Beyond Lipoprotein(a) plasma measurements: Lipoprotein(a) and inflammation

Is lipoprotein(a) measurement important for cardiovascular risk stratification in children and adolescents?

BACKGROUND

Elevated lipoprotein (Lp(a)) levels are associated with increased risk of atherosclerotic processes and cardiovascular events in adults. The amount of Lp(a) is mainly genetically determined. Therefore, it is important to identify individuals with elevated Lp(a) as early as possible, particularly if other cardiovascular risk factors are present. The purpose of the study was to investigate whether, in a population of children and adolescents already followed for the presence of one or more cardiovascular risk factors (elevated blood pressure (BP), and/or excess body weight, and/or dyslipidemia), the measurement of Lp(a) can be useful for better stratifying their risk profile.

METHODS

In a sample of 195 children and adolescents, height, body weight, waist circumference and systolic (SBP) and diastolic (DBP) BP were measured. Body Mass Index (BMI) and SBP and DBP z-scores were calculated. Plasma Lp(a), total cholesterol, high-density lipoprotein (HDL), triglycerides, glucose, insulin, uric acid and creatinine were assessed. Low-density lipoprotein (LDL) cholesterol was calculated with the Friedewald formula. High Lp(a) was defined as ≥ 75 nmol/L and high LDL cholesterol as ≥ 3.37 mmol/L.

RESULTS

Our sample of children and adolescents (54.4% males, mean age 11.5 years) had median LDL cholesterol and Lp(a) values equal to 2.54 (interquartile range, IQR: 2.07-3.06) mmol/L and 22 (IQR: 7.8-68.6) nmol/L respectively. 13.8% of children had LDL cholesterol ≥ 3.37 mmol/L and 22.6 Lp(a) values ≥ 75 nmol/L. Lp(a) values were higher in children of normal weight than in those with excess weight (p = 0.007), but the difference disappeared if normal weight children referred for dyslipidemia only were excluded from the analysis (p = 0.210). 69.4% of children had normal Lp(a) and LDL cholesterol values and only 6.2% showed both elevated Lp(a) and LDL cholesterol levels. However, 16.6% of the sample, despite having normal LDL cholesterol, had elevated Lp(a) values. Multivariable analyses showed a significant association of LDL cholesterol both with Lp(a) values, and with the presence of elevated Lp(a) levels. For each mmol/L increase in LDL cholesterol the risk of having an elevated Lp(a) value increased by 73%. There was an inverse correlation between BMI z-score and Lp(a). Neither BP z-scores, nor other biochemical parameters were associated with Lp(a).

CONCLUSIONS

In our population more than one out of five children had elevated Lp(a) values, and in about 17% of children elevated Lp(a) values were present in the absence of increased LDL cholesterol. Our results suggest that Lp(a) measurement can be useful to better define the cardiovascular risk profile in children and adolescents already followed for the presence of other cardiovascular risk factors such as elevated BP, excess body weight and high LDL cholesterol.

A multi-biomarker panel for predicting Tocilizumab response in Rheumatoid arthritis patients

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease characterized by inflammation in the synovial lining of the joints. Key inflammatory cytokines such as interleukin-6 (IL-6), TNF-α, and others play a critical role in the activation of local synovial leukocytes and the induction of chronic inflammation. Tocilizumab (TCZ), a humanized anti-IL-6 receptor monoclonal antibody, has demonstrated significant clinical efficacy in treating RA patients. However, similar to other inflammatory cytokine blockers, such as TNF-alpha inhibitors, Interleukin-1 inhibitors, or CD20 inhibitors, some patients do not respond to treatment. To address this challenge, our study employed a high-precision proteomics approach to identify protein biomarkers capable of predicting clinical responses to Tocilizumab in RA patients. Through the use of data-independent acquisition (DIA) mass spectrometry, we analyzed serum samples from both TCZ responders and non-responders to discover potential biomarker candidates. These candidates were subsequently validated using individual serum samples from two independent cohorts: a training set (N = 70) and a test set (N = 18), allowing for the development of a robust multi-biomarker panel. The constructed multi-biomarker panel demonstrated an average discriminative power of 86 % between response and non-response groups, with a high area under the curve (AUC) value of 0.84. Additionally, the panel exhibited 100 % sensitivity and 60 % specificity. Collectively, our multi-biomarker panel holds promise as a diagnostic tool to predict non-responders to TCZ treatment in RA patients.

Small apolipoprotein(a) isoforms may predict primary patency following peripheral arterial revascularization

Background

High lipoprotein (a) [Lp(a)] is associated with adverse limb events in patients undergoing lower extremity revascularization. Lp(a) levels are genetically pre-determined, with LPA gene encoding for two apolipoprotein (a) [apo(a)] isoforms. Isoform size variations are driven by the number of kringle IV type 2 (KIV-2) repeats. Lp(a) levels are inversely correlated with isoform size. In this study, we examined the role of Lp(a) levels, apo(a) size, and inflammatory markers with lower extremity revascularization outcomes.

Methods

Twenty-five subjects with chronic peripheral arterial disease (PAD) underwent open or endovascular lower extremity revascularization (mean age, 66.7 ± 9.7 years; Female = 12; Male = 13; Black = 8; Hispanic = 5; and White = 12). Pre- and postoperative medical history, self-reported symptoms, ankle-brachial indices (ABIs), and lower extremity duplex ultrasounds were obtained. Plasma Lp(a), apoB100, lipid panel, and pro-inflammatory markers (IL-6, IL-18, hs-CRP, TNFα) were assayed preoperatively. Isoform size was estimated using gel electrophoresis and weighted isoform size (wIS) calculated based on % isoform expression. Firth logistic regression was used to examine the relationship between Lp(a) levels and wIS with procedural outcomes: symptoms (better/worse), early primary patency at 2 to 4 weeks, ABIs, and reintervention within 3 to 6 months. We controlled for age, sex, history of diabetes, smoking, statin, antiplatelet, and anticoagulation use.

Results

Median plasma Lp(a) level was 108 (interrquartile range, 44-301) nmol/L. The mean apoB100 level was 168.0 ± 65.8 mg/dL. These values were not statistically different among races. We found no association between Lp(a) levels and wIS with measured plasma pro-inflammatory markers. However, smaller apo(a) wIS was associated with occlusion of the treated lesion(s) in the postoperative period (odds ratio, 1.97; 95% confidence interval, 1.01-3.86; P < .05). The relationship of smaller apo(a) wIS with reintervention was not as strong (odds ratio, 1.57; 95% confidence interval, 0.96-2.56; P = .07). We observed no association between wIS with patient reported symptoms or change in ABIs.

Conclusions

In this small study, subjects with smaller apo(a) isoform size undergoing peripheral arterial revascularization were more likely to experience occlusion in the postoperative period and/or require reintervention. Larger cohort studies identifying the mechanism and validating these preliminary data are needed to improve understanding of long-term peripheral vascular outcomes.

High lipoprotein(a): Actionable strategies for risk assessment and mitigation

High levels of lipoprotein(a) [Lp(a)] are causal for atherosclerotic cardiovascular disease (ASCVD). Lp(a) is the most prevalent inherited dyslipidemia and strongest genetic ASCVD risk factor. This risk persists in the presence of at target, guideline-recommended, LDL-C levels and adherence to lifestyle modifications. Epidemiological and genetic evidence supporting its causal role in ASCVD and calcific aortic stenosis continues to accumulate, although various facets regarding Lp(a) biology (genetics, pathophysiology, and expression across race/ethnic groups) are not yet fully understood. The evolving nature of clinical guidelines and consensus statements recommending universal measurements of Lp(a) and the scientific data supporting its role in multiple disease states reinforce the clinical merit to start population screening for Lp(a) now. There is a current gap in the implementation of recommendations for primary and secondary cardiovascular disease (CVD) prevention in those with high Lp(a), in part due to a lack of protocols for management strategies. Importantly, targeted apolipoprotein(a) [apo(a)]-lowering therapies that reduce Lp(a) levels in patients with high Lp(a) are in phase 3 clinical development. This review focuses on the identification and clinical management of patients with high Lp(a). Specifically, we highlight the clinical value of measuring Lp(a) and its use in determining Lp(a)-associated CVD risk by providing actionable guidance, based on scientific knowledge, that can be utilized now to mitigate risk caused by high Lp(a).

Crosstalk between Inflammation and Atherosclerosis in Rheumatoid Arthritis and Systemic Lupus Erythematosus: Is There a Common Basis?

Cardiovascular disease is the leading cause of morbidity and mortality in patients with rheumatoid arthritis and systemic lupus erythematosus. Traditional cardiovascular risk factors, although present in lupus and rheumatoid arthritis, do not explain such a high burden of early cardiovascular disease in the context of these systemic connective tissue diseases. Over the past few years, our understanding of the pathophysiology of atherosclerosis has changed from it being a lipid-centric to an inflammation-centric process. In this review, we examine the pathogenesis of atherosclerosis in systemic lupus erythematosus and rheumatoid arthritis, the two most common systemic connective tissue diseases, and consider them as emblematic models of the effect of chronic inflammation on the human body. We explore the roles of the inflammasome, cells of the innate and acquired immune system, neutrophils, macrophages, lymphocytes, chemokines and soluble pro-inflammatory cytokines in rheumatoid arthritis and systemic lupus erythematosus, and the roles of certain autoantigens and autoantibodies, such as oxidized low-density lipoprotein and beta2-glycoprotein, which may play a pathogenetic role in atherosclerosis progression.

Apolipoprotein(a) production and clearance are associated with plasma IL-6 and IL-18 levels, dependent on ethnicity

BACKGROUND AND AIMS

High plasma lipoprotein (a) [Lp(a)] levels are associated with increased atherosclerotic cardiovascular disease (ASCVD), in part attributed to elevated inflammation. High plasma Lp(a) levels inversely correlate with apolipoprotein (a) [(APO(a)] isoform size. APO(a) isoform size is negatively associated with APO(a) production rate (PR) and positively associated with APO(a) fractional catabolic rate (FCR). We asked whether APO(a) PR and FCR (kinetics) are associated with plasma levels of interleukin (IL)-6 and IL-18, pro-inflammatory interleukins that promote ASCVD.

METHODS

We used samples from existing data of APO(a) kinetic studies from an ethnically diverse cohort (n = 25: 10 Black, 9 Hispanic, and 6 White subjects) and assessed IL-6 and IL-18 plasma levels. We performed multivariate linear regression analyses to examine the relationships between predictors APO(a) PR or APO(a) FCR, and outcome variables IL-6 or IL-18. In these analyses, we adjusted for parameters known to affect Lp(a) levels and APO(a) PR and FCR, including race/ethnicity and APO(a) isoform size.

RESULTS

APO(a) PR and FCR were positively associated with plasma IL-6, independent of isoform size, and dependent on race/ethnicity. APO(a) PR was positively associated with plasma IL-18, independent of isoform size and race/ethnicity. APO(a) FCR was not associated with plasma IL-18.

CONCLUSIONS

Our studies demonstrate a relationship between APO(a) PR and FCR and plasma IL-6 or IL-18, interleukins that promote ASCVD. These studies provide new insights into Lp(a) pro-inflammatory properties and are especially relevant in view of therapies targeting APO(a) to decrease cardiovascular risk.

Small apolipoprotein(a) isoforms may predict primary patency following peripheral arterial revascularization

Background

High lipoprotein (a) [Lp(a)] is associated with adverse limb events in patients undergoing lower extremity revascularization. Lp(a) levels are genetically pre-determined, with LPA gene encoding for two apolipoprotein (a) [apo(a)] isoforms. Isoform size variations are driven by the number of kringle IV type 2 (KIV-2) repeats. Lp(a) levels are inversely correlated with isoform size. In this study, we examined the role of Lp(a) levels, apo(a) size and inflammatory markers with lower extremity revascularization outcomes.

Methods

25 subjects with chronic peripheral arterial disease (PAD), underwent open or endovascular lower extremity revascularization (mean age of 66.7±9.7 years; F=12, M=13; Black=8, Hispanic=5, and White=12). Pre- and post-operative medical history, self-reported symptoms, ankle brachial indices (ABIs), and lower extremity duplex ultrasounds were obtained. Plasma Lp(a), apoB100, lipid panel, and pro-inflammatory markers (IL-6, IL-18, hs-CRP, TNFα) were assayed preoperatively. Isoform size was estimated using gel electrophoresis and weighted isoform size ( wIS ) calculated based on % isoform expression. Firth logistic regression was used to examine the relationship between Lp(a) levels, and wIS with procedural outcomes: symptoms (better/worse), primary patency at 2-4 weeks, ABIs, and re-intervention within 3-6 months. We controlled for age, sex, history of diabetes, smoking, statin, antiplatelet and anticoagulation use.

Results

Median plasma Lp(a) level was 108 (44, 301) nmol/L. The mean apoB100 level was 168.0 ± 65.8 mg/dL. These values were not statistically different among races. We found no association between Lp(a) levels and w IS with measured plasma pro-inflammatory markers. However, smaller apo(a) wIS was associated with occlusion of the treated lesion(s) in the postoperative period [OR=1.97 (95% CI 1.01 - 3.86, p<0.05)]. The relationship of smaller apo(a) wIS with re-intervention was not as strong [OR=1.57 (95% CI 0.96 - 2.56), p=0.07]. We observed no association between wIS with patient reported symptoms or change in ABIs.

Conclusions

In this small study, subjects with smaller apo(a) isoform size undergoing peripheral arterial revascularization were more likely to experience occlusion in the perioperative period and/or require re-intervention. Larger cohort studies identifying the mechanism and validating these preliminary data are needed to improve understanding of long-term peripheral vascular outcomes.

Key Findings

25 subjects with symptomatic PAD underwent open or endovascular lower extremity revascularization in a small cohort. Smaller apo(a) isoforms were associated with occlusion of the treated lesion(s) within 2-4 weeks [OR=1.97 (95% CI 1.01 - 3.86, p<0.05)], suggesting apo(a) isoform size as a predictor of primary patency in the early period after lower extremity intervention.

Take Home Message

Subjects with high Lp(a) levels, generally have smaller apo(a) isoform sizes. We find that, in this small cohort, patients undergoing peripheral arterial revascularization subjects with small isoforms are at an increased risk of treated vessel occlusion in the perioperative period.

Table of Contents Summary

Subjects with symptomatic PAD requiring lower extremity revascularization have high median Lp(a) levels. Individuals with smaller apo(a) weighted isoform size (wIS) have lower primary patency rates and/or require re-intervention.

Vascular Health of Females with History of Assisted Reproductive Technology

The use of assisted reproductive technologies (ART) for the treatment of infertility is gaining popularity. Limited data on the overall vascular health of females with history of ART are available. This pilot study aimed to investigate the overall vascular health of females with history of ART compared to individuals who conceived spontaneously. The assessment of overall vascular health included the measurement of brachial blood pressure, central blood pressure, and pulse wave velocity, as well as the evaluation of the arterial stiffness and carotid intima-media thickness (cIMT) of the common carotid arteries. Conventional blood lipids including lipoprotein a (Lp(a)) were also determined. In total, 45 females with history of ART and 52 females who conceived spontaneously were included (mean age: 47.72 ± 5.96 years vs. 46.84 ± 7.43 years, p = 0.525). An initial comparison revealed a significantly higher prevalence of elevated Lp(a) in ART females (p = 0.011). However, after multiple comparison correction, the significant result disappeared (p = 0.132). Within the cohort of ART females, no significantly higher cardiovascular risk was detected regarding vascular function. The potentially higher prevalence of elevated Lp(a) in ART females must be further investigated in future studies, as it might contribute to the impaired reproductive process in this cohort.

Serum Lipoprotein(a) Is Not Associated with Graves' Ophthalmopathy

Aim: To investigate the relationship of serum lipoprotein(a) [Lp(a)] and other serum lipids with presence of Graves' ophthalmopathy (GO). Methods: A total of 99 consecutive patients diagnosed with Graves' disease (GD), aged 18-65 years, who had not received prior treatment for GO, thyroid surgery, or radioactive iodine therapy, were recruited between June 2020 and July 2022. In addition, 56 healthy controls (HCs) were included as the control group. All patients underwent an ophthalmological examination, and were classified based on the presence of GO into the GO group (n = 45) and no GO group (n = 54). Fasting blood samples were collected from all participants to analyze serum lipid parameters, including Lp(a), total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, and triglycerides. Results: The median serum levels of Lp(a) were 5.7 [4.3-9.2] in the GO group, 6.7 [3.7-9.9] in the no GO group, and 4.7 [3-7.6] in the HC group. The intergroup comparisons of serum Lp(a) levels showed no significant result. The serum levels of total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides were also similar between the groups (P > 0.05 for all). However, when analyzing only euthyroid GD patients and the control group, the serum LDL cholesterol levels were found to be significantly higher in the euthyroid GO group [median: 132 interquartile range (IQR) (110-148) mg/dL] than in the HCs [median: 96 IQR (94-118) mg/dL] (P = 0.002). Conclusion: The findings of our study did not support the association between serum Lp(a) levels and GO.

LP(a): Structure, Genetics, Associated Cardiovascular Risk, and Emerging Therapeutics

Lipoprotein(a) [Lp(a)] is a molecule bound to apolipoprotein(a) with some similarity to low-density lipoprotein cholesterol (LDL-C), which has been found to be a risk factor for cardiovascular disease (CVD). Lp(a) appears to induce inflammation, atherogenesis, and thrombosis. Approximately 20% of the world's population has increased Lp(a) levels, determined predominantly by genetics. Current clinical practices for the management of dyslipidemia are ineffective in lowering Lp(a) levels. Evolving RNA-based therapeutics, such as the antisense oligonucleotide pelacarsen and small interfering RNA olpasiran, have shown promising results in reducing Lp(a) levels. Phase III pivotal cardiovascular outcome trials [Lp(a)HORIZON and OCEAN(a)] are ongoing to evaluate their efficacy in secondary prevention of major cardiovascular events in patients with elevated Lp(a). The future of cardiovascular residual risk reduction may transition to a personalized approach where further lowering of either LDL-C, triglycerides, or Lp(a) is selected after high-intensity statin therapy based on the individual risk profile and preferences of each patient.

The value of Lp(a) and TG/HDLC in peripheral blood to assess the stability of carotid plaque in patients with ischemic stroke

OBJECTIVE

The objective of this study was to investigate the relationship between lipoprotein (a) (Lp(a)), triglyceride/high-density lipoprotein cholesterol (TG/HDL-C), and the stability of carotid atherosclerotic plaque in patients with acute ischemic stroke.

METHODS

A total of 142 patients with acute ischemic stroke were selected and divided into group A (59 cases of stable plaque formation) and group B (83 cases of unstable plaque formation) according to the characteristics of carotid artery plaque formation detected by carotid color Doppler ultrasound. The serum Lp(a), lipid metabolism indexes, peripheral blood routine indexes, and related serum inflammatory factors indexes were compared between the two groups. Receiver operating characteristic curve and multivariate logistic regression model were used to analyze the relationship between each index and the formation of carotid unstable plaque.

RESULTS

There were no significant differences in serum total cholesterol (TC), HDL-C, and low-density lipoprotein cholesterol (LDL-C) between groups A and B (p > .05). The values of Lp(a), TG, and TG/HDL-C in group B were higher than those in group A, and the differences were statistically significant (p < .05). There were no significant differences in serum TC, HDL-C, and LDL-C between groups A and B (p > .05). The values of Lp(a), TG, and TG/HDL-C in group B were higher than those in group A, and the differences were statistically significant (p < .05). The values of HBA1C, Lp-PLA2, CRP, CysC, Hcy, TNF-α, neutrophils, and NLR in group B were higher than those in group A, and the differences were statistically significant (p < .05). There was no significant difference in FPG, systolic blood pressure, diastolic blood pressure, Hb, white blood cells, platelets, and lymphocytes between groups A and B (p > .05). The results of logistic regression model showed that the increase of Lp(a), TG/HDL-C, HBA1C, Lp-PLA2, CRP, CysC, Hcy, and NLR could increase the risk of carotid artery unstable plaque in patients with ischemic stroke (p < .05).

CONCLUSION

Lp(a) and TG/HDL-C have certain value in evaluating the stability of carotid atherosclerotic plaque in patients with acute ischemic stroke, and the increased levels of LP (a) and TG/HDL-C will significantly increase the risk of carotid unstable plaque in patients.

Risk of incident cardiovascular events with disease-modifying anti-rheumatic drugs among adults with rheumatoid arthritis: a nested case-control study

OBJECTIVE

This study examined the risk of cardiovascular disease (CVD) associated with the disease-modifying anti-rheumatic drugs (DMARDs) in rheumatoid arthritis (RA).

METHOD

This nested case-control study used the MarketScan database (2012-2014), involving adult RA patients (aged ≥18 years) initiating either a conventional synthetic (cs) DMARD, biologic DMARD, or targeted synthetic (ts) DMARD between January 1, 2013 and December 31, 2014 (cohort entry) and had no CVD history. Cases were individuals with incident CVD identified using diagnosis codes or procedure codes from medical claims. For each case, 10 age- and sex-matched controls were selected using the incident density sampling with replacement. Prescriptions of DMARDs were measured 90 days before the event date. Conditional logistic regression examined the association of risk of CVD with DMARDs in combination treatment or individual use, with reference to methotrexate (MTX) monotherapy, adjusting for baseline confounders. Subgroup analyses were performed separately in DMARD combination therapy users or individual DMARD users, respectively.

RESULTS

In total, 270 cases of incident CVD and 2700 controls were included (mean [standard deviation (SD)] age: 54 [1]; 75.6% women). The commonly prescribed DMARD therapies were csDMARD monotherapy (n = 795, 27.04%), followed by  tumor necrosis factor inhibitors (TNFi) monotherapy (n = 367, 12.48%), and TNFi in combination with MTX (n = 314, 10.68%). Compared with MTX monotherapy, overall use of DMARD agents was not associated with the differential risk of CVD, including various types of DMARD combination regimens. The findings were similar across subgroup analyses.

CONCLUSIONS

The study found no differential risk of CVD with DMARDs in combination therapy or monotherapy compared to MTX monotherapy in patients with RA. Key Points • This study evaluated the risk of cardiovascular disease (CVD) associated with the disease-modifying anti-rheumatic drugs (DMARDs) in rheumatoid arthritis (RA). • Findings suggest no differential CVD risk with DMARDs in combination with MTX or used individually compared with MTX monotherapy in patients with early RA. • Further efforts should focus on a better understanding of the mechanism of DMARD combination treatments with MTX in modifying CV risk.

Association between serum lipoprotein(a) and mildly reduced eGFR: a cross-sectional study

Lipoprotein(a) [Lp(a)] is a risk factor for cardiovascular disease (CVD) and aortic stenosis. However, the data on the relationship between Lp(a) and mildly reduced estimated glomerular filtration rate (eGFR) has been disputed. This study was conducted to assess the relationship between Lp(a) concentrations and mildly reduced eGFR in healthy subjects.This community-based, cross-sectional study enrolled 1,064 volunteers aged ≥ 40 years who lived in Yonghong Community, Zhonglou District, Changzhou, China, between December 2016 and December 2017. A mildly reduced eGFR was defined as eGFR between 60 and 90 mL/min/1.73m2. A standardized questionnaire and biochemical measurements were used to gather information about participants. The serum concentration of Lp(a) was determined using the latex-enhanced immunoturbidimetric test. Of the total study population, 34.8% (n = 370) were men, and the mean age was 66.8 ± 8.5 years. A significant association existed between Lp(a) levels and the risk of mildly reduced eGFR. Individuals with the highest tertile of Lp(a) had higher odds of mildly reduced eGFR after adjusting for various confounders (adjusted odds ratio [OR]: 1.80, 95% confidence interval [CI]: 1.24-2.60, P = 0.0025) compared to those with the lowest tertile of Lp(a). Multivariable logistic regression of studies in which Lp(a) was presented as continuous variables showed consistent results (adjusted OR: 1.23 for 1-SD increment of Ln-Lp(a), 95% CI: 1.05-1.43). Subgroup analyses showed that study characteristics such as age, sex, obesity, diabetes, and hypertension status did not significantly affect the association (P for all interactions > 0.05). These results suggest that higher serum Lp(a) level was an independent risk factor for mildly reduced eGFR.

Lipoprotein(a), Interleukin-6 inhibitors, and atherosclerotic cardiovascular disease: Is there an association?

Background and aims

Lipoprotein(a) [Lp(a)] and interleuking-6 (IL-6), an inflammation biomarker, have been established as distinct targets of the residual atherosclerotic cardiovascular disease (ASCVD) risk. We aimed to investigate the association between them, and the potential clinical implications in ASCVD prevention.

Methods

A literature search was conducted in PubMed until December 31st, 2022, using relevant keywords.

Results

Elevated lipoprotein(a) [Lp(a)] levels constitute the most common inherited lipid disorder associated with ASCVD. Although Lp(a) levels are mostly determined genetically by the LPA gene locus, they may be altered by acute conditions of stress and chronic inflammatory diseases. Considering its resemblance with low-density lipoproteins, Lp(a) is involved in atherosclerosis, but it also exerts oxidative, thrombotic, antifibrinolytic and inflammatory properties. The cardiovascular efficacy of therapies lowering Lp(a) by >90% is currently investigated. On the other hand, interleukin (IL)-1b/IL-6 pathway also plays a pivotal role in atherosclerosis and residual ASCVD risk. IL-6 receptor inhibitors [IL-6(R)i] lower Lp(a) by 16-41%, whereas ongoing trials are investigating their potential anti-atherosclerotic effect. The Lp(a)-lowering effect of IL-6(R)i might be attributed to the inhibition of the IL-6 response elements in the promoter region of the LPA gene.

Conclusions

Although the effect of IL-6(R)i on Lp(a) levels is inferior to that of available Lp(a)-lowering therapies, the dual effect of the former on both inflammation and apolipoprotein (a) synthesis may prove of equal or even greater significance when it comes ASCVD outcomes. More trials are required to establish IL-6(R)i in ASCVD prevention and elucidate their interplay with Lp(a) as well as its clinical significance.

Relationship between lipoprotein(a) and whole blood reducing viscosity: A cross-sectional study

Lipoprotein(a) [Lp(a)] has been confirmed as a causal risk factor of atherosclerotic cardiovascular disease, but its role on circulation is not completely clear and is still being explored. Therefore, this study attempts to explore the relationship between Lp(a) and whole blood reducing viscosity (WBRV), to better understand the role of Lp(a) in circulatory and cardiovascular diseases. We retrospectively analyzed the data of consecutive subjects in the physical examination center of the Affiliated Hospital of Ningbo University Medical College from January 2022 to May 2022. Pearson or spearman correlation analysis was used to test the statistical relationship between 2 continuous variables according to whether they are normal; 131 participants were retrospectively enrolled in this study. The low-density lipoprotein concentration was associated with whole blood viscosity at low-shear (R = 0.220, P = .012), middle-shear (R = 0.226, P = .01), and high-shear viscosity (R = 0.212, P = .015), as well as plasma viscosity (RS = 0.207, P = .018). Lp(a) was not associated with whole blood viscosity at low, middle, and high shear rates, but was associated with WBRV at low shear (RS = 0.204, P = .019) and middle shear rates (RS = 0.197, P = .024). Lp(a) is associated with high WBRV, which may impart more insights into the role of Lp(a) in cardiovascular disease.

Lipoprotein(a) in patients with breast cancer after chemotherapy: exploring potential strategies for cardioprotection

Developments in neoadjuvant and adjuvant chemotherapy (CHT) have led to an increase in the number of breast cancer survivors. The determination of an appropriate follow-up for these patients is of increasing importance. Deaths due to cardiovascular disease (CVD) are an important part of mortality in patients with breast cancer.This review suggests that chemotherapeutic agents may influence lipoprotein(a) (Lp(a)) concentrations in breast cancer survivors after CHT based on many convincing evidence from epidemiologic and observational researches. Usually, the higher the Lp(a) concentration, the higher the median risk of developing CVD. However, more clinical trial results are needed in the future to provide clear evidence of a possible causal relationship. This review also discuss the existing and emerging therapies for lowering Lp(a) concentrations in the clinical setting. Hormone replacement therapy, statins, proprotein convertase subtilisin/kexin-type 9 (PCSK9) inhibitors, Antisense oligonucleotides, small interfering RNA, etc. may reduce circulating Lp(a) or decrease the incidence of CVD.

Metabolic systems approaches update molecular insights of clinical phenotypes and cardiovascular risk in patients with homozygous familial hypercholesterolemia

BACKGROUND

Homozygous familial hypercholesterolemia (HoFH) is an orphan metabolic disease characterized by extremely elevated low-density lipoprotein cholesterol (LDL-C), xanthomas, aortic stenosis, and premature atherosclerotic cardiovascular disease (ASCVD). In addition to LDL-C, studies in experimental models and small clinical populations have suggested that other types of metabolic molecules might also be risk factors responsible for cardiovascular complications in HoFH, but definitive evidence from large-scale human studies is still lacking. Herein, we aimed to comprehensively characterize the metabolic features and risk factors of human HoFH by using metabolic systems strategies.

METHODS

Two independent multi-center cohorts with a total of 868 individuals were included in the cross-sectional study. First, comprehensive serum metabolome/lipidome-wide analyses were employed to identify the metabolomic patterns for differentiating HoFH patients (n = 184) from heterozygous FH (HeFH, n = 376) and non-FH (n = 100) subjects in the discovery cohort. Then, the metabolomic patterns were verified in the validation cohort with 48 HoFH patients, 110 HeFH patients, and 50 non-FH individuals. Subsequently, correlation/regression analyses were performed to investigate the associations of clinical/metabolic alterations with typical phenotypes of HoFH. In the prospective study, a total of 84 HoFH patients with available follow-up were enrolled from the discovery cohort. Targeted metabolomics, deep proteomics, and random forest approaches were performed to investigate the ASCVD-associated biomarkers in HoFH patients.

RESULTS

Beyond LDL-C, various bioactive metabolites in multiple pathways were discovered and validated for differentiating HoFH from HoFH and non-FH. Our results demonstrated that the inflammation and oxidative stress-related metabolites in the pathways of arachidonic acid and lipoprotein(a) metabolism were independently associated with the prevalence of corneal arcus, xanthomas, and supravalvular/valvular aortic stenosis in HoFH patients. Our results also identified a small marker panel consisting of high-density lipoprotein cholesterol, lipoprotein(a), apolipoprotein A1, and eight proinflammatory and proatherogenic metabolites in the pathways of arachidonic acid, phospholipid, carnitine, and sphingolipid metabolism that exhibited significant performances on predicting first ASCVD events in HoFH patients.

CONCLUSIONS

Our findings demonstrate that human HoFH is associated with a variety of metabolic abnormalities and is more complex than previously known. Furthermore, this study provides additional metabolic alterations that hold promise as residual risk factors in HoFH population.

Incident CHD and ischemic stroke associated with lipoprotein(a) by levels of Factor VIII and inflammation

BACKGROUND

Inflammation and coagulation may contribute to the increased risk for atherosclerotic cardiovascular disease (ASCVD) associated with high lipoprotein(a). The association of lipoprotein(a) with ASCVD is stronger in individuals with high versus low high-sensitivity C-reactive protein (hs-CRP), a marker of inflammation.

OBJECTIVES

Determine the association of lipoprotein(a) with incident ASCVD by levels of coagulation Factor VIII controlling for hs-CRP.

METHODS

We analyzed data from 6,495 men and women 45 to 84 years of age in the Multi-Ethnic Study of Atherosclerosis (MESA) without prevalent ASCVD at baseline (2000-2002). Lipoprotein(a) mass concentration, Factor VIII coagulant activity, and hs-CRP were measured at baseline and categorized as high or low (≥75th or <75th percentile of the distribution). Participants were followed for incident coronary heart disease (CHD) and ischemic stroke through 2015.

RESULTS

Over a median follow-up of 13.9 years, there were 390 CHD and 247 ischemic stroke events. The hazard ratio (95%CI) for CHD associated with high lipoprotein(a) (≥40.1 versus <40.1 mg/dL) including adjustment for hs-CRP among participants with low and high Factor VIII was 1.07 (0.80-1.44) and 2.00 (1.33-3.01), respectively (p-value for interaction 0.016). The hazard ratio (95%CI) for CHD associated with high lipoprotein(a) including adjustment for Factor VIII was 1.16 (0.87-1.54) and 2.00 (1.29-3.09) among participants with low and high hs-CRP, respectively (p-value for interaction 0.042). Lp(a) was not associated with ischemic stroke regardless of Factor VIII or hs-CRP levels.

CONCLUSION

High lipoprotein(a) is a risk factor for CHD in adults with high levels of hemostatic or inflammatory markers.

Evidence and Uncertainties on Lipoprotein(a) as a Marker of Cardiovascular Health Risk in Children and Adolescents

Lipoprotein(a) (Lp(a)) is made up of apoprotein(a) (apo(a)) and an LDL-like particle. The LPA gene encodes apo(a) and thus determines the characteristics and amount of apo(a) and Lp(a). The proportion of Lp(a) in each individual is genetically determined and is only minimally modifiable by the environment or diet. Lp(a) has important pro-atherosclerotic and pro-inflammatory effects. It has been hypothesized that Lp(a) also has pro-coagulant and antifibrinolytic actions. For these reasons, high Lp(a) values are an important independent risk factor for cardiovascular disease and calcific aortic valve stenosis. Numerous studies have been performed in adults about the pathophysiology and epidemiology of Lp(a) and research is under way for the development of drugs capable of reducing Lp(a) plasma values. Much less information is available regarding Lp(a) in children and adolescents. The present article reviews the evidence on this topic. The review addresses the issues of Lp(a) changes during growth, the correlation between Lp(a) values in children and those in their parents, and between Lp(a) levels in children, and the presence of cardiovascular disease in the family. Gaining information on these points is particularly important for deciding whether Lp(a) assay may be useful for defining the cardiovascular risk in children, in order to plan a prevention program early.

Supporting evidence for lipoprotein(a) measurements in clinical practice

High levels of lipoprotein(a) [Lp(a)] are causal for development of atherosclerotic cardiovascular disease and highly regulated by genetics. Levels are higher in Blacks compared to Whites, and in women compared to men. Lp(a)'s main protein components are apolipoprotein (apo) (a) and apoB100, the latter being the main component of Low-Density Lipoprotein (LDL) particles. Studies have identified Lp(a) to be associated with inflammatory, coagulation and wound healing pathways. Lack of validated and accepted assays to measure Lp(a), risk cutoff values, guidelines for diagnosis, and targeted therapies have added challenges to the field. Scientific efforts are ongoing to address these, including studies evaluating the cardiovascular benefits of decreasing Lp(a) levels with targeted apo(a) lowering treatments. This review will provide a synopsis of evidence-based effects of high Lp(a) on disease presentation, highlight available guidelines and discuss promising therapies in development. We will conclude with current clinical information and future research needs in the field.

Mechanism of oxidized phospholipid-related inflammatory response in vascular ageing

Vascular ageing is an important factor in the morbidity and mortality of the elderly. Atherosclerosis is a characteristic disease of vascular ageing, which is closely related to the enhancement of vascular inflammation. Phospholipid oxidation products are important factors in inducing cellular inflammation. Through interactions with vascular cells and immune cells, they regulate intracellular signaling pathways, activate the expression of various cytokines, and affect cell behavior, such as metabolic level, proliferation, apoptosis, etc. Intervention in lipid metabolism and anti-inflammation are the two key pathways of drugs for the treatment of atherosclerosis. This review aims to sort out the signaling pathway of oxidized phospholipids-induced inflammatory factors in vascular cells and immune cells and the mechanism leading to changes in cell behavior, and summarize the therapeutic targets in the inflammatory signaling pathway for the development of atherosclerosis drugs.

Absence of High Lipoprotein(a) Levels Is an Independent Predictor of Acute Myocardial Infarction without Coronary Lesions

The pathophysiological mechanisms underlying Myocardial Infarction with Non-Obstructive Coronary Artery Disease (MINOCA) are still under debate. Lipoprotein (a) [Lp(a)] has proinflammatory and prothrombotic actions and has been involved in the pathogenesis of atherosclerosis. However, no previous studies have linked Lp(a) levels with the probability of developing MINOCA. Moreover, the relationship between MINOCA and the plasma levels of other proatherogenic and proinflammatory molecules such as Interleukin-18 (IL18) and proprotein convertase subtilisin/kexin type 9 (PCSK9) has not been studied. We conducted a prospective, multicenter study involving 1042 patients with acute myocardial infarction (AMI). Seventy-six patients had no significant coronary lesions. All patients underwent plasma analysis on admission. MINOCA patients were younger (57 (47-68) vs. 61 (52-72) years; p = 0.010), more frequently female (44.7% vs. 21.0%; p < 0.001), and had lower rates of diabetes and of Lp(a) > 60 mg/dL (9.2% vs. 19.8%; p = 0.037) than those with coronary lesions; moreover, High Density Lipoprotein cholesterol (HDL-c) levels were higher in MINOCA patients. The absence of Lp(a) > 60 mg/dL and of diabetes were independent predictors of MINOCA, as well as female sex, high HDL-c levels, and younger age. IL-18 and PCSK9 levels were not predictors of MINOCA. During a follow-up of 5.23 (2.89, 7.37) years, the independent predictors of the primary outcome (acute ischemic events or death) in the whole sample were Lp(a) > 60 mg/dL, older age, low estimated Glomerular Filtration rate (eGFR), hypertension, previous heart failure (HF), coronary artery bypass graft, use of insulin, and no therapy with acetylsalicylic acid. In conclusion, in AMI patients, the absence of high Lp(a) levels, as well high HDL-c levels, were independent predictors of the inexistence of coronary artery disease. High Lp (a) levels were also an independent predictor of ischemic events or death.

Metabolomic Approach to Screening Homozygotes in Chinese Patients with Severe Familial Hypercholesterolemia

Homozygous familial hypercholesterolemia (HoFH) is a rare inborn-errors-of-metabolism disorder characterized by devastatingly elevated low-density lipoprotein cholesterol (LDL-C) and premature cardiovascular disease. The gold standard for screening and diagnosing HoFH is genetic testing. In China, it is expensive and is always recommended for the most likely HoFH subjects with aggressive LDL-C phenotype. However, the LDL-C levels of HoFH patients and a substantial proportion of heterozygous FH (HeFH) patients overlapped considerably. Here, we performed a cost-effective metabolomic profiling on genetically diagnosed HoFH (n = 69) and HeFH patients (n = 101) with overlapping LDL-C levels, aiming to discovery a unique metabolic pattern for screening homozygotes in patients with severe FH. We demonstrated a differential serum metabolome profile in HoFH patients compared to HeFH patients. Twenty-one metabolomic alterations showed independent capability in differentiating HoFH from severe HeFH. The combined model based on seven identified metabolites yielded a corrected diagnosis in 91.3% of HoFH cases with an area under the curve value of 0.939. Collectively, this study demonstrated that metabolomic profiling serves as a useful and economical approach to preselecting homozygotes in FH patients with severe hypercholesterolemia and may help clinicians to conduct selective genetic confirmation testing and familial cascade screening.

Lipoprotein(a) and residual vascular risk in statin-treated patients with first acute ischemic stroke: A prospective cohort study

OBJECTIVES

Statins either barely affect or increase lipoprotein(a) [Lp(a)] levels. This study aimed to explore the factors correlated to the change of Lp(a) levels as well as the relationship between Lp(a) and the recurrent vascular events in statin-treated patients with first acute ischemic stroke (AIS).

METHODS

Patients who were admitted to the hospital with first AIS from October 2018 to September 2020 were eligible for inclusion. Correlation between the change of Lp(a) levels and potential influencing factors was assessed by linear regression analysis. Cox proportional regression models were used to estimate the association between Lp(a) and recurrent vascular events including AIS, transient ischemic attack, myocardial infarction and coronary revascularization.

RESULTS

In total, 303 patients, 69.6% males with mean age 64.26 ± 11.38 years, completed the follow-up. During the follow-up period, Lp(a) levels increased in 50.5% of statin-treated patients and the mean percent change of Lp(a) levels were 14.48% (95% CI 6.35-22.61%). Creatinine (β = 0.152, 95% CI 0.125-0.791, P = 0.007) and aspartate aminotransferase (AST) (β = 0.160, 95% CI 0.175-0.949, P = 0.005) were positively associated with the percent change of Lp(a) levels. During a median follow-up of 26 months, 66 (21.8%) patients had a recurrent vascular event. The median time period between AIS onset and vascular events recurrence was 9.5 months (IQR 2.0-16.3 months). The on-statin Lp(a) level ≥70 mg/dL (HR 2.539, 95% CI 1.076-5.990, P = 0.033) and the change of Lp(a) levels (HR 1.003, 95% CI 1.000-1.005, P = 0.033) were associated with the recurrent vascular events in statin-treated patients with first AIS. Furthermore, the on-statin Lp(a) levels ≥70 mg/dL (HR 3.612, 95% CI 1.018-12.815, P = 0.047) increased the risk of recurrent vascular events in patients with low-density lipoprotein cholesterol (LDL-C) levels < 1.8 mmol/L.

CONCLUSIONS

Lp(a) levels increased in half of statin-treated patients with first AIS. Creatinine and AST were positively associated with the percent change of Lp(a) levels. Lp(a) is a determinant of residual vascular risk and the change of Lp(a) is positively associated with the risk of recurrent vascular events in these patients.

Statin therapy is not warranted for a person with high LDL-cholesterol on a low-carbohydrate diet

PURPOSE OF REVIEW

Although there is an extensive literature on the efficacy of the low carbohydrate diet (LCD) for weight loss and in the management of type 2 diabetes, concerns have been raised that the LCD may increase cardiovascular disease (CVD) risk by increasing the level of low-density lipoprotein cholesterol (LDL-C). We have assessed the value of LDL-C as a CVD risk factor, as well as effects of the LCD on other CVD risk factors. We have also reviewed findings that provide guidance as to whether statin therapy would be beneficial for individuals with high LDL-C on an LCD.

RECENT FINDINGS

Multiple longitudinal trials have demonstrated the safety and effectiveness of the LCD, while also providing evidence of improvements in the most reliable CVD risk factors. Recent findings have also confirmed how ineffective LDL-C is in predicting CVD risk.

SUMMARY

Extensive research has demonstrated the efficacy of the LCD to improve the most robust CVD risk factors, such as hyperglycemia, hypertension, and atherogenic dyslipidemia. Our review of the literature indicates that statin therapy for both primary and secondary prevention of CVD is not warranted for individuals on an LCD with elevated LDL-C who have achieved a low triglyceride/HDL ratio.

Lipoprotein(a) in atherosclerotic cardiovascular disease and aortic stenosis: a European Atherosclerosis Society consensus statement

This 2022 European Atherosclerosis Society lipoprotein(a) [Lp(a)] consensus statement updates evidence for the role of Lp(a) in atherosclerotic cardiovascular disease (ASCVD) and aortic valve stenosis, provides clinical guidance for testing and treating elevated Lp(a) levels, and considers its inclusion in global risk estimation. Epidemiologic and genetic studies involving hundreds of thousands of individuals strongly support a causal and continuous association between Lp(a) concentration and cardiovascular outcomes in different ethnicities; elevated Lp(a) is a risk factor even at very low levels of low-density lipoprotein cholesterol. High Lp(a) is associated with both microcalcification and macrocalcification of the aortic valve. Current findings do not support Lp(a) as a risk factor for venous thrombotic events and impaired fibrinolysis. Very low Lp(a) levels may associate with increased risk of diabetes mellitus meriting further study. Lp(a) has pro-inflammatory and pro-atherosclerotic properties, which may partly relate to the oxidized phospholipids carried by Lp(a). This panel recommends testing Lp(a) concentration at least once in adults; cascade testing has potential value in familial hypercholesterolaemia, or with family or personal history of (very) high Lp(a) or premature ASCVD. Without specific Lp(a)-lowering therapies, early intensive risk factor management is recommended, targeted according to global cardiovascular risk and Lp(a) level. Lipoprotein apheresis is an option for very high Lp(a) with progressive cardiovascular disease despite optimal management of risk factors. In conclusion, this statement reinforces evidence for Lp(a) as a causal risk factor for cardiovascular outcomes. Trials of specific Lp(a)-lowering treatments are critical to confirm clinical benefit for cardiovascular disease and aortic valve stenosis.

The Effect of Bariatric Surgery on Circulating Levels of Lipoprotein (a): A Meta-analysis

Background

Obesity, especially severe obesity, is associated with a higher risk of atherosclerotic cardiovascular disease (ASCVD) morbidity and mortality. Bariatric surgery is a durable and effective weight loss therapy for patients with severe obesity and weight-related comorbidities. Elevated plasma levels of lipoprotein (a) (Lp(a)) are causally associated with ASCVD. The aim of this meta-analysis was to analyze whether bariatric surgery is associated with Lp(a) concentrations.

Methods

A literature search in PubMed, Scopus, Embase, and Web of Science was performed from inception to May 1st, 2021. A random-effects model and the generic inverse variance weighting method were used to compensate for the heterogeneity of studies in terms of study design, treatment duration, and the characteristics of the studied populations. A random-effects metaregression model was used to explore the association with an estimated effect size. Evaluation of funnel plot, Begg's rank correlation, and Egger's weighted regression tests were used to assess the presence of publication bias in the meta-analysis.

Results

Meta-analysis of 13 studies including 1551 patients showed a significant decrease of circulating Lp(a) after bariatric surgery (SMD: -0.438, 95% CI: -0.702, -0.174, p < 0.001, I²: 94.05%). The results of the metaregression did not indicate any significant association between the changes in Lp(a) and duration of follow-up after surgery, reduction in body mass index, or baseline Lp(a) concentration. The reduction in circulating Lp(a) was robust in the leave-one-out sensitivity analysis.

Conclusion

Bariatric surgery significantly decreases circulating Lp(a) concentrations. This decrease may have a positive effect on ASCVD in obese patients.

Lipid Profile, Lp(a) Levels, and HDL Quality in Adolescents with Down Syndrome

The improvement in the lifespan of individuals with Down syndrome (DS) has created interest in the context of the development of age-related diseases. Among them is atherosclerosis-based cardiovascular disease (CVD), which seems to be an especially urgent and important issue. The aim of the present study was to evaluate the lipid markers that may clarify cardiovascular risk profiles in individuals with DS. To this end, we analyzed lipid profile parameters, including lipoprotein(a) (Lp(a)) levels, protein composition, and the antioxidative properties of high-density lipoprotein (HDL), in 47 adolescents with DS and 47 individuals without DS. Compared with the control group (C), subjects with DS had significantly increased concentrations of low-density lipoprotein cholesterol (105 ± 31 vs. 90 ± 24 mg/dL, p = 0.014), non-high-density lipoprotein cholesterol (120 ± 32 vs. 103 ± 26 mg/dL, p = 0.006), and triglycerides (72 [55−97] vs. 60 [50−77] mg/dL, p = 0.048). We found that patients with DS were characterized by significantly higher Lp(a) levels (31.9 [21.5−54.3] vs. 5.2 (2.4−16.1) mg/dL, p < 0.001). In fact, 57% of individuals with DS had Lp(a) levels above 30 mg/dL, which was approximately four times higher than those in the control group (DS 57% vs. C 15%). Apart from decreased high-density lipoprotein cholesterol levels in the subjects with DS (53 ± 11 vs. 63 ± 12 mg/dL, p < 0.001), differences in parameters showing the quality of HDL particles were observed. The concentrations of the main proteins characterizing the HDL fraction, apolipoprotein A-I and apolipoprotein A-II, were significantly lower in the DS group (144 ± 21 vs. 181 ± 33 mg/dL, p < 0.001; 33 ± 6 vs. 39 ± 6 mg/dL, p < 0.001, respectively). No significant differences between the groups were observed for the concentration of paraoxonase-1 (DS 779 ± 171 vs. C 657 ± 340 ng/mL, p = 0.063), enzyme activities toward paraoxon (DS 219 [129−286] vs. C 168 [114−272] IU/L, p = 0.949), or phenyl acetate (DS 101 ± 20 vs. C 93 ± 21 kIU/L, p = 0.068). There were no differences in myeloperoxidase activity between the study groups (DS 327 [300−534] vs. C 426 [358−533] ng/mL, p = 0.272). Our results are the first to demonstrate an unfavorable lipid profile combined with higher Lp(a) levels and quality changes in HDL particles in individuals with DS. This sheds new light on cardiovascular risk and traditional healthcare planning for adolescents with DS.

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.

Lipoprotein(a): Knowns, unknowns and uncertainties

Over the last 10 years, there have been advances on several aspects of lipoprotein(a) which are reviewed in the present article. Since the standard immunoassays for measuring lipoprotein(a) are not fully apo(a) isoform-insensitive, the application of an LC-MS/MS method for assaying molar concentrations of lipoprotein(a) has been advocated. Genome wide association, epidemiological, and clinical studies have established high lipoprotein(a) as a causal risk factor for atherosclerotic cardiovascular diseases (ASCVD). However, the relative importance of molar concentration, apo(a) isoform size or variants within the LPA gene is still controversial. Lipoprotein(a)-raising single nucleotide polymorphisms has not been shown to add on value in predicting ASCVD beyond lipoprotein(a) concentrations. Although hyperlipoproteinemia(a) represents an important confounder in the diagnosis of familial hypercholesterolemia (FH), it enhances the risk of ASCVD in these patients. Thus, identification of new cases of hyperlipoproteinemia(a) during cascade testing can increase the identification of high-risk individuals. However, it remains unclear whether FH itself increases lipoprotein(a). The ASCVD risk associated with lipoprotein(a) seems to follow a linear gradient across the distribution, regardless of racial subgroups and other risk factors. The inverse association with the risk of developing type 2 diabetes needs consideration as effective lipoprotein(a) lowering therapies are progressing towards the market. Considering that Mendelian randomization analyses have identified the degree of lipoprotein(a)-lowering that is required to achieve ASCVD benefit, the findings of the ongoing outcome trial with pelacarsen will clarify whether dramatically lowering lipoprotein(a) levels can reduce the risk of ASCVD.