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Volgman AS, Koschinsky ML, Mehta A, Rosenson RS. Genetics and Pathophysiological Mechanisms of Lipoprotein(a)-Associated Cardiovascular Risk. J Am Heart Assoc 2024; 13:e033654. [PMID: 38879448 PMCID: PMC11255763 DOI: 10.1161/jaha.123.033654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 06/19/2024]
Abstract
Elevated lipoprotein(a) is a genetically transmitted codominant trait that is an independent risk driver for cardiovascular disease. Lipoprotein(a) concentration is heavily influenced by genetic factors, including LPA kringle IV-2 domain size, single-nucleotide polymorphisms, and interleukin-1 genotypes. Apolipoprotein(a) is encoded by the LPA gene and contains 10 subtypes with a variable number of copies of kringle -2, resulting in >40 different apolipoprotein(a) isoform sizes. Genetic loci beyond LPA, such as APOE and APOH, have been shown to impact lipoprotein(a) levels. Lipoprotein(a) concentrations are generally 5% to 10% higher in women than men, and there is up to a 3-fold difference in median lipoprotein(a) concentrations between racial and ethnic populations. Nongenetic factors, including menopause, diet, and renal function, may also impact lipoprotein(a) concentration. Lipoprotein(a) levels are also influenced by inflammation since the LPA promoter contains an interleukin-6 response element; interleukin-6 released during the inflammatory response results in transient increases in plasma lipoprotein(a) levels. Screening can identify elevated lipoprotein(a) levels and facilitate intensive risk factor management. Several investigational, RNA-targeted agents have shown promising lipoprotein(a)-lowering effects in clinical studies, and large-scale lipoprotein(a) testing will be fundamental to identifying eligible patients should these agents become available. Lipoprotein(a) testing requires routine, nonfasting blood draws, making it convenient for patients. Herein, we discuss the genetic determinants of lipoprotein(a) levels, explore the pathophysiological mechanisms underlying the association between lipoprotein(a) and cardiovascular disease, and provide practical guidance for lipoprotein(a) testing.
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Affiliation(s)
| | - Marlys L. Koschinsky
- Robarts Research Institute, Schulich School of Medicine and DentistryWestern UniversityLondonONCanada
| | | | - Robert S. Rosenson
- Metabolism and Lipids Program, Mount Sinai Fuster Heart HospitalIcahn School of Medicine at Mount SinaiNew YorkNYUSA
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Reijnders E, van der Laarse A, Ruhaak LR, Cobbaert CM. Closing the gaps in patient management of dyslipidemia: stepping into cardiovascular precision diagnostics with apolipoprotein profiling. Clin Proteomics 2024; 21:19. [PMID: 38429638 PMCID: PMC10908091 DOI: 10.1186/s12014-024-09465-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Accepted: 02/14/2024] [Indexed: 03/03/2024] Open
Abstract
In persons with dyslipidemia, a high residual risk of cardiovascular disease remains despite lipid lowering therapy. Current cardiovascular risk prediction mainly focuses on low-density lipoprotein cholesterol (LDL-c) levels, neglecting other contributing risk factors. Moreover, the efficacy of LDL-c lowering by statins resulting in reduced cardiovascular risk is only partially effective. Secondly, from a metrological viewpoint LDL-c falls short as a reliable measurand. Both direct and calculated LDL-c tests produce inaccurate test results at the low end under aggressive lipid lowering therapy. As LDL-c tests underperform both clinically and metrologically, there is an urging need for molecularly defined biomarkers. Over the years, apolipoproteins have emerged as promising biomarkers in the context of cardiovascular disease as they are the functional workhorses in lipid metabolism. Among these, apolipoprotein B (ApoB), present on all atherogenic lipoprotein particles, has demonstrated to clinically outperform LDL-c. Other apolipoproteins, such as Apo(a) - the characteristic apolipoprotein of the emerging risk factor lipoprotein(a) -, and ApoC-III - an inhibitor of triglyceride-rich lipoprotein clearance -, have attracted attention as well. To support personalized medicine, we need to move to molecularly defined risk markers, like the apolipoproteins. Molecularly defined diagnosis and molecularly targeted therapy require molecularly measured biomarkers. This review provides a summary of the scientific validity and (patho)physiological role of nine serum apolipoproteins, Apo(a), ApoB, ApoC-I, ApoC-II, ApoC-III, ApoE and its phenotypes, ApoA-I, ApoA-II, and ApoA-IV, in lipid metabolism, their association with cardiovascular disease, and their potential as cardiovascular risk markers when measured in a multiplex apolipoprotein panel.
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Affiliation(s)
- Esther Reijnders
- Department of Clinical Chemistry and Laboratory Medicine, Leiden University Medical Center, Leiden, the Netherlands.
| | - Arnoud van der Laarse
- Department of Clinical Chemistry and Laboratory Medicine, Leiden University Medical Center, Leiden, the Netherlands
| | - L Renee Ruhaak
- Department of Clinical Chemistry and Laboratory Medicine, Leiden University Medical Center, Leiden, the Netherlands
| | - Christa M Cobbaert
- Department of Clinical Chemistry and Laboratory Medicine, Leiden University Medical Center, Leiden, the Netherlands
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Abstract
PURPOSE OF REVIEW Lp(a) is one of the most atherogenic lipoproteins, and significant progress has been made to understand its pathophysiology over the last 20 years. There are now selective therapies in late-stage clinical trials to lower Lp(a). Yet there are many outstanding questions about Lp(a). This review outlines 10 of the most burning questions and tries to answer some of them. RECENT FINDINGS Antisense oligonucleotide (ASO) treatment is currently the most advanced therapy to lower plasma Lp(a) by 60-80%. There are, however, also two small molecule medications in early stage of development with similar efficacy. SUMMARY This review aims to answer important preclinical and clinical questions about the metabolism and physiological role of Lp(a) and also outlines possible therapeutic approaches with nutraceuticals, currently available lipid-lowering therapies and new medications. In addition, ways are illustrated to use Lp(a) as a marker to better predict cardiovascular risk.
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Affiliation(s)
- Karam M Kostner
- Department of Cardiology Mater Hospital and University of Queensland, Brisbane, Australia
| | - Gerhard M Kostner
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
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Jacob EO, McIntyre AD, Wang J, Hegele RA. Lipoprotein(a) in Familial Hypercholesterolemia. CJC Open 2024; 6:40-46. [PMID: 38313344 PMCID: PMC10837708 DOI: 10.1016/j.cjco.2023.09.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 09/25/2023] [Indexed: 02/06/2024] Open
Abstract
Background Low density lipoprotein (LDL) and Lipoprotein (Lp)(a) are proatherogenic apolipoprotein (apo) B-containing members of the non-high-density lipoprotein (non-HDL) family of particles. Elevated plasma levels of LDL cholesterol (C), non-HDL-C, and apo B are defining features of heterozygous familial hypercholesterolemia (HeFH), but reports of elevated plasma Lp(a) concentration are inconsistent. Methods We performed retrospective chart reviews of 256 genetically characterized patients with hypercholesterolemia and 272 control subjects from the Lipid Genetics Clinic at University Hospital in London, Ontario. We evaluated pairwise correlations between plasma levels of Lp(a) and those of LDL-C, non-HDL-C and apo B. Results Mean Lp(a) levels were not different between individuals with hypercholesterolemia and control subjects. No correlations were found between Lp(a) and LDL-C or non-HDL-C levels in controls or patients with hypercholesterolemia; all r values < 0.079 and all P values > 0.193. Borderline weak correlations between Lp(a) and apo B were identified in patients r = 0.103; P = 0.112) and controls (r = 0.175; P = 0.005). Results were similar across genotypic subgroups. Conclusions Lp(a) levels are independent of LDL-C and non-HDL-C; in particular Lp(a) levels are not increased in patients with hypercholesterolemia and molecularly proven HeFH. Apo B was only weakly associated with Lp(a). Elevated Lp(a) does not cause FH in our clinic patients. Genetic variants causing HeFH that raise LDL-C do not affect Lp(a), confirming that these lipoproteins are metabolically distinct. Lp(a) cannot be predicted from LDL-C and must be determined separately to evaluate its amplifying effect on atherosclerotic risk in patients with hypercholesterolemia.
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Affiliation(s)
- Erin O Jacob
- Department of Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
- Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Adam D McIntyre
- Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Jian Wang
- Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Robert A Hegele
- Department of Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
- Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
- Department of Medicine, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
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Jayaraman S, Pérez A, Miñambres I, Sánchez-Quesada JL, Gursky O. LDL binding to cell receptors and extracellular matrix is proatherogenic in obesity but improves after bariatric surgery. J Lipid Res 2023; 64:100451. [PMID: 37777014 PMCID: PMC10665669 DOI: 10.1016/j.jlr.2023.100451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 09/08/2023] [Accepted: 09/22/2023] [Indexed: 10/02/2023] Open
Abstract
Obesity is a major global public health issue involving dyslipidemia, oxidative stress, inflammation, and increased risk of CVD. Weight loss reduces this risk, but the biochemical underpinnings are unclear. We explored how obesity and weight loss after bariatric surgery influence LDL interactions that trigger proatherogenic versus antiatherogenic processes. LDL was isolated from plasma of six patients with severe obesity before (basal) and 6-12 months after bariatric surgery (basal BMI = 42.7 kg/m2; 6-months and 12-months postoperative BMI = 34.1 and 30 kg/m2). Control LDL were from six healthy subjects (BMI = 22.6 kg/m2). LDL binding was quantified by ELISA; LDL size and charge were assessed by chromatography; LDL biochemical composition was determined. Compared to controls, basal LDL showed decreased nonatherogenic binding to LDL receptor, which improved postoperatively. Conversely, basal LDL showed increased binding to scavenger receptors LOX1 and CD36 and to glycosaminoglycans, fibronectin and collagen, which is proatherogenic. One year postoperatively, this binding decreased but remained elevated, consistent with elevated lipid peroxidation. Serum amyloid A and nonesterified fatty acids were elevated in basal and postoperative LDL, indicating obesity-associated inflammation. Aggregated and electronegative LDL remained elevated, suggesting proatherogenic processes. These results suggest that obesity-induced inflammation contributes to harmful LDL alterations that probably increase the risk of CVD. We conclude that in obesity, LDL interactions with cell receptors and extracellular matrix shift in a proatherogenic manner but are partially reversed upon postoperative weight loss. These results help explain why the risk of CVD increases in obesity but decreases upon weight loss.
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Affiliation(s)
- Shobini Jayaraman
- Department of Pharmacology, Physiology & Biophysics, Chobanian and Avedisian School of Medicine, Boston University, Boston, MA, USA.
| | - Antonio Pérez
- Endocrinology Department, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain; CIBER of Diabetes and Metabolic Diseases (CIBERDEM), Barcelona, Spain
| | - Inka Miñambres
- Endocrinology Department, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - Jose Luis Sánchez-Quesada
- CIBER of Diabetes and Metabolic Diseases (CIBERDEM), Barcelona, Spain; Cardiovascular Biochemistry Group, Research Institute of the Hospital de Sant Pau, CIBERDEM, Barcelona, Spain.
| | - Olga Gursky
- Department of Pharmacology, Physiology & Biophysics, Chobanian and Avedisian School of Medicine, Boston University, Boston, MA, USA
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Conlon DM, Welty FK, Reyes-Soffer G, Amengual J. Sex-Specific Differences in Lipoprotein Production and Clearance. Arterioscler Thromb Vasc Biol 2023; 43:1617-1625. [PMID: 37409532 PMCID: PMC10527393 DOI: 10.1161/atvbaha.122.318247] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 06/19/2023] [Indexed: 07/07/2023]
Abstract
Therapeutic approaches to reduce atherogenic lipid and lipoprotein levels remain the most effective and assessable strategies to prevent and treat cardiovascular disease. The discovery of novel research targets linked to pathways associated with cardiovascular disease development has enhanced our ability to decrease disease burden; however, residual cardiovascular disease risks remain. Advancements in genetics and personalized medicine are essential to understand some of the factors driving residual risk. Biological sex is among the most relevant factors affecting plasma lipid and lipoprotein profiles, playing a pivotal role in the development of cardiovascular disease. This minireview summarizes the most recent preclinical and clinical studies covering the effect of sex on plasma lipid and lipoprotein levels. We highlight the recent advances in the mechanisms regulating hepatic lipoprotein production and clearance as potential drivers of disease presentation. We focus on using sex as a biological variable in studying circulating lipid and lipoprotein levels.
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Affiliation(s)
| | | | - Gissette Reyes-Soffer
- Department of Medicine, Division of Preventive Medicine and Nutrition, Columbia University College of Physicians and Surgeons
| | - Jaume Amengual
- Department of Food Science and Human Nutrition and Division of Nutritional Sciences. University of Illinois Urbana Champaign
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Koschinsky ML, Stroes ESG, Kronenberg F. Daring to dream: Targeting lipoprotein(a) as a causal and risk-enhancing factor. Pharmacol Res 2023; 194:106843. [PMID: 37406784 DOI: 10.1016/j.phrs.2023.106843] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 06/15/2023] [Accepted: 06/27/2023] [Indexed: 07/07/2023]
Abstract
Lipoprotein(a) [Lp(a)], a distinct lipoprotein class, has become a major focus for cardiovascular research. This review is written in light of the recent guideline and consensus statements on Lp(a) and focuses on 1) the causal association between Lp(a) and cardiovascular outcomes, 2) the potential mechanisms by which elevated Lp(a) contributes to cardiovascular diseases, 3) the metabolic insights on the production and clearance of Lp(a) and 4) the current and future therapeutic approaches to lower Lp(a) concentrations. The concentrations of Lp(a) are under strict genetic control. There exists a continuous relationship between the Lp(a) concentrations and risk for various endpoints of atherosclerotic cardiovascular disease (ASCVD). One in five people in the Caucasian population is considered to have increased Lp(a) concentrations; the prevalence of elevated Lp(a) is even higher in black populations. This makes Lp(a) a cardiovascular risk factor of major public health relevance. Besides the association between Lp(a) and myocardial infarction, the relationship with aortic valve stenosis has become a major focus of research during the last decade. Genetic studies provided strong support for a causal association between Lp(a) and cardiovascular outcomes: carriers of genetic variants associated with lifelong increased Lp(a) concentration are significantly more frequent in patients with ASCVD. This has triggered the development of drugs that can specifically lower Lp(a) concentrations: mRNA-targeting therapies such as anti-sense oligonucleotide (ASO) therapies and short interfering RNA (siRNA) therapies have opened new avenues to lower Lp(a) concentrations more than 95%. Ongoing Phase II and III clinical trials of these compounds are discussed in this review.
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Affiliation(s)
- Marlys L Koschinsky
- Robarts Research Institute, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada; Department of Physiology & Pharmacology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Erik S G Stroes
- Department of Vascular Medicine, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Florian Kronenberg
- Institute of Genetic Epidemiology, Medical University of Innsbruck, Innsbruck, Austria.
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Genovesi S, Giussani M, Lieti G, Orlando A, Patti I, Parati G. Evidence and Uncertainties on Lipoprotein(a) as a Marker of Cardiovascular Health Risk in Children and Adolescents. Biomedicines 2023; 11:1661. [PMID: 37371756 PMCID: PMC10295837 DOI: 10.3390/biomedicines11061661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 06/05/2023] [Accepted: 06/06/2023] [Indexed: 06/29/2023] Open
Abstract
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.
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Affiliation(s)
- Simonetta Genovesi
- School of Medicine and Surgery, Milano-Bicocca University, 20126 Milan, Italy; (G.L.); (I.P.); (G.P.)
- Istituto Auxologico Italiano, Istituto Ricovero Cura Carattere Scientifico (IRCCS), 20135 Milan, Italy; (M.G.); (A.O.)
| | - Marco Giussani
- Istituto Auxologico Italiano, Istituto Ricovero Cura Carattere Scientifico (IRCCS), 20135 Milan, Italy; (M.G.); (A.O.)
| | - Giulia Lieti
- School of Medicine and Surgery, Milano-Bicocca University, 20126 Milan, Italy; (G.L.); (I.P.); (G.P.)
| | - Antonina Orlando
- Istituto Auxologico Italiano, Istituto Ricovero Cura Carattere Scientifico (IRCCS), 20135 Milan, Italy; (M.G.); (A.O.)
| | - Ilenia Patti
- School of Medicine and Surgery, Milano-Bicocca University, 20126 Milan, Italy; (G.L.); (I.P.); (G.P.)
| | - Gianfranco Parati
- School of Medicine and Surgery, Milano-Bicocca University, 20126 Milan, Italy; (G.L.); (I.P.); (G.P.)
- Istituto Auxologico Italiano, Istituto Ricovero Cura Carattere Scientifico (IRCCS), 20135 Milan, Italy; (M.G.); (A.O.)
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Barbagelata L, Masson W, Corral P, Lavalle-Cobo A, Nogueira JP, Rosa Diez G. Relationship between lipoprotein(a) levels, cardiovascular outcomes and death in patients with chronic kidney disease: a systematic review of prospective studies. J Nephrol 2023:10.1007/s40620-023-01590-3. [PMID: 37029883 DOI: 10.1007/s40620-023-01590-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 01/29/2023] [Indexed: 04/09/2023]
Abstract
INTRODUCTION AND AIM In the general population, high levels of lipoprotein(a) (Lp(a)) are an independent risk factor for atherosclerotic cardiovascular diseases. However, the information available in patients with chronic kidney disease (CKD) is less robust. The main objective of this updated systematic review of prospective studies was to analyze the association between elevated Lp(a) levels and cardiovascular outcomes or death in patients with CKD. METHODS The PRISMA guidelines were used to carry out this systematic review. Randomized clinical trials or prospective observational studies that evaluated the association between Lp(a) levels and cardiovascular outcomes or death in CKD patients were searched in the current literature. RESULTS Fifteen studies including 12,260 individuals were identified and considered eligible for this systematic review. In total, 14 prospective cohorts and one post-hoc analysis of a randomized clinical trial were analyzed. Eight studies evaluated hemodialysis patients, one study analyzed patients on peritoneal dialysis, while six studies evaluated subjects with different stages of CKD. Median follow-up duration ranged from 1 to 8.6 years. Our findings showed that elevated Lp(a) values were associated with a higher risk of cardiovascular events or death in most studies, despite adjusting for traditional risk factors. CONCLUSION The findings of this systematic review show that there is a positive association between Lp(a) levels and fatal and non-fatal cardiovascular events in patients with CKD.
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Affiliation(s)
- Leandro Barbagelata
- Cardiology Department, Hospital Italiano de Buenos Aires, Perón 4190, C1199ABB, Buenos Aires, Argentina.
| | - Walter Masson
- Cardiology Department, Hospital Italiano de Buenos Aires, Perón 4190, C1199ABB, Buenos Aires, Argentina
| | - Pablo Corral
- Facultad de Medicina, Universidad FASTA, Mar del Plata, Argentina
| | | | - Juan Patricio Nogueira
- Centro de Investigación en Endocrinología, Nutrición y Metabolismo (CIENM), Facultad de Ciencias de la Salud, Universidad Nacional de Formosa, Formosa, Argentina
| | - Guillermo Rosa Diez
- Nephrology Department, Hospital Italiano de Buenos Aires, Buenos Aires, Argentina
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Matveyenko A, Matienzo N, Ginsberg H, Nandakumar R, Seid H, Ramakrishnan R, Holleran S, Thomas T, Reyes-Soffer G. Relationship of apolipoprotein(a) isoform size with clearance and production of lipoprotein(a) in a diverse cohort. J Lipid Res 2023; 64:100336. [PMID: 36706955 PMCID: PMC10006688 DOI: 10.1016/j.jlr.2023.100336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 01/16/2023] [Accepted: 01/22/2023] [Indexed: 01/26/2023] Open
Abstract
Lipoprotein(a) [Lp(a)] has two main proteins, apoB100 and apo(a). High levels of Lp(a) confer an increased risk for atherosclerotic cardiovascular disease. Most people have two circulating isoforms of apo(a) differing in their molecular mass, determined by the number of Kringle IV Type 2 repeats. Previous studies report a strong inverse relationship between Lp(a) levels and apo(a) isoform sizes. The roles of Lp(a) production and fractional clearance and how ancestry affects this relationship remain incompletely defined. We therefore examined the relationships of apo(a) size with Lp(a) levels and both apo(a) fractional clearance rates (FCR) and production rates (PR) in 32 individuals not on lipid-lowering treatment. We determined plasma Lp(a) levels and apo(a) isoform sizes, and used the relative expression of the two isoforms to calculate a "weighted isoform size" (wIS). Stable isotope studies were performed, using D3-leucine, to determine the apo(a) FCR and PR. As expected, plasma Lp(a) concentrations were inversely correlated with wIS (R2 = 0.27; P = 0.002). The wIS had a modest positive correlation with apo(a) FCR (R2 = 0.10, P = 0.08), and a negative correlation with apo(a) PR (R2 = 0.11; P = 0.06). The relationship between wIS and PR became significant when we controlled for self-reported race and ethnicity (SRRE) (R2 = 0.24, P = 0.03); controlling for SRRE did not affect the relationship between wIS and FCR. Apo(a) wIS plays a role in both FCR and PR; however, adjusting for SRRE strengthens the correlation between wIS and PR, suggesting an effect of ancestry.
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Affiliation(s)
- Anastasiya Matveyenko
- Department of Medicine, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Nelsa Matienzo
- Department of Medicine, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Henry Ginsberg
- Department of Medicine, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Renu Nandakumar
- Irving Institute for Clinical and Translational Research, Columbia University, New York, NY, USA
| | - Heather Seid
- Irving Institute for Clinical and Translational Research, Columbia University, New York, NY, USA
| | - Rajasekhar Ramakrishnan
- Center for Biomathematics, Department of Pediatrics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Steve Holleran
- Center for Biomathematics, Department of Pediatrics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Tiffany Thomas
- Department of Pathology and Cell Biology, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Gissette Reyes-Soffer
- Department of Medicine, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA.
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