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Zhang X, Stiekema LCA, Stroes ESG, Groen AK. Metabolic effects of PCSK9 inhibition with Evolocumab in subjects with elevated Lp(a). Lipids Health Dis 2020; 19:91. [PMID: 32393252 PMCID: PMC7216641 DOI: 10.1186/s12944-020-01280-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 05/06/2020] [Indexed: 11/16/2022] Open
Abstract
Background Epidemiological studies substantiated that subjects with elevated lipoprotein(a) [Lp(a)] have a markedly increased cardiovascular risk. Inhibition of proprotein convertase subtilisin/kexin type 9 (PCSK9) lowers both LDL cholesterol (LDL-C) as well as Lp(a), albeit modestly. Effects of PCSK9 inhibition on circulating metabolites such as lipoprotein subclasses, amino acids and fatty acids remain to be characterized. Methods We performed nuclear magnetic resonance (NMR) metabolomics on plasma samples derived from 30 individuals with elevated Lp(a) (> 150 mg/dL). The 30 participants were randomly assigned into two groups, placebo (N = 14) and evolocumab (N = 16). We assessed the effect of 16 weeks of evolocumab 420 mg Q4W treatment on circulating metabolites by running lognormal regression analyses, and compared this to placebo. Subsequently, we assessed the interrelationship between Lp(a) and 14 lipoprotein subclasses in response to treatment with evolocumab, by running multilevel multivariate regression analyses. Results On average, evolocumab treatment for 16 weeks resulted in a 17% (95% credible interval: 8 to 26%, P < 0.001) reduction of circulating Lp(a), coupled with substantial reduction of VLDL, IDL and LDL particles as well as their lipid contents. Interestingly, increasing concentrations of baseline Lp(a) were associated with larger reduction in triglyceride-rich VLDL particles after evolocumab treatment. Conclusions Inhibition of PCSK9 with evolocumab markedly reduced VLDL particle concentrations in addition to lowering LDL-C. The extent of reduction in VLDL particles depended on the baseline level of Lp(a). Our findings suggest a marked effect of evolocumab on VLDL metabolism in subjects with elevated Lp(a). Trial registration Clinical trial registration information is registered at ClinicalTrials.gov on April 14, 2016 with the registration number NCT02729025.
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Affiliation(s)
- Xiang Zhang
- Department of Experimental Vascular Medicine, Amsterdam University Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands. .,Human and Animal Physiology, Wageningen University, De Elst 1, 6708 WD, Wageningen, The Netherlands.
| | - Lotte C A Stiekema
- Department of Vascular Medicine, Amsterdam University Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - Erik S G Stroes
- Department of Vascular Medicine, Amsterdam University Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - Albert K Groen
- Department of Experimental Vascular Medicine, Amsterdam University Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
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Quispe R, Hendrani AD, Baradaran-Noveiry B, Martin SS, Brown E, Kulkarni KR, Banach M, Toth PP, Brinton EA, Jones SR, Joshi PH. Characterization of lipoprotein profiles in patients with hypertriglyceridemic Fredrickson-Levy and Lees dyslipidemia phenotypes: the Very Large Database of Lipids Studies 6 and 7. Arch Med Sci 2019; 15:1195-1202. [PMID: 31572464 PMCID: PMC6764300 DOI: 10.5114/aoms.2019.87207] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Accepted: 02/13/2019] [Indexed: 12/25/2022] Open
Abstract
INTRODUCTION The association between triglycerides (TG) and cardiovascular diseases is complex. The classification of hypertriglyceridemic (HTG) phenotypes proposed by Fredrickson, Levy and Lees (FLL) helps inform treatment strategies. We aimed to describe levels of several lipoprotein variables from individuals with HTG FLL phenotypes from the Very Large Database of Lipids. MATERIAL AND METHODS We included fasting samples from 979,539 individuals from a contemporary large study population of US adults. Lipids were directly measured by density-gradient ultracentrifugation using the Vertical Auto Profile test while TG levels were measured in whole plasma using the Abbott ARCHITECT C-8000 system. Hyperchylomicronemic (Hyper-CM) and non-chylomicronemic (non-CM) phenotypes were defined using computationally derived models. Individuals with FLL type IIa phenotype were excluded. Distributions of lipid variables were compared using medians and Kruskal-Wallis test. RESULTS A total of 11.9% (n = 116,925) of individuals met criteria for HTG FLL phenotypes. Those with hyper-CM phenotypes (n = 5, < 0.1% of population) had two-fold higher TG levels compared with non-chylomicronemic (non-CM) individuals (11.9% of population) (p < 0.001). Type IIb individuals had the highest non-HDL-C levels (median 242 mg/dl). Cholesterol in large VLDL1+2 particles was higher than in small VLDL3 particles in all phenotypes except FLL type III. Hyper-CM phenotypes had significantly lower HDL-C levels but greater HDL2/HDL3-C ratio compared to non-CM phenotypes. Cholesterol content of the lipoprotein (a) peak was significantly higher in the hyper-CM groups compared to non-CM phenotypes (p < 0.0001). CONCLUSIONS This observational hypothesis-generating study provides insight into the complexity of lipid metabolism in HTG phenotypes, including less traditional lipid measures such as LDL density, HDL subclasses and Lp(a)-C.
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Affiliation(s)
- Renato Quispe
- Johns Hopkins Ciccarone Center for the Prevention of Heart Disease, Baltimore, MD, USA
- Department of Medicine, Albert Einstein College of Medicine, Jacobi Medical Center, Bronx, NY, USA
| | - Aditya D. Hendrani
- Johns Hopkins Ciccarone Center for the Prevention of Heart Disease, Baltimore, MD, USA
- Louisiana State University Health Science Center-Shreveport, LA, USA
| | | | - Seth S. Martin
- Johns Hopkins Ciccarone Center for the Prevention of Heart Disease, Baltimore, MD, USA
- Welch Center for Prevention, Epidemiology, and Clinical Research, Baltimore, MD, USA
| | - Emily Brown
- Center for Inherited Heart Disease, Johns Hopkins Hospital, Baltimore, MD, USA
| | | | - Maciej Banach
- Department of Hypertension, Medical University of Lodz, Lodz, Poland
| | - Peter P. Toth
- Johns Hopkins Ciccarone Center for the Prevention of Heart Disease, Baltimore, MD, USA
- Department of Preventive Cardiology, CGH Medical Center, Sterling, IL, USA
- Department of Family and Community Medicine, University of Illinois College of Medicine, Peoria, IL, USA
| | | | - Steven R. Jones
- Johns Hopkins Ciccarone Center for the Prevention of Heart Disease, Baltimore, MD, USA
| | - Parag H. Joshi
- Johns Hopkins Ciccarone Center for the Prevention of Heart Disease, Baltimore, MD, USA
- Department of Internal Medicine, Division of Cardiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
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Kostner KM, Kostner GM, Wierzbicki AS. Is Lp(a) ready for prime time use in the clinic? A pros-and-cons debate. Atherosclerosis 2018; 274:16-22. [PMID: 29747086 DOI: 10.1016/j.atherosclerosis.2018.04.032] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 04/16/2018] [Accepted: 04/25/2018] [Indexed: 12/11/2022]
Abstract
Lipoprotein (a) (Lp(a)) is a cholesterol-rich lipoprotein known since 1963. In spite of extensive research on Lp(a), there are still numerous gaps in our knowledge relating to its function, biosynthesis and catabolism. One reason for this might be that apo(a), the characteristic glycoprotein of Lp(a), is expressed only in primates. Results from experiments using transgenic animals therefore may need verification in humans. Studies on Lp(a) are also handicapped by the great number of isoforms of apo(a) and the heterogeneity of apo(a)-containing fractions in plasma. Quantification of Lp(a) in the clinical laboratory for a long time has not been standardized. Starting from its discovery, reports accumulated that Lp(a) contributed to the risk of cardiovascular disease (CVD), myocardial infarction (MI) and stroke. Early reports were based on case control studies but in the last decades a great deal of prospective studies have been published that highlight the increased risk for CVD and MI in patients with elevated Lp(a). Final answers to the question of whether Lp(a) is ready for wider clinical use will come from intervention studies with novel selective Lp(a) lowering medications that are currently underway. This article expounds arguments for and against this proposition from currently available data.
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Affiliation(s)
- Karam M Kostner
- Department of Cardiology, Mater Hospital and University of Queensland, Brisbane, Australia
| | - Gert M Kostner
- Department of Molecular Biology and Biochemistry, Gottfried Schatz Research Center for Cell Signaling, Medical University of Graz, Austria
| | - Anthony S Wierzbicki
- Department of Metabolic Medicine/Chemical Pathology, Guy's & St Thomas' Hospitals, London, UK.
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Reyes-Soffer G, Ginsberg HN, Ramakrishnan R. The metabolism of lipoprotein (a): an ever-evolving story. J Lipid Res 2017; 58:1756-1764. [PMID: 28720561 DOI: 10.1194/jlr.r077693] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 07/18/2017] [Indexed: 02/06/2023] Open
Abstract
Lipoprotein (a) [Lp(a)] is characterized by apolipoprotein (a) [apo(a)] covalently bound to apolipoprotein B 100. It was described in human plasma by Berg et al. in 1963 and the gene encoding apo(a) (LPA) was cloned in 1987 by Lawn and colleagues. Epidemiologic and genetic studies demonstrate that increases in Lp(a) plasma levels increase the risk of atherosclerotic cardiovascular disease. Novel Lp(a) lowering treatments highlight the need to understand the regulation of plasma levels of this atherogenic lipoprotein. Despite years of research, significant uncertainty remains about the assembly, secretion, and clearance of Lp(a). Specifically, there is ongoing controversy about where apo(a) and apoB-100 bind to form Lp(a); which apoB-100 lipoproteins bind to apo(a) to create Lp(a); whether binding of apo(a) is reversible, allowing apo(a) to bind to more than one apoB-100 lipoprotein during its lifespan in the circulation; and how Lp(a) or apo(a) leave the circulation. In this review, we highlight past and recent data from stable isotope studies of Lp(a) metabolism, highlighting the critical metabolic uncertainties that exist. We present kinetic models to describe results of published studies using stable isotopes and suggest what future studies are required to improve our understanding of Lp(a) metabolism.
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Affiliation(s)
- Gissette Reyes-Soffer
- Departments of Medicine Columbia University College of Physicians and Surgeons, New York, NY 10032
| | - Henry N Ginsberg
- Departments of Medicine Columbia University College of Physicians and Surgeons, New York, NY 10032
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Konerman M, Kulkarni K, Toth PP, Jones SR. Lipoprotein(a) particle concentration and lipoprotein(a) cholesterol assays yield discordant classification of patients into four physiologically discrete groups. J Clin Lipidol 2012; 6:368-73. [DOI: 10.1016/j.jacl.2012.01.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Revised: 12/09/2011] [Accepted: 01/18/2012] [Indexed: 11/25/2022]
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Konerman M, Kulkarni K, Toth PP, Jones SR. Evidence of dependence of lipoprotein(a) on triglyceride and high-density lipoprotein metabolism. J Clin Lipidol 2012; 6:27-32. [DOI: 10.1016/j.jacl.2011.08.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Revised: 07/22/2011] [Accepted: 08/26/2011] [Indexed: 10/17/2022]
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Tholstrup T, Samman S. Postprandial lipoprotein(a) is affected differently by specific individual dietary fatty acids in healthy young men. J Nutr 2004; 134:2550-5. [PMID: 15465746 DOI: 10.1093/jn/134.10.2550] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Lipoprotein(a) [Lp(a)] is considered a risk factor for coronary heart disease. Our aim was to investigate the effect of individual fatty acids on postprandial plasma Lp(a) and its association with lipemia and tissue plasminogen activator (t-PA). Five test fats dominated by (approximately 43% g/kg) stearic (S), palmitic (P), oleic, C18:1 trans (T), or linoleic acid were produced by interesterification. Sixteen young healthy men were served the individual test fats incorporated into meals (1g fat/kg body wt) after a 12-h fast in random order on different days, separated by 3-wk washout periods. Blood samples were drawn before and 2, 4, 6, and 8 h after eating. There was a pronounced increase in Lp(a) concentrations after intake of the test meals, and the test fats resulted in a difference in Lp(a) response (P < 0.001; diet x time interaction). However, T fat did not change Lp(a) during the time course studied. T fat resulted in less area under the plasma Lp(a) concentration curve compared to S and P fat (P </= 0.003). Test fat with saturated fatty acids resulted in the highest Lp(a) and lowest plasma triacylglycerol (TAG) response, with the reversed situation for T fat. There was no association between Lp(a) and t-PA. In conclusion, intake of meals high in individual dietary fatty acids increased postprandial plasma Lp(a) differently. There seems to be a complex regulatory role of plasma TAG on nonfasting plasma Lp(a) concentrations.
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Affiliation(s)
- Tine Tholstrup
- Research Department of Human Nutrition and Center for Advanced Food Studies, The Royal Veterinary and Agricultural University, Frederiksberg, Denmark.
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Ikewaki K, Cain W, Thomas F, Shamburek R, Zech LA, Usher D, Brewer HB, Rader DJ. Abnormal in vivo metabolism of apoB-containing lipoproteins in human apoE deficiency. J Lipid Res 2004; 45:1302-11. [PMID: 15102883 DOI: 10.1194/jlr.m400020-jlr200] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The present study was undertaken to elucidate the metabolic basis for the increased remnants and lipoprotein(a) [Lp(a)] and decreased LDL apolipoprotein B (apoB) levels in human apoE deficiency. A primed constant infusion of (13)C(6)-phenylalanine was administered to a homozygous apoE-deficient subject. apoB-100 and apoB-48 were isolated, and tracer enrichments were determined by gas chromatography-mass spectrometry, then kinetic parameters were calculated by multicompartmental modeling. In the apoE-deficient subject, fractional catabolic rates (FCRs) of apoB-100 in VLDL and intermediate density lipoprotein and apoB-48 in VLDL were 3x, 12x, and 12x slower than those of controls. On the other hand, the LDL apoB-100 FCR was increased by 2.6x. The production rate of VLDL apoB-100 was decreased by 45%. In the Lp(a) kinetic study, two types of Lp(a) were isolated from plasma with apoE deficiency: buoyant and normal Lp(a). (125)I-buoyant Lp(a) was catabolized at a slower rate in the patient. However, (125)I-buoyant Lp(a) was catabolized at twice as fast as (131)I-normal Lp(a) in the control subjects. In summary, apoE deficiency results in: 1) a markedly impaired catabolism of VLDL/chylomicron and their remnants due to lack of direct removal and impaired lipolysis; 2) an increased rate of catabolism of LDL apoB-100, likely due to upregulation of LDL receptor activity; 3) reduced VLDL apoB production; and 4) a delayed catabolism of a portion of Lp(a).
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Affiliation(s)
- Katsunori Ikewaki
- Molecular Disease Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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Hernández C, Chacón P, García-Pascual L, Simó R. Differential influence of LDL cholesterol and triglycerides on lipoprotein(a) concentrations in diabetic patients. Diabetes Care 2001; 24:350-5. [PMID: 11213891 DOI: 10.2337/diacare.24.2.350] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE To evaluate the relationship between plasma lipid profiles and lipoprotein(a) [Lp(a)] concentrations in diabetic patients, taking into account the Lp(a) phenotype. RESEARCH DESIGN AND METHODS We included 191 consecutive diabetic outpatients (69 type 1 and 122 type 2 diabetic patients) in a cross-sectional study Serum Lp(a) was determined by enzyme-linked immunosorbent assay, and Lp(a) phenotypes were assessed by SDS-PAGE followed by immunoblotting. The statistical methods included a stepwise multiple regression analysis using the Lp(a) serum concentration as the dependent variable. The lipid profile consisted of total cholesterol, HDL cholesterol, LDL cholesterol, corrected LDL cholesterol, triglycerides, and apolipoproteins AI and B. RESULTS In the multiple regression analysis, LDL cholesterol (positively) and triglycerides (negatively) were independently related to the Lp(a) concentration, and they explained the 6.6 and 7.8% of the Lp(a) variation, respectively. After correcting LDL cholesterol, the two variables explained 3.8 and 6.4% of the Lp(a) variation, respectively. In addition, we observed that serum Lp(a) concentrations were significantly lower in patients with type IV hyperlipidemia (mean 1.0 mg/dl [range 0.5-17], n = 16) than in normolipidemic patients (6.5 mg/dl [0.5-33.5], n = 117) and in type II hyperlipidemic patients (IIa 15.5 mg/dl [3.5-75], n = 13; IIb 9 mg/dl [1-80], n = 45); P < 0.001 by analysis of variance. CONCLUSIONS Lp(a) concentrations were directly correlated with LDL cholesterol and negatively correlated with triglyceride levels in diabetic patients. Therefore, our results suggest that the treatment of diabetic dyslipemia may indirectly affect Lp(a) concentrations.
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Affiliation(s)
- C Hernández
- Diabetes Unit, Hospital General Vall d'Hebron, Barcelona, Spain
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van der Mooren MJ, Mijatovic V, van Baal WM, Stehouwer CD. Hormone replacement therapy in postmenopausal women with specific risk factors for coronary artery disease. Maturitas 1998; 30:27-36. [PMID: 9819780 DOI: 10.1016/s0378-5122(98)00056-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Hormone replacement therapy (HRT) in postmenopausal women is associated with a reduction in the risk of developing coronary artery disease (CAD) of about 50%. Women with an elevated risk for CAD appear to benefit most by HRT. The HRT-associated cardiovascular protection may be related to favourable changes in several important cardiovascular risk estimators, such as circulating blood concentrations of cholesterol, lipoprotein(a) (Lp(a)) and homocysteine. This paper reviews the literature presently available on the effects of HRT on cholesterol, Lp(a) and homocysteine concentrations, and special attention will be given to the effects on their elevated concentrations. The effect of HRT in women with hypertension is reviewed as well. From this overview it can be concluded that risk factors such as cholesterol, Lp(a), and homocysteine can be favourably modulated by HRT, and especially, that the strongest reductions can be achieved in those women with the highest concentrations. Although clinical trials still need to demonstrate the impact of lowering concentrations of Lp(a) and homocysteine, HRT appears to be a promising risk reduction strategy in this respect.
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Affiliation(s)
- M J van der Mooren
- Department of Obstetrics and Gynaecology, University Hospital-Vrije Universiteit, Amsterdam, The Netherlands.
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Marcoux C, Lussier-Cacan S, Davignon J, Cohn JS. Association of Lp(a) rather than integrally-bound apo(a) with triglyceride-rich lipoproteins of human subjects. BIOCHIMICA ET BIOPHYSICA ACTA 1997; 1346:261-74. [PMID: 9219911 DOI: 10.1016/s0005-2760(97)00049-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The majority of apolipoprotein (a) [apo(a)] in plasma is characteristically associated with Lipoprotein (a) [Lp(a)], having a buoyant density (1.05-1.08 g/ml) intermediate between low density lipoproteins (LDL) and high density lipoproteins (HDL). In the fed (postprandial) state or in the presence of fasting (endogenous) hypertriglyceridemia, a small proportion of plasma apo(a) is found in the density < 1.006 g/ml fraction of plasma, associated with larger and less dense triglyceride-rich lipoproteins (TRL). In order to further characterize the presence of apo(a) in ultracentrifugally-separated TRL (UTC-TRL), this lipoprotein fraction was isolated from plasma obtained in the fed state (three hours after an oral fat load) from healthy normolipidemic subjects (Lp(a): 38 +/- 8 mg/dl (mean +/- S.E.), n = 4) and also from plasma obtained after an overnight fast from hypertriglyceridemic patients (plasma TG: 8.16 +/- 2.00 mmol/l, Lp(a): 41 +/- 3 mg/dl, n = 18). Apo(a) in 3 h-postprandial UTC-TRL (5 +/- 2% of total plasma apo(a)) and in hypertriglyceridemic UTC-TRL (8 +/- 2% total apo(a)) was separable by electrophoresis and/or gel chromatography (FPLC) from the majority of UTC-TRL lipid. Apo(a) in UTC-TRL fractions had slow pre-beta electrophoretic mobility and was isolated in a lipoprotein size-range smaller than VLDL and larger than LDL, consistent with it being Lp(a). Recentrifugation of UTC-TRL resulted in the majority of apo(a) being recovered in the density > 1.006 g/ml fraction. Addition of proline to plasma samples before ultracentrifugation (final concentration: 0.1 M) substantially reduced the amount of Lp(a) in UTC-TRL. TRL separated from plasma by FPLC contained less apo(a) (2-5% of total plasma apo(a)), but this apo(a) was also readily dissociable from TRL lipid, had slow pre-beta electrophoretic mobility, and was associated with a lipoprotein with the size of Lp(a). Our data suggest that apo(a) in the TRL fraction of subjects with postprandial triglyceridemia or endogenous hypertriglyceridemia is not an integral component of plasma VLDL or chylomicrons, but represents the presence of non-covalently bound Lp(a).
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Affiliation(s)
- C Marcoux
- Hyperlipidemia and Atherosclerosis Research Group, Clinical Research Institute of Montreal, Quebec, Canada
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Jones PH, Pownall HJ, Patsch W, Herd JA, Farmer JA, Payton-Ross C, Kimball KT, Gotto AM, Morrisett JD. Effect of gemfibrozil on levels of lipoprotein[a] in type II hyperlipoproteinemic subjects. J Lipid Res 1996. [DOI: 10.1016/s0022-2275(20)39159-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Jungner I, Mendis S, Bjellerup P. Lipoprotein(a): levels in a Swedish population in relation to other lipid parameters and in comparison with a male Sri Lankan population. Clin Biochem 1995; 28:427-34. [PMID: 8521598 DOI: 10.1016/0009-9120(95)00009-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
OBJECTIVE To evaluate differences in Lipoprotein (a) [Lp(a)] concentrations between a Swedish and Sri Lankan population. METHODS The distribution of Lp(a) and its relation to other lipid parameters, measured with an automated turbidimetric method, in 4646 Swedes (1944 females and 2702 males) undergoing health screening and 757 randomly selected Sri Lankan males (667 non-CHD and 80 CHD subjects) was evaluated. RESULTS The distribution was highly skewed towards low values in both the Swedish population and the Sri Lankan male population. The Swedish population had a median of 0.16 g/L (reported as total mass) whereas the Sri Lankan population median of 0.06 g/L was much lower. For the Swedes, there was a small significant difference of 0.03 g/L between the sexes (F < M; p < 0.001) and Lp(a) was significantly higher in subjects > 50 years of age in both sexes (p < 0.002(F); p < 0.02(M)). 29% had Lp(a) values > 0.30 g/L. In the Sri Lankan males population Lp(a) was also significantly higher in subjects > 50 years of age (p < 0.009) but only 7% had an Lp(a) concentration of > 0.30 g/L. In the CHD subgroup, though not significant, subjects > 50 years of age had a lower Lp(a) concentration, indicating that Lp(a) may be a more significant risk factor in younger subjects. Both the Swedish female and male hypercholesterolemic subgroups had significantly higher Lp(a) concentrations than normolipemic subgroups and the male hypertriglyceridemic subgroups significantly lower Lp(a) concentrations than normolipemic. Great differences in Lp(a) levels are thus found between the two populations. The differences are similar in normolipemic subjects and probably they reflect mainly genetic differences. Lipid/lipoprotein concentrations were also found to differ. It is being investigated if this reflects differences in CHD prevalence. CONCLUSION Our data support the importance of including Lp(a) measurements when assessing the risk profile for premature development of CHD in the individual patient.
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Affiliation(s)
- I Jungner
- CALAB Medical Laboratories, Stockholm, Sweden
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Trieu VN, Olsson U, McConathy WJ. The apolipoprotein B3304-3317 peptide as an inhibitor of the lipoprotein (a):apolipoprotein B-containing lipoprotein interaction. Biochem J 1995; 307 ( Pt 1):17-22. [PMID: 7717972 PMCID: PMC1136739 DOI: 10.1042/bj3070017] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Lipoprotein (a) [Lp(a)] is a risk factor for coronary artery disease. It is characterized by apolipoprotein (a) [apo(a)] disulphide linked to apolipoprotein B (apoB), by Cys4057 of apo(a) and possibly Cys3734 of apoB. We call this the covalent apo(a):apoB-Lp interaction, to distinguish it from the non-covalent Lp(a):apoB-Lp interaction, mediated by the proline-binding kringle-4-like domain(s) of Lp(a). The Lp(a):apoB-Lp interaction was inhibited by an apoB peptide spanning residues 3304-3317. This peptide was found by a computerized search for sites on apoB similar to the plasminogen's kringle-4-binding site of alpha 2-antiplasmin. It probably constitutes part of the Lp(a)-binding site on apoB because: (1) it corresponds to the alpha 2-antiplasmin minimum binding domain for plasminogen's kringle-4; (2) the competitive nature of inhibition [KI = (1.5 +/- 0.7) x 10(-4) M, n = 5] suggested that it and apoB-Lp bound to Lp(a) by the same mechanism at the same site; and (3) it specifically bound Lp(a) and not apoB-Lp, and the bound Lp(a) was dissociated by inhibitors of the Lp(a):apoB-Lp interaction, 6-aminohexanoic acid and L-proline. Inhibition was independent of its proline residue, suggesting that proline in the context of a peptide is not a ligand for the kringle(s) which mediated the binding of Lp(a) to apoB-Lp.
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Affiliation(s)
- V N Trieu
- Department of Medicine, University of North Texas Health Science Center at Fort Worth 76107, USA
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