Lipoprotein alterations in endocrine disorders - a review of the recent developments in the field

Dyslipidemia is one of the most common disorders worldwide, which, if left untreated, results in a multitude of complications. Thus proper diagnostics, which includes identifying of secondary causes of dyslipidemia is crucial. Endocrine disorders are an important cause of secondary dyslipidemia. This paper aims to review the publications on lipoprotein alterations in endocrine disorders from the past two years and provide an overview of the recent discoveries in this dynamically developing and large field. Significant changes in lipoprotein serum concentrations are present in most endocrinological diseases and can be modified with proper treatment. Some lipoproteins have also been proposed as markers in some endocrine diseases, e.g., thyroid carcinoma. From the scope of endocrine disorders, the largest number of studies explored the lipoprotein changes in polycystic ovary syndrome and in women during the menopausal and peri-menopausal period. Even though the association of thyroid disorders with dyslipidemia is already well studied, new research has delivered some exciting findings about lipoprotein alterations in euthyroid patients with either positive antithyroid peroxidase antibodies or reduced sensitivity to thyroid hormones. The problem of the adverse metabolic profile, including dyslipidemia in hypoprolactinemia has been recognized. Moreover, this review describes other significant discoveries encompassing lipoprotein alterations in disorders of the adrenals, thyroid, parathyroid glands, pituitary, and gonads. The up-to-date knowledge of the influence of endocrine disorders and hormonal changes on serum lipoproteins is prudent as it can significantly impact therapeutic decisions.

Digital droplet PCR versus quantitative PCR for lipoprotein (a) kringle IV type 2 repeat polymorphism genetic characterization

BACKGROUND

Lipoprotein(a) [Lp(a)] level variability, related to atherothrombotic risk increase, is mainly attributed to LPA gene, encoding apolipoprotein(a), with kringle IV type 2 (KIV2) copy number variation (CNV) acting as the primary genetic determinant. Genetic characterization of Lp(a) is in continuous growth; nevertheless, the peculiar structural characteristics of this variant constitute a significant challenge to the development of effective detection methods. The aim of the study was to compare quantitative real-time PCR (qPCR) and digital droplet PCR (ddPCR) in the evaluation of KIV2 repeat polymorphism.

METHODS

We analysed 100 subjects tested for cardiovascular risk in which Lp(a) plasma levels were assessed.

RESULTS

Correlation analysis between CNV values obtained with the two methods was slightly significant (R = 0.413, p = 0.00002), because of the wider data dispersion in qPCR compared with ddPCR. Internal controls C1, C2 and C3 measurements throughout different experimental sessions revealed the superior stability of ddPCR, which was supported by a reduced intra/inter-assay coefficient of variation determined in this method compared to qPCR. A significant inverse correlation between Lp(a) levels and CNV values was confirmed for both techniques, but it was higher when evaluated by ddPCR than qPCR (R = -0.393, p = 0.000053 vs R = -0.220, p = 0.028, respectively). When dividing subjects into two groups according to 500 mg/L Lp(a) cut-off value, a significantly lower number of KIV2 repeats emerged among subjects with greater Lp(a) levels, with stronger evidence in ddPCR than in qPCR (p = 0.000013 and p = 0.001, respectively).

CONCLUSIONS

Data obtained support a better performance of ddPCR in the evaluation of KIV2 repeat polymorphism.

Early Initiation of PCSK9 Inhibitor Therapy Versus Placebo in Patients With Acute Coronary Syndrome: A Systematic Review and Meta-Analysis

In patients with stable atherosclerotic cardiovascular disease, proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9is) have shown a 50% to 60% reduction in low-density lipoprotein cholesterol (LDL-C) from baseline when added to high-intensity statin therapy. However, less is known about the impact of PCSK9is in the setting of an acute coronary syndrome (ACS). Therefore, we performed a systematic review and meta-analysis comparing PCSK9is with placebo in the setting of ACS added to guideline-directed high-intensity or maximally tolerated statin therapy. We included randomized controlled trials with initiation of a PCSK9i or placebo within 1 week of presentation or percutaneous coronary intervention for ACS. PubMed, EMBASE, and Cochrane Central were searched. This study followed the Cochrane and Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) recommendations. A total of 6 randomized controlled trials were included, with a total of 996 patients, of whom 503 (50.5%) received PCSK9is. The mean follow-up ranged from 4 to 52 weeks. The LDL-C (mean difference [MD] -44.0 mg/100 ml, CI -54.3 to -33.8, p <0.001) and lipoprotein (a) levels (MD -24.0 nmol/L, confidence interval [CI] -43.0 to -4.9, p = 0.01) were significantly lower at follow-up with PCSK9is. Similarly, the total cholesterol (MD -49.2 mg/100 ml, CI -59.0 to -39.3), triglycerides (MD -19.0 mg/100 ml, CI -29.9 to -8.2), and apolipoprotein B (MD -33.3 mg/100 ml, CI -44.4 to -22.1) were significantly reduced with PCSK9is. In conclusion, in patients with ACS, early initiation of PCSK9i added to statin significantly reduces LDL-C and lipoprotein (a) levels compared with placebo. Whether the differences in these atherogenic lipoproteins translate into a reduction in clinical end points is yet to be determined.

Lipoprotein(a) and Long-Term Recurrent Infarction After an Acute Myocardial Infarction

Lipoprotein(a) (Lp[a]) is an emerging risk factor for incident ischemic heart disease. However, its role in risk stratification in in-hospital survivors to an index acute myocardial infarction (AMI) is scarcer, especially for predicting the risk of long-term recurrent AMI. We aimed to assess the relation between Lp(a) and very long-term recurrent AMI after an index episode of AMI. It is a retrospective analysis that included 1,223 consecutive patients with an AMI discharged from October 2000 to June 2003 in a single-teaching center. Lp(a) was assessed during index admission in all cases. The relation between Lp(a) at discharge and total recurrent AMI was evaluated through negative binomial regression. The mean age of the patients was 67.0 ± 12.3 years, 379 (31.0%) were women, and 394 (32.2%) were diabetic. The index event was more frequently non-ST-segment elevation myocardial infarction (66.0%). The median Lp(a) was 28.8 (11.8 to 63.4) mg/100 ml. During a median follow-up of 9.9 (4.6 to 15.5) years, 813 (66.6%) deaths and 1,205 AMI in 532 patients (43.5%) occurred. Lp(a) values were not associated with an increased risk of long-term all-cause mortality (p = 0.934). However, they were positively and nonlinearly associated with an increased risk of total long-term reinfarction (p = 0.016). In the subgroup analysis, there was no evidence of a differential effect for the most prevalent subgroups. In conclusion, after an AMI, elevated Lp(a) values assessed during hospitalization were associated with an increased risk of recurrent reinfarction in the very long term. Further prospective studies are warranted to evaluate their clinical implications.

Healthy lifestyle, lipoprotein (a) levels and the risk of coronary artery disease

BACKGROUND

Lipoprotein (a) [Lp(a)] is associated with coronary artery disease (CAD). However, the role of healthy lifestyle against the risk of CAD with consideration of high Lp(a) levels remains unclear.

METHODS

This study examined 4512 participants who underwent serum Lp(a) level assessment at Kanazawa University Hospital from 2008 to March 2016. Their lifestyle habits were examined based on four questionnaires regarding dietary pattern, exercise habits, smoking status and body weight. Logistic regression analyses were performed to identify the association between healthy lifestyle and CAD independent of Lp(a) levels.

RESULTS

The Lp(a) levels were significantly associated with CAD (odds ratio [OR]: 1.12, 95% confidence interval [CI]: 1.08-1.17, p = 1.3 × 10-7 per 10 mg/dL). Under these circumstances, the lifestyle risk score was also significantly associated with CAD (OR: 1.24, 95% CI: 1.12-1.36, p = 2.4 × 10-8 ). Compared with patients with a favourable lifestyle who have Lp(a) levels of <30 mg/dL, those with an intermediate or unfavourable lifestyle were at higher risk for CAD (OR: 1.11, 95% CI: 1.02-1.20, p = 0.003 and OR: 1.40, 95% CI: 1.16-1.54, p = 3.6 × 10-5 , respectively). Further, patients with a favourable, intermediate or unfavourable lifestyle who have Lp(a) levels of ≥30 mg/dL were at high risk for CAD (OR: 1.21, 95% CI: 1.08-1.34, p = 0.0014; OR: 1.31, 95% CI: 1.14-1.48, p = 1.2 × 10-4 ; and OR: 1.81, 95% CI: 1.44-2.18, p = 2.2 × 10-7 , respectively).

CONCLUSIONS

Healthy lifestyle was associated with a lower risk of CAD regardless of Lp(a) levels.

The ins and outs of lipoprotein(a) assay methods

Pathophysiological, epidemiological and genetic studies convincingly showed lipoprotein(a) (Lp(a)) to be a causal mediator of atherosclerotic cardiovascular disease (ASCVD). This happens through a myriad of mechanisms including activation of innate immune cells, endothelial cells as well as platelets. Although these certainties whether or not Lp(a) is ready for prime-time clinical use remain debated. Thus, remit of the present review is to provide an overview of different methods that have been employed for the measurement of Lp(a). The methods include dynamic light scattering, multi-angle light scattering analysis, near-field imaging, sedimentation, gel filtration, and electron microscopy. The development of multiple Lp(a) detection methods is vital for improved prediction of ASCVD risk.

Efficacy of Proprotein Convertase Subtilisin/Kexin Type 9 Inhibitor Treatment for Repeated In-stent Restenosis in a Coronary Artery

A 57-year-old woman experienced chest pain. A coronary angiogram revealed middle left anterior descending artery stenosis. Despite receiving adequate anti-hyperlipidemia treatment and undergoing percutaneous coronary intervention (PCI), she experienced angina and required PCI six more times for in-stent restenosis. As she had high lipoprotein (a) [LP-(a)] levels at the seventh PCI procedure, proprotein convertase subtilisin/kexin type 9 inhibitor (PCSK9i) was administered, and a reduction in the LP-(a) and low-density lipoprotein cholesterol (LDL-C) values was observed. She experienced no recurrence of angina for five years with PCSK9i treatment. PCSK9i can reduce not only LDL-C but also LP-(a) levels, resulting in cardiac event risk reduction.

Lipoprotein(a)-60 Years Later-What Do We Know?

Lipoprotein(a) (Lp(a)) molecule includes two protein components: apolipoprotein(a) and apoB100. The molecule is the main transporter of oxidized phospholipids (OxPL) in plasma. The concentration of this strongly atherogenic lipoprotein is predominantly regulated by the LPA gene expression. Lp(a) is regarded as a risk factor for several cardiovascular diseases. Numerous epidemiological, clinical and in vitro studies showed a strong association between increased Lp(a) and atherosclerotic cardiovascular disease (ASCVD), calcific aortic valve disease/aortic stenosis (CAVD/AS), stroke, heart failure or peripheral arterial disease (PAD). Although there are acknowledged contributions of Lp(a) to the mentioned diseases, clinicians struggle with many inconveniences such as a lack of well-established treatment lowering Lp(a), and common guidelines for diagnosing or assessing cardiovascular risk among both adult and pediatric patients. Lp(a) levels are different with regard to a particular race or ethnicity and might fluctuate during childhood. Furthermore, the lack of standardization of assays is an additional impediment. The review presents the recent knowledge on Lp(a) based on clinical and scientific research, but also highlights relevant aspects of future study directions that would approach more suitable and effective managing risk associated with increased Lp(a), as well as control the Lp(a) levels.

Case report: lipoprotein apheresis reduces the risk of cardiovascular events and prolongs pregnancy in a woman with severely elevated lipoprotein(a), cardiovascular disease, and a high risk of preeclampsia

Background

Preeclampsia is a common and serious pregnancy-induced disease, with potential severe maternal and fetal complications. Recently, an increased lipoprotein (a) (Lp[a]) concentration, an important factor in cardiovascular diseases (CVDs) pathogenesis, has been identified as a sensitive and specific marker of preeclampsia severity. Although lipoprotein apheresis (LA) is currently used in patients with hyperlipoproteinemia(a) and CVD, real-life data on its efficacy among pregnant women with an increased risk of preeclampsia are limited.

Case presentation

We present the case of a pregnant woman with severely elevated Lp(a), two previous episodes of the acute coronary syndrome and multivessel coronary disease treated with long-term LA before pregnancy, and a high risk of preeclampsia (as assessed using combined test screening). An increased pulsatility index and early diastolic notch were observed on Doppler interrogation at 18 weeks' gestation. Biweekly LA therapy was re-initiated at 21 weeks' gestation. The LA safely removed 70% of the serum Lp(a) concentration and reduced low-density lipoprotein-cholesterol (LDL-C) levels by 60%. We also observed an improvement in her urine protein/creatinine ratio, a reduction in the pulsatility index, and a notch on Doppler interrogation. The pregnancy lasted until week 36, when severe preeclampsia prompted an emergency cesarean delivery.

Conclusion

Pregnancy in women with elevated Lp(a), CVD, and a high risk of preeclampsia can present challenges in clinical management. Our case report indicates the benefits of LA in preventing atherosclerotic CVD progression during pregnancy, its potential influence on uteroplacental circulation, and prolongation of pregnancy for the best possible intrauterine fetus development. LA may be considered as a treatment option during pregnancy in such conditions. In addition, in pregnant women with CVD, we suggest screening using a combined test and measurement of Lp(a) as a marker of preeclampsia severity.

Impact of alirocumab/evolocumab on lipoprotein (a) concentrations in patients with familial hypercholesterolaemia: a systematic review and meta-analysis of randomized controlled trials

INTRODUCTION

Familial hypercholesterolaemia (FH) is a common hereditary genetic disorder, characterized by elevated circulating low-density lipoprotein cholesterol (LDL-C) and lipoprotein (a) [Lp(a)] concentrations, leading to atherosclerotic cardiovascular disease (ASCVD). Two types of proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors- alirocumab and evolocumab- are efficient drugs in the treatment of FH, which can effectively reduce Lp(a) levels.

MATERIAL AND METHODS

Embase, MEDLINE, and PubMed up to November 2022 were searched for randomized clinical trials (RCTs) evaluating the effect of alirocumab/evolocumab and placebo treatment on plasma Lp(a) levels in FH. Statistics were analysed by Review Manager (RevMan 5.3) and Stata 15.1.

RESULTS

Eleven RCTs involved a total of 2408 participants. Alirocumab/evolocumab showed a significant efficacy in reducing Lp(a) [weighted mean difference (WMD): -20.10%, 95% confidence interval (CI): -25.59% to -14.61%] compared with placebo. In the drug type subgroup analyses, although the efficacy of evolocumab was slightly low (WMD: -19.98%, 95% CI: -25.23% to -14.73%), there was no difference with alirocumab (WMD: -20.54%, 95% CI: -30.07% to -11.02%). In the treatment duration subgroup analyses, the efficacy of the 12-week duration group (WMD: -17.61%, 95% CI: -23.84% to -11.38%) was lower than in the group of ≥ 24 weeks' duration (WMD: -22.81%, 95% CI: -31.56% to -14.07%). In the participants' characteristics subgroup analyses, the results showed that no differential effect of alirocumab/evolocumab therapy on plasma Lp(a) concentrations was observed (heterozygous FH [HeFH] WMD: -20.07%, 95% CI: -26.07% to -14.08%; homozygous FH [HoFH] WMD: -20.04%, 95% CI: -36.31% to -3.77%). Evaluation of all-cause adverse events (AEs) between alirocumab/evolocumab groups and placebo groups [relative risk (RR): 1.05, 95% CI: 0.98-1.12] implied no obvious difference between the 2 groups.

CONCLUSIONS

Anti-PCSK9 drugs (alirocumab and evolocumab) may be effective as therapy for reducing serum Lp(a) levels in FH, and no differences were observed in treatment durations, participant characteristics, and other aspects of the 2 types of PCSk9 inhibitors. However, further experimental studies and RCTs are warranted to clarify the mechanism of PSCK9 inhibitors to lowering Lp(a) concentrations in FH.

Consensus document for lipid profile testing and reporting in Spanish clinical laboratories: what parameters should a basic lipid profile include?

Cardiovascular diseases (CVD) continue to be the main cause of death in our country. Adequate control of lipid metabolism disorders is a key challenge in cardiovascular prevention that is far from being achieved in real clinical practice. There is a great heterogeneity in the reports of lipid metabolism from Spanish clinical laboratories, which may contribute to its poor control. For this reason, a working group of the main scientific societies involved in the care of patients at vascular risk, has prepared this document with a consensus proposal on the determination of the basic lipid profile in cardiovascular prevention, recommendations for its realization and unification of criteria to incorporate the lipid control goals appropriate to the vascular risk of the patients in the laboratory reports.

Association of aortic dissection and lipoprotein (a): a meta-analysis

Some studies reported a positive relation between aortic dissection (AD) and increased lipoprotein (a) (LP(a)), while other studies reported no association, so the authors aimed to do a meta-analysis to establish the relation between AD and high levels of LP(a).

Methods

PubMed, Scopus, Web of Science, SAGE, EMBASE, Science Direct, and Cochrane Library were searched. The inclusion criteria were any randomized control trials or observational studies that measured the levels of LP(a) in AD patients and healthy controls. The authors excluded case reports, case series, noncontrolled studies, reviews, editorials, and animal studies.

Results

After a search of the literature, four studies were included in the meta-analysis with 678 patients included in the analysis. The pooled analysis showed a statistically significant association between the AD group and increased levels of LP(a), decreased levels of TG, low-density lipoprotein cholesterol, and TC compared with the control group (MD=11.71, 95% CI=4.11-19.32, P-value=0.003), (MD=-0,32, 95% CI=-0.48 to -0.16, P-value<0.0001 ), (MD=-0,21, 95% CI=-0.42 to -0.1, P-value=0.04), (MD=-0,58, 95% CI=-0.62 to -0.54, P-value<0.00001), respectively.

Conclusion

Our study showed that AD is significantly associated with increased levels of LP(a). The significant increase in LP(a) in AD was associated with decreased levels of TG, low-density lipoprotein cholesterol, and TC. Future clinical trials testing Lp (a) targeting medications could be useful in the primary, or secondary prevention of AD in high risk patients.

Lipid-Lowering Nutraceuticals for an Integrative Approach to Dyslipidemia

Dyslipidemia is a treatable risk factor for atherosclerotic cardiovascular disease that can be addressed through lifestyle changes and/or lipid-lowering therapies. Adherence to statins can be a clinical challenge in some patients due to statin-associated muscle symptoms and other side effects. There is a growing interest in integrative cardiology and nutraceuticals in the management of dyslipidemia, as some patients desire or are actively seeking a more natural approach. These agents have been used in patients with and without established atherosclerotic cardiovascular disease. We provide an updated review of the evidence on many new and emerging nutraceuticals. We describe the mechanism of action, lipid-lowering effects, and side effects of many nutraceuticals, including red yeast rice, bergamot and others.

Inclisiran, Low-Density Lipoprotein Cholesterol and Lipoprotein (a)

Dyslipidemia treatment is of major importance in reducing the risk of atherosclerotic cardiovascular disease (ASCVD), which is still the most common cause of death worldwide. During the last decade, a novel lipid-lowering drug category has emerged, i.e., proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors. Apart from the two available anti-PCSK9 monoclonal antibodies (alirocumab and evolocumab), other nucleic acid-based therapies that inhibit or "silence" the expression of PCSK9 are being developed. Among them, inclisiran is the first-in-class small interfering RNA (siRNA) against PCSK9 that has been approved by both the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA) for the treatment of hypercholesterolemia. Importantly, inclisiran therapy may improve low-density lipoprotein cholesterol (LDL-C) target achievement by offering a prolonged and significant LDL-C-lowering effect with the administration of only two doses per year. The present narrative review discusses the ORION/VICTORION clinical trial program that has been designed to investigate the impact of inclisiran on atherogenic lipoproteins and major adverse cardiac events in different patient populations. The results of the completed clinical trials are presented, focusing on the effects of inclisiran on LDL-C and lipoprotein (a) (Lp(a)) levels as well as on other lipid parameters such as apolipoprotein B and non-high-density lipoprotein cholesterol (non-HDL-C). Ongoing clinical trials with inclisiran are also discussed.

Determinants of Lipid Parameters in Patients without Diagnosed Cardiovascular Disease-Results of the Polish Arm of the EUROASPIRE V Survey

To assess the determinants of lipid parameters in primary care patients without diagnosed cardiovascular disease (CVD), a cross-sectional study was conducted during 2018-2019 with a total of 200 patients. The following lipid parameters were measured: total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), small, dense LDL (sdLDL-C), and lipoprotein (a) (Lp(a)). Predictors of elevated and adequately controlled lipid parameters were assessed with logistic regression analysis. Older age was related to higher risk of TC ≥ 6.2 mmol/L [OR 1.03 (95% CI 1.0-1.05)], sdLDL-C ≥ 1.0 mmol/L [OR 1.05 (95% CI 1.0-1.1)], and decreased risk of Lp(a) ≥ 50 mg/dL [OR 0.97 (95% CI 0.94-0.99)]. Patients with diabetes mellitus (DM) had increased probability of TG ≥ 2.25 mmol/L [OR 3.77 (95% CI 1.34-10.6)] and Lp(a) ≥ 50 mg/dL [OR 2.97 (1.34-6.10)] as well as adequate control of TG and Lp(a). Higher material status was related to lower risk of TC ≥ 6.2 mmol/L [OR 0.19 (95% CI 0.04-0.82)] and LDL-C ≥ 3.6 mmol/L [OR 0.33 (95% CI 0.12-0.92)]. High BMI was related to increased [OR 1.14 (95% CI 1.02-1.29)], and female gender [OR 0.33 (95% CI 0.12-0.96)] and hypertension [OR 0.29 (95% CI 0.1-0.87)] to decreased risk of TG ≥ 2.25 mmol/L [OR 1.14 (95% CI 1.02-1.29)]. Taking lipid-lowering drugs (LLD) was associated with LDL-C < 2.6 mmol/L [OR 2.1 (95% CI 1.05-4.19)] and Lp(a) < 30 mg/dL [OR 0.48 (95% CI 0.25-0.93)]. Physical activity was related to LDL-C < 2.6 mmol/L [OR 2.02 (95% CI 1.02-3.98)]. Higher abdominal circumference was associated with decreased risk of TG < 1.7 mmol/L [OR 0.96 (95% CI 0.93-0.99)]. Elevated lipid parameters were related to age, gender, material status, BMI, history of DM, and hypertension. Adequate control was associated with age, education, physical activity, LLD, history of DM, and abdominal circumference.

A Systematic Review on the Risk Modulators of Myocardial Infarction in the "Young"-Implications of Lipoprotein (a)

The presence of a myocardial infarction at a younger age is of special interest, considering the psychological and socioeconomic impact, as well as long-term morbidity and mortality. However, this group has a unique risk profile, with less traditional cardiovascular risk factors that are not well studied. This systematic review aims to evaluate traditional risk factors of myocardial infarction in the "young", highlighting the clinical implications of lipoprotein (a). We performed a comprehensive search using Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) standards; we systematically searched the PubMed, EMBASE, and Science Direct Scopus databases, using the terms: "myocardial infarction", "young", "lipoprotein (a)", "low-density lipoprotein", "risk factors". The search identified 334 articles which were screened, and, at the end, 9 original research articles regarding the implications of lipoprotein (a) in myocardial infarction in the "young" were included in the qualitative synthesis. Elevated lipoprotein (a) levels were independently associated with an increased risk of coronary artery disease, especially in young patients, where this risk increased by threefold. Thus, it is recommended to measure the lipoprotein (a) levels in individuals with suspected familial hypercholesterolaemia or with premature atherosclerotic cardiovascular disease and no other identifiable risk factors, in order to identify patients who might benefit from a more intensive therapeutic approach and follow-up.

Monoclonal Antibodies, Gene Silencing and Gene Editing (CRISPR) Therapies for the Treatment of Hyperlipidemia-The Future Is Here

Hyperlipidemia is a significant risk factor for atherosclerotic cardiovascular disease. Undertreatment of elevated lipids persists despite existing therapies. Here, we provide an update on monoclonal antibodies, gene silencing therapies, and gene editing techniques for the management of hyperlipidemia. The current era of cutting-edge pharmaceuticals targeting low density lipoprotein cholesterol, PCSK9, lipoprotein (a), angiopoietin-like 3, and apolipoprotein C3 are reviewed. We outline what is known, studies in progress, and futuristic goals. This review of available and upcoming biotechnological lipid therapies is presented for clinicians managing patients with familial hyperlipidemia, statin intolerance, hypertriglyceridemia, or elevated lipoprotein (a) levels.

Predictive effect of different blood lipid parameters combined with carotid intima-media thickness on coronary artery disease

Background

Blood lipids disorder and atherosclerosis are closely related to coronary artery disease (CAD). This study aims to compare different blood lipid parameters combined with carotid intima-media thickness (cIMT) in predicting CAD.

Methods

This was a retrospective study including patients who underwent coronary angiography for highly suspected CAD. Blood samples were taken for lipid profile analysis and cIMT was evaluated by carotid ultrasound. Logistic analysis was used to establish different models of different lipid parameters in predicting CAD. The area under the receiver operating characteristic curve (AUC) was used to examine the predictive value. The optimal lipid parameter was also used to explore the relationship with multi-vessel CAD.

Results

Patients were classified into two groups based on whether CAD existed. Compared with non-CAD patients, the CAD group had higher lipoprotein (a) [Lp (a)], apolipoprotein B/apolipoprotein A, total cholesterol/high-density lipoprotein cholesterol (HDL-C), triglyceride/HDL-C and LDL-C/HDL-C. According to the AUCs, Lp (a) combined with cIMT (AUC: 0.713, P < 0.001) had the best performance in predicting CAD compared to other lipid parameters. High level of Lp (a) was also associated with multi-vessel CAD (odds ratio: 1.41, 95% confidence interval: 1.02-1.95, P = 0.036).

Conclusion

For patients with highly suspected CAD, Lp (a) better improved the predictive value of CAD rather than most of blood lipid indices, especially in the absence of high levels of LDL-C. Lp (a) also can be used to predict the multi-vessel CAD.

The LDL-C/Apo B predicts coronary atherosclerotic heart disease in non-diabetic patients without high LDL-C

The apolipoprotein B (Apo B), Apo B/A1 ratio, lipoprotein (a), and low-density lipoprotein cholesterol (LDL-C)/Apo B ratio are associated with coronary artery disease (CAD). However, the association between these parameters and CAD in non-diabetic patients without high LDL-C levels is unclear. Our goal was to assess which parameter was most strongly associated with CAD in non-diabetic patients without high LDL-C levels. This study included 487 non-diabetic patients with LDL-C < 130.0 mg/dL. All the patients underwent coronary computed tomographic angiography. We assessed the significance of each continuous atherogenic biomarker for CAD (incidence of coronary plaque and revascularization) without and after adjustment for standard risk factors. The LDL-C/Apo B ratio and lipoprotein (a) were significant risk factors for the incidence of coronary plaque on multivariate analysis after adjustment for standard risk factors. The LDL-C/Apo B ratio was significant for the incidence of revascularization in multivariate analysis after adjustment for standard risk factors. The degree of coronary calcification and plaque burden according to the tertile of LDL-C/Apo B showed significant differences between the groups. Our data indicate that LDL-C/Apo B ratio is the most predictive parameter for coronary atherosclerosis in non-diabetic patients without high LDL-C levels.

Targeted Treatment against Lipoprotein (a): The Coming Breakthrough in Lipid Lowering Therapy

Atherosclerotic cardiovascular diseases (ASCVD) are a very important cause of premature death. The most important risk factor for ASCVD is lipid disorders. The incidence of lipid disorders and ASCVD is constantly increasing, which means that new methods of prevention and treatment of these diseases are still being searched for. In the management of patients with lipid disorders, the primary goal of therapy is to lower the serum LDL-C concentration. Despite the available effective lipid-lowering therapies, the risk of ASCVD is still increased in some patients. A high level of serum lipoprotein (a) (Lp(a)) is a risk factor for ASCVD independent of serum LDL-C concentration. About 20% of Europeans have elevated serum Lp(a) levels, requiring treatment to reduce serum Lp(a) concentrations in addition to LDL-C. Currently available lipid lowering drugs do not sufficiently reduce serum Lp(a) levels. Hence, drugs based on RNA technology, such as pelacarsen, olpasiran, SLN360 and LY3819469, are undergoing clinical trials. These drugs are very effective in lowering the serum Lp(a) concentration and have a satisfactory safety profile, which means that in the near future they will fill an important gap in the armamentarium of lipid-lowering drugs.

The nonlinear correlation between lipoprotein (a) and the prevalence of aortic valve calcification in patients with new-onset acute myocardial infarction

BACKGROUND

Growing studies show that lipoprotein (a) [Lp(a)] is related to calcified aortic valve diseases in general population, while the relationship between Lp(a) and aortic valve calcification (AVC) in patients with new-onset acute myocardial infarction (AMI) remains unclear. Therefore, this study was to evaluate the correlation between Lp(a) and AVC in patients with new-onset AMI.

METHODS

This cross-sectional study included 410 patients with new-onset AMI who were hospitalised in Zhongda Hospital affiliated to Southeast University from January 1, 2020 to December 31, 2021. Multivariable logistic regression, subgroup analysis, generalised additive model, threshold and saturation effect and receiver operator characteristic (ROC) curve were used to explore the association between Lp(a) and AVC.

RESULTS

Patients with AVC had higher levels of Lp(a) than those without AVC. Multivariable logistic regression analysis showed that higher Lp(a) was still associated with higher risk of AVC after adjusting for confounding factors, and this correlation was robust in most subgroups and sensitivity analyses (p < 0.05). Additionally, the generalised additive model showed that there was a nonlinear correlation between Lp(a) and AVC (P for nonlinearity = 0.037). Threshold and saturation effect analysis indicated that when Lp(a) < 840 mg/L, it was positively correlated with the prevalence of AVC (p < 0.05), but when Lp(a) ≥ 840 mg/L, this correlation no longer existed. Besides, ROC curve analysis demonstrated that Lp(a) had a good diagnostic performance for AVC.

CONCLUSION

Lp(a) was independently associated with the prevalence of AVC in patients with new-onset AMI.

Association of Lipoprotein (a) With Coronary-Computed Tomography Angiography-Assessed High-Risk Coronary Disease Attributes and Cardiovascular Outcomes

BACKGROUND

Lipoprotein(a) [Lp(a)] is a risk factor for cardiovascular events. This study evaluated the relationship between Lp(a) and high-risk attributes by coronary computed tomography angiography as well as their prognostic value.

METHODS

Lp(a) and coronary computed tomography angiography from 377 consecutive patients at Zhongshan Hospital (Shanghai, China) were evaluated. High-risk attributes were defined as high-risk morphological attributes (low attenuation plaque, positive remodeling, napkin-ring sign, spotty calcification, minimum lumen area <4 mm², or plaque burden [ratio between cross-sectional plaque area at the site of maximum stenosis and cross-sectional vessel area] ≥70%); inflammatory attribute represented by fat attenuation index; high-risk physiological attributes [lesion-specific ischemia defined by fractional flow reserve by coronary computed tomography angiography ≤0.8, physiologic diffuseness defined by fractional flow reserve by coronary computed tomography angiography pullback pressure gradient]. Total plaque volume in mm³ was also quantified. Quintiles or binary classification of Lp(a) levels were used to evaluate its relationships with plaque features and clinical outcomes with ANOVA, Cox models, and log-rank tests, as appropriate. The major adverse cardiovascular event included cardiovascular death, nonfatal myocardial infarction, and target vessel revascularization.

RESULTS

Lp(a) was significantly associated with total plaque volume (P=0.004), fat attenuation index (P=0.031), and fractional flow reserve by coronary computed tomography angiography pullback pressure gradient (P=0.038). Patients with a high Lp(a) level had a higher total plaque volume (393.3 mm³ versus 293.9 mm³, P<0.001), lower pullback pressure gradient (0.62 versus 0.69, P=0.023), higher fat attenuation index (-70.5HU versus -73.9HU, P=0.004), and higher incidence of major adverse cardiovascular event (14.5% versus 6.3%, adjusted hazard ratio: 2.52, 95% CI: 1.12-5.63, P=0.025). In a 4-group classification according to Lp(a) and high-risk attributes, patients with high Lp(a) and ≥3 high-risk attributes had the highest risk of major adverse cardiovascular event (25.9%; overall P<0.001). Causal mediation analysis revealed that around 40% of the prognostic effect of Lp(a) was mediated by high-risk attributes.

CONCLUSIONS

Lp(a) level is associated with coronary computed tomography angiography high-risk characteristics, including morphologic, physiologic, and inflammatory attributes as well as major adverse cardiovascular event. This effect is partly mediated by inflammation and vulnerable plaque.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT05323227.

Clinical application and comparison of serum lipoprotein (a) particle concentration and mass concentration in stroke patients and healthy adults: a prospective cohort study

BACKGROUND

Serum Lp(a) is routinely detected by mass concentration in clinical laboratory, but the results of which cannot be standardized. On the other hand, particle concentration detection has gained increasing popularity and facilitated the standardization of Lp(a) testing in clinical practice. This study aimed to compare the Lp(a) mass concentration and particle concentration between patients with stroke and healthy controls.

METHODS

The participants admitted in the Third Hospital of Hebei Medical University between January 2021 and October 2021 were assigned to hemorrhagic stroke, cerebral infarction and healthy control group. Serum Lp(a) particle and mass concentration were detected by using the Shenzhen Mindray BS-2000I and Beckman AU5821 detection system, respectively. The primary study endpoint was the difference between Lp(a) mass concentration and particle concentration among the 3 groups.

RESULTS

There was no statistically significant difference in age and gender among the 3 groups. Serum Lp(a) mass concentration [227.7 (113.1-447.1) mg/L vs. 117.1 (59.8-210.7) mg/L, P=0.001] and particle concentration [30.1 (12.9-72.3) nmol/L vs. 13.5 (6.8-29.9) nmol/L, P=0.001] in the cerebral infarction group were significantly higher than those in the healthy control group. The areas under the receiver operating characteristic (ROC) curve (AUC) of Lp(a) mass concentration and particle concentration for the diagnosis of cerebral infarction were 0.67 and 0.66, respectively, and the cut-off value was 181.1 mg/L and 15.6 nmol/L, respectively. There was no statistically significant difference in the efficacy of the two parameters for the diagnosis of cerebral infarction (Z=0.88, P=0.38). The conversion factors for the two concentrations were not significantly different between gender nor age subgroups, and decreased as mass concentrations increased. Compared with healthy control group, the positive rate of Lp(a) mass concentration (37.8% vs. 17.5%, P<0.01) and the positive rate of particle concentration (24.4% vs. 10.8%, P=0.005) were significantly increased in the cerebral infarction group.

CONCLUSIONS

The particle concentration detection of Lp(a) has significant clinical relevance in patients with ischemic stroke. The mass concentration test results may overestimate the actual serum Lp(a) content in stroke patients.

New Horizons: Revival of Lipoprotein (a) as a Risk Factor for Cardiovascular Disease

The status of lipoprotein (a) [Lp(a)] as a cardiovascular risk factor has been resurrected by advances in genetics. Mendelian randomization studies show a causal link of Lp(a) with coronary artery disease (CAD), peripheral artery disease (PAD), and calcific aortic valve stenosis (CAVS). The genetics of Lp(a) is complex and extends beyond the kringle-IV type 2, as it is also dependent on ancestry. The plasma concentration of Lp(a) is determined by the hepatic production of apolipoprotein(a) [apo(a)] component of Lp(a), supporting the use of nucleic acids that inhibit the messenger RNA (mRNA) gene transcript for apo(a). Analytical barriers to measurement of Lp(a) are being addressed using isoform independent assays and a traceable standard. The association of Lp(a) and atherosclerotic cardiovascular disease is higher for myocardial infarction than PAD and CAVS. Increased risk of type 2 diabetes mellitus associated with low Lp(a) levels is perplexing and requires further investigation. The greatest advancement in Lp(a)-lowering therapies is based on using RNA therapeutics that are now being investigated in clinical trials. Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibition lowers Lp(a) modestly, but whether cardiovascular benefit is independent of low-density lipoprotein lowering remains unclear. Opportunistic and selective testing for Lp(a) is supported by moderate evidence, with the case for universal screening premature. Modification of behavioral and clinical risk factors may be targeted to mitigate Lp(a)-mediated risk of cardiovascular disease. Clinical practice guidelines have been developed to address gaps in care of high Lp(a), but full implementation awaits the findings of clinical outcome trials using RNA-directed therapies currently underway.

Lipoprotein Subfractions as Markers for Predicting the Presence and Severity of Coronary Artery Disease in Patients Undergoing Coronary Angiography

Patients with coronary artery disease (CAD) often have normal blood cholesterol profiles that make it difficult to identify those at risk. The role of lipoprotein subfractions in the development of CAD has attracted increasing attention, and can further stratify risks. We enrolled 1578 patients undergoing coronary angiography and not taking any lipid-lowering drugs; 1033 of them were diagnosed with CAD. The severity of CAD was assessed using Gensini score (GS) and divided into 3 groups. Multivariate regression analysis showed that low-density lipoprotein particle 6 (LDL-P6) and lipoprotein (a) (Lp(a)) were independent risk factors for CAD, apart for the traditional risk factors. In receiver-operating characteristic (ROC) analysis for predicting the presence of CAD, the area under the ROC curve of traditional risk factors combined with Lp(a) and LDL-P6 for predicting CAD was .723, which was better than for traditional risk factors (P = .023). The plasma LDL-P6 and Lp(a) concentrations in the highest tertile GS group were significantly higher than that in the lowest GS group (P < .001). Stepwise linear regression analysis demonstrated positive correlations between Lp(a), LDL-P6 and GS (P = .007 and P < .001). LDL-P6 and Lp(a) are useful markers for predicting the presence and severity of CAD.

The effect of apolipoprotein E gene polymorphism and Lp(a) levels on coronary artery disease with atrial fibrillation

Objective

To explore the influence of apolipoprotein E (APOE) genotypes and blood lipid metabolism on coronary artery disease (CAD) with atrial fibrillation (AF).

Methods

Patients with suspected CAD were consecutively enrolled and divided into groups with or without CAD and/or AF. Blood lipid levels and APOE genotypes were determined and analysed for associations with CAD and AF.

Results

A total of 2048 patients were included (400 patients without CAD or AF [controls], 126 patients without CAD but with AF, 1294 patients with CAD without AF, and 228 patients with CAD and AF). Age and lipoprotein (a) (Lp[a]) levels were significantly higher in patients with CAD and AF versus those with CAD without AF. Among patients with CAD, the E3/E3 genotype and ε3 allele frequencies were significantly lower in patients with AF than in those without AF, and the E4/E4 genotype and ε4 allele frequencies were significantly increased. Multivariate logistic regression revealed that increased Lp(a) levels and age were independent risk factors for AF in patients with CAD.

Conclusion

Among patients with CAD, those with AF had increased age, ε4 frequencies and Lp(a) levels. Age and Lp(a) levels may be independent risk factors for AF in patients with CAD.

Lipoprotein(a) Modulates Carotid Atherosclerosis in Metabolic Syndrome

Background and Aim: High lipoprotein(a) [Lp(a)] is a well-established cardiovascular (CV) risk factor, but the effect of mildly elevated Lp(a) on CV health is largely unknown. Our aim was to evaluate if Lp(a) is associated with the severity of carotid atherosclerosis (CA) in the specific subset of metabolic syndrome (MetS).

Patients and Methods: Subjects with diagnosed MetS and ultrasound-assessed CA were enrolled. Those patients were categorized according to the severity of CA (moderate vs. severe), and the circulating levels of Lp(a) alongside with clinical, anthropometric, and biochemical data were collected.

Results: Sixty-five patients were finally included: twenty-five with moderate and forty with severe CA (all with asymptomatic disease). Intergroup comparison showed Lp(a) as the only significantly different variable [6 (2–12) mg/dl vs. 11.5 (6–29.5) mg/dl; p = 0.018]. Circulating levels of Lp(a) were also confirmed as the only variable independently associated with severity of CA at logistic regression analysis [OR 2.9 (95% CI 1.1–7.8); p = 0.040]. ROC curve analysis for Lp(a) confirmed a serum level of 10 mg/dl as the best cut-off value [AUC 0.675 (95% CI 0.548–0.786)]. Although sensitivity and specificity were suboptimal (69.0 and 70.4%, respectively)—likely due to the small sample size—this result is in line with those previously reported in the literature.

Conclusion: Lp(a) is independently associated with severity of CA in the subgroup of MetS patients.

Circulating PCSK9 Linked to Dyslipidemia in Lebanese Schoolchildren

In adults, elevated levels of circulating Proprotein Convertase Subtilisin/Kexin type 9 (PCSK9) have been associated with increased Low-density lipoprotein cholesterol (LDL-C), triglycerides (TG), and worse cardiovascular outcomes. However, few studies analyzed the relation between PCSK9 and lipid parameters in pediatric populations. The aim of our study is to evaluate the distribution and the correlation of serum PCSK9 levels with lipid parameters in a sample of Lebanese school children. Using an immunofluorescence assay, we measured serum PCSK9 levels in 681 school children recruited from ten public and private Lebanese schools. We analyzed the association between PCSK9 and age, sex, Body Mass Index (BMI), and lipid parameters (total cholesterol (TC), LDL-C, TG, High-density lipoprotein cholesterol (HDL-C), non-HDL-C, and lipoprotein (a) (Lp(a)). Serum PCSK9 levels were significantly correlated with TC, LDL-C, and non-HDL-C (p value < 0.0001) but not with TG, HDL-C, and Lp(a). PCSK9 levels were also significantly higher in children with high TC, LDL-C, and non-HDL-C (p values = 0.0012, 0.0002, 0.001, respectively). No significant gender differences in PCSK9 were found. In addition, no significant associations between PCSK9 and both age and BMI percentiles were observed. In girls, no difference in PCSK9 values was observed according to menarche while in boys, testosterone levels were not significantly associated with PCSK9. Serum PCSK9 levels were significantly correlated with TC, LDL-C, and non-HDL-C levels. Further studies are needed to find if PCSK9 measurements have an additional value to predict future cardiovascular outcomes in pediatric populations.

Familial Hypercholesterolemia and Elevated Lipoprotein(a): Cascade Testing and Other Implications for Contextual Models of Care

Elevated lipoprotein(a) [Lp(a)], a predominantly genetic disorder, is a causal risk factor for atherosclerotic cardiovascular disease (ASCVD) and calcific aortic valvular disease, particularly in patients with familial hypercholesterolemia (FH), a Tier I genomic condition. The combination from birth of the cumulative exposure to elevated plasma concentrations of both Lp(a) and low-density lipoprotein is particularly detrimental and explains the enhanced morbidity and mortality risk observed in patients with both conditions. An excellent opportunity to identify at-risk patients with hyper-Lp(a) at increased risk of ASCVD is to test for hyper-Lp(a) during cascade testing for FH. With probands having FH and hyper-Lp(a), the yield of detection of hyper-Lp(a) is 1 individual for every 2.1-2.4 relatives tested, whereas the yield of detection of both conditions is 1 individual for every 3-3.4 relatives tested. In this article, we discuss the incorporation of assessment of Lp(a) in the cascade testing in FH as a feasible and crucial part of models of care for FH. We also propose a simple management tool to help physicians identify and manage elevated Lp(a) in FH, with implications for the care of Lp(a) beyond FH, noting that the clinical use of RNA therapeutics for specifically targeting the overproduction of Lp(a) in at risk patients is still under investigation.

Elevated lipoprotein (a) levels and risk of peripheral artery disease outcomes: A systematic review

BACKGROUND

Despite strong association of elevated lipoprotein (a) (Lp(a)) levels with incident coronary and cerebrovascular disease, data for incident peripheral artery disease (PAD) are less robust. The main objective of the present systematic review was to analyze the association between elevated Lp(a) levels and PAD outcomes.

METHODS

This systematic review was performed according to PRISMA guidelines. A literature search was performed to detect randomized clinical trials or observational studies with a cohort design that evaluated the association between Lp(a) levels and PAD outcomes.

RESULTS

Fifteen studies including 493,650 subjects were identified and considered eligible for this systematic review. This systematic review showed that the vast majority of the studies reported a significant association between elevated Lp(a) levels and the risk of PAD outcomes. The elevated Lp(a) levels were associated with a higher risk of incident claudication (RR: 1.20), PAD progression (HR: 1.41), restenosis (HR: 6.10), death and hospitalization related to PAD (HR: 1.37), limb amputation (HR: 22.75), and lower limb revascularization (HR: 1.29 and 2.90). In addition, the presence of elevated Lp(a) values were associated with a higher risk of combined PAD outcomes, with HRs in a range between 1.14 and 2.80, despite adjusting for traditional risk factors. Heterogeneity of results can be explained by different patient populations studied and varying Lp(a) cut-off points of Lp(a) analyzed.

CONCLUSION

This systematic review suggests that evidence is available to support an independent positive association between Lp(a) levels and the risk of future PAD outcomes. PROSPERO Registration No.: 289253.

Clinical investigation of lipoprotein (a) levels in type 2 diabetics for cariovascular diseases prediction and prognosis

OBJECTIVES

We aimed to evaluate the levels of serum lipoprotein a, LP (a), in Jordanian patients with type 2 diabetes mellitus (DM); and to examine its relation to glycemic control, metabolic syndrome (MS) and duration of DM. The LP (a) is considered one of the independent risk factors for coronary artery disease (CAD) in the general population.

METHODS

Fasting blood samples were drawn from 51 diabetic patients with type 2 DM and 31 non-diabetic age and sex control subjects. Serum LP (a) was measured along with other parameters, including triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c) and glycosylated haemoglobin (HbA_1c). Correlation analyses were performed between LP (a) and the various variables measured.

RESULTS

LP (a) measurement showed a skewed distribution towards the lower levels in both groups. Mean LP (a) levels showed a statistically insignificant difference between the two groups. No correlations of LP (a) were observed with age, sex or body mass index (BMI). No correlations of LP (a) with LDL-c, HDL-c, TG, TC, MS, DM duration or HbA_1c were observed. The LP (a) serum levels were significantly higher in type 2 diabetic patients with retinopathy.

CONCLUSIONS

LP (a) serum levels are not increased in type 2 diabetic patients; so, LP (a) may not be a reliable marker for early therapeutic interventions in DM patients, even in high-risk for thrombosis groups.

Changes of lipoprotein(a) levels with endogenous steroid hormones

BACKGROUND

Lipoprotein(a) [Lp(a)] is an LDL-like molecule that is likely causal for cardiovascular events and Lp(a) variability has been shown to be mostly of genetic origin. Exogenous hormones (hormone replacement therapy) seem to influence Lp(a) levels, but the impact of endogenous hormone levels on Lp(a) is still unknown. The aim of the study was to assess the effect of endogenous steroid hormone metabolites on Lp(a).

METHODS

Lipoprotein(a) levels were measured in 1,021 participants from the Swiss Kidney Project on Genes in Hypertension, a family-based, multicentre, population-based prospective cohort study. Endogenous levels of 28 steroid hormone precursors were measured in 24-h urine collections from 883 individuals. Of the participants with Lp(a) data, 1,011 participants had also genotypes available.

RESULTS

The participants had an average age of 51 years and 53% were female. Median Lp(a) levels were 62 mg/L, and the 90^th percentile was 616 mg/L. The prevalence of a Lp(a) elevation ≥700 mg/L was 3.2%. Forty-three per cent of Lp(a) variability was explained respectively by: age (2%, p < .001), LDL-C (1%, p = .001), and two SNPs (39%, p value<2⋅10^-16 ). Of the 28 endogenous steroid hormones assessed, androstenetriol, androsterone, 16α-OH-DHEA and estriol were nominatively associated with serum Lp(a) levels in univariable analyses and explained 0.4%-1% of Lp(a) variability, but none of them reached significance in multivariable models.

CONCLUSIONS

In this contemporary population-based study, the prevalence of a Lp(a) elevation ≥700 mg/L was 3.2%. The effect of endogenous steroid hormone levels of Lp(a) variability was small at best, suggesting a negligible impact on the wide range of Lp(a) variability.

Serum lipoprotein (a) associates with the risk of renal function damage in the CHCN-BTH Study: Cross-sectional and Mendelian randomization analyses

BACKGROUND

Evidence regarding the effects of lipoprotein (a) [lp(a)] and renal function remains unclear. The present study aimed to explore the causal association of serum lp(a) with renal function damage in Chinese general adults.

METHODS

A total of 25343 individuals with available lp(a) data were selected from the baseline survey of the Cohort Study on Chronic Disease of Communities Natural Population in Beijing, Tianjin, and Hebei (CHCN-BTH). Five renal function indexes [estimated glomerular filtration rate (eGFR), serum creatinine (Scr), blood urea nitrogen (BUN), uric acid (UA), high-sensitivity C-reactive protein(CRPHS)] were analyzed. The restricted cubic spline (RCS) method, logistic regression, and linear regression were used to test the dose-response association between lp(a) and renal function. Stratified analyses related to demographic characteristics and disease status were performed. Two-sample Mendelian randomization (MR) analysis was used to obtain the causal association of lp(a) and renal function indexes. Genotyping was accomplished by MassARRAY System.

RESULTS

Lp(a) levels were independently associated with four renal function indexes (eGFR, Scr, BUN, CRPHS). Individuals with a higher lp(a) level had a lower eGFR level, and the association with Scr estimated GFR was stronger in individuals with a lower lp(a) level (under 14 mg/dL). . The association was similar in individuals regardless of diabetes or hypertension. MR analysis confirmed the causal association of two renal function indexes (Scr and BUN). For MR analysis, each one unit higher lp(a) was associated with 7.4% higher Scr (P=0.031) in the inverse-variance weighted method. But a causal effect of genetically increased lp(a) level with increased eGFR level which contrasted with our observational results was observed.

CONCLUSION

The observational and causal effect of lp(a) on Scr and BUN were founded, suggesting the role of lp(a) on the risk of renal function damage in general Chinese adults.

Airborne particles and cardiovascular morbidity in severe inherited hypercholesterolemia: Vulnerable endothelium under multiple attacks

Despite recent advances in the research related to air pollution and associated adverse cardiovascular events, the combined effects of air pollution, climate change, and SARS-CoV-2 infection on cardiovascular health need to be researched further. This Commentary addresses their impacts on cardiovascular health in the approximately 25 million people with a severe form of inherited hypercholesterolemia, called familial hypercholesterolemia (FH). The arterial endothelium in these individuals is potentially under multiple attacks caused by particles of both endogenous and exogenous origin. Thus, they have a lifelong highly elevated level of circulating low density lipoprotein (LDL) cholesterol which drives premature atherosclerosis. The high levels of LDL particles, often associated with an elevated level of circulating lipoprotein(a) particles, are both capable of inducing and maintaining endothelial dysfunction. Such pre-existing endothelial dysfunction can be exacerbated by exposure to SARS-CoV-2 viral particles, by exposure to fine particulate matter generated by climate change-associated wildfires, and by dehydration during deadly heatwaves linked to the globally rising temperatures. The external factors can severely worsen the pre-existing endothelial dysfunction, and thereby significantly increase the risk of a cardiovascular event in the exposed FH patients.

Association between lipoprotein (a) and heart failure with reduced ejection fraction development

Background

The current study aimed to evaluate the relationship between baseline serum lipoprotein (a) [Lp(a)] level and heart failure with reduced ejection fraction (HFrEF) development.

Methods

This was a retrospective study, and participants were enrolled from the outpatient clinic. All data were extracted from the electronic health record of the outpatient clinic system. The follow‐up was performed through reviewing the clinical notes at the outpatient clinic system, and study outcome of the current study was the first diagnosis of HFrEF. Participants were divided into low Lp(a) (<30 mg/dl, n = 336) and high Lp(a) (≥30 mg/dl, n = 584) groups.

Results

Individuals in the high Lp(a) group were more likely to be men and have diabetes mellitus (DM) and dyslipidemia. Increased Lp(a) at baseline was positively associated with serum N‐terminal pro‐B natriuretic peptide level while negatively associated with left ventricular ejection fraction (LVEF) at follow‐up. After adjusting for covariates, per 10 mg/dl increase in baseline Lp(a) remained significantly associated with HFrEF, with odds ratio of 1.17 (95% confidence interval of 1.05, 1.46). The magnitude of association between baseline Lp(a) level and HFrEF was greater in men and in individuals with DM or coronary heart disease (CHD), while it was weaker in individuals treated with beta‐blocker at baseline.

Conclusion

Increased Lp(a) at baseline was associated with HFrEF development. The adverse effects of Lp(a) were greater on men and individuals with DM or CHD, which were mitigated by beta‐blocker therapy. These findings together underscore the possibility and usefulness of Lp(a) as a new risk factor to predict HFrEF.

A Sorbent with Synthetic Ligand for Removing Pro-atherogenic and Pro-inflammatory Components from Human Blood Plasma

Elevated levels of apoB-100 containing lipoproteins and markers of systemic inflammation are often observed in patients with cardiovascular diseases. The concentrations can be reduced by pharmacotherapy or extracorporeal treatment. The sorbent, which removes CRP and atherogenic lipoproteins, simultaneously reduces the bloodstream concentration of these components. The efficacy and selectivity of the designed sorbent were studied, desorption constants of CRP (Kd = 4.2 × 10-8 M) and LDL (Kd = 7.7 × 10-7 M) were distribution coefficients of CRP (Kc = 101) and Lp(a) (Kc = 38) were calculated, and the ability to bind large amounts of atherogenic lipoproteins (up to 32 mg of TC per mL of the sorbent gel) was demonstrated. Our sorbent can be recommended for performing complex removal of CRP and atherogenic lipoproteins from the blood plasma in patients with refractory hyperlipidemia and CVD that are accompanied by elevated levels of CRP.

Association of Lipoprotein(a) With Recurrent Ischemic Events Following Percutaneous Coronary Intervention

OBJECTIVES

This study evaluated the association between elevated levels of lipoprotein(a) [Lp(a)] and risk of recurrent ischemic events in patients who underwent percutaneous coronary intervention (PCI).

BACKGROUND

Elevated levels of Lp(a) have been identified as an independent, possibly causal, risk factor for atherosclerotic cardiovascular disease in a general population study.

METHODS

A prospective single-center registry was used to identify 12,064 patients with baseline Lp(a) measurements who underwent PCI between 2003 and 2013. The primary outcomes were a composite of cardiovascular death, spontaneous myocardial infarction, and ischemic stroke.

RESULTS

From the registry, 3,747 (31.1%) patients had high Lp(a) (>30 mg/dL) and 8,317 (68.9%) patients had low Lp(a) (≤30 mg/dL). During a median follow-up of 7.4 years, primary outcomes occurred in 1,490 patients, and the incidence rates of primary outcomes were 2.0 per 100 person-years in the high-Lp(a) group and 1.6 per 100 person-years in the low-Lp(a) group (adjusted hazard ratio [aHR]: 1.17; 95% confidence interval [CI]: 1.05-1.30; P = 0.004). Increased risk of recurrent ischemic cardiovascular events in the high-Lp(a) group was consistent in various subgroups including patients receiving statin treatment at discharge (aHR: 1.18; 95% CI: 1.03-1.34; P = 0.011). In addition, the risk of repeated revascularization was significantly higher in the high-Lp(a) group (aHR: 1.13; 95% CI: 1.02-1.25; P = 0.022).

CONCLUSIONS

Elevated levels of Lp(a) were significantly associated with the recurrent ischemic events in patients who underwent PCI. This study provides a rationale for outcome trials to test Lp(a)-lowering therapy for secondary prevention in patients undergoing PCI.

Elevated Lipoprotein(a): Background, Current Insights and Future Potential Therapies

Lipoprotein(a) forms a subfraction of the lipid profile and is characterized by the addition of apolipprotein(a) (apo(a)) to apoB100 derived particles. Its levels are mostly genetically determined inversely related to the number of protein domain (kringle) repeats in apo(a). In epidemiological studies, it shows consistent association with cardiovascular disease (CVD) and most recently with extent of aortic stenosis. Issues with standardizing the measurement of Lp(a) are being resolved and consensus statements favor its measurement in patients at high risk of, or with family histories of CVD events. Major lipid-lowering therapies such as statin, fibrates, and ezetimibe have little effect on Lp(a) levels. Therapies such as niacin or cholesterol ester transfer protein (CETP) inhibitors lower Lp(a) as well as reducing other lipid-related risk factors but have failed to clearly reduce CVD events. Proprotein convertase subtilisin kexin-9 (PCSK9) inhibitors reduce cholesterol and Lp(a) as well as reducing CVD events. New antisense therapies specifically targeting apo(a) and hence Lp(a) have greater and more specific effects and will help clarify the extent to which intervention in Lp(a) levels will reduce CVD events.

The impact of race and ethnicity on lipoprotein(a) levels and cardiovascular risk

PURPOSE OF REVIEW

Lipoprotein(a) [Lp(a)] is a plasma circulating apoB100 (apoB) containing lipoprotein. It has a unique glycoprotein bound to the apoB100, apolipoprotein(a) [apo(a)]. The majority of the population expresses two apo(a) isoforms, when bound to apoB100 they create two circulating Lp(a) particles. Lp(a) levels are genetically determined and epidemiological studies have established elevated levels of Lp(a) to be a causal risk factor of cardiovascular disease (CVD). Lp(a) levels differ across racial groups and Blacks of Sub-Saharan decent have higher levels when compared to white. In comparison to white populations, studies in minorities are less represented in the published literature. Additionally, there is a lack of standardization in the commercial assays used to measured Lp(a) levels, and hence it is difficult to assess risk based on individual Lp(a) levels, but risk seems to occur in the upper percentiles of the population.

RECENT FINDINGS

A recent study using data from the UK biobank highlights the racial differences in Lp(a) levels and the increase risk in CVD amongst all races.

SUMMARY

This review will highlight Lp(a) biology and physiology with a focus on available data from racially diverse cohorts. There is a need to perform studies in diverse populations to understand if they are at higher risk than whites are.

Existing and emerging therapies for the treatment of familial hypercholesterolemia

Familial hypercholesterolemia (FH), an autosomal dominant disorder of LDL metabolism that is characterized by elevated LDL-cholesterol, is commonly encountered in patients with atherosclerotic coronary heart disease. Combinations of cholesterol-lowering therapies are often used to lower LDL-cholesterol in patients with FH; however, current treatment goals for LDL-cholesterol are rarely achieved in patients with homozygous FH (HoFH) and are difficult to achieve in patients with heterozygous FH (HeFH). Therapies that lower LDL-cholesterol through LDL receptor-mediated mechanisms have thus far been largely ineffective in patients with HoFH, particularly in those with negligible (<2%) LDL receptor activity. Among patients with HeFH who were at very high risk for atherosclerotic cardiovascular disease events, combined therapy consisting of a high dose of high-intensity statin, ezetimibe, and proprotein convertase subtilisin Kexin type 9 inhibitor failed to lower LDL-cholesterol to minimal acceptable goals in more than 50%. This article provides a framework for the use of available and emerging treatments that lower LDL-cholesterol in adult patients with HoFH and HeFH. A framework is provided for the use of angiopoietin-like protein 3 inhibitors in the treatment of HoFH and HeFH.

Coronary calcification is associated with elevated serum lipoprotein (a) levels in asymptomatic men over the age of 45 years: A cross-sectional study of the Korean national health checkup data

Lipoprotein a (Lp (a)) and coronary artery calcification (CAC) are markers of coronary artery and cardiovascular diseases. However, the association between Lp (a) and CAC in asymptomatic individuals remains unclear. In this study, we aimed to determine the influence of Lp (a) on CAC in asymptomatic individuals.We included 2019 asymptomatic Korean adults who underwent testing for a coronary artery calcium score (CACS) and Lp (a) at the Gangnam Severance Hospital Health Checkup Center in Korea from January 2017 to August 2019. Participants were divided into 2 groups: CACS = 0 and CACS > 0. Factors affecting the CACS were analyzed by sex. Because age is a major risk factor for atherosclerosis, ≥45 years in men and ≥55 years in women, we further divided participants into 4 subgroups (≥45 and <45 in men, ≥55 and <55 in women). Factors affecting the CACS in the 4 groups were analyzed.There was a positive correlation between the CACS and traditional cardiovascular risk factors. Lp (a) positively correlated with the CACS in men (P < .01) and remained significant after multivariable logistic regression (P < .01). The same result was observed in men aged ≥45 years (P < .01).Lp (a) is an independently associated factor of CAC and a marker of coronary atherosclerosis in asymptomatic men aged ≥45 years. In asymptomatic men aged ≥45 years, Lp (a) should be measured, and intensive Lp (a)-lowering treatment should be considered.

Lipoprotein metabolism in familial hypercholesterolemia

Familial hypercholesterolemia (FH) is one of the most common genetic disorders in humans. It is an extremely atherogenic metabolic disorder characterized by lifelong elevations of circulating LDL-C levels often leading to premature cardiovascular events. In this review, we discuss the clinical phenotypes of heterozygous and homozygous FH, the genetic variants in four genes (LDLR/APOB/PCSK9/LDLRAP1) underpinning the FH phenotype as well as the most recent in vitro experimental approaches used to investigate molecular defects affecting the LDL receptor pathway. In addition, we review perturbations in the metabolism of lipoproteins other than LDL in FH, with a major focus on lipoprotein (a). Finally, we discuss the mode of action and efficacy of many of the currently approved hypocholesterolemic agents used to treat patients with FH, with a special emphasis on the treatment of phenotypically more severe forms of FH.

Adverse effects of conjugated linoleic acids supplementation on circulating lipoprotein (a) levels in overweight and obese individuals: results of a systematic review and meta-analysis of randomized controlled trials

Conjugated Linoleic Acids (CLA) may have beneficial effects on the prevention of atherosclerosis, but their net effects on circulating levels of lipoprotein (a) [Lp (a)] are unclear. The present study aimed to systematically review and analyze the Randomized Clinical Trials (RCTs) assessing the effects of CLA on circulating Lp (a) concentrations. A literature search of SCOPUS, PubMed-Medline, ISI, Web of Science, and Cochrane library databases was conducted for the relevant RCTs investigating the effects of CLA supplementation on circulating Lp (a) levels, which had been published up to 20 August 2020. Weighted Mean Difference (WMD) and 95% Confidence Intervals (CI) were reported as the summary statistics. Statistical analysis were done with Comprehensive Meta-Analysis (CMA) V2 software (Biostat, NJ). Totally, six studies with 13 treatment arms including 752 subjects were included in the meta-analysis. The results showed a significant increase in circulating Lp (a) levels after CLA supplementation (WMD: 16.68 mg/L, 95% CI: 5.43-27.93; P=0.004) with no evidence of heterogeneity across the studies. In the subgroup analysis, a more significant elevation of Lp (a) levels was observed in the trials lasting for six months or more (WMD: 21.61 mg/L, 95% CI: 9.85-33.37, P<0.001) as well as in those with a supplementation dosage of ≥3.5 g/d (WMD: 26.13 mg/L, 95% CI: 7.02-45.24, P=0.007). These findings were sensitive to one study. It can be concluded that CLA supplementation with a dose of ≥3.5 g/d over a six-month period might significantly increase the circulating Lp (a) concentrations.

FH through the retrospectoscope

After training as a gastroenterologist in the UK, the author became interested in lipidology while he was a research fellow in the USA and switched careers after returning home. Together with Nick Myant, he introduced the use of plasma exchange to treat familial hypercholesterolemia (FH) homozygotes and undertook non-steady state studies of LDL kinetics, which showed that the fractional catabolic rate of LDL remained constant irrespective of pool size. Subsequent steady-state turnover studies showed that FH homozygotes had an almost complete lack of receptor-mediated LDL catabolism, providing in vivo confirmation of the Nobel Prize-winning discovery by Goldstein and Brown that LDL receptor dysfunction was the cause of FH. Further investigation of metabolic defects in FH revealed that a significant proportion of LDL in homozygotes and heterozygotes was produced directly via a VLDL-independent pathway. Management of heterozygous FH has been greatly facilitated by statins and proprotein convertase subtilisin/kexin type 9 inhibitors but remains dependent upon lipoprotein apheresis in homozygotes. In a recent analysis of a large cohort treated with a combination of lipid-lowering measures, survival was markedly enhanced in homozygotes in the lowest quartile of on-treatment serum cholesterol. Emerging therapies could further improve the prognosis of homozygous FH; whereas in heterozygotes, the current need is better detection.

Serum Lipoprotein (a) on Postoperative Day 3: A Strong Predictor of Portal and/or Splenic Vein Thrombosis in Cirrhotic Patients With Splenectomy

Elevated lipoprotein (a) [Lp(a)] is related to the incidence of lower limb deep vein thrombosis and pulmonary embolism. Its role in portal and/or splenic vein thrombosis (PSVT) is not established. A total of 77 consecutive patients who underwent splenectomy for cirrhotic portal hypertension were prospectively studied between 2014 and 2017. The impact of Lp(a) on preoperative day 1 and postoperative days (PODs) 1, 3, 5, 7, and 14 was analyzed. Color Doppler ultrasound examination was performed for the diagnosis of PSVT. The median interval between surgery and postoperative PSVT was 6 days (range: 2-13 days). The levels of Lp(a) were highly increased in patients with PSVT and significant intergroup differences (vs non-PSVT) were found until day 3 and day 5 after operation, respectively. On POD 3, at a threshold of 309.06 mg/L, Lp(a) was a better predictor of PSVT (area under the curve [AUC] = 0.872) compared to the levels on PODs 1, 5, and 7 (AUC = 0.775, 0.796, and 0.791, respectively). The median Lp(a) values peaked at 382.5 mg/L on POD 5 for patients without PSVT. After POD 5, the Lp(a) decreased with values at 347.4 mg/L on POD 7 and 150.7 mg/L on POD 14. For the first time, Lp(a) was shown to be abnormal in patients with PSVT following splenectomy. Monitoring of serum Lp(a) levels on POD 3 might represent a valuable tool to predict early PSVT after splenectomy in cirrhotic patients.

Cardiovascular events in patients with familial hypercholesterolemia and hyperlipoproteinaemia (a): Indications for lipoprotein apheresis in Poland

BACKGROUND

Lipoprotein apheresis (LA) is a safe method of reducing atherogenic lipoproteins and improving cardiovascular (CV) outcomes. We aimed to assess the reductions in low-density lipoprotein cholesterol (LDL-C) and lipoprotein (a) [Lp(a)] levels in patients undergoing regular LA therapy and to evaluate its influence on the incidence rate of adverse cardiac and vascular events (ACVE) and major adverse cardiac events (MACE).

METHODS

A longitudinal study in Poland evaluated the prospective and retrospective observational data of 23 patients with hyperlipoproteinaemia (a) [hyper-Lp(a)] and familial hypercholesterolemia (FH), undergoing 1014 LA sessions between 2013 and 2020. Their pre- and post-apheresis LDL-C and Lp(a) levels were assessed to calculate the acute percent reductions. The time period used to evaluate annual rates of ACVE and MACE before and after initiation of LA was matched in each patient.

RESULTS

The pre-apheresis LDL-C and Lp(a) concentrations were 155 (107-228) (mg/dL) (median and interquartile range) and 0.56 (0.14-1.37) (g/L), respectively. LA therapy resulted in a reduction of LDL-C to 50 (30-73.5) (mg/dL) and of Lp(a) to 0.13 (0.05-0.34) (g/L), representing a percent reduction of 70.0% and 72.7% for LDL-C and Lp(a), respectively. We found a significant reduction in the annual rate of ACVE (0.365[0.0-0.585] vs (0.0[0.0-0.265]; P = .047) and MACE (0.365[0.0-0.585] vs 0.0[0.0-0.265]; P = .031).

CONCLUSIONS

The findings of our study indicate that LA treatment in patients with hyperlipoproteinaemia (a) and FH on maximally tolerated lipid lowering therapies leads to a substantial reduction in LDL-C and Lp(a) concentrations and lowers CV event rates in Polish patients.

Association Between Lipoprotein (A) and Diabetic Nephropathy in Patients With Type 2 Diabetes Mellitus: A Meta-Analysis

BACKGROUND

Lipoprotein (a) [Lp (a)] has been well recognized as a risk factor of cardiovascular disease. However, the association between serum Lp (a) and diabetic nephropathy in patients with type 2 diabetes mellitus (T2DM) remains unknown. We performed a meta-analysis to comprehensively evaluate the above association.

METHODS

Observational studies aiming to evaluate the independent association between serum Lp (a) and diabetic nephropathy in T2DM patients were identified by systematic search of PubMed and Embase databases. A random-effect model which incorporated the potential intra-study heterogeneity was used for the meta-analysis.

RESULTS

Eleven observational studies with 9304 T2DM patients were included. Results showed that compared to those with the lowest Lp (a), patients with the highest Lp (a) level had higher odds of diabetic nephropathy (adjusted odds ratio [OR]: 1.63, 95% confidence interval [CI]: 1.25-2.14, I² = 54%, P < 0.001). Meta-analysis of studies in which Lp (a) was presented as continuous variables showed consistent result (adjusted OR: 1.13 for 1 mg/dl increment of Lp (a), 95% CI: 1.03-1.24, I2 = 36%, P = 0.008). Subgroup analyses showed that study characteristics such as definitions of diabetic nephropathy and study design did not significantly affect the association (P for subgroup difference all > 0.05).

CONCLUSIONS

Higher serum Lp (a) in patients with T2DM is independently associated with higher odds of diabetic nephropathy. Large scale prospective cohort studies are needed to validate this finding. Moreover, the potential influence of Lp (a) lowering on renal function in T2DM patients may be further investigated.