifestyle choices, impaired metabolism, and increased cardiovascular risk. Low HDL-C is also associated with increased risk of inflammatory disorders, malignancy, diabetes, and other diseases. This epidemiologic evidence has not translated to raising HDL-C as a viable therapeutic target, partly because HDL-C does not reflect high-density lipoprotein (HDL) function. Mendelian randomization analyses that have found no evidence of a causal relationship between HDL-C levels and cardiovascular risk have decreased interest in increasing HDL-C levels as a therapeutic target. HDLs comprise distinct subpopulations of particles of varying size, charge, and composition that have several dynamic and context-dependent functions, especially with respect to acute and chronic inflammatory states. These functions include reverse cholesterol transport, inhibition of inflammation and oxidation, and antidiabetic properties. HDLs can be anti-inflammatory (which may protect against atherosclerosis and diabetes) and proinflammatory (which may help clear pathogens in sepsis). The molecular regulation of HDLs is complex, as evidenced by their association with multiple proteins, as well as bioactive lipids and noncoding RNAs. Clinical investigations of HDL biomarkers (HDL-C, HDL particle number, and apolipoprotein A through I) have revealed nonlinear relationships with cardiovascular outcomes, differential relationships by sex and ethnicity, and differential patterns with coronary versus noncoronary events. Novel HDL markers may also have relevance for heart failure, cancer, and diabetes. HDL function markers (namely, cholesterol efflux capacity) are associated with coronary disease, but they remain research tools. Therapeutics that manipulate aspects of HDL metabolism remain the holy grail. None has proven to be successful, but most have targeted HDL-C, not metrics of HDL function. Future therapeutic strategies should focus on optimizing HDL function in the right patients at the optimal time in their disease course. We provide a framework to help the research and clinical communities, as well as funding agencies and stakeholders, obtain insights into current thinking on these topics, and what we predict will be an exciting future for research and development on HDLs.

HDL Particle Subspecies and Their Association With Incident Type 2 Diabetes: The PREVEND Study

CONTEXT

High-density lipoproteins (HDL) may be protective against type 2 diabetes (T2D) development, but HDL particles vary in size and function, which could lead to differential associations with incident T2D. A newly developed nuclear magnetic resonance (NMR)-derived algorithm provides concentrations for 7 HDL subspecies.

OBJECTIVE

We aimed to investigate the association of HDL particle subspecies with incident T2D in the general population.

METHODS

Among 4828 subjects of the Prevention of Renal and Vascular End-Stage Disease (PREVEND) study without T2D at baseline, HDL subspecies with increasing size from H1P to H7P were measured by NMR (LP4 algorithm of the Vantera NMR platform).

RESULTS

A total of 265 individuals developed T2D (median follow-up of 7.3 years). In Cox regression models, HDL size and H4P (hazard ratio [HR] per 1 SD increase 0.83 [95% CI, 0.69-0.99] and 0.85 [95% CI, 0.75-0.95], respectively) were inversely associated with incident T2D, after adjustment for relevant covariates. In contrast, levels of H2P were positively associated with incident T2D (HR 1.15 [95% CI, 1.01-1.32]). In secondary analyses, associations with large HDL particles and H6P were modified by body mass index (BMI) in such a way that they were particularly associated with a lower risk of incident T2D, in subjects with BMI < 30 kg/m2.

CONCLUSION

Greater HDL size and lower levels of H4P were associated with a lower risk, whereas higher levels of H2P were associated with a higher risk of developing T2D. In addition, large HDL particles and H6P were inversely associated with T2D in nonobese subjects.

Changes in lipoprotein particle subclasses, standard lipids, and apolipoproteins after supplementation with n-3 or n-6 PUFAs in abdominal obesity: A randomized double-blind crossover study

BACKGROUND & AIMS

Marine-derived omega-3 (n-3) polyunsaturated fatty acids (PUFAs), mainly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), lower circulating levels of triacylglycerols (TAGs), and the plant-derived omega-6 (n-6) PUFA linoleic acid (LA) may reduce cholesterol levels. Clinical studies on effects of these dietary or supplemental PUFAs on other blood fat fractions are few and have shown conflicting results. This study aimed to determine effects of high-dose supplemental n-3 (EPA + DHA) and n-6 (LA) PUFAs from high-quality oils on circulating lipoprotein subfractions and standard lipids (primary outcomes), as well as apolipoproteins, fatty acids, and glycemic control (secondary outcomes), in females and males with abdominal obesity.

METHODS

This was a randomized double-blind crossover study with two 7-wk intervention periods separated by a 9-wk washout phase. Females (n = 16) were supplemented with 3 g/d of EPA + DHA (TAG fish oil) or 15 g/d of LA (safflower oil), while males (n = 23) received a dose of 4 g/d of EPA + DHA or 20 g/d of LA. In fasting blood samples, we investigated lipoprotein particle subclasses by nuclear magnetic resonance spectroscopy, as well as standard lipids, apolipoproteins, fatty acid profiles, and glucose and insulin. Data were analyzed by linear mixed-effects modeling with 'subjects' as the random factor.

RESULTS

The difference between interventions in relative change scores was among the lipoprotein subfractions significant for total very-low-density lipoproteins (VLDLs) (n-3 vs. n-6: -38%∗ vs. +16%, p < 0.001; ∗: significant within-treatment change score), large VLDLs (-58%∗ vs. -0.91%, p < 0.001), small VLDLs (-57%∗ vs. +41%∗, p < 0.001), total low-density lipoproteins (LDLs) (+5.8%∗ vs. -4.3%∗, p = 0.002), large LDLs (+23%∗ vs. -2.1%, p = 0.004), total high-density lipoproteins (HDLs) (-6.0%∗ vs. +3.7%, p < 0.001), large HDLs (+11%∗ vs. -5.3%, p = 0.001), medium HDLs (-24%∗ vs. +6.2%, p = 0.030), and small HDLs (-9.9%∗ vs. +9.6%∗, p = 0.002), and among standard lipids for TAGs (-16%∗ vs. -2.6%, p = 0.014), non-esterified fatty acids (-19%∗ vs. +5.5%, p = 0.033), and total cholesterol (-0.28% vs. -4.4%∗, p = 0.042). A differential response in relative change scores was also found for apolipoprotein (apo)B (+0.40% vs. -6.0%∗, p = 0.008), apoA-II (-6.0%∗ vs. +1.5%, p = 0.001), apoC-II (-11%∗ vs. -1.7%, p = 0.025), and apoE (+3.3% vs. -3.8%, p = 0.028).

CONCLUSIONS

High-dose supplementation of high-quality oils with n-3 (EPA + DHA) or n-6 (LA) PUFAs was followed by reductions in primarily TAG- or cholesterol-related markers, respectively. The responses after both interventions point to changes in the lipoprotein-lipid-apolipoprotein profile that have been associated with reduced cardiometabolic risk, also among people with TAG or LDL-C levels within the normal range.

REGISTRATION

Registered under ClinicalTrials.gov Identifier: NCT02647333.

CLINICAL TRIAL REGISTRATION

Registered at https://clinicaltrials.gov/ct2/show/NCT02647333.

Remote Ischemic Postconditioning Inhibited Mitophagy to Achieve Neuroprotective Effects in the Rat Model of Cardiac Arrest

Remote ischemic postconditioning (RI-postC) is an effective measure to improve nerve function after cardiac arrest. However, the brain protective mechanism of RI-postC has not been fully elucidated, and whether it is related to mitophagy is unclear. In this study, we used the rat model of cardiac arrest to study the effect of RI-postC on mitophagy and explore its possible signaling pathways. Rats were randomly divided into Sham group, CA/CPR group, Mdivi-1 group and RI-postC group. The animal model of cardiac arrest was established by asphyxia. RI-postC was performed by clamping and loosening the left femoral artery. Mdivi-1 was treated with a single intravenous injection. Levels of TOMM20, TIM23, Mfn1, PINK1 and parkin were detected by western blots. Mitochondrial membrane potential was measured by flow cytometry. Real-time PCR was used to detect relative mitochondrial DNA levels. The apoptosis of hippocampal neurons was detected by flow and TUNEL. In addition, Histopathological tests were performed. The results showed that RI-postC was similar to the mitophagy inhibitor Mdivi-1, which could inhibit the decrease of mitophagy-related protein level, improve mitochondrial membrane potential and up-regulate the ratio of mt-Atp6/Rpl13 after cardiopulmonary resuscitation (CPR). Furthermore, RI-postC could also reduce the rate of hippocampal nerve apoptosis and the damage of hippocampal neurons after CPR. Moreover, RI-postC and Mdivi-1 could reduce the protein levels of PINK1 and parkin in mitochondria after CPR, while increasing PINK1 levels in the cytoplasm. These findings suggested that RI-postC could inhibit the overactivation mitophagy through the PINK1/parkin signaling pathway, thus providing neuroprotective effects.

Independent association of atherogenic dyslipidaemia with all-cause mortality in individuals with type 2 diabetes and modifying effect of gender: a prospective cohort study

Background

Atherogenic dyslipidaemia has been implicated in the residual risk for cardiovascular morbidity and mortality, which remains despite attainment of LDL cholesterol goals especially in individuals with type 2 diabetes. However, its relationship with all-cause death has not been sufficiently explored. This analysis evaluated the independent association of increased triglycerides and triglyceride:HDL cholesterol ratio (TG:HDL) and decreased HDL cholesterol with total mortality and the possible modifying effect of gender in a large cohort of patients with type 2 diabetes.

Methods

This observational, prospective study enrolled 15,773 patients in 19 Diabetes Clinics throughout Italy in the years 2006–2008. Triglycerides and total and HDL cholesterol were measured by colorimetric enzymatic methods. Vital status was retrieved on 31 October 2015 for 15,656 patients (99.3%). Participants were stratified by quartiles of triglycerides, HDL cholesterol, and TG:HDL.

Results

There were 3,602 deaths over a follow-up 7.42 ± 2.05 years (31.0 × 1000 person-years). In the unadjusted analyses, the highest TG:HDL (but not triglyceride) and the lowest HDL cholesterol quartile were associated with increased death rate and mortality risk. When sequentially adjusting for confounders, including total, LDL, or non-HDL cholesterol and lipid-lowering treatment, mortality risk was significantly higher in the highest triglyceride (hazard ratio 1.167 [95% confidence interval 1.055–1.291], p = 0.003) and TG:HDL (1.192 [1.082–1.314], p < 0.0001) and the lowest HDL cholesterol (1.232 [1.117–1.360], p < 0.0001) quartile, though the association of triglycerides and HDL cholesterol disappeared after further adjustment for each other. Interaction with gender was significant only for HDL cholesterol (p = 0.0009). The relationship with death was stronger for triglycerides in males and HDL cholesterol in females, with these associations remaining significant even after adjustment for HDL cholesterol (1.161 [1.019–1.324], p = 0.025, for the highest vs the lowest triglyceride quartile) and triglycerides (1.366 [1.176–1.587], p < 0.0001, for the lowest vs the highest HDL cholesterol quartile).

Conclusions

In patients with type 2 diabetes, higher triglycerides and TG:HDL and lower HDL cholesterol were independently associated with increased all-cause mortality, with a modifying effect of gender for triglycerides and HDL cholesterol. These data suggest that atherogenic dyslipidaemia, especially TG:HDL, may serve as predictor of all-cause death in these individuals.

Trial registration ClinicalTrials.gov, NCT00715481, 15 July, 2008

Inhibition of Cholesteryl Ester Transfer Protein Preserves High-Density Lipoprotein Cholesterol and Improves Survival in Sepsis

BACKGROUND

The high-density lipoprotein hypothesis of atherosclerosis has been challenged by clinical trials of cholesteryl ester transfer protein (CETP) inhibitors, which failed to show significant reductions in cardiovascular events. Plasma levels of high-density lipoprotein cholesterol (HDL-C) decline drastically during sepsis, and this phenomenon is explained, in part, by the activity of CETP, a major determinant of plasma HDL-C levels. We tested the hypothesis that genetic or pharmacological inhibition of CETP would preserve high-density lipoprotein levels and decrease mortality in clinical cohorts and animal models of sepsis.

METHODS

We examined the effect of a gain-of-function variant in CETP (rs1800777, p.Arg468Gln) and a genetic score for decreased CETP function on 28-day sepsis survival using Cox proportional hazard models adjusted for age and sex in the UK Biobank (n=5949), iSPAAR (Identification of SNPs Predisposing to Altered Acute Lung Injury Risk; n=882), Copenhagen General Population Study (n=2068), Copenhagen City Heart Study (n=493), Early Infection (n=200), St Paul's Intensive Care Unit 2 (n=203), and Vasopressin Versus Norepinephrine Infusion in Patients With Septic Shock studies (n=632). We then studied the effect of the CETP inhibitor, anacetrapib, in adult female APOE*3-Leiden mice with or without human CETP expression using the cecal-ligation and puncture model of sepsis.

RESULTS

A fixed-effect meta-analysis of all 7 cohorts found that the CETP gain-of-function variant was significantly associated with increased risk of acute sepsis mortality (hazard ratio, 1.44 [95% CI, 1.22-1.70]; P<0.0001). In addition, a genetic score for decreased CETP function was associated with significantly decreased sepsis mortality in the UK Biobank (hazard ratio, 0.77 [95% CI, 0.59-1.00] per 1 mmol/L increase in HDL-C) and iSPAAR cohorts (hazard ratio, 0.60 [95% CI, 0.37-0.98] per 1 mmol/L increase in HDL-C). APOE*3-Leiden.CETP mice treated with anacetrapib had preserved levels of HDL-C and apolipoprotein-AI and increased survival relative to placebo treatment (70.6% versus 35.3%, Log-rank P=0.03), whereas there was no effect of anacetrapib on the survival of APOE*3-Leiden mice that did not express CETP (50.0% versus 42.9%, Log-rank P=0.87).

CONCLUSIONS

Clinical genetics and humanized mouse models suggest that inhibiting CETP may preserve high-density lipoprotein levels and improve outcomes for individuals with sepsis.