Remnant lipoproteinemia predicts cardiovascular events in patients with type 2 diabetes and chronic kidney disease

Distribution of triglyceride-rich lipoproteins and their remnants and their contribution to cardiovascular risk in the Mexican population

BACKGROUND AND AIMS

In recent years, scientific interest in triglyceride-rich lipoproteins (TRL) and remnant cholesterol has increased, focusing on the evidence that these lipoproteins are a causal factor for developing atherosclerotic cardiovascular disease (ASCVD). Furthermore, a high remnant concentration (>38 mg/dL) has been associated with several non-cardiovascular risks. We aimed in this study to describe the percentile distribution of remnant cholesterol. Additionally, we evaluated the association between remnant cholesterol plasma concentration and epidemiologically relevant cardio-metabolic outcomes such as hypertension, type 2 diabetes (T2D), and ASCVD.

METHODS

We analyzed data from 9,591 adults from the National Survey of Health and Nutrition (ENSANUT) 2018 with fasting blood samples and complete medical history questionnaires. We built multivariate models to evaluate the association between chronic diseases and blood remnant concentration. To compare our 2018-sub-sample against a population reference, we used the NHANES (2005-2014) publicly available datasets by ethnicity.

RESULTS

Remnants were independently associated with cardiovascular risk, diabetes, hypertension, obesity, and metabolic syndrome. For all outcomes, the blood remnant concentration was a stronger predictor than LDL. At all deciles, the blood remnant concentration was higher in ENSANUT-2018.

CONCLUSIONS

A remnant blood concentration above 38 mg/dL was highly prevalent among Mexicans. Remnants were significantly associated with a higher risk of diabetes, hypertension, obesity, and cardiovascular risk. This association occurred independently of other lipid markers.

Remnant cholesterol in atherosclerotic cardiovascular disease: A systematic review and meta-analysis

BACKGROUND

Accumulating evidence suggests a substantial contribution of remnant cholesterol (RC) to residual risk for the development or relapse of atherosclerotic cardiovascular disease (ASCVD). We aimed to evaluate the association of RC levels with ASCVD risk by different risk categories and methods of RC assessment. We also assessed available evidence of the effects of lipid-lowering therapies (LLTs) on RC levels.

METHODS

English-language searches of Medline, PubMed, and Embase (inception to 31 January 2023); ClinicalTrials.gov (October 2022); and reference lists of studies and reviews. Studies reporting on the risk of the composite endpoint [all-cause mortality, cardiovascular mortality, and major adverse cardiac events (MACE)] by RC levels were included. Moreover, we searched for studies reporting differences in RC levels after the administration of LLT(s).

RESULTS

Among n = 29 studies with 257,387 participants, we found a pooled linear (pooled HR: 1.27 per 1-SD increase, 95% CI: 1.12-1.43, P < 0.001, I2 = 95%, n = 15 studies) and non-linear association (pooled HR: 1.59 per quartile increase, 95% CI: 1.35-1.85, P < 0.001, I2 = 87.9%, n = 15 studies) of RC levels and the risk of M ACE both in patients with and without established ASCVD. Interestingly, the risk of MACE was higher in studies with directly measured vs. calculated RC levels. In a limited number of studies and participants, LLTs reduced RC levels.

CONCLUSION

RC levels are associated with ASCVD risk both in primary and secondary prevention. Directly measured RC levels are associated with ASCVD risk more evidently. Available LLTs tend to decrease RC levels, although the clinical relevance of RC decrease merits further investigation.

PROSPERO REGISTRATION

CRD42022371346.

Non-fasting lipids and cardiovascular disease in those with and without diabetes in Alberta's Tomorrow Project: A prospective cohort study

AIMS

Non-fasting remnant cholesterol (RC) is a novel marker of cardiovascular disease (CVD) risk, however, data on this relationship in Canadians with diabetes (at high risk of CVD) is lacking. The objective of this analysis was to determine the relationship of RC with CVD in individuals with and without diabetes in the Alberta's Tomorrow Project (ATP) cohort.

METHODS

Non-fasting lipid data collected as part of the ATP was linked to administrative health records (October 2000-March 2015) to ascertain incident CVD and prevalent diabetes. Participants without prevalent CVD or incident diabetes and who had complete, non-negative non-fasting lipid data collected with triglycerides <4.5 mmol/L were included (n = 13,631). The relationship between non-fasting RC and incident CVD diagnoses was assessed by Cox proportional hazards regression, after stratification by diabetes status.

RESULTS

Participants were 69.8% women with a mean age of 61.6 ± 9.7 years, and 6.5% had prevalent diabetes. Non-fasting RC was higher in participants with diabetes compared to those without (mean 0.94 ± 0.41 mmol/L vs. 0.77 ± 0.38 mmol/L, p < 0.0001) and was associated with increased risk of incident CVD among those without diabetes (adjusted hazard ratio (aHR) 1.22, 95% CI 1.03-1.43, p = 0.02). Although a similar trend was observed in participants with diabetes it did not reach statistical significance (aHR 1.31, 95% CI 0.84-2.05, p = 0.23).

CONCLUSIONS

Elevated non-fasting RC predicted increased CVD risk in middle and older-aged adults without diabetes; similar trends were observed in participants with diabetes and require further testing in a larger sample.

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.

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 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.

Relation Between New York Heart Association Functional Class and Remnant Cholesterol, and Non-high Density Lipoprotein Cholesterol in Coronary Heart Disease Patients With Type 2 Diabetes Mellitus

Remnant cholesterol (RC) and non-high-density lipoprotein cholesterol (non-HDL-C) are associated with coronary heart disease (CHD) and type 2 diabetes mellitus (T2DM). However, the association between RC, non-HDL-C, and CHD patients with T2DM has not been comprehensively investigated. We analyzed the association between RC, non-HDL-C, and cardiac function in CHD patients with T2DM. Of the 22 022 CHD patients from six hospitals in Tianjin, 5373 (24.4%) patients with T2DM had higher levels of RC and non-HDL-C (P < .001) than those without T2DM. Among CHD patients with T2DM, RC and non-HDL-C were positively associated with New York Heart Association (NYHA) class Ⅱ [RC: odds ratio (OR), 1.74; 95% confidence interval (CI), 1.50-2.01; P < .01; non-HDL-C: OR, 1.23; 95% CI, 1.15-1.31; P < .01]. After adjusting for confounding factors, this association remained (RC: OR, 1.22; 95% CI, 1.03-1.45; P < .05; non-HDL-C: OR, 1.09; 95% CI, 1.02-1.17; P < .05). These findings provide evidence of an independent positive association between RC, non-HDL-C, and NYHA functional classes. More research is warranted to confirm these findings and determine the mechanisms involved.

Directly measured vs. calculated remnant cholesterol identifies additional overlooked individuals in the general population at higher risk of myocardial infarction

AIMS 

We tested the hypothesis that high directly measured remnant cholesterol is associated with increased risk of ischaemic heart disease (IHD) and myocardial infarction (MI) in the general population. We also explored whether directly measured vs. calculated remnant cholesterol is superior in identifying individuals at increased risk.

METHODS AND RESULTS 

Overall, 16 207 individuals from the Copenhagen General Population Study with both directly measured and calculated remnant cholesterol, both representing cholesterol content in triglyceride-rich lipoproteins, were followed up for 14 years to analyse the risk for IHD and MI. For directly measured and calculated remnant cholesterol, hazard ratios for individuals with concentrations ≥95th percentile vs. <40th percentile were 1.75 (95% confidence interval 1.42-2.15) and 1.76 (1.42-2.17) for IHD and 2.05 (1.50-2.80) and 1.93 (1.40-2.66) for MI. Compared to individuals with both directly measured and calculated remnant cholesterol <80th percentile (75% of the whole population), those with only directly measured remnant cholesterol ≥80th percentile (5%) had hazard ratios of 1.42 (1.15-1.75) for IHD and 1.83 (1.35-2.47) for MI. Corresponding hazard ratios for individuals with only calculated remnant cholesterol ≥80th percentile (5%) were 1.14 (0.91-1.44) and 1.14 (0.80-1.62), respectively, and corresponding hazard ratios for individuals with both directly measured and calculated remnant cholesterol ≥80th percentiles (15%) were 1.48 (1.30-1.68) and 1.67 (1.38-2.01), respectively. In individuals with high directly measured or high calculated remnant cholesterol, the median directly measured remnant cholesterol was 1.9 and 1.5 mmol/L, the median plasma triglycerides were 2.0 and 2.7 mmol/L, and the median plasma apolipoprotein B was 132 and 142 mg/dL, respectively.

CONCLUSIONS 

Directly measured vs. calculated remnant cholesterol identifies 5% overlooked individuals in the general population with cholesterol-rich, triglyceride-poor remnants and 1.8-fold increased risk of MI.

Lipoprotein Abnormalities in Chronic Kidney Disease and Renal Transplantation

Chronic kidney disease (CKD) is one of the most important risk factors for cardiovascular disease (CVD). Despite the kidney having no direct implications for lipoproteins metabolism, advanced CKD dyslipidemia is usually present in patients with CKD, and the frequent lipid and lipoprotein alterations occurring in these patients play a role of primary importance in the development of CVD. Although hypertriglyceridemia is the main disorder, a number of lipoprotein abnormalities occur in these patients. Different enzymes pathways and proteins involved in lipoprotein metabolism are impaired in CKD. In addition, treatment of uremia may modify the expression of lipoprotein pattern as well as determine acute changes. In renal transplantation recipients, the main lipid alteration is hypercholesterolemia, while hypertriglyceridemia is less pronounced. In this review we have analyzed lipid and lipoprotein disturbances in CKD and also their relationship with progression of renal disease. Hypolipidemic treatments may also change the natural history of CVD in CKD patients and may represent important strategies in the management of CKD patients.

The relation between VLDL-cholesterol and risk of cardiovascular events in patients with manifest cardiovascular disease

INTRODUCTION

Apolipoprotein B containing lipoproteins are atherogenic. There is evidence that with low plasma low density lipoprotein cholesterol (LDL-C) levels residual vascular risk might be caused by triglyceride rich lipoproteins such as very-low density lipoproteins (VLDL), chylomicrons and their remnants. We investigated the relationship between VLDL-cholesterol (VLDL-C) and recurrent major adverse cardiovascular events (MACE), major adverse limb events (MALE) and all-cause mortality in a cohort of patients with cardiovascular disease.

METHODS

Prospective cohort study in 8057 patients with cardiovascular disease from the UCC-SMART study. The relation between calculated VLDL-C levels and the occurrence of MACE, MALE and all-cause mortality was analyzed with Cox regression models.

RESULTS

Patients mean age was 60 ± 10 years, 74% were male, 4894 (61%) had coronary artery disease, 2445 (30%) stroke, 1425 (18%) peripheral arterial disease and 684 (8%) patients had an abdominal aorta aneurysm at baseline. A total of 1535 MACE, 571 MALE and 1792 deaths were observed during a median follow up of 8.2 years (interquartile range 4.512.2). VLDL-C was not associated with risk of MACE or all-cause mortality. In the highest quartile of VLDL-C the risk was higher for major adverse limb events (MALE) (HR 1.49; 95%CI 1.16-1.93) compared to the lowest quartile, after adjustment for confounders including LDL-C and lipid lowering medication.

CONCLUSION

In patients with clinically manifest cardiovascular disease plasma VLDL-C confers an increased risk for MALE, but not for MACE and all-cause mortality, independent of established risk factors including LDL-C and lipid-lowering medication.

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.

Association between remnant lipoprotein cholesterol levels and non-alcoholic fatty liver disease in adolescents

Background & Aims

Remnant lipoprotein cholesterol (RLP-C) is an atherogenic lipid profile associated with non-alcoholic fatty liver disease (NAFLD) and cardiovascular disease (CVD). With increased rates of CVD seen in adults with NAFLD, RLP-C has the potential to identify individuals with NAFLD who are at increased risk of CVD. This study examined in adolescents sex-different associations among RLP-C, NAFLD, and cardiometabolic risk factors, and whether RLP-C is associated with NAFLD beyond traditional cardiometabolic risk factors.

Methods

Adolescents in the Raine Study had anthropometry, clinical, biochemistry and arterial stiffness measurements recorded at 17 years of age. Fatty liver, subcutaneous and visceral adipose thickness were assessed using abdominal ultrasound. Relationships among RLP-C, NAFLD, liver biochemistry, insulin resistance, adipokines, adiposity and arterial stiffness were assessed.

Results

NAFLD was diagnosed in 15.1% (19.6% females and 10.7% males) of adolescents. Increasing RLP-C levels were associated with increasing severity of hepatic steatosis and metabolic syndrome. Adolescents with NAFLD and serum RLP-C levels in the highest quartile compared with the lowest quartile, had higher serum leptin, homeostatic model assessment of insulin resistance (HOMA-IR), high-sensitivity C-reactive protein, low-density-lipoprotein cholesterol, triglycerides, BMI, subcutaneous and visceral adipose thickness, systolic blood pressure and arterial stiffness, but lower adiponectin and high-density-lipoprotein cholesterol. Using multivariable logistic regression, RLP-C in the lowest quartile compared with the highest quartile was associated with 85% lower odds of NAFLD in males and 55% in females, after adjusting for waist circumference, leptin, ALT, adiponectin and HOMA-IR.

Conclusions

There is an association between RLP-C and NAFLD beyond traditional risk factors of adiposity and insulin resistance in adolescents. Although raised serum RLP-C levels were associated with the severity of hepatic steatosis and markers of cardiometabolic risk, lower serum RLP-C might reflect reduced cardiovascular risk.

Lay summary

Remnant lipoprotein cholesterol (RLP-C) is a part of the blood cholesterol that is linked with heart disease and non-alcoholic fatty liver disease (NAFLD) in adults. In the Raine Study, teenagers with high RLP-C levels had more severe fat accumulation in their liver. Thus, RLP-C might be the hidden link between NAFLD and future risk of heart disease.

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Non-alcoholic fatty liver disease (NAFLD) and heart disease share risk factors.

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Serum remnant lipoprotein cholesterol (RLP-C) is linked with severity of liver fat.

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Males with NAFLD have higher cardiometabolic risk.

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RLP-C may contribute to risk of cardiovascular disease in people with NAFLD.

Remnant lipoproteins: are they equal to or more atherogenic than LDL?

PURPOSE OF REVIEW

To critically appraise new insights into the biology of remnant lipoproteins and their putative role in the pathophysiology of atherosclerotic cardiovascular disease, and to compare the atherogenicity of remnant particles with that of low-density lipoproteins (LDL).

RECENT FINDINGS

New in-vivo stable isotope tracer studies of the kinetics of apoB48 and apoB100-containing lipoproteins in postprandial conditions have revealed that apoB48-containing very low-density lipoproteins (VLDL) accumulated markedly in hypertriglyceridemic patients. These intestinally-derived particles were cleared slowly, and represented up to 25% of circulating VLDL; as part of the remnant particle population, they may increase cardiovascular risk. Importantly, the PCSK9 inhibitor, evolocumab, was shown to reduce remnant levels (-29%) during the postprandial period in diabetic patients on statin therapy - an effect which may be additive to that of LDL-cholesterol reduction in conferring cardiovascular benefit. In recent Mendelian randomization studies, the effect of lowering triglyceride-rich lipoproteins or LDL-cholesterol translated to similar clinical benefit per unit of apoB. Finally, in randomized trials involving statin-treated patients with atherosclerotic cardiovascular disease, remnant cholesterol levels were associated with coronary atheroma progression independently of LDL-cholesterol.

SUMMARY

Overall, data from observational studies in large cohorts, Mendelian randomization studies, meta-regression analyses, and post-hoc analyses of randomized trials are consistent with the contention that remnants are highly atherogenic particles and contribute to the atherosclerotic burden in an equivalent manner to that of LDL.

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.

Icosapent ethyl reduces atherogenic markers in high-risk statin-treated patients with stage 3 chronic kidney disease and high triglycerides

Objective: Patients with chronic kidney disease (CKD) have increased cardiovascular disease (CVD) risk, likely driven by atherogenic and inflammatory markers beyond low-density lipoprotein cholesterol (LDL-C). The objective of this hypothesis-generating post hoc subgroup analysis was to explore the effects of icosapent ethyl at 2 or 4 g/day (prescription pure ethyl ester of the omega-3 fatty acid eicosapentaenoic acid [EPA]) on atherogenic lipid, apolipoprotein, inflammatory parameters (high-sensitivity C-reactive protein [hsCRP], lipoprotein-associated phospholipase A₂ [Lp-PLA₂]), and oxidative parameters (oxidized-LDL [ox-LDL]) in statin-treated patients from ANCHOR with stage 3 CKD.Methods: The 12-week ANCHOR study evaluated icosapent ethyl in 702 statin-treated patients at increased CVD risk with triglycerides (TG) 200-499 mg/dL despite controlled LDL-C (40-99 mg/dL). This post-hoc analysis included patients from ANCHOR with stage 3 CKD (estimated glomerular filtration rate [eGFR] ≤60 mL/min/1.73 m² for ≥3 months) randomized to icosapent ethyl 4 g/day (n = 19), 2 g/day (n = 30), or placebo (n = 36).Results: At the prescription dose of 4 g/day, icosapent ethyl significantly reduced TG (-16.9%; P = 0.0074) and other potentially atherogenic lipids/lipoproteins, ox-LDL, hsCRP, and Lp-PLA₂, and increased plasma and red blood cell EPA levels (+879% and +579%, respectively; both P < 0.0001) versus placebo. Icosapent ethyl did not significantly alter eGFR or serum creatinine. Safety and tolerability were similar to placebo.Conclusions: In patients with stage 3 CKD at high CVD risk with persistent high TG despite statins, icosapent ethyl 4 g/day reduced potentially atherogenic and other cardiovascular risk factors without raising LDL-C, with safety similar to placebo. These findings suggest prospective investigation may be warranted.

Lipids, Apolipoproteins, and Risk of Atherosclerotic Cardiovascular Disease in Persons With CKD

RATIONALE & OBJECTIVE

A large residual risk for atherosclerotic cardiovascular disease (ASCVD) remains in the setting of chronic kidney disease (CKD) despite treatment with statins. We sought to evaluate the associations of lipid and apolipoprotein levels with risk for ASCVD in individuals with CKD.

STUDY DESIGN

Prospective cohort study.

SETTINGS & PARTICIPANTS

Adults aged 21 to 74 years with non-dialysis-dependent CKD at baseline enrolled in the Chronic Renal Insufficiency Cohort (CRIC) Study in 7 clinical study centers in the United States.

PREDICTOR

Baseline total cholesterol, non-high-density lipoprotein cholesterol (non-HDL-C), very low-density lipoprotein cholesterol (VLDL-C), triglycerides, low-density lipoprotein cholesterol (LDL-C), apolipoprotein B (Apo-B), HDL-C, and apolipoprotein AI (Apo-AI) values stratified into tertiles.

OUTCOME

A composite ASCVD event of myocardial infarction or ischemic stroke.

ANALYTIC APPROACH

Multivariable Cox proportional hazards regression to estimate the risk for ASCVD for each tertile of lipoprotein predictor.

RESULTS

Among 3,811 CRIC participants (mean age, 57.7 years; 41.8% white), there were 451 ASCVD events during a median follow-up of 7.9 years. There was increased ASCVD risk among participants with VLDL-C levels in the highest tertile (HR, 1.28; 95% CI, 1.01-1.64), Apo-B levels in the middle tertile (HR, 1.30; 95% CI, 1.03-1.64), HDL-C levels in the middle and lowest tertiles (HRs of 1.40 [95% CI, 1.08-1.83] and 1.77 [95% CI, 1.35-2.33], respectively), and Apo-AI levels in the middle and lowest tertiles (HRs of 1.77 [95% CI, 1.02-1.74] and 1.77 [95% CI, 1.36-2.32], respectively). LDL-C level was not significantly associated with the ASCVD outcome in this population (HR, 1.00 [95% CI, 0.77-1.30] for the highest tertile).

LIMITATIONS

Associations based on observational data do not permit inferences about causal associations.

CONCLUSIONS

Higher VLDL-C and Apo-B levels, as well as lower HDL-C and Apo-AI levels, are associated with increased risk for ASCVD. These findings support future investigations into pharmacologic targeting of lipoproteins beyond LDL-C, such as triglyceride-rich lipoproteins, to reduce residual risk for ASCVD among individuals with CKD.

The Forgotten Lipids: Triglycerides, Remnant Cholesterol, and Atherosclerotic Cardiovascular Disease Risk

Atherosclerotic cardiovascular disease (ASCVD) remains the leading cause of death worldwide. Low-density lipoprotein cholesterol (LDL-C) is a well-established mediator of atherosclerosis and a key target for intervention for the primary and secondary prevention of ASCVD. However, despite substantial reduction in LDL-C, patients continue to have recurrent ASCVD events. Hypertriglyceridemia may be an important contributor of this residual risk. Observational and genetic epidemiological data strongly support a causal role of triglycerides (TGs) and the cholesterol content within triglyceride-rich lipoproteins (TGRLs) and/or remnant cholesterol (RC) in the development of ASCVD. TGRLs are composed of hepatically derived very low-density lipoprotein and intestinally derived chylomicrons. RC is the cholesterol content of all TGRLs and plasma TGs serve as a surrogate measure of TGRLs and RC. Although lifestyle modification remains the cornerstone for management of hypertriglyceridemia, many novel drugs are in development and have shown impressive efficacy in lowering TG levels. Several ongoing, randomized controlled trials are underway to examine the impact of these novel agents on ASCVD outcomes. In this comprehensive review, we provide an overview of the biology, epidemiology, and genetics of TGs and ASCVD; we discuss current and novel TG-lowering therapies under development.

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.

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 lipoproteins

PURPOSE OF REVIEW

To review recent advances in the field of remnant lipoproteins and remnant cholesterol with a focus on cardiovascular disease risk.

RECENT FINDINGS

In line with previous years' research, current observational, genetic, and mechanistic studies find remnant lipoproteins (defined in different ways) to be involved in atherosclerosis development and cardiovascular disease risk. High concentrations of remnant cholesterol could explain some of the residual risk of cardiovascular disease seen after LDL cholesterol lowering. This will be increasingly important as populations worldwide become more obese and more have diabetes, both of which elevate remnant cholesterol concentrations. Many smaller scale studies and post hoc analyses show that remnant cholesterol can be lowered by different types of drugs; however, results from large scale studies with the primary aim of reducing cardiovascular disease risk through lowering of remnant cholesterol in individuals with elevated concentrations are still missing, although some are under way.

SUMMARY

Remnant cholesterol is a risk factor for cardiovascular disease, and can be lowered by different types of drugs; however, large scale studies of cardiovascular disease risk reduction through remnant lipoprotein lowering are under way.

Icosapent ethyl (eicosapentaenoic acid ethyl ester): Effects on remnant-like particle cholesterol from the MARINE and ANCHOR studies

BACKGROUND AND AIMS

Remnant-like particle cholesterol (RLP-C) is atherogenic and may increase atherosclerotic cardiovascular disease risk. Icosapent ethyl is a high-purity prescription eicosapentaenoic acid ethyl ester (approved as an adjunct to diet to reduce triglyceride [TG] levels in adult patients with TGs ≥500 mg/dL [≥5.65 mmol/L] at 4 g/day). In the MARINE and ANCHOR studies, icosapent ethyl reduced TG and other atherogenic lipid parameter levels without increasing low-density lipoprotein cholesterol (LDL-C) levels. This exploratory analysis evaluated the effects of icosapent ethyl on calculated and directly measured RLP-C.

METHODS

MARINE (TGs ≥500 and ≤2000 mg/dL [≥5.65 mmol/L and ≤22.6 mmol/L]) and ANCHOR (TGs ≥200 and <500 mg/dL [≥2.26 and <5.65 mmol/L] despite statin-controlled LDL-C) were phase 3, 12-week, double-blind studies that randomized adult patients to icosapent ethyl 4 g/day, 2 g/day, or placebo. This analysis assessed median percent change from baseline to study end in directly measured (immunoseparation assay) RLP-C levels (MARINE, n = 218; ANCHOR, n = 252) and calculated RLP-C levels in the full populations.

RESULTS

Icosapent ethyl 4 g/day significantly reduced directly measured RLP-C levels -29.8% (p = 0.004) in MARINE and -25.8% (p = 0.0001) in ANCHOR versus placebo, and also reduced directly measured RLP-C levels to a greater extent in subgroups with higher versus lower baseline TG levels, in patients receiving statins versus no statins (MARINE), and in patients receiving medium/higher-intensity versus lower-intensity statins (ANCHOR). Strong correlations were found between calculated and directly measured RLP-C for baseline, end-of-treatment, and percent change values in ANCHOR and MARINE (0.73-0.92; p < 0.0001 for all).

CONCLUSIONS

Icosapent ethyl 4 g/day significantly reduced calculated and directly measured RLP-C levels versus placebo in patients with elevated TG levels from the MARINE and ANCHOR studies.