Remnant lipoprotein levels in fasting serum predict coronary events in patients with coronary artery disease

Research trends in lipid-lowering therapies for coronary heart disease combined with hyperlipidemia: a bibliometric study and visual analysis

Background

Cardiovascular disease (CVD) poses a significant global health and economic challenge, with atherosclerosis being a primary cause. Over the past 40 years, substantial research has been conducted into the prevention and reversal of atherosclerosis, resulting in the development of lipid-lowering agents such as statins and fibrates. Despite the extensive literature and formulation of numerous therapeutic guidelines in this domain, a comprehensive bibliometric analysis of the current research landscape and trends has not been performed. This study aimed to elucidate the evolution and milestones of research into lipid-lowering treatments for coronary heart disease (CHD) in conjunction with hyperlipidemia through bibliometric analysis, offering insights into future directions for treatment strategies.

Methods

This study examined publications from 1986 to 2023 retrieved from the Web of Science database (Core Collection). Utilizing tools such as VOSviewer, Pajek, and CiteSpace, we analyzed publication and citation numbers, H-indexes, contributions by countries and institutions, authorship, journal sources, and keyword usage to uncover research trajectories and areas of focus.

Results

Our analysis of 587 publications revealed a recent surge in research output, particularly post-2003. The American Journal of Cardiology published the highest number of studies, with 40 articles, whereas Circulation received the highest number of citations (6,266). Key contributors included the United States, Japan, and China, with the United States leading in citation numbers and the H-index. Harvard University and Leiden University emerged as pivotal institutions, and Professors J. Wouter Jukema and Robert P. Giugliano were identified as leading experts. Keyword analysis disclosed five thematic clusters, indicating a shift in research towards new drug combinations and strategies, signaling future research directions.

Conclusion

The last 4 decades have seen a notable rise in publications on lipid-lowering therapies for CHD and hyperlipidemia, with the United States retaining world-leading status. The increase in international collaboration aids the shift towards research into innovative lipid-lowering agents and therapeutic approaches. PCSK9 inhibitors and innovative combination therapies, including antisense oligonucleotides and angiopoietin-like protein 3 inhibitors, provide avenues for future research, intending to maximize the safety and efficacy of treatment approaches.

A realistic approach to evaluating the effect of baseline lipid profile in postcoronary artery bypass grafting surgery

BACKGROUND

There are still many uncertainties in the association between lipid profile and postcoronary artery bypass grafting (CABG) outcomes. Although simplifying the association to linear equations makes it understandable but cannot explain many findings.

HYPOTHESIS

There is a nonlinear associatin between lipid profile indices and adverse outcomes after CABG.

METHODS

A total of 17 555 patients who underwent isolated CABG between 2005 and 2016 were evaluated. During the median follow-up of 75.24 months, the Restricted Cubic Splines (RCS) estimated from the Cox regression model adjusted for all possible confounders was applied to show a nonlinear relationship of lipid profile contents with the "ln hazard ratio" of mortality and major cerebro-cardiac events (MACCE).

RESULTS

The relationship between LDL-C and HDL-C with all-cause mortality was nonlinear (nonlinear p were .004 and <.001, respectively). The relationship between remnant cholesterol and all-cause mortality was linear (linearity p = .023). Among men, those in the highest LDL-C level (Q4, LDL-C > 114) and those in the lowest HDL-C level (Q1, HDL-C < 30) showed a significantly higher risk of all-cause mortality compared to other groups (compared with Q3, LDL-C Q4, HR = 1.16, 95% confidence interval [CI]:1.02-1.26, p = .014; HDL-C Q1, HR = 1.14, 95% CI: 1.01-1.31, p = .041). Female patients in the lowest HDL-C level (Q1, HDL-C < 30) showed a significantly higher (compared with Q3, HR = 1.14, 95% CI:1.01-1.31, p = .028) and those in the highest HDL-C level (Q4, HDL-C > 43) showed a significantly lower (compared with Q3, HR = 0.74, 95% CI:0.58-0.98, p = .019) risk of all-cause mortality.

CONCLUSION

Determining a universal cut off for components of lipid profile may be misleading and should better be revised. Extreme values (very low or very high) for HDL-C and LDL-C have different effects on cardiovascular outcomes.

Sirt6 enhances macrophage lipophagy and improves lipid metabolism disorder by regulating the Wnt1/β-catenin pathway in atherosclerosis

Lipid metabolism disorders are considerably involved in the pathology of atherosclerosis; nevertheless, the fundamental mechanism is still largely unclear. This research sought to examine the function of lipophagy in lipid metabolism disorder-induced atherosclerosis and its fundamental mechanisms. Previously, Sirt6 has been reported to stimulate plaque stability by promoting macrophage autophagy. However, its role in macrophage lipophagy and its relationship with Wnt1 remains to be established. In this study, ApoE-/-: Sirt6-/- and ApoE-/-: Sirt6Tg mice were used and lipid droplets were analysed via transmission electron microscopy and Bodipy 493/503 staining in vitro. Atherosclerotic plaques in ApoE-/-: Sirt6-/- mice showed greater necrotic cores and lower stability score. Reconstitution of Sirt6 in atherosclerotic mice improved lipid metabolism disorder and prevented the progression of atherosclerosis. Furthermore, macrophages with Ac-LDL intervention showed more lipid droplets and increased expression of adipophilin and PLIN2. Reconstitution of Sirt6 recruited using SNF2H suppressed Wnt1 expression and improved lipid metabolism disorder by promoting lipophagy. In addition, downregulation of Sirt6 expression in Ac-LDL-treated macrophages inhibited lipid droplet degradation and stimulated foam cell formation. Innovative discoveries in the research revealed that atherosclerosis is caused by lipid metabolism disorders due to downregulated Sirt6 expression. Thus, modulating Sirt6's function in lipid metabolism might be a useful therapeutic approach for treating atherosclerosis.

Butyrate inhibits LPC-induced endothelial dysfunction by regulating nNOS-produced NO and ROS production

Lipids oxidation is a key risk factor for cardiovascular diseases. Lysophosphatidylcholine (LPC), the major component of oxidized LDL, is an important triggering agent for endothelial dysfunction and atherogenesis. Sodium butyrate, a short-chain fatty acid, has demonstrated atheroprotective properties. So, we evaluate the role of butyrate in LPC-induced endothelial dysfunction. Vascular response to phenylephrine (Phe) and acetylcholine (Ach) was performed in aortic rings from male mice (C57BL/6J). The aortic rings were incubated with LPC (10 μM) and butyrate (0.01 or 0.1 Mm), with or without TRIM (an nNOS inhibitor). Endothelial cells (EA.hy296) were incubated with LPC and butyrate to evaluate nitric oxide (NO) and reactive oxygen species (ROS) production, calcium influx, and the expression of total and phosphorylated nNOS and ERK½. We found that butyrate inhibited LPC-induced endothelial dysfunction by improving nNOS activity in aortic rings. In endothelial cells, butyrate reduced ROS production and increased nNOS-related NO release, by improving nNOS activation (phosphorylation at Ser1412). Additionally, butyrate prevented the increase in cytosolic calcium and inhibited ERk½ activation by LPC. In conclusion, butyrate inhibited LPC-induced vascular dysfunction by increasing nNOS-derived NO and reducing ROS production. Butyrate restored nNOS activation, which was associated with calcium handling normalization and reduction of ERK½ activation.

Significance of Circulating Remnant Lipoprotein Cholesterol Levels Measured by Homogeneous Assay in Patients with Type 2 Diabetes

Remnant lipoproteins (RLs), which are typically present at high concentrations in patients with type 2 diabetes mellitus (T2DM), are associated with cardiovascular disease (CVD). Although an RL cholesterol homogeneous assay (RemL-C) is available for the measurement of RL concentrations, there have been no studies of the relationship between RemL-C and clinical parameters in T2DM. Therefore, we evaluated the relationships between RemL-C and CVD-related parameters in patients with T2DM. We performed a cross-sectional study of 169 patients with T2DM who were hospitalized at Kumamoto University Hospital. Compared with those with low RemL-C, those with higher RemL-C had higher fasting plasma glucose, homeostasis model assessment for insulin resistance (HOMA-R), total cholesterol, triglyceride, small dense low-density lipoprotein cholesterol (sdLDL-C), and urinary albumin-creatinine ratio; and lower high-density lipoprotein cholesterol, adiponectin, and ankle brachial pressure index (ABI). Multivariate logistic regression analysis showed that sdLDL-C and ABI were significantly and independently associated with high RemL-C. Although LDL-C was lower in participants with CVD, there was no difference in RemL-C between participants with or without CVD. Thus, RemL-C may represent a useful index of lipid and glucose metabolism, and that may be a marker of peripheral atherosclerotic disease (PAD) in male patients with T2DM.

Cholesterol Remnants, Triglyceride-Rich Lipoproteins and Cardiovascular Risk

Randomized clinical trials with statins and other lipid-lowering drugs have shown the presence of a "residual cardiovascular risk" in those treated to "target" for LDL-cholesterol. This risk is mainly associated to lipid components other than LDL and in particular to remnant cholesterol (RC) and to lipoproteins rich in triglycerides in fasting and non-fasting conditions. During fasting, RCs correspond to the cholesterol content of the VLDL and their partially depleted triglyceride remnant containing apoB-100. Conversely, in non-fasting conditions, RCs include also cholesterol present in chylomicrons containing apoB-48. Therefore, RCs refer to total plasma cholesterol minus HDL-cholesterol and LDL-cholesterol, that is, all the cholesterol present in the VLDL, chylomicrons and in their remnants. A large body of experimental and clinical data suggests a major role of RCs in the development of atherosclerosis. In fact, RCs easily pass the arterial wall and bind to the connective matrix stimulating the progression of smooth muscle cells and the proliferation of resident macrophages. RCs are a causal risk factor for cardiovascular events. Fasting and non-fasting RCs are equivalent for predicting vascular events. Further studies on drugs effect on RC levels and clinical trials to evaluate the efficacy of RC reduction on cardiovascular events are needed.

The effects of pemafibrate and omega-3 fatty acid ethyl on apoB-48 in dyslipidemic patients treated with statin: A prospective, multicenter, open-label, randomized, parallel group trial in Japan (PROUD48 study)

Background

We compared the lowering effects of pemafibrate and omega-3 fatty acid ethyl on fasting apolipoprotein (apo) B-48 (apoB-48), a marker that reflects postprandial hypertriglyceridemia, which is one of the residual risks for atherosclerotic cardiovascular disease (ASCVD) with statin treatment.

Methods

This prospective, multicenter, open-label, randomized, parallel group trial was conducted at 4 medical institutions between April 2020 and May 2022. A total of 126 ambulatory patients with dyslipidemia receiving statin treatment for more than 4 weeks, aged 20-79 years with fasting triglyceride (TG) levels of ≥177 mg/dl were randomly assigned to 16-week pemafibrate 0.4 mg per day treatment group (PEMA, n = 63) or omega-3 fatty acid ethyl 4 g per day treatment group (OMEGA-3, n = 63). The primary endpoint was the percentage change in fasting apoB-48 from baseline to week 16.

Results

The percentage changes in fasting apoB-48 in PEMA and OMEGA-3 were -50.8% (interquartile range -62.9 to -30.3%) and -17.5% (-38.3 to 15.3%) (P < 0.001), respectively. As the secondary endpoints, the changes in fasting apoB-48 in PEMA and OMEGA-3 were -3.10 μg/ml (-5.63 to -1.87) and -0.90 μg/ml (-2.95 to 0.65) (P < 0.001), respectively. Greater decreases with significant differences in the percentage changes in TG, remnant lipoprotein cholesterol, apoC-III, fasting plasma glucose, alanine aminotransferase, gamma-glutamyl transpeptidase, and alkaline phosphatase were observed in PEMA, compared with OMEGA-3. Greater increases with significant differences in those in high-density lipoprotein (HDL) cholesterol, apoA-I, and apoA-II were observed in PEMA, compared with OMEGA-3. PEMA showed anti-atherosclerotic lipoprotein profiles in gel-permeation high-performance liquid chromatography analyses, compared with OMEGA-3. Although adverse events occurred in 9 of 63 (14.3%) patients in PEMA and 3 of 63 (4.8%) patients in OMEGA-3, no serious adverse events associated with drug were observed in either group.

Conclusions

This is the first randomized trial to compare the lowering effects of pemafibrate and omega-3 fatty acid ethyl on fasting apoB-48. We concluded that pemafibrate was superior to omega-3 fatty acid ethyl in lowering effect of fasting apoB-48. Pemafibrate is expected to reduce the residual risk for ASCVD with statin treatment.

Clinical trial registration

https://rctportal.niph.go.jp/en, identifier jRCTs071200011.

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

Background

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

Methods

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

Results

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

Conclusion

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

Remnant-Like Particle Cholesterol and the Risk of Major Adverse Cardiovascular Events: A Systematic Review and Meta-Analysis

Background: The remnant-like particle cholesterol (RLP-C) has been demonstrated to be associated with residual cardiovascular risk. The meta-analysis aimed to evaluate the impact of baseline RLP-C on the incidence of major cardiovascular adverse events (MACEs) in patients with coronary artery disease (CAD). Methods: A systematic literature search was performed in PubMed and Embase electronic databases from the inception of the databases through 1 October 2022. Studies evaluating the association between baseline RLP-C and the risk of MACEs in patients with CAD were included. Hazard ratios (HRs) with 95% confidence intervals (CIs) were pooled by a random-effect method (RLP-C analyzed as a categorical variable) and a fixed-effects model (RLP-C analyzed as a continuous variable). Results: Ten studies including 18,053 subjects were finally included in this meta-analysis. In our pooled analysis, compared to CAD patients with the lowest RLP-C category, the CAD patients with the highest RLP-C category had a significantly higher risk of future MACEs during follow-up (HR 1.79, 95% CI, 1.42−2.26, I2 = 60.31%, p < 0.01), which was consistent with outcomes of meta-analysis with the RLP-C analyzed as a continuous variable (HR 1.40, 95% CI, 1.28−1.53, I2 = 38.20%, p < 0.01). The sensitivity analysis confirmed the robustness of the results, and no significant publication bias was identified. Conclusion: The present meta-analysis suggests that the RLP-C was associated with an increased risk of long-term MACEs in patients with CAD at baseline. It is necessary to conduct randomized controlled trials to explore whether reducing the RLP-C level is conducive to reducing residual cardiovascular risk, even coronary plaque regression.

Study protocol of the PROUD48 study comparing the effects of pemafibrate and omega-3 fatty acid ethyl esters on ApoB-48 in statin-treated patients with dyslipidaemia: a prospective, multicentre, open-label, randomised, parallel group trial in Japan

INTRODUCTION

This study will compare the lowering effects of pemafibrate and omega-3 fatty acid ethyl esters on fasting apolipoprotein B-48 (apoB-48), a surrogate marker reflecting postprandial hypertriglyceridaemia, which is a residual risk for atherosclerotic cardiovascular disease with statin treatment.

METHODS AND ANALYSIS

This is a prospective, multicentre, open-label, randomised, parallel group, comparative trial. Adult Japanese patients with dyslipidaemia receiving statin treatment for more than 4 weeks with a fasting triglyceride level ≥177 mg/dL will be randomly assigned in a 1:1 ratio to receive pemafibrate (0.4 mg orally per day) or omega-3 fatty acid ethyl esters (4 g orally per day) for 16 weeks. The primary endpoint is the percentage change in fasting apoB-48 from baseline to 16 weeks. The key secondary endpoints include the change in fasting apoB-48 from baseline to 16 weeks, the percentage changes in clinical variables from baseline to 16 weeks and the incidence of adverse events. A total sample size of 128 was set by considering the increased drop-out rate due to the COVID-19 pandemic, in addition to estimation based on a two-sided alpha of 0.05 and a power of 0.8 for apoB-48.

ETHICS AND DISSEMINATION

The study protocol has been approved by the Certified Review Board of the University of the Ryukyus for Clinical Research Ethics (No. CRB7200001) and will be performed in accordance with the Declaration of Helsinki. Written informed consent will be obtained from all participants. The results of the study will be disseminated through publications and conference presentations to participants, healthcare professionals and the public.

TRIAL REGISTRATION NUMBER

jRCTs071200011.

Atherogenic Lipoproteins for the Statin Residual Cardiovascular Disease Risk

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

Association between remnant lipoprotein cholesterol, high-sensitivity C-reactive protein, and risk of atherosclerotic cardiovascular disease events in the Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND

Elevated remnant-lipoprotein (RLP)-cholesterol (RLP-C) and high-sensitivity C-reactive protein (hsCRP) are each individually associated with atherosclerotic cardiovascular disease (ASCVD).

OBJECTIVE

To evaluate the interplay of nuclear magnetic resonance (NMR)-derived RLP-C and hsCRP and their association with ASCVD in the Multi-Ethnic Study of Atherosclerosis (MESA).

METHODS

Lipoprotein particles were measured using NMR spectroscopic analysis at baseline. RLP-C includes very-low-density lipoprotein cholesterol and intermediate-density lipoprotein cholesterol. Four groups were created as follows: Group 1: RLP-C ≤ median (≤29.14 mg/dL) and hsCRP < 2 mg/L; Group 2: RLP-C ≤ median and hsCRP≥ 2 mg/L; Group 3: RLP-C > median and hsCRP level < 2 mg/L; and Group 4: RLP-C > median and hsCRP level ≥ 2 mg/L. Kaplan-Meier survival curves and multivariable-adjusted Cox proportional hazard models were used to examine the relationship between RLP-C and hsCRP with incident ASCVD.

RESULTS

A total of 6,720 MESA participants (mean age 62.2 y, 53% female) with a median follow-up of 15.6 years were included. In the fully adjusted model, compared to those in the reference group (Group 1), participants in Group 2, Group 3, and Group 4 demonstrated a 20% (95% CI, -2%-48%), 18% (-4%-44%), and 43% (18%-76%) increased risk of incident ASCVD events, respectively (p < 0.01). An additive and multiplicative interaction between RLP-C and hsCRP was not statistically significant.

CONCLUSION

NMR-derived RLP-C and hsCRP showed a similar independent association with incident ASCVD. Notably, the combination of increased RLP-C and hsCRP was associated with an increased risk of future ASCVD events.

Association of remnant cholesterol and lipid parameters with new-onset carotid plaque in Chinese population

Background

Remnant lipoprotein cholesterol (RC) is an independent risk factor for cardiovascular disease (CVD). However, the relationships of remnant cholesterol and other conventional lipid parameters with new-onset carotid plaque are not fully understood in the Chinese community-based population.

Materials and methods

A total of 872 plaque-free participants (51.39 ± 4.96 years old) with no history of CVD were included in this study. The plasma concentrations of RC were calculated by subtracting low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) from total cholesterol (TC). Multivariate regression models were used to evaluate and compare the associations between RC and other lipid parameters and new-onset carotid plaque.

Results

After a mean 6.77-year follow-up, the incidence of new-onset carotid plaque was 188 (21.56%). RC was significantly associated with new-onset carotid plaque [Odd ratio (OR) = 1.57 per 1 mmol/L increase, 95% confidence interval (CI): 1.03–2.41, p = 0.038]. The highest tertile of RC (T3 group) had the highest risk of new-onset carotid plaque (OR = 2.53, 95% CI: 1.63–3.95). Similar results were seen for increased other lipid parameters, but decreased HDL-C levels. When adding another lipid parameter into the adjusted model with RC simultaneously, only RC remained significantly associated with new-onset carotid plaque after adjusting for other lipid parameters (all p value < 0.005). Furthermore, RC was strongly associated with new-onset carotid plaque in participants with lower baseline LDL-C levels.

Conclusion

Increased RC levels were superior to other conventional lipid parameters to be associated with new-onset carotid plaque in the Chinese community-based population. Furthermore, RC should be considered in participants with lower LDL-C levels for the purpose of early atherosclerosis prevention.

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

Background

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

Methods

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

Results

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

Conclusions

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

Non-Fasting Hypertriglyceridemia as an Independent Risk Factor for Coronary In-Stent Restenosis after Primary Bare Metal Stent Implantation in Patients with Coronary Artery Disease

After a percutaneous coronary intervention (PCI) in patients with coronary artery disease (CAD), in-stent neoatherosclerosis may pose a risk of in-stent restenosis (ISR). To clarify whether non-fasting hypertriglyceridemia contributes to ISR, we examined the relationship between non-fasting hypertriglyceridemia (i.e., triglyceride (TG) level ≥ 200 mg/dL) and ISR after stenting with a bare metal stent (BMS) post-primary PCI in patients with CAD by means of a single-site retrospective analysis. A total of 1,039 patients with CAD were enrolled, and 86 patients (112 lesions) were evaluated for BMS-ISR 3-6 months post-primary PCI. The percentage of patients with non-fasting hypertriglyceridemia was significantly higher in the ISR (+) group than in the ISR (-) group (P < 0.009). The follow-up period and number of patients in the ISR (+) group were significantly smaller than those in the ISR (-) group (P < 0.001). There were no significant between-group differences in the other baseline patient characteristics before the primary PCI or at the time of the follow-up coronary angiography. However, at the follow-up period, the ISR (+) group had significantly lower diastolic blood pressure and high-density lipoprotein cholesterol levels (P = 0.015) and significantly higher TG levels (P = 0.012) than the ISR (-) group. A multiple logistic regression analysis demonstrated that non-fasting hypertriglyceridemia and a follow-up period of ≥ 6 months were independent risk factors for ISR after primary PCI in patients with BMS implantation for stenotic CAD (P = 0.006), with an adjusted odds ratio of 8.232 (1.201-56.410) and 0.006 (95% confidence interval < 0.001-0.045), respectively. Non-fasting hypertriglyceridemia may be an additional independent risk factor for BMS-ISR after primary PCI in patients with CAD.

Correlation between estimated plasma remnant-like particle cholesterol and vegetable fat intake in Uku town, Japan

Background

Remnant-like particle cholesterol (RLP-C) is highly atherogenic, which is associated with atherosclerosis. However, RLP-C has not been routinely measured in the clinical practice. We estimated RLP-C levels using conventional lipid profiles and examined the association between estimated RLP-C and related factors including nutrient intake.

Methods

This study was performed in Uku town, Nagasaki prefecture, Japan in 2019. A total of 225 subjects were enrolled and directly measured RLP-C levels. Estimated RLP-C levels were defined as the following formula [total cholesterol − (LDL-cholesterol) − (HDL-cholesterol)]. Multivariate analyses were used to assess the relationship between estimated RLP-C and atherogenic factors. We calculated cut-off values on dichotomized RLP-C (< 7.5 mg/dL vs. ≥ 7.5 mg/dL) by receiver operating characteristic (ROC) curve.

Results

The mean values of directly measured RLP-C levels and estimated RLP-C were 4.0 mg/dL and 16.4 mg/dL, respectively. In the multiple stepwise linear regression analysis, directly measured and estimated RLP-C levels were independently and commonly associated with apolipoprotein E, triglycerides, and vegetable fat intake (inversely). Using ROC curves, we found the cut-off value of estimated RLP-C was 22.0 mg/dL.

Conclusion

We demonstrated that the estimated RLP-C levels using conventional lipid profiles may substitute for directly measured RLP-C and these levels were independently and inversely associated with vegetable fat intake in the community-dwelling Japanese population.

Triglyceride-Rich Lipoprotein Remnants and Cardiovascular Disease

BACKGROUND

Triglycerides, cholesterol, and their metabolism are linked due to shared packaging and transport within circulating lipoprotein particles. While a case for a causal role of cholesterol-carrying low-density lipoproteins (LDLs) in atherosclerosis is well made, the body of scientific evidence for a causal role of triglyceride-rich lipoproteins (TRLs) is rapidly growing, with multiple lines of evidence (old and new) providing robust support.

CONTENT

This review will discuss current perspectives and accumulated evidence that an overabundance of remnant lipoproteins stemming from intravascular remodeling of nascent TRLs-chylomicrons and very low-density lipoproteins (VLDL)-results in a proatherogenic milieu that augments cardiovascular risk. Basic mechanisms of TRL metabolism and clearance will be summarized, assay methods reviewed, and pivotal clinical studies highlighted.

SUMMARY

Remnant lipoproteins are rendered highly atherogenic by their high cholesterol content, altered apolipoprotein composition, and physicochemical properties. The aggregate findings from multiple lines of evidence suggest that TRL remnants play a central role in residual cardiovascular risk.

Association of triglyceride-rich lipoprotein-cholesterol with recurrent cardiovascular events in statin-treated patients according to different inflammatory status

BACKGROUND AND AIMS

The association of triglyceride-rich lipoprotein-cholesterol (TRL-C) with recurrent cardiovascular events (RCVEs) has not been studied. Moreover, whether inflammation can affect TRL-C-associated cardiovascular risk is unknown. This study sought to examine the association between TRL-C and RCVEs, and whether this relationship is modulated by systemic inflammation in statin-treated patients with coronary artery disease (CAD) and nearly normal triglyceride.

METHODS

In this study, 6723 CAD patients were consecutively enrolled, following a first CVE with triglyceride <2.3 mmol/L. Baseline lipid profile and high-sensitivity C-reactive protein (hsCRP) levels were determined. All patients were searched for RCVEs. The risk of RCVEs was assessed across quartiles (Q) of baseline TRL-C and further stratified by the median of hsCRP.

RESULTS

Over a mean follow-up of 58.91 ± 17.79 months, 538 RCVEs were recorded. After adjustment for potential confounders, Q4 of TRL-C was significantly associated with the risk of RCVEs, which remained unchanged after hsCRP stratification. When subjects were grouped according to both TRL-C and hsCRP levels, patients with Q4 of TRL-C and hsCRP had the highest increase of the risk of RCVEs compared with the reference group (TRL-C Q1-3 and hsCRP Q1-3; HR, 1.90; 95%CI: 1.27-2.87). Furthermore, adding TRL-C to the original predicting model led to a slight but significant improvement.

CONCLUSIONS

The present analysis firstly showed that elevated TRL-C was associated with an increased RCVEs risk in statin-treated patients with CAD independent of systemic inflammation, suggesting that it might be a useful marker for risk stratification and a treatment target in this patient population.

Predictive value of small dense low-density lipoprotein cholesterol for cardiovascular events in Chinese elder diabetes mellitus patients

BACKGROUND

As a subcomponent of low-density lipoprotein cholesterol (LDL-C), small dense LDL-C (sdLDL-C) has been suggested to be a better predictor of cardiovascular diseases (CVD). The aim of this research was to evaluate the predictive value of the sdLDL-C in cardiovascular events (CVs) in Chinese elderly patients with type 2 diabetes mellitus (DM).

METHODS

A total of 386 consecutive type 2 DM patients were included into this study during December 2014 to December 2016. The serum sdLDL-C level of each subject was measured by homogeneous method. During a period of 48-month's follow-up, the occurrence of CVs and associated clinical information were recorded. Receiver operating characteristic (ROC) curves were used to assess the predictive value of serum sdLDL-C to occurrence of major CVs.

RESULTS

A total of 92 CVs occurred during the study period. The ROC curve analysis manifested that sdLDL-C in the study population had a matchable discriminatory power (AUC for sdLDL-C was 0.7366, P = 0.003). In addition, Kaplan-Meier event-free survival curves displayed an obvious increase of CVs risk for sdLDL-C ≧ 26 mg/dL (log-rank = 9.10, P = 0.003). This phenomenon had analogous results in patients who received statins at baseline (log rank = 7.336, P = 0.007). Cox regression analysis revealed that the increase in HbA1c, glucose, LDL-C, sdLDL-C, non-high-density lipoprotein cholesterol (non-HDL-C) and apolipoprotein B (ApoB) and the decrease in apolipoprotein AI (ApoAI) were obviously interrelated with heightened CVs risk. Multiple Cox regression demonstrated that the increase of sdLDL-C and hemoglobin A1c (HbA1c) was significantly correlated with CVs. The results of the study indicated that high sdLDL-C level (> 10 mg/dL) was a risk factor for CVs in the multivariate model (HR 1.281, 95% CI 1.225-16.032; P < 0.01).

CONCLUSION

sdLDL-C level could be an effective predictor in predicting the future CVs for Chinese elderly patients with type 2 DM and dyslipidemia.

Real-world analyses of patients with elevated atherosclerotic cardiovascular disease risk from the Optum Research Database

More than 56 million Americans have hypertriglyceridemia, including over 12 million statin-treated individuals. However, the contribution of elevated and high triglyceride levels to cardiovascular disease and death has not been extensively studied using real-world analyses. We review recent analyses of the Optum Research Database, which included patients aged ≥45 years with diabetes and/or atherosclerotic cardiovascular disease and on statin therapy. Triglyceride levels ≥150 and 200-499 mg/dl were significantly associated with a 25.8 and 34.9% increased relative risk of cardiovascular events, respectively, versus patients with triglyceride levels <150 mg/dl. In addition, hypertriglyceridemia predicted peripheral arterial revascularization, new heart failure diagnosis and new-onset renal disease. Increased triglyceride levels were also significantly associated with increased healthcare resource utilization and costs. Interventions such as icosapent ethyl reduce triglycerides and associated cardiovascular disease risk.

Prognostic utility of triglyceride-rich lipoprotein-related markers in patients with coronary artery disease

TG-rich lipoprotein (TRL)-related biomarkers, including TRL-cholesterol (TRL-C), remnant-like lipoprotein particle-cholesterol (RLP-C), and apoC-III have been associated with atherosclerosis. However, their prognostic values have not been fully determined, especially in patients with previous CAD. This study aimed to examine the associations of TRL-C, RLP-C, and apoC-III with incident cardiovascular events (CVEs) in the setting of secondary prevention of CAD. Plasma TRL-C, RLP-C, and total apoC-III were directly measured. A total of 4,355 participants with angiographically confirmed CAD were followed up for the occurrence of CVEs. During a median follow-up period of 5.1 years (interquartile range: 3.9-6.4 years), 543 (12.5%) events occurred. Patients with incident CVEs had significantly higher levels of TRL-C, RLP-C, and apoC-III than those without events. Multivariable Cox analysis indicated that a log unit increase in TRL-C, RLP-C, and apoC-III increased the risk of CVEs by 49% (95% CI: 1.16-1.93), 21% (95% CI: 1.09-1.35), and 40% (95% CI: 1.11-1.77), respectively. High TRL-C, RLP-C, and apoC-III were also independent predictors of CVEs in individuals with LDL-C levels ≤1.8 mmol/l (n = 1,068). The addition of RLP-C level to a prediction model resulted in a significant increase in discrimination, and all three TRL biomarkers improved risk reclassification. Thus, TRL-C, RLP-C, and apoC-III levels were independently associated with incident CVEs in Chinese CAD patients undergoing statin therapy.

Prognostic impact of estimated remnant-like particle cholesterol in patients with differing glycometabolic status: an observational cohort study from China

Background

It is uncertain whether estimated remnant-like particle cholesterol (RLP-C) could predict residual risk in patients with different glycometabolic status. This study aimed to evaluate the relationship between estimated RLP-C and adverse prognosis in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS) treated with percutaneous coronary intervention (PCI) and to identify the potential impact of glycometabolism on the predictive value of estimated RLP-C.

Methods

The study assessed 2419 participants with NSTE-ACS undergoing PCI at Beijing Anzhen Hospital from January to December 2015. Estimated RLP-C was calculated as follows: total cholesterol (TC) minus low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C). The adverse events included all-cause death, non-fatal myocardial infarction (MI), and ischemia-driven revascularization.

Results

Estimated RLP-C was prominently associated with adverse prognosis in the total population [hazard ratio (HR) 1.291 per 1-SD increase, 95% confidence interval (CI) 1.119–1.490, P <  0.001], independent of confounding risk factors. However, subgroup analysis showed that increasing estimated RLP-C was related to a higher risk of adverse events in the diabetic population only [HR 1.385 per 1-SD increase, 95% CI 1.183–1.620, P <  0.001]. Estimated RLP-C failed to be a significant determinant of adverse prognosis in non-diabetic and pre-diabetic subgroups. The addition of estimated RLP-C to a baseline model including traditional risk factors enhanced the predictive performance both in total and diabetic populations.

Conclusions

High estimated RLP-C level is a significant predictor for recurrent adverse events in patients with diabetes and NSTE-ACS treated with PCI.

The longitudinal association of remnant cholesterol with cardiovascular outcomes in patients with diabetes and pre-diabetes

Background

The atherogenicity of remnant cholesterol (RC) has been underlined by recent guidelines, which was linked to coronary artery disease (CAD), especially for patients with diabetes mellitus (DM). This study aimed to examine the prognostic value of plasma RC in the patients with CAD under different glucose metabolism status.

Methods

Fasting plasma RC were directly calculated or measured in 4331 patients with CAD. Patients were followed for the occurrence of major adverse cardiovascular events (MACEs) and categorized according to both glucose metabolism status [DM, pre-DM, normoglycemia (NG)] and RC levels. Cox proportional hazards model was used to calculate hazard ratios (HRs) with 95% confidence intervals.

Results

During a mean follow-up of 5.1 years, 541 (12.5%) MACEs occurred. The risk for MACEs was significantly higher in patients with elevated RC levels after adjustment for potential confounders. No significant difference in MACEs was observed between pre-DM and NG groups (p > 0.05). When stratified by combined status of glucose metabolism and RC, highest levels of calculated and measured RC were significant and independent predictors of developing MACEs in pre-DM (HR: 1.64 and 1.98; both p < 0.05) and DM (HR: 1.62 and 2.05; both p < 0.05). High RC levels were also positively associated with MACEs in patients with uncontrolled DM. .

Conclusions

In this large-scale and long-term follow-up cohort study, data firstly demonstrated that higher RC levels were significantly associated with the worse prognosis in DM and pre-DM patients with CAD, suggesting that RC may be a target for patients with impaired glucose metabolism.

Cholesterol Subfraction Analysis in Patients with Acute Coronary Syndrome

BACKGROUND

There is a close relationship between lipid metabolism disorders and atherosclerosis. Guidelines focus on lowering Low-Density Lipoprotein Cholesterol (LDL-C) levels. However, it should be kept in mind that LDL and High-Density Lipoprotein (HDL) consist of subfractions which can affect the progression of atherosclerosis.

OBJECTIVE

We assessed the concentration of LDL and HDL subfractions in patients with Acute Coronary Syndromes (ACS). The influence of the presence of type 2 diabetes mellitus on LDL and HDL subfractions was also analyzed.

METHODS

The study group consisted of 127 patients (62 men, 65 women) with ACS. All patients had coronary angiography and coronary angioplasty and stenting when necessary. Medical history was collected during 12 months of follow-up. HDL and LDL subfraction distribution was measured using Lipoprint (Quantimetrix).

RESULTS

No differences in LDL nor HDL subfractions were observed between ST-Segment Elevation Myocardial Infarction (STEMI), Non-ST-Segment Elevation Myocardial Infarction (NSTEMI) and unstable angina (UA) patients. However, those with restenosis and the necessity of repeated revascularization had higher levels of intermediate-density lipoprotein C (IDL-C) (p=0.055) and LDL3 (p=0.048) as compared with the patients without, while the level of IDL A (IDLA) was lower than in the latter group (p=0.036). In diabetic patients, the percentage share of HDL10 and small-dense HDL was significantly higher while the share of HDL1 (small-dense) (p=0.028), HDL4 (intermediate density) (p=0.052) and HDL5 (intermediate density) (p=0.060) were lower than in patients without DM.

CONCLUSION

Patients with multi-vessel CAD disease had higher levels of LDL3 subfraction and IDL-C and a lower proportion of IDLA.

Could remnant-like particle cholesterol become a risk factor in diabetic menopausal women with coronary artery disease? A cross-sectional study of single academic center in China

BACKGROUND AND AIMS

It has been confirmed that remnant-like particle cholesterol (RLP-C) mediates the progression of coronary artery disease (CAD). Currently there is limited information on RLP-C in menopausal women. With the special status of diabetes mellitus (DM) combined with the special body changes of the menopausal women, the RLP-C is particularly important when studying the changes that occurred in response to CAD and its associated risk factors. This study discussed whether RLP-C could be an independent risk factor for menopausal women with CAD and DM.

METHODS

The cohort consisted of 4753 menopausal women who had undergone coronary angiography. Subjects were separated into CAD and non-CAD groups, and univariate and multivariate logistic regression analysis of CAD risk factors were performed. All patients with a history of DM were divided into DM subgroups. Then, the univariate and multivariate logistic regression analysis of the risk factors of CAD and the comparison among age groups in the DM subgroup were performed. After age stratification of the DM group, the Kruskal-Wallis test was used to analyze the differences of various lipid indexes among age groups.

RESULTS

The multivariate logistic regression showed that RLP-C was an independent risk factor for CAD in menopausal women (OR 1.232, 95%CI 1.070-1.419). In the DM subgroup, it was also found that RLP-C was an independent risk factor for CAD (OR 1.366, 95%CI 1.043-1.791). Kruskal-Wallis test analysis found that RLP-C had no significant difference among three groups (P > 0.05).

CONCLUSIONS

RLP-C was proved to be an independent risk factor for menopausal women with CAD and DM.

Risk of cardiovascular events in patients with hypertriglyceridaemia: A review of real-world evidence

AIMS

To describe the real-world prevalence and consequences of hypertriglyceridaemia.

MATERIALS AND METHODS

We searched two large patient databases, the National Health and Nutrition Examination Survey (NHANES) database (2007-2014) and the Optum Research Database, as well as electronic medical records from two Kaiser Permanente regions.

RESULTS

The NHANES data showed that ~26% of US adults, including nearly one-third of statin users, had at least borderline hypertriglyceridaemia (triglycerides [TGs] ≥1.69 mmol/L), and ~40% of adults with diabetes had levels of ≥150 mg/dL despite statin use. The Optum analyses demonstrated that those with TG levels ≥1.69 mmol/L who were on statins had a significantly increased risk of composite initial major cardiovascular (CV) events (hazard ratio [HR] 1.26, 95% confidence interval [CI] 1.19-1.34; P < 0.001 vs. patients with TGs <150 mg/dL). This was accompanied by increased healthcare utilization and direct healthcare costs (HR 1.12, 95% CI 1.08-1.16; P < 0.001). In the analyses of the Kaiser Permanente records, patients with diabetes and TG levels 2.26-5.64 mmol/L had significantly higher adjusted incidence rates of non-fatal myocardial infarction (rate ratio 1.30, 95% CI 1.08-1.58; P = 0.006), non-fatal stroke (rate ratio 1.23; 95% CI 1.01-1.49; P = 0.037) and coronary revascularization (rate ratio 1.21; 95% CI 1.02-1.43; P = 0.027), but not unstable angina (rate ratio 1.33; 95% CI 0.87-2.03; P = 0.185) compared with patients with TG levels <1.69 mmol/L.

CONCLUSIONS

Real-world analyses suggest that elevated TGs are prevalent and commonly associated with increased CV risk. CV outcomes trials in patients with established hypertriglyceridaemia will clarify whether strategies to reduce TG levels can ameliorate residual CV risk in patients taking statins.

Effects of Dietary Blueberry (Vaccinium ashei Reade) Leaves on Mildly Postprandial Hypertriglyceridemia

Prevention of postprandial hypertriglyceridemia is an important consideration for reducing the risk of developing cardiovascular disease. While blueberry fruits have been reported to ameliorate lipid metabolism in humans, there are only few research reports on the effects of blueberry leaves (BL). Here, we investigated the efficacy of BL on postprandial hyperlipidemia in subjects with high fasting triacylglycerol (TG) concentrations. Randomized, double-blind, cross-over design study was conducted. The subjects consumed a BL containing beverage or a placebo beverage before a fat-enriched test meal. Blood samples were collected prior to and 1, 2, 3, 4, and 5 hours after consuming the test beverage. The postprandial serum TG and remnant-like particle cholesterol (RLP-C) concentrations were significantly lower in the BL beverage compared with those in the placebo beverage. Additionally, BL was more effective in subjects with high fasting ghrelin with gastric emptying function. In current study, fasting ghrelin correlated with the increase in postprandial serum TG, suggesting that BL ameliorates hypertriglyceridemia through delayed gastric emptying. In conclusion, this pilot study suggests that BL may be useful as an early dietary therapy for treating postprandial hyperlipidemia.

Comparison of remnant cholesterol levels estimated by calculated and measured LDL-C levels in Chinese patients with coronary heart disease

BACKGROUND

Evidence about whether remnant cholesterol (RC), especially non-fasting RC, is a causal risk factor for coronary heart disease (CHD) in Chinese subjects is rare. Recently, estimated RC level (RCe) was applied in many studies with large population. We aimed to compare fasting and non-fasting RCe calculated by LDL-C level determined by different methods in Chinese subjects, and investigate their contributions to CHD.

METHODS

Levels of TC, TG and HDL-C were measured directly in 273 CHD patients (CHD group) and 136 controls (CON group) before and at 4 h after a daily breakfast. LDL-C level was measured directly or calculated by Friedewald equation at TG < 4.5 mmol/L. RC level estimated by calculated or measured LDL-C was termed as RCe1 or RCe2. Contributions of different RC levels to CHD were evaluated by multivariable logistic regression analysis.

RESULTS

Both RCe1 and RCe2 increased significantly at 4 h after breakfast (both p < 0.05). RCe1 was significantly higher than RCe2 in fasting or non-fasting state (p < 0.05). RCe1 was closely related to RCe2, especially in the highest quartile of RCe1 (p < 0.05). Non-fasting RCe1 or RCe2 and fasting RCe2 independently predicted CHD after adjustment for traditional risk factors (all p < 0.05).

CONCLUSIONS

Although RCe1 was significantly higher than RCe2, non-fasting RCe, no matter RCe1 or RCe2, after a daily breakfast was an independent predictor for CHD risk in Chinese subjects, indicating that the non-fasting state is critical in the development of atherosclerosis.

Very low-density lipoprotein cholesterol is associated with extent and severity of coronary artery disease in patients with type 2 diabetes mellitus

Objective:

Patients with type 2 diabetes mellitus usually have multiple cardiovascular disease risk factors. The objective of this study was to examine the severity and associated risk factors in coronary artery disease patients with type 2 diabetes mellitus.

Methods:

Two hundred and five coronary artery disease patients with type 2 diabetes mellitus and 205 age-, gender- and smoking-matched coronary artery disease patients without type 2 diabetes mellitus were recruited from the Department of Cardiology of our hospital. Demographic and clinical data were collected for all participants. Severity of coronary artery disease was assessed using Gensini scoring system, the number of diseased coronary arteries, and the extent of coronary stenosis.

Results:

Coronary artery disease patients with type 2 diabetes mellitus had higher Gensini scores (p < 0.01), more numbers of diseased coronary arteries (p < 0.001), and higher degrees of coronary stenosis (p = 0.05) than coronary artery disease patients without type 2 diabetes mellitus. The plasma levels of very low-density lipoprotein cholesterol (p < 0.001) and triglycerides (p < 0.001) were also higher in coronary artery disease patients with type 2 diabetes mellitus than in coronary artery disease patients without type 2 diabetes mellitus. In coronary artery disease patients with type 2 diabetes mellitus, very low-density lipoprotein cholesterol was positively correlated with Gensini scores (r = 0.15, p = 0.03), the number of diseased coronary arteries (r = 0.15, p = 0.04), and the extent of coronary stenosis (r = 0.14, p = 0.05) by partial correlation analysis after controlling for other lipid parameters, and independently associated with Gensini scores (beta = 0.18, p = 0.02) and the number of diseased coronary arteries (odds ratio = 2.09, p = 0.05) after adjusting for other cardiovascular risk factors in the following multiple regression analysis.

Conclusion:

Very low-density lipoprotein cholesterol may represent a marker for the severity of coronary artery disease and be a target for the treatment in diabetic patients. Further research is needed to determine whether very low-density lipoprotein cholesterol plays a causal role of coronary artery disease in diabetic patients.

Remnant lipoproteins play an important role of in-stent restenosis in type 2 diabetes undergoing percutaneous coronary intervention: a single-centre observational cohort study

BACKGROUND

Increasing evidence has suggested that the presence of remnant lipoproteins is a significant risk factor for atherosclerosis. Remnant lipoproteins are lipoproteins that are rich in triglycerides (TGs), and the main components include very-low-density lipoprotein (VLDL) in the fasting state. Diabetic patients often have hypertriglyceridemia with elevated levels of VLDL cholesterol but normal levels of low-density lipoprotein cholesterol (LDL-C). The aim of the present study was to elucidate the potential role of remnant lipoproteins-induced atherosclerosis in the occurrence and development of in-stent restenosis (ISR) in diabetic patients with coronary artery disease.

METHODS

The present study enrolled 2312 patients with type 2 diabetes mellitus who underwent percutaneous coronary intervention from January 2013 to December 2014 and who were followed up by angiography. Patients were divided into two groups based on the presence or absence of ISR, and multivariate Cox's proportional hazards regression modelling showed that remnant-like particle cholesterol (RLP-C) was an independent risk factor for ISR. According to the receiver operating characteristic curve, the optimal cutoff point of the RLP-C was identified, and the patients were further divided into 2 groups. Propensity score matching analysis was performed, and 762 pairs were successfully matched. Log-rank tests were used to compare Kaplan-Meier curves for overall follow-up to assess ISR.

RESULTS

The multivariate Cox's proportional hazards regression analysis showed that RLP-C was independently associated with ISR, and the baseline RLP-C level at 0.505 mmol/L was identified as the optimal cutoff point to predict ISR. Patients were divided into 2 groups by RLP levels. After propensity score matching analysis, a total of 762 pairs matched patients were generated. Kaplan-Meier curves showed that the estimated cumulative rate of ISR was significantly higher in patients with RLP-C levels ≥ 0.505 mmol/L (log-rank P < 0.001; HR equal to 4.175, 95% CI = 3.045-5.723, P < 0.001) compared to patients with RLP-C levels < 0.505 mmol/L.

CONCLUSIONS

The present study emphasized the importance of remnant-like particle cholesterol in cardiovascular pathology in diabetic patients. Physicians should take measures to control RLP-C below the level of 0.505 mmol/L to better prevent of in-stent restenosis in diabetic patients.

Remnant Lipoprotein Cholesterol and Cardiovascular and Cerebrovascular Events in Patients with Non-Alcoholic Fatty Liver Disease

: Non-alcoholic fatty liver disease (NAFLD) is characterized by an atherogenic dyslipidaemia and an increased cardiovascular risk. Remnant lipoprotein cholesterol (RLP-C) is emerging as a novel cardiovascular risk factor, but its predictive value in patients with NAFLD is unknown. We investigated factors affecting RLP-C levels, and the association with major adverse cardiovascular and cerebrovascular events (MACCE) in NAFLD. A prospective observational cohort study was carried out including 798 unselected patients with cardio-metabolic diseases screened by ultrasound for the presence of NAFLD. Fasting RLP-C (mg/dL) was calculated as total cholesterol-(HDL (high-density lipoprotein) + LDL (low-density-lipoprotein)). Primary endpoint of the follow-up study was a combined endpoint of MACCE. Patients with NAFLD (79.2%) had higher median fasting RLP-C in comparison to those without (27.0 vs. 20.0 mg/ dL, respectively p < 0.001). Metabolic syndrome, NAFLD, age above median, and female sex were independently associated to fasting RLP-C above the median. In patients with NAFLD, values of RLP-C were associated with liver disease severity, as shown by the increasing value of RLP-C across tertiles of aspartate aminotransferase (AST) (p = 0.002) and gamma-glutamyl transpeptidase (GGT) (p < 0.001). Furthermore, levels of RLP-C and Hamaguchi score, were significantly correlated (r = 0.193, p < 0.001). During a median follow-up of 32 months (interquartile range: 14.2⁻51.7, 1700 person-years), 41 MACCE (2.41%/year) were registered in 596 NAFLD patients. The rate of events was higher in NAFLD patients with RLP-C above the median compared to those below (log-rank test p = 0.040). Age (hazard ratio (HR) 1.039, 95% confidence interval (CI), 1.005⁻1.074, p = 0.024), previous cardiovascular events (HR 2.210, 95% CI, 1.052⁻4.643, p = 0.036), female sex (HR 0.454, 95% CI, 0.208⁻0.989, p = 0.047) and RLP-C above the median (HR 2.202, 95% CI, 1.132⁻4.285, p = 0.020) were associated with MACCE. In conclusion, we found that NAFLD was independently associated with higher circulating RLP-C, and that high RLP-C levels were predictive of MACCE in patients with NAFLD.

Empagliflozin decreases remnant-like particle cholesterol in type 2 diabetes patients with insulin resistance

AIMS/INTRODUCTION

Remnant lipoproteins are thought to be atherogenic. Remnant-like particle cholesterol (RLP-C), which reflects the levels of various kinds of remnant lipoproteins in the blood, has a significant correlation with insulin resistance.

MATERIALS AND METHODS

In the present study, we measured the effect of empagliflozin (EMPA) on the levels of RLP-C, and investigated whether EMPA-mediated change in RLP-C is associated with a change in insulin resistance in type 2 diabetes patients who have insulin resistance.

RESULTS

Patients were allocated to receive a placebo (n = 51) or EMPA (n = 58) as an add-on treatment. Fasting blood samples were collected before and 12 weeks after this intervention. EMPA significantly decreased glycated hemoglobin, bodyweight, systolic blood pressure, plasma triglycerides, liver transaminases and estimated glomerular filtration rate, and increased high-density lipoprotein cholesterol. Furthermore, EMPA decreased RLP-C and homeostatic model assessment of insulin resistance. In the placebo group, there were no significant changes in these factors except for slight increases in liver transaminases. Multiple regression analysis showed that the change in homeostatic model assessment of insulin resistance (P = 0.0102) and the change in alanine aminotransferase (P = 0.0301) were significantly associated with the change in RLP-C in the EMPA group. The change in RLP-C significantly correlated with the change in homeostatic model assessment of insulin resistance (Pearson correlation coefficient 0.503, 95% confidence interval 0.199-0.719; P = 0.00241).

CONCLUSION

EMPA decreases RLP-C levels, which is closely associated with amelioration of insulin sensitivity in diabetes patients who have insulin resistance.

Development of a Novel Homogeneous Assay for Remnant Lipoprotein Particle Cholesterol

Background

Quantification of remnant lipoprotein particle cholesterol (RLP-C) by automated assay is useful in routine clinical laboratories to assess coronary artery disease risk and diagnose type III hyperlipoproteinemia.

Methods

Enzymes and surfactants were screened to establish a homogeneous RLP-C assay using the chylomicron-VLDL, LDL, and HDL fractions isolated by ultracentrifugation, along with the RLP fraction isolated by immunoaffinity gel. All data were generated using a Hitachi analyzer.

Results

A specific cholesterol esterase with a polyoxyethelene styrenated phenyl ether derivative (surfactant) was used for the establishment of a homogeneous RLP-C assay. This cholesterol esterase with subunits of &gt;40 kDa (H-CE) was found to react with lipoproteins other than RLP, whereas this enzyme with subunits of &lt;40 kDa (L-CE) reacted with RLP. H-CE was applied for the first reaction step with the specific surfactant to decompose non-RLP lipoproteins, degrading non-RLP cholesterol into water and oxygen in the presence of cholesterol oxidase and catalase. For the second step, L-CE was applied to release cholesterol from RLP, and then the released RLP-C was determined in a standard cholesterol oxidase and peroxidase system. This new homogeneous assay exhibited good correlation with the RLP-C immunoseparation method.

Conclusions

We established a simple, rapid, automated homogeneous assay for RLP-C. The assay can determine RLP-C levels in 10 min in a fully automated manner, processing a large number of samples in routine clinical laboratories.

Remnant-like particles and coronary artery disease in familial hypercholesterolemia

BACKGROUND

Although remnant-like particle cholesterol (RLP-C) has been associated with coronary artery disease (CAD) in the general population, few data exist regarding this issue in patients with familial hypercholesterolemia (FH). The aim of our study was to investigate the association between RLP-C and the presence of CAD in patients with FH.

METHODS

We examined 282 patients with FH (144 males, mean age, 41 ± 17 years) whose RLP-C levels were measured. We assessed the baseline characteristics, including lipid levels, other conventional risk factors for cardiovascular events, the presence of CAD, and the serum RLP-C levels.

RESULTS

Serum RLP-C levels significantly correlated with serum triglyceride (TG) levels (Pearson's r = 0.631, p < 0.001). We observed that a larger proportion of individuals in the higher tertiles of serum RLP-C had a larger number of diseased coronary arteries (p < 0.001 for the trend of multi-vessel disease). Logistic regression analysis, after adjusting for age, sex, hypertension, diabetes, smoking, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and lipoprotein (a) [Lp(a)], revealed that RLP-C was significantly associated with CAD [odds ratio (OR): 1.08, 95% confidence interval (CI): 1.00-1.16, p = 0.046]; however, adding serum TG levels into the logistic regression model nullified this association (OR: 1.07, 95% CI: 0.98-1.17, p = 0.141), whereas Lp(a) was independently associated with CAD (OR: 1.02, 95% CI: 1.00-1.03, p = 0.015).

CONCLUSIONS

Serum RLP-C levels were significantly associated with the presence and severity of CAD in patients with FH. However, the clinical usefulness of measuring RLP-C levels beyond that of measuring TG levels should be further assessed.

Small dense low-density lipoprotein cholesterol is a promising biomarker for secondary prevention in older men with stable coronary artery disease

AIM

The study objective was to investigate whether small dense low-density lipoprotein cholesterol (sdLDL-C) is superior to low-density lipoprotein cholesterol (LDL-C) and other biomarkers to predict future cardiovascular events (CE) in secondary prevention.

METHODS

sdLDL-C measured by a homogeneous assay, remnant lipoprotein cholesterol, LDL particle diameter and other biomarkers were compared in 345 men aged ≥65 years with stable coronary artery disease. Baseline LDL-C was 100.5 ± 30.1 mg/dL. CE including cardiovascular death, onset of acute coronary syndrome, need for arterial revascularization, hospitalization for heart failure, surgery procedure for cardiovascular disease and hospitalization for stroke were monitored for 5 years.

RESULTS

CE occurred in 96 patients during the study period. LDL-C, sdLDL-C non-high-density lipoprotein cholesterol, apolipoprotein B, remnant lipoprotein cholesterol, glucose, glycated hemoglobin and brain natriuretic peptide were significantly higher; LDL particle diameter and apolipoprotein A-1 were significantly lower in patients with than in those without CE. Age-adjusted Cox regression analysis showed that sdLDL-C per 10 mg/dL, but not LDL-C, was significantly associated with CE (HR 1.206, 95% CI 1.006-1.446). A significant association of sdLDL-C and incident CE was observed in statin users (HR 1.252, 95% CI 1.017-1.540), diabetes patients (HR 1.219, 95% CI 1.018-1.460), patients without diabetes (HR 1.257, 95% CI 1.019-1.551) and patients with hypertriglyceridemia (HR 1. 376, 95% CI 1.070-1.770).

CONCLUSIONS

sdLDL-C was the most effective predictor of residual risk of future CE in stable coronary artery disease patients using statins and in high-risk coronary artery disease patients with diabetes or hypertriglyceridemia. Geriatr Gerontol Int 2018; 18: 965-972.

Effects of a Dipeptidyl Peptidase 4 Inhibitor Sitagliptin on Glycemic Control and Lipoprotein Metabolism in Patients with Type 2 Diabetes Mellitus (GLORIA Trial)

Aim: The morbidity of cardiovascular disease in patients with type 2 diabetes mellitus (DM) deteriorates in combination with dyslipidemia. The accumulation of remnant lipoproteins in patients with fasting and postprandial hypertriglyceridemia is highly atherogenic. The current study investigated whether the dipeptidyl peptidase-4 inhibitor sitagliptin ameliorates dyslipidemia and hyperglycemia.

Methods: We enrolled 38 patients with type 2 DM (20 males and 18 females, 65.7 ± 9.9 years old, HbA1c levels < 8.4%), and all patients gave written informed consent. Sitagliptin (50 mg/day) was added to current antidiabetic treatments and increased to 100 mg/day to achieve low HbA1c levels (< 7.4%). Glucose and lipoprotein metabolism profiles were analyzed at 0, 4, and 12 weeks after sitagliptin administration.

Results: Sitagliptin significantly decreased fasting levels of triglyceride (TG) (161 ± 90 vs. 130 ± 66 mg/dl, p < 0.01) and non-HDL-C (129 ± 29 vs. 116 ± 20 mg/dl, p < 0.01) in combination with glucose (150 ± 47 vs. 129 ± 27 mg/dl, p < 0.01) and HbA1c (7.1 ± 0.6 vs. 6.6 ± 0.7 mg/dl, p < 0.001). Sitagliptin also significantly decreased the fasting levels of apolipoprotein (apo) B-48 (7.8 ± 6.7 vs. 5.6 ± 4.0 µg/ml, p < 0.01), remnant lipoprotein cholesterol (15.3 ± 9.5 vs. 12.0 ± 7.9 mg/dl, p < 0.05) and other apolipoproteins, such as apoB, apoC-II, apoC-III, and apoE. Analyses of the lipoprotein profiles of fasting sera revealed that sitagliptin significantly decreased cholesterol and TG levels of lipoprotein fractions in the size of very low density lipoprotein and low density lipoprotein.

Conclusions: These findings indicated that sitagliptin administration ameliorated the lipid and lipoprotein profiles in patients with diabetes, which may be due to the decrease in atherogenic remnant lipoproteins (UMIN#000013218).

Abbreviations:apo

apolipoprotein

ASCVD

atherosclerotic cardiovascular disease

CHD

coronary heart disease

CLEIA

chemiluminescence enzyme immunoassay

CM

Chylomicron

DPP-4

dipeptidyl peptidase-4

FFAs

free fatty acids

HPLC

high-performance liquid chromatography

IMT

intima-media thickness

LDL

low-density lipoprotein

LPL

lipoprotein lipase

PHTG

postprandial hypertriglyceridemia

RemL-C

remnant lipoprotein cholesterol

RLP-C

remnant-like particle cholesterol

TG

triglyceride

TRL

triglyceride-rich lipoprotein

VLDL

very low density lipoprotein

Effect of Combination Therapy of Ezetimibe and Atorvastatin on Remnant Lipoprotein Versus Double Atorvastatin Dose in Egyptian Diabetic Patients

A high level of remnant lipoprotein cholesterol (RLP-C) is a predominant feature in diabetic patients with atherosclerosis. This study aimed to investigate the effect of ezetimibe added to statin therapy compared to doubling standard statin dose. Sixty-five eligible patients were recruited then prospectively randomized to receive ezetimibe 10 mg/day plus their 40 mg daily atorvastatin dose (group 1) or atorvastatin 80 mg/day (group 2) for 3 months. Efficacy was evaluated using plasma levels of RLP-C, apolipoprotein B, non-high-density lipoprotein cholesterol (non-HDL), percentage of brachial artery flow-mediated dilation, and lipid profile. Forty patients completed the study and provided efficacy data. Group 1 showed more reduction in RLP-C (45.7% vs 31.7%, P = .02), apolipoprotein B (28.5% vs 9.5%, P = .01), total cholesterol (34.7% vs 24.6%, P = .003), triglycerides (49% vs 24.4%, P = .000), non-HDL (49.3% vs 33%, P = .002), and low-density lipoprotein cholesterol (49.6% vs 35.2%, P = .02) compared to group 2. Group 1 showed a greater increase in HDL (66% vs 35%, P = .002); and flow-mediated dilation (30% vs 17%, P = .01) compared to group 2. It is concluded that adding ezetimibe 10 mg to atorvastatin 40 mg may be a better choice than doubling atorvastatin dose in improving RLPs, endothelial function, and lipid profile in diabetic cardiovascular patients who could not achieve their therapeutic treatment goals with the standard atorvastatin dose.

The impact of triglycerides on glucose tolerance: Lipotoxicity revisited

Elevated plasma triglycerides (TGs) are early key features of conditions associated with a dysregulation in glucose metabolism and may predict the development of type 2 diabetes (T2D) over time. Although the acute ingestion of lipid, either mixed with or shortly before the meal, is neutral or slightly beneficial on glucose tolerance, a short-term increase in plasma TGs induced by either an i.v. lipid infusion or a high-fat diet produces a deterioration of glucose control. Accordingly, chronic lowering of plasma TGs by fibrates improves glucose homeostasis and may also prevent T2D. The chronic effects of the elevation of dietary lipid intake are less clear, particularly in humans, being the quality of fat probably more important than total fat intake. Although on the bases of the available experimental and clinical evidence it cannot be easily disentangled, with respect to elevated non-esterified fatty acids (NEFA) the relative contribution of elevated TGs to glucose homeostasis disregulation seems to be greater and also more plausible. In conclusion, although the association between elevated plasma TGs and impaired glucose tolerance is commonly considered not causative or merely a consequence of NEFA-mediated lipotoxicity, the available data suggest that TGs per se may directly contribute to disorders of glucose metabolism.

Greater remnant lipoprotein cholesterol reduction with pitavastatin compared with pravastatin in HIV-infected patients

OBJECTIVE

Cardiovascular disease (CVD) is a leading cause of morbidity and mortality in those with HIV. An emerging CVD risk factor is triglyceride-rich remnant lipoprotein cholesterol (RLP-C: the sum of intermediate-density lipoprotein and very low-density lipoprotein cholesterol). The effects of statin therapy on lipoprotein subfractions, including RLP-C, in HIV dyslipidemia are unknown.

METHODS

This is a post hoc analysis of the randomized INTREPID trial (NCT 01301066) comparing pitavastatin 4 mg daily vs. pravastatin 40 mg daily in study participants with HIV. We measured apolipoproteins AI and B and lipoprotein cholesterol subfractions separated by density gradient ultracentrifugation at baseline and 12 weeks. We compared changes in atherogenic subfractions over 12 weeks in INTREPID participants using analysis of covariance.

RESULTS

Lipoprotein subfraction data were available for 213 study participants (pitavastatin n = 104, pravastatin n = 109). Baseline characteristics were similar between treatment groups. Reductions in RLP-C were significantly greater in the pitavastatin group compared with pravastatin group (-11.6 mg/dl vs. -8.5 mg/dl; P = 0.01). Similarly, ratios of risk [apolipoproteins B/apolipoproteins AI, total cholesterol/high-density lipoprotein cholesterol (HDL-C)] showed greater reductions with pitavastatin (P < 0.05). There were no differences in changes in HDL-C, HDL-C subfractions or lipoprotein(a) cholesterol levels.

CONCLUSION

In patients with HIV, pitavastatin 4 mg/dl lowered both RLP-C and established apolipoprotein and lipid risk ratios more so than pravastatin 40 mg/dl. The impact of RLP-C reduction on CVD in HIV dyslipidemic patients merits further study.

Triglyceride Rich Lipoprotein -LPL-VLDL Receptor and Lp(a)-VLDL Receptor Pathways for Macrophage Foam Cell Formation

Very low-density lipoprotein (VLDL) receptor is a member of the low-density lipoprotein (LDL) receptor family. It binds triglyceride rich lipoprotein (TGRL) but not LDL, because it recognizes apolipoprotein (apo)E only but not apoB. The VLDL receptor functions as a peripheral lipoprotein receptor in concert with lipoprotein lipase (LPL) in heart, muscle, adipose tissue and macrophages. In contrast to the LDL receptor, VLDL receptor binds apo E2/2 VLDL and apoE3/3 VLDL particles, and its expression is not down-regulated by intracellular lipoproteins. It has been reported that both LDL-cholesterol (LDL-C) and postprandial triglyceride (chyromicron and VLDL remnants) are risk factors for human atherosclerotic cardiovascular disease (ASCVD). True ligands such as lipoprotein particles of the VLDL receptor are chyromicron remnant (CMR) and VLDL remnant (postprandial hyperlipidemia). Although the oxidized LDL (oxLDL)-scavenger receptors pathway is considered to be the main mechanism for macrophage foam cell formation, it seems that the TGRL-LPL-VLDL receptor pathway is also involved. Since Lp(a) is one of the ligands for the VLDL receptor, the Lp(a)- VLDL receptor pathway is another potential alternative. The expression of VLDL receptor protein in mouse macrophages is modest compared to that in rabbit and human macrophages, both in vitro and in vivo. Therefore, we need to elucidate the mechanism of human ASCVD not by using the mouse model and scavenger receptors pathway but instead using the rabbit model and VLDL receptor pathway, respectively.

Association of very Low-density Lipoprotein Cholesterol with All-cause and Cardiovascular Mortality in Peritoneal Dialysis

BACKGROUND/AIMS

Cardiovascular disease (CVD) is the leading cause of death in dialysis patients. Little is known about the relationship between very low-density lipoprotein cholesterol (VLDL-C) and cardiovascular mortality in these patients.

METHODS

A total of 1324 incident patients who began continuous ambulatory peritoneal dialysis (CAPD) therapy at our hospital between January 1, 2005, and September 30, 2014, with baseline serum VLDL-C values were investigated. The associations of the VLDL-C levels with all-cause and cardiovascular mortality were assessed.

RESULTS

The mean age of the cohort was 50.2 ± 14.8 years, and the mean VLDL-C level was 33.6 ± 18.0 mg/dl. One hundred sixty-five (12.5%) patients died during the study period. Multivariable models revealed that the high VLDL-C group was associated with significantly higher all-cause (HR, 2.08, 95% CI, 1.13 to 3.29, P = 0.002) and cardiovascular mortality (HR, 1.92, 95% CI, 1.18 to 4.29, P = 0.013) compared with the low VLDL-C group even after adjusting for various covariates. Using the VLDL-C level as a continuous variable, the hazard ratios (HRs) of all-cause and cardiovascular mortality associated with a 10-mg/dl increase in VLDL-C level were 1.12 (95% CI, 1.02 to 1.26, P = 0.025) and 1.11 (95% CI, 1.02 to 1.22, P = 0.029), respectively. VLDL-C was associated more strongly to all-cause (e.g., Akaike information criteria of 1990.205 vs. 1994.451) and cardiovascular (e.g., Akaike information criteria of 984.146 vs. 985.634) mortality than triglyceride (TG) levels.

CONCLUSIONS

An elevated VLDL-C level is an independent risk factor for all-cause and cardiovascular mortality in peritoneal dialysis (PD) patients.

Remnant cholesterol predicts periprocedural myocardial injury following percutaneous coronary intervention in poorly-controlled type 2 diabetes

BACKGROUND

Remnant cholesterol (RC) is receiving increasing attention regarding its relation to cardiovascular risk. Whether RC is associated with periprocedural myocardial injury (PMI) following percutaneous coronary intervention (PCI) in type 2 diabetes (T2D) is currently unknown.

METHODS

We prospectively enrolled 1182 consecutive T2D patients who were scheduled for PCI but with baseline normal preprocedural cardiac troponin I (cTnI). Patients were divided according to their glycemic control status: group A [glycated hemoglobin (HbA1c)<7%, n=563] and group B (HbA1c≥7%, n=619). PMI was evaluated by cTnI analysis within 24h. The associations of preprocedural RC and the RC to high-density lipoprotein cholesterol ratio (RC/HDL-C) with PMI were investigated.

RESULTS

The associations of RC and RC/HDL-C with PMI were observed in group B (both p<0.05) but not in group A (both p>0.05). Patients in group B, a 1-SD increase of RC produced 30% and 32% increased risk for postprocedural cTnI>3× upper limit of normal (ULN) and >5×ULN, respectively. The odds ratios for RC/HDL-C were the highest compared with any cholesterol fractions including total cholesterol (TC)/HDL-C, low density lipoprotein cholesterol (LDL-C)/HDL-C, nonHDL-C/HDL-C, and triglyceride/HDL-C with 1.43 [95% confidence interval (CI): 1.10-1.88] for >3× ULN and 1.49 (95% CI: 1.13-1.97) for >5× ULN. However, no such associations were found in group A. Furthermore, patients with RC >27.46mg/dL (third tertile) [RC≤14.15mg/dL (first tertile) as reference] were associated with a 1.57-fold and 2-fold increased risk for >3× ULN and >5× ULN in group B, respectively.

CONCLUSIONS

RC and RC/HDL-C might be valuable, independent predictors for PMI in poorly-controlled diabetic patients undergoing PCI.