Low-density lipoprotein and high-density lipoprotein particle subclasses predict coronary events and are favorably changed by gemfibrozil therapy in the Veterans Affairs High-Density Lipoprotein Intervention Trial

Association of high-density lipoprotein particle concentration with cardiovascular risk following acute coronary syndrome: A case-cohort analysis of the dal-Outcomes trial

BACKGROUND

High-density lipoprotein cholesterol (HDL-C) concentration is inversely related to risk of major adverse cardiovascular events (MACE) in epidemiologic studies but is a poorer predictor of MACE in patients with established coronary heart disease. HDL particle concentration (HDLP) has been proposed as a better predictor of risk. We investigated whether HDLP is associated with risk of MACE after acute coronary syndrome (ACS).

METHODS

The dal-Outcomes trial compared the CETP inhibitor dalcetrapib with placebo in patients with recent ACS. In a nested case-cohort analysis, total, large, medium, and small HDLPs were measured by nuclear magnetic resonance spectroscopy at baseline (4-12 weeks after ACS) in 476 cases with MACE and 902 controls. Hazard ratios (HRs; case-control) for 1-SD increment of HDLP or HDL-C at baseline were calculated with and without adjustment for demographic, clinical, laboratory, and treatment variables. Similarly, HRs for MACE were calculated for changes in HDLP or HDL-C from baseline to month 3 of assigned treatment.

RESULTS

Over median follow-up of 28 months, the risk of MACE was not associated with baseline HDLP (adjusted HR = 0.98, 95% CI = 0.84-1.15, P = .81), any HDLP subclass, or HDL-C. Dalcetrapib increased HDL-C and total, medium, and large HDLP and decreased small HDLP but had no effect on MACE compared with placebo. There were no association of risk of MACE with change in HDLP or HDL-C and no interaction with assigned study treatment.

CONCLUSIONS

Neither baseline HDLP nor the change in HDLP on treatment with dalcetrapib or placebo was associated with risk of MACE after ACS.

Assessing Atherosclerotic Cardiovascular Disease Risk with Advanced Lipid Testing: State of the Science

Cardiovascular disease is the number one cause of death and disability worldwide. While substantial gains have been made in reducing cardiovascular mortality, future projections suggest that we have reached a nadir and may be at an inflection point, given the rising tide of obesity and diabetes. Evaluation and management of plasma lipids is central to the prevention of atherosclerotic cardiovascular disease. Although the standard lipid panel represents a well-established platform to assess risk, this test alone can be insufficient and/or misleading. Advances in our understanding of atherosclerosis have led to the development of lipid-based biomarkers that help to discriminate the risk of cardiovascular disease when it is unclear. While these biomarkers provide novel information, their implementation into clinical medicine remains difficult given discrepancies in the literature, lack of assay standardisation, poor accessibility and high cost. However, additional measures of atherogenic lipoproteins or their surrogates may offer insight beyond the standard lipid panel, providing a more precise assessment of risk and more accurate assessment of lipid-lowering therapy.

Interaction between adipocytes and high-density lipoprotein:new insights into the mechanism of obesity-induced dyslipidemia and atherosclerosis

Obesity is the most common nutritional disorder worldwide and is associated with dyslipidemia and atherosclerotic cardiovascular disease. The hallmark of dyslipidemia in obesity is low high density lipoprotein (HDL) cholesterol (HDL-C) levels. Moreover, the quality of HDL is also changed in the obese setting. However, there are still some disputes on the explanations for this phenomenon. There is increasing evidence that adipose tissue, as an energy storage tissue, participates in several metabolism activities, such as hormone secretion and cholesterol efflux. It can influence overall reverse cholesterol transport and plasma HDL-C level. In obesity individuals, the changes in morphology and function of adipose tissue affect plasma HDL-C levels and HDL function, thus, adipose tissue should be the main target for the treatment of HDL metabolism in obesity. In this review, we will summarize the cross-talk between adipocytes and HDL related to cardiovascular disease and focus on the new insights of the potential mechanism underlying obesity and HDL dysfunction.

Greater IL-6, D-dimer, and ICAM-1 Levels Are Associated With Lower Small HDL Particle Concentration in the Multicenter AIDS Cohort Study

OBJECTIVE

Low HDL cholesterol (HDL-C) is common in people living with HIV infection, which is associated with inflammation, and correlates with greater cardiovascular disease (CVD) risk. Particles of HDL are HDL subfractions, and in some general population studies, higher small HDL particle number (HDL-P) has been associated with lower CVD risk. The objective of this study was to determine whether HIV serostatus and systemic inflammation were associated with small HDL-P in the Multicenter AIDS Cohort Study (MACS).

METHOD

The MACS is composed of HIV-infected and HIV-uninfected men. Separate linear regression analyses were conducted to evaluate the associations between outcomes (small HDL-P, large HDL-P, total HDL-P, and HDL size) and variables of interest (interleukin-6 [IL-6], D-dimer, and intercellular adhesion molecule-1 [ICAM-1] levels), with adjustment for other CVD risk factors.

RESULTS

The study population included 553 HIV-infected (88.1% on current ART) and 319 HIV-uninfected men. The mean age was 52.7 years for HIV-infected men and 55.3 years for HIV-uninfected men. In separate models of the study population, higher log IL-6 was associated with lower total and small HDL-P (P < .01 for both), independent of HIV serostatus and CVD risk factors. Similar results were seen with ICAM-1. Positive HIV serostatus was associated with lower small and total HDL-P, adjusted for inflammatory markers.

CONCLUSIONS

Greater systemic inflammation and HIV infection both were associated with lower atheroprotective small HDL-P. This may be a potential mechanism contributing to increased cardiovascular risk among HIV-infected people.

Residual Hypertriglyceridemia and Estimated Atherosclerotic Cardiovascular Disease Risk by Statin Use in U.S. Adults With Diabetes: National Health and Nutrition Examination Survey 2007-2014

OBJECTIVE

Hypertriglyceridemia (HTG) is common in patients with diabetes, and statins remain the first-line therapy. However, the proportion of patients with diabetes having elevated triglycerides (TGs) on statin treatment and their atherosclerotic cardiovascular disease (ASCVD) risk has not been described. We quantified the prevalence of HTG in U.S. adults with diabetes currently treated versus not treated with statins and the estimated 10-year ASCVD risk.

RESEARCH DESIGN AND METHODS

Among 1,448 U.S. adults aged 20 years and over with diabetes (projected to 24.4 million) in the 2007-2014 National Health and Nutrition Examination Survey (NHANES), we compared the prevalence of borderline HTG (TG 150-199 mg/dL) and HTG (TG ≥200 mg/dL) by statin use and LDL cholesterol (LDL-C) levels, and we used logistic regression to identify risk factors for HTG. We also estimated the 10-year ASCVD risk in those without prior ASCVD.

RESULTS

The prevalence of borderline HTG and HTG was 20.0% and 19.5%, respectively, in statin users and 20.1% and 25.3%, respectively, in nonstatin users (P < 0.0001). Even among statin users with LDL-C <70 mg/dL, borderline HTG prevalence was 16.8% and HTG prevalence was 16.7%. Approximately 77.5% of those with HTG had an estimated 10-year ASCVD risk of ≥7.5%, with almost 40% of statin users having ASCVD risk ≥20%.

CONCLUSIONS

Residual HTG occurs in over one-fifth (∼5.5 million) of U.S. adults with diabetes, including those on statin therapy and with well-controlled LDL-C. Over three-quarters of adults with diabetes with HTG are at moderate or high 10-year risk for ASCVD. Greater efforts are needed to promote lifestyle and pharmacologic means to address residual HTG.

Lipoprotein Particle Profiles, Standard Lipids, and Peripheral Artery Disease Incidence

BACKGROUND

Despite strong and consistent prospective associations of elevated low-density lipoprotein (LDL) cholesterol concentration with incident coronary and cerebrovascular disease, data for incident peripheral artery disease (PAD) are less robust. Atherogenic dyslipidemia characterized by increased small LDL particle (LDL-P) concentration, rather than total LDL cholesterol content, along with elevated triglyceride-rich lipoproteins and low high-density lipoprotein (HDL) cholesterol (HDL-C), may be the primary lipid driver of PAD risk.

METHODS

The study population was a prospective cohort study of 27 888 women ≥45 years old free of cardiovascular disease at baseline and followed for a median of 15.1 years. We tested whether standard lipid concentrations, as well as nuclear magnetic resonance spectroscopy-derived lipoprotein measures, were associated with incident symptomatic PAD (n=110) defined as claudication and/or revascularization.

RESULTS

In age-adjusted analyses, while LDL cholesterol was not associated with incident PAD, we found significant associations for increased total and small LDL-P concentrations, triglycerides, and concentrations of very LDL (VLDL) particle (VLDL-P) subclasses, increased total cholesterol (TC):HDL-C, low HDL-C, and low HDL particle (HDL-P) concentration (all P for extreme tertile comparisons <0.05). Findings persisted in multivariable-adjusted models comparing extreme tertiles for elevated total LDL-P (adjusted hazard ratio [HR_adj] 2.03; 95% CI, 1.14-3.59), small LDL-P (HR_adj 2.17; 95% CI, 1.10-4.27), very large VLDL-P (HR_adj 1.68; 95% CI, 1.06-2.66), medium VLDL-P (HR_adj 1.98; 95% CI, 1.15-3.41), and TC:HDL-C (HR_adj, 3.11; 95% CI, 1.67-5.81). HDL was inversely associated with risk; HR_adj for extreme tertiles of HDL-C and HDL-P concentration were 0.30 ( P trend < 0.0001) and 0.29 ( P trend < 0.0001), respectively. These components of atherogenic dyslipidemia, including small LDL-P, medium and very large VLDL-P, TC:HDL-C, HDL-C, and HDL-P, were more strongly associated with incident PAD than incident coronary and cerebrovascular disease. Finally, the addition of LDL-P and HDL-P concentration to TC:HDL-C measures identified women at heightened PAD risk.

CONCLUSIONS

In this prospective study, nuclear magnetic resonance-derived measures of LDL-P, but not LDL cholesterol, were associated with incident PAD. Other features of atherogenic dyslipidemia, including elevations in TC:HDL-C, elevations in triglyceride-rich lipoproteins, and low standard and nuclear magnetic resonance-derived measures of HDL, were significant risk determinants. These data help clarify prior inconsistencies and may elucidate a unique lipoprotein signature for PAD compared to coronary and cerebrovascular disease.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov/ . Unique Identifier: NCT00000479.

High-Density Lipoprotein Subclasses and Mild Cognitive Impairment: Study of Outcome and aPolipoproteins in Dementia (STOP-Dementia)1

BACKGROUND

High-density lipoprotein (HDL) containing apolipoprotein A-I is associated with the pathogenesis of Alzheimer's disease (AD). HDL particle size is modified in the presence of pathological conditions, while the significance of the HDL particle size remains controversial.

OBJECTIVE

The aim of this study was to investigate the HDL lipoprotein subclasses in mild cognitive impairment (MCI) and AD.

METHODS

This cross-sectional study included 20 AD patients, 17 MCI patients, and 17 age-matched controls without cognitive impairment, selected from the database of the Study of Outcome and aPolipoproteins in Dementia (STOP-Dementia) registry. The diagnoses of AD and MCI were performed by expert neurologists according to the Diagnostic and Statistical Manual of Mental Disorders-Fifth Edition criteria. Serum HDL subclasses were measured by electrophoretic separation of lipoproteins using the Lipoprint System. The neutrophil-lymphocyte ratio (NLR), a marker of inflammation, was calculated by dividing the neutrophil count by the lymphocyte count.

RESULTS

Small-sized HDL particle levels in the MCI group were significantly higher than in the control group, although there was no difference in serum HDL-cholesterol levels between MCI and control groups. NLR in the MCI group was higher than in the control group, but this difference was non-significant (p = 0.09). There was no difference in HDL subclasses or NLR between the AD and control groups.

CONCLUSION

These findings suggest that HDL subclasses might be associated with the development of MCI.

Impact of improved low-density lipoprotein cholesterol assessment on guideline classification in the modern treatment era-Results from a racially diverse Brazilian cross-sectional study

BACKGROUND

The Martin/Hopkins low-density lipoprotein cholesterol equation (LDL-C_N) was previously demonstrated as more accurate than Friedewald LDL-C estimation (LDL-C_F) in a North American database not able to take race into account.

OBJECTIVES

We hypothesized that LDL-C_N would be more accurate than LDL-C_F and correlate better with LDL particle number (LDL-P) in a racially diverse Brazilian cohort.

METHODS

We performed a cross-sectional analysis of 4897 participants in the Brazilian Longitudinal Study of Adult Health, assessing LDL-C_F and LDL-C_N accuracy via overlap with ultracentrifugation-based measurement among clinical guideline LDL-C categories as well as mg/dL and percent error differences. We analyzed by triglyceride categories and correlated LDL-C estimation with LDL-P.

RESULTS

LDL-C_N demonstrated improved accuracy at 70 to <100 and <70 mg/dL (P < .001), with large errors ≥20 mg/dL about 9 times more frequent in LDL-C_F at LDL-C <70 mg/dL, mainly due to underestimation. Among individuals with LDL-C <70 mg/dL and triglycerides ≥150 mg/dL, 65% vs 100% of ultracentrifugation-based low-density lipoprotein cholesterol calculation fell within appropriate categories of estimated LDL-C_F and LDL-C_N, respectively (P < .001). Similar results were observed when analyzed for age, sex, and race. Participants at LDL-C <70 and 70 to <100 mg/dL with discordantly elevated LDL-C_N vs LDL-C_F had a 58.5% and 41.5% higher LDL-P than those with concordance (P < .0001), respectively.

CONCLUSIONS

In a diverse Brazilian cohort, LDL-C_N was more accurate than LDL-C_F at low LDL-C and high triglycerides. LDL-C_N may avoid underestimation of LDL-C and better reflect atherogenic lipid burden in low particle size, high particle count states.

Two-Hour Postprandial Lipoprotein Particle Concentration Differs Between Lean and Obese Individuals

The concentrations of lipoprotein particles [high-density lipoproteins (HDLs), low-density lipoproteins (LDLs), very-low-density lipoproteins (VLDLs), and chylomicrons] are associated with the risk of cardiovascular diseases. Most studies have examined these associations in the fasting state. Previous studies have shown lipoprotein particle concentration change following meal, and these changes are different in individuals with obesity. In this study, we aimed to assess whether various meal compositions lead to adverse short-term (2-h) postprandial lipoproteinemia in obese insulin resistant (obese-IR) subjects as compared to lean insulin sensitive (lean-IS) subjects. In a randomized crossover trial, nine lean-IS and nine obese-IR Chinese men aged 22–35 years were challenged with isoenergetic and isovolumic meals rich in protein (HP), fat (HF), or carbohydrate (HC). Plasma samples were collected after a 10-h fast, as well as 1-h and 2-h post-meal and analyzed using nuclear magnetic resonance. Plasma concentration of large VLDLs and chylomicron particles was higher and increased more after all meals in obese-IR compared to lean-IS subjects. The HP meal decreased small LDL particle concentration in obese-IR subjects, and increased small HDL particle concentration in all subjects. The HF meal led to a decrease in small HDL concentration in all subjects. In conclusion, obese-IR subjects revealed a detrimental response to meal challenges even as early as 2-h after meal intake.

Relation of oxidized-low-density lipoprotein and high-density lipoprotein subfractions in non-treated patients with coronary artery disease

BACKGROUND

Oxidized-low-density lipoprotein (ox-LDL), as well as high-density lipoprotein (HDL) and its subfractions play important role in the development of coronary artery disease (CAD).

METHODS

A total of 1417 individuals who received selective coronary angiography (CAG) without lipids-lowering treatments were consecutively enrolled. Patients were divided into CAD (n = 942) and non-CAD group (n = 475). The severity of CAD was assessed by Gensini Scores (GS) system. The correlations of ox-LDL with HDL subfractions were analyzed.

RESULTS

Compared with non-CAD subjects, CAD patients had higher ox-LDL but lower concentrations of HDL cholesterol (p = 0.002) and large HDL subfractions (p = 0.004). And ox-LDL was negatively correlated with large HDL subfractions in patients with severe CAD (p < 0.05). Moreover, ox-LDL was elevated and large HDL subfractions decreased with the increase of the number of stenotic coronary arteries and GS (p < 0.05, respectivelly).

CONCLUSIONS

The correlations between ox-LDL and cholesterol level of large HDL particles varied among CAD and non-CAD, and CAD with different severities of atherosclerosis.

Small Dense Low-Density Lipoprotein Cholesterol Predicts Cardiovascular Events in Liver Transplant Recipients

Cardiovascular disease (CVD) is an important cause of morbidity and mortality after liver transplantation (LT). Although LT is associated with dyslipidemia, particularly atherogenic lipoprotein subparticles, the impact of these subparticles on CVD-related events is unknown. Therefore, the aim of the current study was to evaluate the impact of small dense (sdLDL-C) low-density lipoprotein (LDL) cholesterol (LDL-C) on CVD events. Prospectively enrolled patients (N = 130) had detailed lipid profile consisting of traditional lipid parameters and sdLDL-C and were followed for CVD events. The primary endpoint was a CVD composite consisting of myocardial infarction (MI), angina, need for coronary revascularization, and cardiac death. Mean age of the cohort was 58 ± 11 years, and the most common etiology of liver disease (LD) was hepatitis C virus (N = 48) and nonalcoholic steatohepatitis (N = 23). A total of 20 CVD events were noted after median follow-up of 45 months. The baseline traditional profile was similar in patients with and without CVD events. A serum LDL-C cutoff of 100 mg/dL was unable to identify individuals at risk of a CVD event (P = 0.86). In contrast, serum concentration of atherogenic sdLDL-C >25 mg/dL was predictive of CVD events with a hazard ratio of 6.376 (95% confidence interval, 2.65, 15.34; P < 0.001). This relationship was independent of diabetes, hypertension, sex, ethnicity, LD, obesity, and statin use. Conclusion: sdLDL-C independently predicted CVD events whereas LDL-C did not. Thus, sdLDL-C may provide a useful clinical tool in risk stratifying and managing patients after LT.

Optimal Non-invasive Strategies to Reduce Recurrent Atherosclerotic Cardiovascular Disease Risk

PURPOSE OF REVIEW

Cardiovascular disease (CVD) remains the leading cause of death worldwide, with coronary artery disease (CAD) responsible for the vast majority of these deaths. Incidence is increasing in developing countries, and prevalence is increasing globally as populations age. Once CAD is manifest, recurrent event risk remains high.

RECENT FINDINGS

Multiple therapeutic avenues have had significant recent developments, including diet, low-density lipoprotein cholesterol management, triglycerides, hypoglycemic agents, antiplatelet agents, and oral anticoagulants. Combined approaches involving specific, tailored lifestyle, and pharmacological interventions will provide the most effective strategy for reducing the risk of recurrent CVD events. Here, we review risk prediction and non-invasive non-pharmacologic and pharmacologic approaches to mitigate residual coronary artery disease risk.

Lorcaserin treatment decreases body weight and reduces cardiometabolic risk factors in obese adults: A six-month, randomized, placebo-controlled, double-blind clinical trial

Lorcaserin is a serotonin 2c receptor agonist that promotes weight loss while contributing to the prevention and improvement of type 2 diabetes and improvement of atherogenic lipid profiles, without higher rates of major cardiovascular events. The full spectrum of possible lorcaserin-induced improvements in cardiometabolic health remains to be clarified. Thus, we investigated the way in which lorcaserin treatment may alter cardiovascular disease risk, either independently or through changes in body weight. We measured, for the first time, lipid particle quantification, lipid peroxidation, appetite-regulating hormones and mRNA expression of the 5-hydroxytryptamine 2c receptor (5-HT2c receptor). A total of 48 obese participants were enrolled in this six-month, randomized (1:1), placebo-controlled, double-blinded clinical trial. Lorcaserin treatment reduced fat mass (P < 0.001), the fatty liver index (P < 0.0001) and energy intake (P < 0.03) without affecting energy expenditure or lean mass. Total low-density lipoprotein (LDL) (P < 0.04) and small LDL particles (P < 0.03) decreased, while total high-density lipoprotein (HDL) P < 0.02) increased and heart rate significantly decreased with lorcaserin treatment. No mRNA expression of the 5-HT2c receptor was observed in peripheral organs. These data suggest that lorcaserin treatment for six months improves cardiometabolic health in obese individuals, acting mainly through the brain.

Separating extracellular vesicles and lipoproteins via acoustofluidics

Extracellular vesicles (EVs) and lipoproteins are abundant and co-exist in blood. Both have been proven to be valuable as diagnostic biomarkers and for therapeutics. However, EVs and lipoproteins are both on the submicron scale and overlap in size distributions. Conventional methods to separate EVs and lipoproteins are inefficient and time-consuming. Here we present an acoustofluidic-based separation technique that is based on the acoustic property differences of EVs and lipoproteins. By using the acoustofluidic technology, EVs and subgroups of lipoproteins are separated in a label-free, contact-free, and continuous manner. With its ability for simple, rapid, efficient, continuous-flow isolation, our acoustofluidic technology could be a valuable tool for health monitoring, disease diagnosis, and personalized medicine.

The Effect of Bromodomain and Extra-Terminal Inhibitor Apabetalone on Attenuated Coronary Atherosclerotic Plaque: Insights from the ASSURE Trial

BACKGROUND

Apabetalone is a selective bromodomain and extra-terminal (BET) inhibitor which modulates lipid and inflammatory pathways implicated in atherosclerosis. The impact of apabetalone on attenuated coronary atherosclerotic plaque (AP), a measure of vulnerability, is unknown.

METHODS

The ApoA-1 Synthesis Stimulation and intravascular Ultrasound for coronary atheroma Regression Evaluation (ASSURE; NCT01067820) study employed serial intravascular ultrasound (IVUS) measures of coronary atheroma in 281 patients treated with apabetalone or placebo for 26 weeks. AP was measured at baseline and follow-up. Factors associated with changes in AP were investigated.

RESULTS

AP was observed in 31 patients (11%) [27 (13.0%) in the apabetalone group and four (5.5%) in the placebo group]. The apabetalone group demonstrated reductions in AP length by - 1 mm [interquartile range (IQR) - 4, 1] (p = 0.03), AP arc by - 37.0° (IQR - 59.2, 8.2) (p = 0.003) and the AP index by - 34.6 mm° (IQR - 52.6, 10.1) (p = 0.003) from baseline. The change in AP index correlated with on-treatment concentration of high-density lipoprotein (HDL) particles (r = - 0.52, p = 0.006), but not HDL cholesterol (r = - 0.11, p = 0.60) or apolipoprotein A-1 (r = - 0.16, p = 0.43). Multivariable analysis revealed that on-treatment concentrations of HDL particles (p = 0.03) and very low-density lipoprotein particles (p = 0.01) were independently associated with changes in AP index.

CONCLUSIONS

Apabetalone favorably modulated ultrasonic measures of plaque vulnerability in the population studied, which may relate to an increase in HDL particle concentrations. The clinical implications are currently being investigated in the phase 3 major adverse cardiac event outcomes trial BETonMACE.

Primary aldosteronism is associated with decreased low-density and high-density lipoprotein particle concentrations and increased GlycA, a pro-inflammatory glycoprotein biomarker

BACKGROUND

Primary aldosteronism (PA) may confer increased cardiovascular risk beyond effects on systemic blood pressure, but contributing mechanisms remain incompletely understood. We compared plasma (apo)lipoproteins and lipoprotein particle characteristics, GlycA, a pro-inflammatory glycoprotein biomarker of enhanced chronic inflammation, and plasma total branched-chain amino acids (BCAA), measured using nuclear magnetic resonance (NMR) spectroscopy, between patients with PA, control subjects without hypertension, subjects with untreated hypertension and subjects with treated hypertension.

METHODS

Twenty PA patients were individually matched with 2819 control subjects without hypertension, 501 subjects with untreated hypertension and 878 subjects with treated hypertension participating in the PREVEND (Prevention of Renal and Vascular End-Stage Disease) cohort study with respect to age, sex, body mass index, smoking and statin use. The Vantera® Clinical Analyzer was used to determine NMR-based laboratory parameters.

RESULTS

Total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), apolipoprotein (apo) B, apolipoprotein A-I (apoA-I), LDL particle and HDL particle concentrations were all decreased in PA subjects vs control subjects and subjects with untreated hypertension (P < 0.016). Triglycerides (TG) and triglyceride-rich lipoprotein (TRL) concentrations were lower in PA subjects vs subjects with (untreated) hypertension. GlycA was increased in PA vs the three comparator groups (P < 0.016). Total BCAA concentrations were unaltered in PA.

CONCLUSIONS

Primary aldosteronism is associated with lower concentrations of LDL and HDL particles and to some extent also with lower TG and TRL particle concentrations. PA is also characterized by increased GlycA levels, indicating enhanced low-grade chronic inflammation. Low HDL particle concentrations and increased GlycA could contribute to accelerated cardiovascular disease development in PA.

Small HDL subclass is associated with coronary plaque stability: An optical coherence tomography study in patients with coronary artery disease

BACKGROUND

The role of high-density lipoprotein (HDL) subclasses in atherosclerotic diseases remains an open question. Previous clinical trials have attempted to explore the predictive effect of HDL subspecies on cardiovascular risk. However, no studies have assessed the connections between these subclasses and characteristics of plaque microstructure.

OBJECTIVE

To investigate the relationship of HDL subclasses and coronary plaque stability assessed by optical coherence tomography (OCT).

METHODS

Morphological characteristics of 160 nontarget lesions from 85 patients with coronary artery disease were assessed by OCT. HDL subclass profiles were analyzed using nondenaturing polyacrylamide gel electrophoresis.

RESULTS

The plasma levels of small HDL subclass (percentage or concentration) were found to be positively associated with fibrous cap thickness (r = 0.232, P = .007; r = 0.243, P = .005) and negatively with maximum lipid arc (r = -0.240, P = .005; r = -0.252, P = .003) and lipid core length (r = -0.350, P < .001; r = -0.367, P < .001). Multivariate logistic regression analysis showed the small HDL subclass (percentage or concentration) (odds ratio [OR]: 0.457, 95% confidence interval [CI]: 0.214-0.974, P = .043; OR: 0.438, 95% CI: 0.204-0.938, P = .034) to be an independent factor in predicting OCT-detected thin-cap fibroatheroma of nontarget lesions.

CONCLUSION

High levels of small HDL are associated with coronary nontarget plaque stability. Our findings suggest that the small HDL subtype might represent the atheroprotective activity of HDL.

Markers of Atherosclerosis: Part 1 - Serological Markers

Atherosclerosis is a major contributor to morbidity and mortality worldwide. With therapeutic consequences in mind, several risk scores are being used to differentiate individuals with low, intermediate or high cardiovascular (CV) event risk. The most appropriate management of intermediate risk individuals is still not known, therefore, novel biomarkers are being sought to help re-stratify them as low or high risk. This narrative review is presented in two parts. Here, in Part 1, we summarise current knowledge on serum (serological) biomarkers of atherosclerosis. Among novel biomarkers, high sensitivity C-reactive protein (hsCRP) has emerged as the most promising in chronic situations, others need further clinical studies. However, it seems that a combination of serum biomarkers offers more to risk stratification than either biomarker alone. In Part 2, we address genetic and imaging markers of atherosclerosis, as well as other developments relevant to risk prediction.

Markers of Atherosclerosis: Part 2 - Genetic and Imaging Markers

This is Part 2 of a two-part review summarising current knowledge on biomarkers of atherosclerosis. Part 1 addressed serological biomarkers. Here, in part 2 we address genetic and imaging markers, and other developments in predicting risk. Further improvements in risk stratification are expected with the addition of genetic risk scores. In addition to single nucleotide polymorphisms (SNPs), recent advances in epigenetics offer DNA methylation profiles, histone chemical modifications, and micro-RNAs as other promising indicators of atherosclerosis. Imaging biomarkers are better studied and already have a higher degree of clinical applicability in cardiovascular (CV) event prediction and detection of preclinical atherosclerosis. With new methodologies, such as proteomics and metabolomics, discoveries of new clinically applicable biomarkers are expected.

Consumption of regular-fat vs reduced-fat cheese reveals gender-specific changes in LDL particle size - a randomized controlled trial

Background

Regular-fat cheese does not seem to increase low density lipoprotein cholesterol (LDL-C) concentrations compared to reduced-fat cheese. However, plasma LDL-C concentrations do not reflect levels and size of LDL particles, which might be a better predictor of cardiovascular risk.

Methods

The aim was to compare the effects of regular-fat cheese vs reduced-fat cheese and carbohydrate-rich foods on LDL particle size distribution in adults with ≥ 2 metabolic syndrome (MetS) risk factors. The study was part of a 12 weeks’ randomized controlled trial in which subjects had been randomly allocated to 1 of 3 intervention groups; regular-fat cheese (REG), reduced-fat cheese (RED) or a no-cheese/carbohydrate (CHO) group. Subjects in the REG and RED groups consumed 80 g cheese/d per 10 MJ, whereas subjects in the CHO consumed bread and jam corresponding to 90 g/d and 25 g/d per 10 MJ, respectively. Fasting blood samples at wk. 0 (baseline) and wk. 12 were analyzed for LDL particle size distribution and cholesterol content using nuclear magnetic resonance (NMR) spectroscopy.

Results

A total of 85 subjects [mean ± SD age: 54.0 ± 12.8 y; BMI: 28.7 ± 3.6 kg/m²] completed the study. Overall, regular-fat cheese did not impact lipoprotein particle number and size differently than reduced-fat cheese. In men (n = 23), the REG diet decreased total LDL particle number (LDL-P, − 223.2 ± 91.1 nmol/l, P = 0.01) compared with the RED diet. The reduction was primarily in the medium-sized LDL fraction (− 128.5 ± 51.8 nmol/l, P = 0.01). In women (n = 62), the REG diet increased the concentration of cholesterol in the small high density lipoprotein (HDL) particles compared with the CHO diet (2.9 ± 1.0 mg/dl, P = 0.006).

Conclusion

Overall, regular-fat cheese did not alter LDL particle size distribution compared to reduced-fat cheese after a 12 wk. intervention in subjects with ≥2 MetS risk factors. However, our results suggest that lipoprotein response to cheese intake is gender-specific. This warrants further investigation.

Trial registration

This trial was registered at Clinicaltrials.gov as NCT0261471. Registered 30 November 2015 - Retrospectively registered.

A comparative study of the effects of palm olein, cocoa butter and extra virgin olive oil on lipid profile, including low-density lipoprotein subfractions in young healthy Chinese people

The aim of this study is to investigate the effects of palm olein (POL), cocoa butter (CB) and extra virgin olive oil (EVOO) on the lipid profile and low-density lipoprotein subfractions in a young, healthy Chinese population. After screening, 72 subjects were randomly assigned to three groups, and an 18-week randomized crossover trial was conducted. The first phase was a 2-week run-in period, followed by three phases of the 4-week experimental periods with a 2-week washout period between experimental periods. Three groups of subjects alternately consumed a Chinese diet enriched with the different test oils. The various indices of subjects were collected before and after each experimental period. Sixty-seven subjects completed the study, and there were no significant differences in conventional indices amongst the three groups at the beginning of the three experimental periods (p > .05). Each test oil accounted for approximately 40% of total fat intake and approximately 11.3% of the total energy supply. After controlling for dietary interventions, only the serum triglyceride level of the POL-Diet was significantly lower than that of the EVOO-Diet (p = .034), and most indices did not significantly differ amongst the three test oil diets (p > .05). POL, CB and EVOO have almost identical effects on serum lipids.

Which Lipids Should Be Analyzed for Diagnostic Workup and Follow-up of Patients with Hyperlipidemias?

PURPOSE OF REVIEW

To summarize and discuss the clinical use of lipid and apolipoprotein tests in the settings of diagnosis and therapeutic follow-up of hyperlipidemia.

RECENT FINDINGS

The joint consensus panel of the European Atherosclerosis Society (EAS) and the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) recently produced recommendations on the measurement of atherogenic lipoproteins, taking into account the strengths and weaknesses of analytical and clinical performances of the tests. Total cholesterol, triglycerides, HDL cholesterol, LDL cholesterol, and calculated non-HDL cholesterol (= LDL + remnant cholesterol) constitute the primary lipid panel for hyperlipidemia diagnosis and cardiovascular risk estimation. LDL cholesterol is the primary target of lipid-lowering therapies. Non-HDL cholesterol or apolipoprotein B should be used as secondary therapeutic target in patients with mild-to-moderate hypertriglyceridemia, 2-10 mmol/l (175-880 mg/dl). Lipoprotein (a) is included in LDL cholesterol and should be measured at least once in all patients at cardiovascular risk, including to explain poor response to statin treatment.

Relation between high density lipoprotein particles concentration and cardiovascular events: a meta-analysis

Background

Trails aimed at raising high density lipoprotein(HDL) cholesterol concentration failed to make better cardiovascular outcomes. HDL particles may be better biomarkers reflecting properties of HDL. This meta-analysis was conducted to evaluate the relation between blood HDL particles level and cardiovascular events.

Methods

PubMed and other databases were searched for eligible studies and NewCastle-Ottawa Quality Assessment Scale(NOS) was used to assess the quality of included studies. A random or fixed-effect model was applied to calculate the pooled hazard ratio(HR).

Results

Twelve studies were finally included. The pooled HR(95%confidence interval) for per standard deviation(SD) increment and top quartile versus bottom quartile were 0.79(0.72,0.86) and 0.65(0.57,0.75), respectively. Subgroup analysis suggested that HR was significantly lower in subjects with a cardiovascular disease(CVD) history than that of people without established CVD. Subclass analysis indicated that HRs for per SD increment of small(0.85) and medium(0.84) HDL particles were significantly lower than that of large HDL particles(0.96).

Conclusions

HDL particle level in blood was inversely related to CVD events, indicating that HDL particles maybe a protective factor in patients with CVD, thus making HDL particles a potential biomarker and therapy target.

Pharmacological Management of Dyslipidemia in Atherosclerosis: Limitations, Challenges, and New Therapeutic Opportunities

Clinical and epidemiological studies during the last 7 decades indicated that elevated low-density lipoprotein cholesterol (LDL-C) levels and reduced high-density lipoprotein cholesterol (HDL-C) levels correlate with the pathogenesis and progression of atherosclerotic lesions in the arterial wall. This observation led to the development of LDL-C-lowering drugs for the prevention and treatment of atherosclerosis, some with greater success than others. However, a body of recent clinical evidence shows that a substantial residual cardiovascular risk exists even at very low levels of LDL-C, suggesting that new therapeutic modalities are still needed for reduction of atherosclerosis morbidity and mortality. Unfortunately, HDL-C-raising drugs developed toward this goal had disappointing results thus far. Here, we critically review the literature presenting available evidence and challenges that need to be met and discuss possible new avenues for the development of novel lipid pharmacotherapeutics to reduce the burden of atherosclerosis.

Quantifying Atherogenic Lipoproteins: Current and Future Challenges in the Era of Personalized Medicine and Very Low Concentrations of LDL Cholesterol. A Consensus Statement from EAS and EFLM

BACKGROUND

The European Atherosclerosis Society-European Federation of Clinical Chemistry and Laboratory Medicine Consensus Panel aims to provide recommendations to optimize atherogenic lipoprotein quantification for cardiovascular risk management.

CONTENT

We critically examined LDL cholesterol, non-HDL cholesterol, apolipoprotein B (apoB), and LDL particle number assays based on key criteria for medical application of biomarkers. (a) Analytical performance: Discordant LDL cholesterol quantification occurs when LDL cholesterol is measured or calculated with different assays, especially in patients with hypertriglyceridemia >175 mg/dL (2 mmol/L) and low LDL cholesterol concentrations <70 mg/dL (1.8 mmol/L). Increased lipoprotein(a) should be excluded in patients not achieving LDL cholesterol goals with treatment. Non-HDL cholesterol includes the atherogenic risk component of remnant cholesterol and can be calculated in a standard nonfasting lipid panel without additional expense. ApoB more accurately reflects LDL particle number. (b) Clinical performance: LDL cholesterol, non-HDL cholesterol, and apoB are comparable predictors of cardiovascular events in prospective population studies and clinical trials; however, discordance analysis of the markers improves risk prediction by adding remnant cholesterol (included in non-HDL cholesterol) and LDL particle number (with apoB) risk components to LDL cholesterol testing. (c) Clinical and cost-effectiveness: There is no consistent evidence yet that non-HDL cholesterol-, apoB-, or LDL particle-targeted treatment reduces the number of cardiovascular events and healthcare-related costs than treatment targeted to LDL cholesterol.

SUMMARY

Follow-up of pre- and on-treatment (measured or calculated) LDL cholesterol concentration in a patient should ideally be performed with the same documented test method. Non-HDL cholesterol (or apoB) should be the secondary treatment target in patients with mild to moderate hypertriglyceridemia, in whom LDL cholesterol measurement or calculation is less accurate and often less predictive of cardiovascular risk. Laboratories should report non-HDL cholesterol in all standard lipid panels.

Sex steroids mediate discrete effects on HDL cholesterol efflux capacity and particle concentration in healthy men

BACKGROUND

Exogenous testosterone decreases serum concentrations of high-density lipoprotein cholesterol (HDL-C) in men, but whether this alters cardiovascular risk is uncertain.

OBJECTIVE

To investigate the effects of testosterone and estradiol on HDL particle concentration (HDL-Pima) and metrics of HDL function.

METHODS

We enrolled 53 healthy men, 19 to 55 years of age, in a double-blinded, placebo-controlled, randomized trial. Subjects were rendered medically castrate using the GnRH receptor antagonist acyline and administered either (1) placebo gel, (2) low-dose transdermal testosterone gel (1.62%, 1.25 g), (3) full replacement dose testosterone gel (1.62%, 5 g) or (4) full replacement dose testosterone gel together with an aromatase inhibitor for 4 weeks. At baseline and end of treatment, serum HDL total macrophage and ABCA1-specific cholesterol efflux capacity (CEC), HDL-Pima and size, and HDL protein composition were determined.

RESULTS

Significant differences in serum HDL-C were observed with treatment across groups (P = .01 in overall repeated measures ANOVA), with increases in HDL-C seen after both complete and partial testosterone deprivation. Medical castration increased total HDL-Pima (median [interquartile range] 19.1 [1.8] nmol/L at baseline vs 21.3 [3.1] nmol/L at week 4, P = .006). However, corresponding changes in total macrophage CEC and ABCA1-specific CEC were not observed. Change in serum 17β-estradiol concentration correlated with change in total macrophage CEC (β = 0.33 per 10 pg/mL change in serum 17β-estradiol, P = .03).

CONCLUSIONS

Testosterone deprivation in healthy men leads to a dissociation between changes in serum HDL-C and HDL CEC. Changes in serum HDL-C specifically due to testosterone exposure may not reflect changes in HDL function.

High-Density Lipoprotein Infusions

High-density lipoproteins (HDLs) have presented an attractive target for development of new therapies for cardiovascular prevention on the basis of epidemiology and preclinical studies demonstrating their protective properties. Development of HDL mimetics provides an opportunity to administer functional HDL. However, clinical trials have produced variable results, with no evidence to date that they reduce cardiovascular events. This article reviews development programs of HDL mimetics.

Relations of GlycA and lipoprotein particle subspecies with cardiovascular events and mortality: A post hoc analysis of the AIM-HIGH trial

BACKGROUND

The Atherothrombosis Intervention in Metabolic Syndrome with Low HDL/High Triglycerides and Impact on Global Health Outcomes trial showed no incremental benefit of extended-release niacin (ERN) therapy added to simvastatin in subjects with cardiovascular disease (CVD).

OBJECTIVES

To examine the effects of ERN treatment on lipoprotein particles and GlycA, a new marker of systemic inflammation, and their relations with incident CVD events including mortality.

METHODS

GlycA and very low-density lipoprotein, low-density lipoprotein (LDL), and high-density lipoprotein (HDL) particle subclasses were quantified by nuclear magnetic resonance spectroscopy using available stored baseline (n = 2754) and 1-year in-trial (n = 2581) samples. Associations with CVD events and all-cause mortality were assessed using multivariable Cox proportional hazards regression adjusted for age, sex, diabetes, treatment assignment, and lipoproteins.

RESULTS

Compared to placebo, ERN treatment lowered very low-density lipoprotein and LDL and increased HDL particle concentrations, increased LDL and HDL particle sizes (all P < .0001), but did not affect GlycA. Baseline and in-trial GlycA levels were associated with increased risk of CVD events: hazard ratio (HR) per SD increment, 1.17 (95% confidence interval [CI], 1.06-1.28) and 1.13 (1.02-1.26), respectively. However, none of the lipoprotein particle classes or subclasses was associated with incident CVD. By contrast, all-cause mortality was significantly associated with both GlycA (baseline HR: 1.46 [1.22-1.75]; in-trial HR: 1.41 [1.24-1.60]) and low levels of small HDL particles (baseline HR: 0.69 [0.56-0.86]; in-trial HR: 0.69 [0.56-0.86]).

CONCLUSIONS

This Atherothrombosis Intervention in Metabolic Syndrome with Low HDL/High Triglycerides and Impact on Global Health Outcomes trial post hoc substudy indicates that inflammation, as indexed by GlycA, is unaffected by ERN treatment but is significantly associated with the residual risk of CVD and death in patients treated to low levels of LDL cholesterol.

Update on the laboratory investigation of dyslipidemias

The role of the clinical laboratory is evolving to provide more information to clinicians to assess cardiovascular disease (CVD) risk and target therapy more effectively. Current routine methods to measure LDL-cholesterol (LDL-C), the Friedewald calculation, ultracentrifugation, electrophoresis and homogeneous direct methods have established limitations. Studies suggest that LDL and HDL size or particle concentration are alternative methods to predict future CVD risk. At this time there is no consensus role for lipoprotein particle or subclasses in CVD risk assessment. LDL and HDL particle concentration are measured by several methods, namely gradient gel electrophoresis, ultracentrifugation-vertical auto profile, nuclear magnetic resonance and ion mobility. It has been suggested that HDL functional assays may be better predictors of CVD risk. To assess the issue of lipoprotein subclasses/particles and HDL function as potential CVD risk markers robust, simple, validated analytical methods are required. In patients with small dense LDL particles, even a perfect measure of LDL-C will not reflect LDL particle concentration. Non-HDL-C is an alternative measurement and includes VLDL and CM remnant cholesterol and LDL-C. However, apolipoprotein B measurement may more accurately reflect LDL particle numbers. Non-fasting lipid measurements have many practical advantages. Defining thresholds for treatment with new measurements of CVD risk remain a challenge. In families with genetic variants, ApoCIII and lipoprotein (a) may be additional risk factors. Recognition of familial causes of dyslipidemias and diagnosis in childhood will result in early treatment. This review discusses the limitations in current laboratory technologies to predict CVD risk and reviews the evidence for emergent approaches using newer biomarkers in clinical practice.

Novel findings in relation to multiple anti-atherosclerotic effects of XueZhiKang in humans

Background

Previous studies have clearly demonstrated that XueZhiKang (XZK), an extract of cholestin, can decrease low-density lipoprotein cholesterol (LDL-C) and cardiovascular events. However, the mechanism of the effects of XZK on atherosclerosis (AS) in humans has been reported less frequently. In the present study, we investigated the impact of XZK on lipoprotein subfractions, oxidized LDL (oxLDL), and interleukin-6 (IL-6).

Methods

From October 2015 to July 2016, 40 subjects were enrolled in this study. Of them, 20 subjects with dyslipidemia received XZK 1200 mg/day for 8 weeks (XZK group); 20 additional healthy subjects who did not receive therapy acted as controls. The plasma lipoprotein subfractions, oxLDL, and IL-6 were examined at baseline and again at 8 weeks.

Results

Data showed that XZK could significantly decrease not only plasma LDL-C levels (87.26 ± 24.45 vs. 123.34 ± 23.99, P < 0.001), total cholesterol (4.14 ± 0.87 vs. 5.08 ± 1.03, P < 0.001), triglycerides (0.95 ± 0.38 vs. 1.55 ± 0.61, P < 0.05), and apolipoprotein B (1.70 ± 0.35 vs. 1.81 ± 0.72, P < 0.05), but also oxLDL (36.36 ± 5.31 vs. 49.20 ± 15.01, P < 0.05) and IL-6 (8.50 ± 7.40 vs. 10.40 ± 9.49, P < 0.05). At the same time, XZK reduced the concentration of small LDL-C (1.78 ± 2.17 vs. 6.33 ± 7.78, P < 0.05) and the percentage of the small LDL subfraction (1.09 ± 1.12 vs. 3.07 ± 3.09, P < 0.05).

Conclusions

Treatment with 1200 mg/day XZK for 8 weeks significantly decreased the atherogenic small LDL subfraction and reduced oxidative stress and inflammatory markers, in addition to affecting the lipid profile, suggesting multiple beneficial effects in coronary artery disease.

The association between HDL particle concentration and incident metabolic syndrome in the multi-ethnic Dallas Heart Study

AIMS

Metabolic syndrome (MetS) increases atherosclerotic cardiovascular disease (ASCVD) risk. Low HDL cholesterol (HDL-C) is a diagnostic criterion of MetS and a major ASCVD risk factor. HDL particle concentration (HDL-P) associates with incident ASCVD independent of HDL-C, but its association with incident MetS has not been studied. We hypothesized that HDL-P would be inversely associated with incident metabolic syndrome independent of HDL-C and markers of adiposity and insulin resistance.

MATERIALS AND METHODS

HDL-P was measured by NMR and visceral fat by MRI in participants of the Dallas Heart Study, a probability-based population sample of adults age 30-65. Participants with prevalent MetS, DM, CVD, and any systemic illlness were excluded. Incident MetS as defined by NCEP ATPIII criteria was determined in all participants after median follow-up period of 7.0 years.

RESULTS

Among 1120 participants without DM or MetS at baseline (57% women, 45% Black, mean age 43), 22.8% had incident MetS at follow-up. HDL-P and HDL-C were modestly correlated (r=0.54, p<0.0001). In models adjusted for traditional risk factors and MetS risk factors including visceral fat, HS-CRP, triglyceride to HDL-C ratio, and HOMA-IR, the lowest quartile of HDL-P was associated with a 2-fold increased risk of incident MetS (OR 2.1, 95%CI 1.4-3.1; p=0.0003).

CONCLUSIONS

Low HDL-P is independently associated with incident MetS after adjustment for traditional risk factors, lipid parameters, adiposity, inflammation, and markers of insulin resistance. Further studies are warranted to validate these findings and elucidate the mechanisms underpinning this association.

Gender-specific association of metabolic syndrome and its components with arterial stiffness in the general Chinese population

OBJECTIVES

Metabolic syndrome (MS) is considered to be a cluster of interrelated risk factors for metabolism, which may increase arterial stiffness and cardiovascular morbidity. The cardio-ankle vascular index (CAVI) is a reliable indicator of arterial stiffness and early arteriosclerosis. The main objective of this study is to evaluate the gender-specific relationship between MS and CAVI in the general Chinese population.

METHODS

A total of 1,301 subjects aged 20 to 60 years participated in this study. CAVI was measured noninvasively using a Vasera VS-1000 device. Blood samples and waist circumference were examined to identify metabolic syndrome according to the criteria set forth in the 2009 Joint Scientific Statement.

RESULTS

The prevalence of MS in the study subjects was 17.4% (30.7% in males and 7.0% in females, P < 0.001). CAVI values were significantly higher in MS subjects than in non-MS subjects and increased linearly as the number of MS components increased in females, but not in males. Using multiple regression analysis, we found that BMI was correlated with CAVI in the overall population and in both genders, and that high-density lipoprotein cholesterol (HDL-C) was associated with CAVI in males, while the number of MS components was related to CAVI in females. CAVI values increased linearly with age in both genders (P-trend < 0.001 for both), and this correlation was stronger in males than in females.

CONCLUSIONS

There are gender-specific differences in the association of MS and CAVI. First, the effects of the number of MS components on CAVI are stronger in females than in males. Second, the effect of each MS component on arterial stiffness may differ in relation to gender. In addition, aging affects arterial stiffness more severely in males, and the increase in arterial stiffness tends to occur at a younger age in males than in females. Larger samples and longitudinal studies are needed to further confirm our results in the future.

High-Density Lipoprotein Subclasses, Coronary Artery Disease, and Cardiovascular Mortality

BACKGROUND

The inverse relationship between HDL cholesterol and cardiovascular mortality is weakened in coronary artery disease (CAD). We aimed to investigate the associations of HDL particle concentrations with cardiovascular mortality and the impact of CAD on these associations. We also sought to comparatively evaluate HDL cholesterol and HDL particle concentrations in predicting cardiovascular mortality.

METHODS

Total and subclass HDL particle concentrations were measured by nuclear magnetic resonance spectroscopy in 2290 participants of the LUdwigshafen RIsk and Cardiovascular Health study referred for coronary angiography. The participants were prospectively followed over a median (interquartile range) duration of 10.0 (6.1-10.6) years.

RESULTS

The mean (SD) age of the participants (1575 males, 715 females) was 62.9 (10.4) years; body mass index, 27.6 (4.1) kg/m²; HDL cholesterol, 39 (11) mg/dL [1 (0.29) mmol/L]; and total HDL particle concentration, 24.1 (5.8) μmol/L. Of the participants, 434 died from cardiovascular diseases. In multivariate analyses, tertiles of total HDL particle concentrations were inversely related to cardiovascular mortality (hazard ratio for third vs first tertile = 0.55, P < 0.001). This association was primarily mediated by small HDL particles (P < 0.001). Adding total or small HDL particle concentrations rather than HDL cholesterol to multivariate prediction models improved performance metrics for cardiovascular mortality. The presence of CAD had no impact on the associations between HDL particle concentrations and cardiovascular mortality.

CONCLUSIONS

High HDL particle concentration is consistently and independently of CAD associated with decreased cardiovascular mortality. Whether the inverse relationship between HDL particle concentration and cardiovascular mortality may be translated into novel therapies is under investigation.

Association of low-density lipoprotein pattern with mortality after myocardial infarction: Insights from the TRIUMPH study

BACKGROUND

Studies of incident coronary heart disease risk within low-density lipoprotein (LDL) subclass (small, dense vs large, buoyant) have shown mixed results. No prospective cohort study has examined the association of small, dense, or large, buoyant LDL with mortality after myocardial infarction (MI).

OBJECTIVE

The objective of the study was to examine association of LDL pattern after MI and death.

METHODS

In 2476 patients hospitalized for MI, LDL pattern (A [large, buoyant], A/B [mixed], and B [small, dense]) was established by ultracentrifugation using Vertical Auto Profile. Using time-to-event analysis, we examined the association with 5-year mortality within LDL patterns, after adjusting for important patient and treatment characteristics. We additionally adjusted for LDL cholesterol (LDL-C) and triglyceride levels and used directly measured LDL-C and non-high-density lipoprotein cholesterol as exposures.

RESULTS

Patterns A, A/B, and B were present in 39%, 28%, and 33% of patients, respectively, with incident rates (per 1000 patient-years) of 50, 34, and 24 for all-cause and 24, 19, and 10 for CV mortality. The hazard ratios (95% confidence interval) with LDL patterns A/B and B compared with pattern A were 0.77 (0.61, 0.99) and 0.67 (0.51, 0.88) for all-cause, 0.94 (0.67, 1.33) and 0.69 (0.46, 1.03) for cardiovascular, and 0.64 (0.45, 0.91) and 0.65 (0.45, 0.93) for noncardiovascular mortalities, respectively. Results were similar when further adjusted for LDL-C and triglycerides, or with LDL-C and non-high-density lipoprotein cholesterol as exposures.

CONCLUSION

Compared with LDL pattern A, pattern B was significantly associated with reduced all-cause and non-CV mortalities with a trend for lower CV mortality after MI, independent of LDL-C and triglycerides.

Advanced lipoprotein testing for cardiovascular diseases risk assessment: a review of the novel approaches in lipoprotein profiling

With the increasing prevalence of cardiovascular diseases (CVD) worldwide, finding reliable and clinically relevant biomarkers to predict acute cardiovascular events has been a major aim of the scientific and medical community. Improvements of the understanding of the pathophysiological pathways of the disease highlighted the major role of lipoprotein particles, and these past decades have seen the emergence of a number of new methodologies to separate, measure and quantitate lipoproteins. Those methods, also known as advanced lipoprotein testing methods (ALT), have gained acceptance in the field of CVD risk assessment and have proven their clinical relevance. In the context of worldwide standardization and harmonization of biological assays, efforts have been initiated toward standardization of ALT methods. However, the complexity of lipoprotein particles and the multiple approaches and methodologies reported to quantify them have rendered these initiatives a critical issue. In this context and to better understand these challenges, this review presents a summary of the major methods available for ALT with the aim to point out the major differences in terms of procedures and quantities actually measured and to discuss the resulting comparability issues.

Serum inhibitory factor 1, high-density lipoprotein and cardiovascular diseases

PURPOSE OF REVIEW

The atheroprotective properties of HDL are supported by epidemiological and preclinical research. However, the results of interventional trials paradoxically indicate that drugs increasing HDL-cholesterol (HDL-C) do not reduce coronary artery disease (CAD) risk. Moreover, Mendelian randomization studies have shown no effect of HDL-C-modifying variants on CAD outcome. Thus, the protective effects of HDL particles are more governed by their functional status than their cholesterol content. In this context, any successful clinical exploitation of HDL will depend on the identification of HDL-related biomarkers, better than HDL-C level, for assessing cardiovascular risk and monitoring responses to treatment.

RECENT FINDINGS

Recent studies have enlightened the role of ecto-F1-ATPase as a cell surface receptor for apoA-I, the major apolipoprotein of HDL, involved in the important metabolic and vascular atheroprotective functions of HDL. In the light of these findings, the clinical relevance of ecto-F1-ATPase in humans has recently been supported by the identification of serum F1-ATPase inhibitor (IF1) as an independent determinant of HDL-C, CAD risk and cardiovascular mortality in CAD patients.

SUMMARY

Serum IF1 measurement might be used as a novel HDL-related biomarker to better stratify risk in high-risk populations or to determine pharmacotherapy.

High-density lipoprotein particle pattern and overall lipid responses to a short-term moderate-intensity aerobic exercise training intervention in patients with chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) is associated with abnormal lipid profiles and altered high-density lipoprotein (HDL) particle size patterns. Lower levels of the larger, cardioprotective HDL particles found in CKD may play a role in the increased risk for cardiovascular disease in these patients. The current study was designed to assess the effects of short-term moderate-intensity aerobic exercise training on the HDL particle pattern and overall lipid profiles in stage 3 CKD patients.

METHODS

Forty-six men and women with stage 3 CKD were randomized to either exercise (EX, n = 25) or control (CON, n = 21). Those in the EX group completed 16 weeks of supervised moderate-intensity aerobic exercise three times per week. Serum total cholesterol, HDL cholesterol (HDL-C), triglycerides (TGs), low-density lipoprotein cholesterol (LDL-C), HDL particle size, estimated glomerular filtration rate (eGFR), body composition and peak oxygen uptake (VO2peak) were assessed at baseline and week 16.

RESULTS

The rate of compliance in the EX group was 97 ± 7.2%. No change was observed in eGFR over time in either group. There was an 8.2% improvement in VO2peak in the EX group (P = 0.05), while VO2peak decreased in the CON group. HDL-C, TGs, HDL particle size and body composition remained unchanged in both groups. A trend was found for lower total cholesterol (TC) (P = 0.051) and LDL-C (P = 0.07) in the CON group.

CONCLUSION

Our findings indicate that a short-term aerobic exercise training intervention in stage 3 CKD patients does not induce changes in HDL particle size or favorable lipid profile modifications.

LDL subfractions are associated with incident cardiovascular disease in the Malmö Prevention Project Study

BACKGROUND AND AIMS

After assessing the risk for cardiovascular disease (CVD) based on traditional risk factors, decisions concerning lipid lowering therapy might remain uncertain. To investigate whether lipoprotein subfraction levels could aid these decisions, we assessed the association between lipoprotein subfractions and CVD, after adjustment for traditional risk factors including standard lipids.

METHODS

Using a case-cohort design, participants were randomly drawn from the Malmö Prevention Project (MPP), a population-based prospective study of 18,240 participants, and supplemented with additional incident CVD events (5764 participants, 1784 CVD events).

RESULTS

Low density lipoprotein particle number (LDL-P) and individual subfractions ranging in size from very-small to large were associated with CVD (continuous p value (p_cont) < 0.001) while adjusting for age, sex, hypertension, smoking, and diabetes. After further adjustment for LDL-C, HDL-C, and triglycerides, very small LDL subfraction (b) (LDL-VS (b)) remained associated with CVD (HR = 1.23, 95% CI, 1.06 to 1.43 for top vs. bottom quartile, p_cont = 0.03). Among participants with low/intermediate risk [without diabetes and with LDL-C <3.36 mmol/L (<130 mg/dL)], the fully adjusted HR for LDL-small (top vs. bottom quartile) was 1.48 (95% CI 1.02 to 2.17, p_cont = 0.03). Among those with very-high risk (>20% 10-year risk of CVD), LDL-VS(a) and LDL-VS(b) were associated with CVD in fully adjusted models (HR = 1.37, 95% CI 1.12 to 1.67 and HR = 1.28, 95% CI 1.07 to 1.53, respectively, p_cont≤0.03).

CONCLUSIONS

Smaller LDL particles are associated with incident CVD independently of traditional risk factors, including standard lipids, in participants with low/intermediate and very-high risk, who might benefit from improved risk assessment.

Low high-density lipoprotein cholesterol and particle concentrations are associated with greater levels of endothelial activation markers in Multi-Ethnic Study of Atherosclerosis participants

BACKGROUND

High-density lipoproteins (HDL) are well characterized for their role in reverse cholesterol transport but may confer other cardiovascular benefits-specifically, HDL may suppress the endothelial activation cascade in the initiating stages of atherogenesis.

OBJECTIVE

It was the primary aim of this study to examine the relations of HDL cholesterol (HDL-C), total HDL particle (HDL-P) concentrations, and HDL-P subclasses with circulating levels of endothelial activation markers in a subcohort of Multi-Ethnic Study of Atherosclerosis participants.

METHODS

HDL-C was measured by enzymatic assay, and total HDL-P and subclass concentrations were assessed by nuclear magnetic resonance spectroscopy. Concentrations of circulating endothelial activation markers were determined through immunoassay. Multivariable linear regression was used to determine the cross-sectional associations between HDL variables and endothelial markers with statistical adjustment for age, race/ethnicity, sex, education, systolic blood pressure, hypertension medication use, body mass index, smoking status, lipid-lowering medication use, serum creatinine, diabetes, low-density lipoprotein cholesterol, and coronary artery calcium.

RESULTS

HDL-C and HDL-P were found to be inversely associated with soluble vascular cell adhesion molecule-1, soluble vascular intracellular adhesion molecule-1, sL-selectin, and sP-selectin; HDL-P was additionally inversely associated with sE-selectin. Participants with low levels of HDL-C (<40 mg/dL) or HDL-P (<25th percentile) showed 3%-12% higher mean levels of soluble vascular cell adhesion molecule and compared with those above these levels (all P < .01).

CONCLUSION

Coupled with previous evidence, our findings suggest a modest to moderate relation of HDL and circulating levels of endothelial activation markers in humans. Whether this relationship may have clinical implications in suppressing atherogenesis or coronary heart disease development requires additional research.

High-density lipoprotein cholesterol levels are associated with coronary severity but not with outcomes in new-onset patients with stable coronary artery disease

BACKGROUND AND AIMS

The atheroprotective role of high-density lipoprotein cholesterol (HDL-C) levels in coronary artery disease (CAD) remains controversial. This study sought to reappraise the value of HDL-C in predicting the severity and outcomes of new-onset patients with stable CAD in Chinese populations.

METHODS

A total of 4205 new-onset patients with stable CAD who received coronary angiography were enrolled to analyze the relation of HDL-C to coronary severity and major adverse cardiovascular events (MACEs). Coronary severity was evaluated by Gensini scoring system. The MACEs included all-cause death, non-fatal myocardial infarction, stroke, unplanned revascularization and hospitalized unstable angina.

RESULTS

Significantly, HDL-C levels were negatively associated with coronary severity (p < 0.001). During an average of 27.32-month follow-up, 341 (8.12%) MACEs occurred. There was no significant difference of HDL-C levels between events group and non-events group. Furthermore, both Kaplan-Meier and Cox regression analyses found no relationship between HDL-C and cardiovascular outcomes (p > 0.05).

CONCLUSIONS

Plasma HDL-C levels appeared to be a predicator for coronary severity, but it is not associated with clinical outcomes in new-onset, Chinese patients with stable CAD.

Lipoprotein particle number and size predict vascular structure and function better than traditional lipids in adolescents and young adults

BACKGROUND

In adults, dyslipidemia is associated with higher carotid thickness and arterial stiffness, predictors of cardiovascular events. In young subjects, lipid concentrations have not been consistently associated with vascular measures.

OBJECTIVE

The objective of the study was to compare nuclear magnetic resonance (NMR) measures of lipoprotein particle number (low-density lipoprotein [LDL] particle, low-density lipoprotein [HDL] particle, very low-density lipoprotein [VLDL] particle) and size (LDL size, HDL size, and VLDL size) to determine if they were associated with vascular measures more strongly than lipid concentrations (LDL cholesterol, HDL cholesterol, and triglyceride [TG]).

METHODS

We evaluated 214 lean (L), 228 obese (O), and 214 diabetic (T2DM) subjects aged 10 to 24 years (33% male and 39% Caucasian). Cardiovascular risk factors, vascular structure, and arterial stiffness were measured. General linear models were constructed including demographics, risk factors, and traditional or NMR lipid parameters. A composite vascular function score was developed as the outcome in receiver operator characteristic scores for determining which lipid parameter was superior in predicting vascular damage.

RESULTS

Risk factors worsened from L to O to T. However, LDL cholesterol was similar in O and T, whereas LDL size differentiated the 3 groups (T > O > L, P ≤ .0001). Models demonstrated the superiority of NMR values, which entered for all but 1 vascular outcome and explained more of the variance than traditional lipid concentrations. Receiver operator characteristic curves demonstrated that NMR values were superior in predicting vascular outcomes. Models stratified by race were similar but cutpoints predicting vascular outcomes differed by race for TG, TG/HDL, and VLDL.

CONCLUSION

Lipoprotein particle number and size are more strongly related to vascular structure and function than traditional lipid values. NMR lipid measures may be a better indicator of risk for target organ damage than traditional lipid measures in adolescents and young adults.

Metabolic profiling of polycystic ovary syndrome reveals interactions with abdominal obesity

Background:

Polycystic ovary syndrome (PCOS) is a common reproductive disorder associated with metabolic disturbances including obesity, insulin resistance and diabetes mellitus. Here we investigate whether changes in the metabolic profile of PCOS women are driven by increased tendency to obesity or are specific features of PCOS related to increased testosterone levels.

Design and methods:

We conducted an NMR metabolomics association study of PCOS cases (n=145) and controls (n=687) nested in a population-based birth cohort (n=3127). Subjects were 31 years old at examination. The main analyses were adjusted for waist circumference (WC) as a proxy measure of central obesity. Subsequently, metabolite concentrations were compared between cases and controls within pre-defined WC strata. In each stratum, additional metabolomics association analyses with testosterone levels were conducted separately among cases and controls.

Results:

Overall, women with PCOS showed more adverse metabolite profiles than the controls. Four lipid fractions in different subclasses of very low density lipoprotein (VLDL) were associated with PCOS, after adjusting for WC and correction for multiple testing (P<0.002). In stratified analysis the PCOS women within large WC strata (⩾98 cm) had significantly lower high density lipoprotein (HDL) levels, Apo A1 and albumin values compared with the controls. Testosterone levels were significantly associated with VLDL and serum lipids in PCOS cases with large WC but not in the controls. The higher testosterone levels, adjusted for WC, associated adversely with insulin levels and HOMA IR in cases but not in the controls.

Conclusions:

Our findings show that both abdominal obesity and hyperandrogenism contribute to the dyslipidaemia and other metabolic traits of PCOS which all may negatively contribute to the long-term health of women with PCOS.

Cholesterol Efflux Capacity, High-Density Lipoprotein Particle Number, and Incident Cardiovascular Events: An Analysis From the JUPITER Trial (Justification for the Use of Statins in Prevention: An Intervention Trial Evaluating Rosuvastatin)

BACKGROUND

Recent failures of drugs that raised high-density lipoprotein (HDL) cholesterol levels to reduce cardiovascular events in clinical trials have led to increased interest in alternative indices of HDL quality, such as cholesterol efflux capacity, and HDL quantity, such as HDL particle number. However, no studies have directly compared these metrics in a contemporary population that includes potent statin therapy and low low-density lipoprotein cholesterol.

METHODS

HDL cholesterol levels, apolipoprotein A-I, cholesterol efflux capacity, and HDL particle number were assessed at baseline and 12 months in a nested case-control study of the JUPITER trial (Justification for the Use of Statins in Prevention: An Intervention Trial Evaluating Rosuvastatin), a randomized primary prevention trial that compared rosuvastatin treatment to placebo in individuals with normal low-density lipoprotein cholesterol but increased C-reactive protein levels. In total, 314 cases of incident cardiovascular disease (CVD) (myocardial infarction, unstable angina, arterial revascularization, stroke, or cardiovascular death) were compared to age- and gender-matched controls. Conditional logistic regression models adjusting for risk factors evaluated associations between HDL-related biomarkers and incident CVD.

RESULTS

Cholesterol efflux capacity was moderately correlated with HDL cholesterol, apolipoprotein A-I, and HDL particle number (Spearman r= 0.39, 0.48, and 0.39 respectively; P<0.001). Baseline HDL particle number was inversely associated with incident CVD (adjusted odds ratio per SD increment [OR/SD], 0.69; 95% confidence interval [CI], 0.56-0.86; P<0.001), whereas no significant association was found for baseline cholesterol efflux capacity (OR/SD, 0.89; 95% CI, 0.72-1.10; P=0.28), HDL cholesterol (OR/SD, 0.82; 95% CI, 0.66-1.02; P=0.08), or apolipoprotein A-I (OR/SD, 0.83; 95% CI, 0.67-1.03; P=0.08). Twelve months of rosuvastatin (20 mg/day) did not change cholesterol efflux capacity (average percentage change -1.5%, 95% CI, -13.3 to +10.2; P=0.80), but increased HDL cholesterol (+7.7%), apolipoprotein A-I (+4.3%), and HDL particle number (+5.2%). On-statin cholesterol efflux capacity was inversely associated with incident CVD (OR/SD, 0.62; 95% CI, 0.42-0.92; P=0.02), although HDL particle number again emerged as the strongest predictor (OR/SD, 0.51; 95% CI, 0.33-0.77; P<0.001).

CONCLUSIONS

In JUPITER, cholesterol efflux capacity was associated with incident CVD in individuals on potent statin therapy but not at baseline. For both baseline and on-statin analyses, HDL particle number was the strongest of 4 HDL-related biomarkers as an inverse predictor of incident events and biomarker of residual risk.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00239681.

Gemfibrozil, food and drug administration-approved lipid-lowering drug, increases longevity in mouse model of late infantile neuronal ceroid lipofuscinosis

Late Infantile Neuronal Ceroid Lipofuscinosis (LINCL) is a rare neurodegenerative disease caused by mutations in the Cln2 gene that leads to deficiency or loss of function of the tripeptidyl peptidase 1 (TPP1) enzyme. TPP1 deficiency is known to cause the accumulation of autofluoroscent lipid-protein pigments in brain. Similar to other neurodegenerative disorders, LINCL is also associated with neuroinflammation and neuronal damage. Despite investigations, no effective therapy is currently available for LINCL. Therefore, we administered gemfibrozil (gem), an food and drug administration (FDA)-approved lipid-lowering drug, which has been shown to stimulate lysosomal biogenesis and induce anti-inflammation, orally, at a dose of 7.5 mg/kg body wt/day to Cln2^(-/-) mice. We observed that gem-fed Cln2^(-/-) mice lived longer by more than 10 weeks and had better motor activity compared to vehicle (0.1% Methyl cellulose) treatment. Gem treatment lowered the burden of storage materials, increased anti-inflammatory factors like SOCS3 and IL-1Ra, up-regulated anti-apoptotic molecule like phospho-Bad, and reduced neuronal apoptosis in the brain of Cln2^(-/-) mice. Collectively, this study reinforces a neuroprotective role of gem that may be of therapeutic interest in improving the quality of life in LINCL patients.

The role of HDL in plaque stabilization and regression: basic mechanisms and clinical implications

On the basis of studies that extend back to the early 1900s, regression and stabilization of atherosclerosis in humans has progressed from being a concept to one that is achievable. Successful attempts at regression generally applied robust measures to improve plasma lipoprotein profiles. Possible mechanisms responsible for lesion shrinkage include decreased retention of atherogenic apolipoprotein B within the arterial wall, efflux of cholesterol and other toxic lipids from plaques, emigration of lesional foam cells out of the arterial wall, and influx of healthy phagocytes that remove necrotic debris as well as other components of the plaque. Currently available clinical agents, however, still fail to stop most cardiovascular events. For years, HDL has been considered the 'good cholesterol.' Clinical intervention studies to causally link plasma HDL-C levels to decreased progression or to the regression of atherosclerotic plaques are relatively few because of the lack of therapeutic agents that can selectively and potently increase HDL-C. The negative results of studies that were carried out have led to uncertainty as to the role that HDL plays in atherosclerosis. It is becoming clearer, however, that HDL function rather than quantity is most crucial and, therefore, discovery of agents that enhance the quality of HDL should be the goal.

Role of Niacin in Current Clinical Practice: A Systematic Review

BACKGROUND

Niacin, a potent high-density lipoprotein cholesterol-raising drug, seems an attractive approach to reduce cardiac events in patients with or at risk of atherosclerotic cardiovascular disease. However, previous evidence for niacin has been challenged recently by negative outcomes in 2 large, randomized, controlled trials comparing niacin to placebo with background statin therapy. We studied the currently available evidence for the role of niacin treatment for reducing the risk of cardiovascular events in current practice.

METHODS

A systematic review of randomized controlled trials in the MEDLINE, EMBASE, CINAHL, and Cochrane databases comparing niacin alone or combined with statin therapy was performed. We extracted trial level data, including basic characteristics and number of patients enrolled, duration of follow up, occurrence of adverse events, and cardiovascular-related outcomes. Random effects meta-analysis was conducted to estimate the risk ratio (RR) for individual trial endpoints.

RESULTS

Thirteen trials (N = 35,206) were selected for final analysis. The mean follow-up duration was 32.8 months. Overall, niacin led to significant increases in serum high-density lipoprotein cholesterol levels from baseline trial enrolment by 21.4%, 9.31 (95% confidence interval [CI] 5.11-13.51) mg/dL. However, we did not observe any differences in all-cause mortality rates (RR 0.99; 95% CI 0.88-1.12) between niacin and control arms. Further, niacin treatment was associated with a trend toward lower risk of cardiovascular mortality (RR 0.91; 95% CI 0.81-1.02), coronary death (RR 0.93; 95% CI 0.78-1.10), nonfatal myocardial infarction (RR 0.85; 95% CI 0.73-1.0), revascularization (coronary and noncoronary) (RR 0.83; 95% CI 0.65-1.06), and stroke (RR 0.89; 95% CI 0.72-1.10), compared with control.

CONCLUSION

Niacin therapy does not lead to significant reductions in total or cause-specific mortality or recurrent cardiovascular events among persons with or at risk of atherosclerotic cardiovascular disease.