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Vinci P, Di Girolamo FG, Panizon E, Tosoni LM, Cerrato C, Pellicori F, Altamura N, Pirulli A, Zaccari M, Biasinutto C, Roni C, Fiotti N, Schincariol P, Mangogna A, Biolo G. Lipoprotein(a) as a Risk Factor for Cardiovascular Diseases: Pathophysiology and Treatment Perspectives. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:6721. [PMID: 37754581 PMCID: PMC10531345 DOI: 10.3390/ijerph20186721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 07/31/2023] [Accepted: 08/09/2023] [Indexed: 09/28/2023]
Abstract
Cardiovascular disease (CVD) is still a leading cause of morbidity and mortality, despite all the progress achieved as regards to both prevention and treatment. Having high levels of lipoprotein(a) [Lp(a)] is a risk factor for cardiovascular disease that operates independently. It can increase the risk of developing cardiovascular disease even when LDL cholesterol (LDL-C) levels are within the recommended range, which is referred to as residual cardiovascular risk. Lp(a) is an LDL-like particle present in human plasma, in which a large plasminogen-like glycoprotein, apolipoprotein(a) [Apo(a)], is covalently bound to Apo B100 via one disulfide bridge. Apo(a) contains one plasminogen-like kringle V structure, a variable number of plasminogen-like kringle IV structures (types 1-10), and one inactive protease region. There is a large inter-individual variation of plasma concentrations of Lp(a), mainly ascribable to genetic variants in the Lp(a) gene: in the general po-pulation, Lp(a) levels can range from <1 mg/dL to >1000 mg/dL. Concentrations also vary between different ethnicities. Lp(a) has been established as one of the risk factors that play an important role in the development of atherosclerotic plaque. Indeed, high concentrations of Lp(a) have been related to a greater risk of ischemic CVD, aortic valve stenosis, and heart failure. The threshold value has been set at 50 mg/dL, but the risk may increase already at levels above 30 mg/dL. Although there is a well-established and strong link between high Lp(a) levels and coronary as well as cerebrovascular disease, the evidence regarding incident peripheral arterial disease and carotid atherosclerosis is not as conclusive. Because lifestyle changes and standard lipid-lowering treatments, such as statins, niacin, and cholesteryl ester transfer protein inhibitors, are not highly effective in reducing Lp(a) levels, there is increased interest in developing new drugs that can address this issue. PCSK9 inhibitors seem to be capable of reducing Lp(a) levels by 25-30%. Mipomersen decreases Lp(a) levels by 25-40%, but its use is burdened with important side effects. At the current time, the most effective and tolerated treatment for patients with a high Lp(a) plasma level is apheresis, while antisense oligonucleotides, small interfering RNAs, and microRNAs, which reduce Lp(a) levels by targeting RNA molecules and regulating gene expression as well as protein production levels, are the most widely explored and promising perspectives. The aim of this review is to provide an update on the current state of the art with regard to Lp(a) pathophysiological mechanisms, focusing on the most effective strategies for lowering Lp(a), including new emerging alternative therapies. The purpose of this manuscript is to improve the management of hyperlipoproteinemia(a) in order to achieve better control of the residual cardiovascular risk, which remains unacceptably high.
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Affiliation(s)
- Pierandrea Vinci
- Clinica Medica, Cattinara Hospital, Department of Medical Surgical and Health Science, University of Trieste, 34149 Trieste, Italy; (F.G.D.G.); (E.P.); (L.M.T.); (C.C.); (F.P.); (N.A.); (A.P.); (M.Z.); (N.F.); (G.B.)
| | - Filippo Giorgio Di Girolamo
- Clinica Medica, Cattinara Hospital, Department of Medical Surgical and Health Science, University of Trieste, 34149 Trieste, Italy; (F.G.D.G.); (E.P.); (L.M.T.); (C.C.); (F.P.); (N.A.); (A.P.); (M.Z.); (N.F.); (G.B.)
- SC Assistenza Farmaceutica, Cattinara Hospital, Azienda Sanitaria Universitaria Integrata di Trieste, 34149 Trieste, Italy; (C.B.); (C.R.); (P.S.)
| | - Emiliano Panizon
- Clinica Medica, Cattinara Hospital, Department of Medical Surgical and Health Science, University of Trieste, 34149 Trieste, Italy; (F.G.D.G.); (E.P.); (L.M.T.); (C.C.); (F.P.); (N.A.); (A.P.); (M.Z.); (N.F.); (G.B.)
| | - Letizia Maria Tosoni
- Clinica Medica, Cattinara Hospital, Department of Medical Surgical and Health Science, University of Trieste, 34149 Trieste, Italy; (F.G.D.G.); (E.P.); (L.M.T.); (C.C.); (F.P.); (N.A.); (A.P.); (M.Z.); (N.F.); (G.B.)
| | - Carla Cerrato
- Clinica Medica, Cattinara Hospital, Department of Medical Surgical and Health Science, University of Trieste, 34149 Trieste, Italy; (F.G.D.G.); (E.P.); (L.M.T.); (C.C.); (F.P.); (N.A.); (A.P.); (M.Z.); (N.F.); (G.B.)
| | - Federica Pellicori
- Clinica Medica, Cattinara Hospital, Department of Medical Surgical and Health Science, University of Trieste, 34149 Trieste, Italy; (F.G.D.G.); (E.P.); (L.M.T.); (C.C.); (F.P.); (N.A.); (A.P.); (M.Z.); (N.F.); (G.B.)
| | - Nicola Altamura
- Clinica Medica, Cattinara Hospital, Department of Medical Surgical and Health Science, University of Trieste, 34149 Trieste, Italy; (F.G.D.G.); (E.P.); (L.M.T.); (C.C.); (F.P.); (N.A.); (A.P.); (M.Z.); (N.F.); (G.B.)
| | - Alessia Pirulli
- Clinica Medica, Cattinara Hospital, Department of Medical Surgical and Health Science, University of Trieste, 34149 Trieste, Italy; (F.G.D.G.); (E.P.); (L.M.T.); (C.C.); (F.P.); (N.A.); (A.P.); (M.Z.); (N.F.); (G.B.)
| | - Michele Zaccari
- Clinica Medica, Cattinara Hospital, Department of Medical Surgical and Health Science, University of Trieste, 34149 Trieste, Italy; (F.G.D.G.); (E.P.); (L.M.T.); (C.C.); (F.P.); (N.A.); (A.P.); (M.Z.); (N.F.); (G.B.)
| | - Chiara Biasinutto
- SC Assistenza Farmaceutica, Cattinara Hospital, Azienda Sanitaria Universitaria Integrata di Trieste, 34149 Trieste, Italy; (C.B.); (C.R.); (P.S.)
| | - Chiara Roni
- SC Assistenza Farmaceutica, Cattinara Hospital, Azienda Sanitaria Universitaria Integrata di Trieste, 34149 Trieste, Italy; (C.B.); (C.R.); (P.S.)
| | - Nicola Fiotti
- Clinica Medica, Cattinara Hospital, Department of Medical Surgical and Health Science, University of Trieste, 34149 Trieste, Italy; (F.G.D.G.); (E.P.); (L.M.T.); (C.C.); (F.P.); (N.A.); (A.P.); (M.Z.); (N.F.); (G.B.)
| | - Paolo Schincariol
- SC Assistenza Farmaceutica, Cattinara Hospital, Azienda Sanitaria Universitaria Integrata di Trieste, 34149 Trieste, Italy; (C.B.); (C.R.); (P.S.)
| | - Alessandro Mangogna
- Institute for Maternal and Child Health, I.R.C.C.S “Burlo Garofolo”, 34137 Trieste, Italy;
| | - Gianni Biolo
- Clinica Medica, Cattinara Hospital, Department of Medical Surgical and Health Science, University of Trieste, 34149 Trieste, Italy; (F.G.D.G.); (E.P.); (L.M.T.); (C.C.); (F.P.); (N.A.); (A.P.); (M.Z.); (N.F.); (G.B.)
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Nordestgaard BG, Langsted A. Lipoprotein (a) as a cause of cardiovascular disease: insights from epidemiology, genetics, and biology. J Lipid Res 2016; 57:1953-1975. [PMID: 27677946 DOI: 10.1194/jlr.r071233] [Citation(s) in RCA: 322] [Impact Index Per Article: 40.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Indexed: 12/24/2022] Open
Abstract
Human epidemiologic and genetic evidence using the Mendelian randomization approach in large-scale studies now strongly supports that elevated lipoprotein (a) [Lp(a)] is a causal risk factor for cardiovascular disease, that is, for myocardial infarction, atherosclerotic stenosis, and aortic valve stenosis. The Mendelian randomization approach used to infer causality is generally not affected by confounding and reverse causation, the major problems of observational epidemiology. This approach is particularly valuable to study causality of Lp(a), as single genetic variants exist that explain 27-28% of all variation in plasma Lp(a). The most important genetic variant likely is the kringle IV type 2 (KIV-2) copy number variant, as the apo(a) product of this variant influences fibrinolysis and thereby thrombosis, as opposed to the Lp(a) particle per se. We speculate that the physiological role of KIV-2 in Lp(a) could be through wound healing during childbirth, infections, and injury, a role that, in addition, could lead to more blood clots promoting stenosis of arteries and the aortic valve, and myocardial infarction. Randomized placebo-controlled trials of Lp(a) reduction in individuals with very high concentrations to reduce cardiovascular disease are awaited. Recent genetic evidence documents elevated Lp(a) as a cause of myocardial infarction, atherosclerotic stenosis, and aortic valve stenosis.
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Affiliation(s)
- Børge G Nordestgaard
- Department of Clinical Biochemistry and Copenhagen General Population Study, Herlev and Gentofte Hospital, Copenhagen University Hospital, Herlev, Denmark; and Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Anne Langsted
- Department of Clinical Biochemistry and Copenhagen General Population Study, Herlev and Gentofte Hospital, Copenhagen University Hospital, Herlev, Denmark; and Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Perera R, McFadden E, McLellan J, Lung T, Clarke P, Pérez T, Fanshawe T, Dalton A, Farmer A, Glasziou P, Takahashi O, Stevens J, Irwig L, Hirst J, Stevens S, Leslie A, Ohde S, Deshpande G, Urayama K, Shine B, Stevens R. Optimal strategies for monitoring lipid levels in patients at risk or with cardiovascular disease: a systematic review with statistical and cost-effectiveness modelling. Health Technol Assess 2016; 19:1-401, vii-viii. [PMID: 26680162 DOI: 10.3310/hta191000] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Various lipid measurements in monitoring/screening programmes can be used, alone or in cardiovascular risk scores, to guide treatment for prevention of cardiovascular disease (CVD). Because some changes in lipids are due to variability rather than true change, the value of lipid-monitoring strategies needs evaluation. OBJECTIVE To determine clinical value and cost-effectiveness of different monitoring intervals and different lipid measures for primary and secondary prevention of CVD. DATA SOURCES We searched databases and clinical trials registers from 2007 (including the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, the Clinical Trials Register, the Current Controlled Trials register, and the Cumulative Index to Nursing and Allied Health Literature) to update and extend previous systematic reviews. Patient-level data from the Clinical Practice Research Datalink and St Luke's Hospital, Japan, were used in statistical modelling. Utilities and health-care costs were drawn from the literature. METHODS In two meta-analyses, we used prospective studies to examine associations of lipids with CVD and mortality, and randomised controlled trials to estimate lipid-lowering effects of atorvastatin doses. Patient-level data were used to estimate progression and variability of lipid measurements over time, and hence to model lipid-monitoring strategies. Results are expressed as rates of true-/false-positive and true-/false-negative tests for high lipid or high CVD risk. We estimated incremental costs per quality-adjusted life-year. RESULTS A total of 115 publications reported strength of association between different lipid measures and CVD events in 138 data sets. The summary adjusted hazard ratio per standard deviation of total cholesterol (TC) to high-density lipoprotein (HDL) cholesterol ratio was 1.25 (95% confidence interval 1.15 to 1.35) for CVD in a primary prevention population but heterogeneity was high (I(2) = 98%); similar results were observed for non-HDL cholesterol, apolipoprotein B and other ratio measures. Associations were smaller for other single lipid measures. Across 10 trials, low-dose atorvastatin (10 and 20 mg) effects ranged from a TC reduction of 0.92 mmol/l to 2.07 mmol/l, and low-density lipoprotein reduction of between 0.88 mmol/l and 1.86 mmol/l. Effects of 40 mg and 80 mg were reported by one trial each. For primary prevention, over a 3-year period, we estimate annual monitoring would unnecessarily treat 9 per 1000 more men (28 vs. 19 per 1000) and 5 per 1000 more women (17 vs. 12 per 1000) than monitoring every 3 years. However, annual monitoring would also undertreat 9 per 1000 fewer men (7 vs. 16 per 1000) and 4 per 1000 fewer women (7 vs. 11 per 1000) than monitoring at 3-year intervals. For secondary prevention, over a 3-year period, annual monitoring would increase unnecessary treatment changes by 66 per 1000 men and 31 per 1000 women, and decrease undertreatment by 29 per 1000 men and 28 per 1000 men, compared with monitoring every 3 years. In cost-effectiveness, strategies with increased screening/monitoring dominate. Exploratory analyses found that any unknown harms of statins would need utility decrements as large as 0.08 (men) to 0.11 (women) per statin user to reverse this finding in primary prevention. LIMITATION Heterogeneity in meta-analyses. CONCLUSIONS While acknowledging known and potential unknown harms of statins, we find that more frequent monitoring strategies are cost-effective compared with others. Regular lipid monitoring in those with and without CVD is likely to be beneficial to patients and to the health service. Future research should include trials of the benefits and harms of atorvastatin 40 and 80 mg, large-scale surveillance of statin safety, and investigation of the effect of monitoring on medication adherence. STUDY REGISTRATION This study is registered as PROSPERO CRD42013003727. FUNDING The National Institute for Health Research Health Technology Assessment programme.
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Affiliation(s)
- Rafael Perera
- National Institute for Health Research School for Primary Care Research, Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
| | - Emily McFadden
- National Institute for Health Research School for Primary Care Research, Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
| | - Julie McLellan
- National Institute for Health Research School for Primary Care Research, Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
| | - Tom Lung
- Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Australia
| | - Philip Clarke
- Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Australia
| | - Teresa Pérez
- National Institute for Health Research School for Primary Care Research, Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
| | - Thomas Fanshawe
- National Institute for Health Research School for Primary Care Research, Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
| | - Andrew Dalton
- National Institute for Health Research School for Primary Care Research, Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
| | - Andrew Farmer
- National Institute for Health Research School for Primary Care Research, Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
| | | | - Osamu Takahashi
- St Luke's International University Center for Clinical Epidemiology, Tokyo, Japan
| | | | - Les Irwig
- Sydney School of Public Health, University of Sydney, Sydney, Australia
| | - Jennifer Hirst
- National Institute for Health Research School for Primary Care Research, Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
| | - Sarah Stevens
- National Institute for Health Research School for Primary Care Research, Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
| | - Asuka Leslie
- St Luke's International University Center for Clinical Epidemiology, Tokyo, Japan
| | - Sachiko Ohde
- St Luke's International University Center for Clinical Epidemiology, Tokyo, Japan
| | - Gautam Deshpande
- St Luke's International University Center for Clinical Epidemiology, Tokyo, Japan
| | - Kevin Urayama
- St Luke's International University Center for Clinical Epidemiology, Tokyo, Japan
| | - Brian Shine
- Oxford University Hospitals Trust, Oxford, UK
| | - Richard Stevens
- National Institute for Health Research School for Primary Care Research, Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
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Abstract
The clinical relevance of lipoprotein(a) (Lp(a)) as a cardiovascular risk factor is currently underestimated. The aim of our study was to assess the influence of increased Lp(a) values on the development and severity of coronary artery disease (CAD).In our retrospective analysis of 31,274 patients, who were hospitalized for the first time, we compared patients with isolated increased Lp(a) (> 110 mg/dl) and normal Lp(a) (< 30 mg/dl), with increased Lp(a) concentrations (30-60 mg/dl, 61-90 mg/dl, 91-110 mg/dl), and in a third analysis with additionally increased LDL cholesterol and HbA1c values.Patients with high Lp(a) levels showed a significantly higher incidence of advanced CAD with a three-vessel disease being present in 50.2 vs. 25.1 %. Patients with high Lp(a) levels had a significantly more frequent history of myocardial infarction (34.6 vs. 16.6 %, p < 0.001), surgical myocardial revascularization (40.8 vs. 20.8 %, p < 0.001) and percutaneous coronary intervention (55.3 vs. 33.6 %, p < 0.001). In addition, there was a marked difference in gender to the disadvantage of male patients regarding development and severity of CAD. CAD risk (Odds ratio) was increased 5.5-fold in patients with Lp(a) ≥ 110 mg/dl. Additionally elevated LDL and HbA1c levels were not associated with increased manifestation and severity of CAD.High Lp(a) concentration leads to an increased manifestation and severity of coronary artery disease. Additional risk factors do not aggravate manifestation of CAD.
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Poly-(R)-3-hydroxybutyrates (PHB) are Atherogenic Components of Lipoprotein Lp(a). Med Hypotheses 2015; 85:1041-3. [DOI: 10.1016/j.mehy.2015.07.027] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 07/24/2015] [Accepted: 07/29/2015] [Indexed: 11/25/2022]
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Lipoprotein(a) in cardiovascular diseases. BIOMED RESEARCH INTERNATIONAL 2012; 2013:650989. [PMID: 23484137 PMCID: PMC3591100 DOI: 10.1155/2013/650989] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Revised: 11/06/2012] [Accepted: 11/08/2012] [Indexed: 11/18/2022]
Abstract
Lipoprotein(a) (Lp(a)) is an LDL-like molecule consisting of an apolipoprotein B-100 (apo(B-100)) particle attached by a disulphide bridge to apo(a). Many observations have pointed out that Lp(a) levels may be a risk factor for cardiovascular diseases. Lp(a) inhibits the activation of transforming growth factor (TGF) and contributes to the growth of arterial atherosclerotic lesions by promoting the proliferation of vascular smooth muscle cells and the migration of smooth muscle cells to endothelial cells. Moreover Lp(a) inhibits plasminogen binding to the surfaces of endothelial cells and decreases the activity of fibrin-dependent tissue-type plasminogen activator. Lp(a) may act as a proinflammatory mediator that augments the lesion formation in atherosclerotic plaques. Elevated serum Lp(a) is an independent predictor of coronary artery disease and myocardial infarction. Furthermore, Lp(a) levels should be a marker of restenosis after percutaneous transluminal coronary angioplasty, saphenous vein bypass graft atherosclerosis, and accelerated coronary atherosclerosis of cardiac transplantation. Finally, the possibility that Lp(a) may be a risk factor for ischemic stroke has been assessed in several studies. Recent findings suggest that Lp(a)-lowering therapy might be beneficial in patients with high Lp(a) levels. A future therapeutic approach could include apheresis in high-risk patients in order to reduce major coronary events.
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Lamon-Fava S, Marcovina SM, Albers JJ, Kennedy H, DeLuca C, White CC, Cupples LA, McNamara JR, Seman LJ, Bongard V, Schaefer EJ. Lipoprotein(a) levels, apo(a) isoform size, and coronary heart disease risk in the Framingham Offspring Study. J Lipid Res 2011; 52:1181-1187. [PMID: 21478162 DOI: 10.1194/jlr.m012526] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The aim of this study was to assess the independent contributions of plasma levels of lipoprotein(a) (Lp(a)), Lp(a) cholesterol, and of apo(a) isoform size to prospective coronary heart disease (CHD) risk. Plasma Lp(a) and Lp(a) cholesterol levels, and apo(a) isoform size were measured at examination cycle 5 in subjects participating in the Framingham Offspring Study who were free of CHD. After a mean follow-up of 12.3 years, 98 men and 47 women developed new CHD events. In multivariate analysis, the hazard ratio of CHD was approximately two-fold greater in men in the upper tertile of plasma Lp(a) levels, relative to those in the bottom tertile (P < 0.002). The apo(a) isoform size contributed only modestly to the association between Lp(a) and CHD and was not an independent predictor of CHD. In multivariate analysis, Lp(a) cholesterol was not significantly associated with CHD risk in men. In women, no association between Lp(a) and CHD risk was observed. Elevated plasma Lp(a) levels are a significant and independent predictor of CHD risk in men. The assessment of apo(a) isoform size in this cohort does not add significant information about CHD risk. In addition, the cholesterol content in Lp(a) is not a significant predictor of CHD risk.
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Affiliation(s)
- Stefania Lamon-Fava
- Lipid Metabolism Laboratory, Jean Mayer United States Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, Boston, MA.
| | - Santica M Marcovina
- Northwest Lipid Metabolism and Diabetes Research Laboratories, University of Washington, Seattle, WA
| | - John J Albers
- Northwest Lipid Metabolism and Diabetes Research Laboratories, University of Washington, Seattle, WA
| | - Hal Kennedy
- Northwest Lipid Metabolism and Diabetes Research Laboratories, University of Washington, Seattle, WA
| | - Carl DeLuca
- Lipid Metabolism Laboratory, Jean Mayer United States Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, Boston, MA
| | | | | | - Judith R McNamara
- Lipid Metabolism Laboratory, Jean Mayer United States Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, Boston, MA
| | - Leo J Seman
- Lipid Metabolism Laboratory, Jean Mayer United States Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, Boston, MA
| | - Vanina Bongard
- Lipid Metabolism Laboratory, Jean Mayer United States Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, Boston, MA
| | - Ernst J Schaefer
- Lipid Metabolism Laboratory, Jean Mayer United States Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, Boston, MA
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Kamstrup PR, Tybjærg-Hansen A, Nordestgaard BG. Lipoprotein(a) and risk of myocardial infarction--genetic epidemiologic evidence of causality. Scandinavian Journal of Clinical and Laboratory Investigation 2011; 71:87-93. [PMID: 21231777 DOI: 10.3109/00365513.2010.550311] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Elevated levels of lipoprotein(a) are associated with an increased risk of myocardial infarction. Our study aimed to test whether genetic data are consistent with this association being causal. Accordingly, we developed a high-throughput realtime PCR assay to genotype for the lipoprotein(a) kringle IV type 2 (KIV-2) repeat polymorphism in the LPA gene in > 40,000 individuals. The LPA KIV-2 genotype associated with plasma levels of lipoprotein(a) (trend p < 0.001), and the LPA KIV-2 genotype associated with risk of myocardial infarction (trend p < 0.001 to 0.03) in a manner consistent with its effect on plasma levels of lipoprotein(a). The association of LPA KIV-2 genotypes raising plasma levels of lipoprotein(a) with increased risk of myocardial infarction strongly supports a causal association of lipoprotein(a) with risk of myocardial infarction.
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Affiliation(s)
- Pia R Kamstrup
- Department of Clinical Biochemistry, Herlev Hospital, Copenhagen University Hospital, Copenhagen, Denmark.
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9
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Apolipoprotein(a) Isoforms and the Risk of Vascular Disease. J Am Coll Cardiol 2010; 55:2160-7. [DOI: 10.1016/j.jacc.2009.10.080] [Citation(s) in RCA: 234] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2009] [Revised: 10/26/2009] [Accepted: 10/26/2009] [Indexed: 11/23/2022]
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Kamstrup PR. Lipoprotein(a) and ischemic heart disease--a causal association? A review. Atherosclerosis 2010; 211:15-23. [PMID: 20106478 DOI: 10.1016/j.atherosclerosis.2009.12.036] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2009] [Revised: 12/29/2009] [Accepted: 12/31/2009] [Indexed: 01/18/2023]
Abstract
The aim of this review is to summarize present evidence of a causal association of lipoprotein(a) with risk of ischemic heart disease (IHD). Evidence for causality includes reproducible associations of a proposed risk factor with risk of disease in epidemiological studies, evidence from in vitro and animal studies in support of pathophysiological effects of the risk factor, and preferably evidence from randomized clinical trials documenting reduced morbidity in response to interventions targeting the risk factor. Elevated and in particular extreme lipoprotein(a) levels have in prospective studies repeatedly been associated with increased risk of IHD, although results from early studies are inconsistent. Data from in vitro and animal studies implicate lipoprotein(a), consisting of a low density lipoprotein particle covalently bound to the plasminogen-like glycoprotein apolipoprotein(a), in both atherosclerosis and thrombosis, including accumulation of lipoprotein(a) in atherosclerotic plaques and attenuation of t-PA mediated plasminogen activation. No randomized clinical trial of the effect of lowering lipoprotein(a) levels on IHD prevention has ever been conducted. Lacking evidence from randomized clinical trials, genetic studies, such as Mendelian randomization studies, can also support claims of causality. Levels of lipoprotein(a) are primarily determined by variation in the LPA gene coding for the apolipoprotein(a) moiety of lipoprotein(a), and genetic epidemiologic studies have documented association of LPA copy number variants, influencing levels of lipoprotein(a), with risk of IHD. In conclusion, results from epidemiologic, in vitro, animal, and genetic epidemiologic studies support a causal association of lipoprotein(a) with risk of IHD, while results from randomized clinical trials are presently lacking.
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Affiliation(s)
- Pia R Kamstrup
- Department of Clinical Biochemistry, Herlev Hospital, Copenhagen University Hospital, Herlev Ringvej 75, DK-2730 Herlev, Denmark.
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Erqou S, Kaptoge S, Perry PL, Di Angelantonio E, Thompson A, White IR, Marcovina SM, Collins R, Thompson SG, Danesh J. Lipoprotein(a) concentration and the risk of coronary heart disease, stroke, and nonvascular mortality. JAMA 2009; 302:412-23. [PMID: 19622820 PMCID: PMC3272390 DOI: 10.1001/jama.2009.1063] [Citation(s) in RCA: 1124] [Impact Index Per Article: 74.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
CONTEXT Circulating concentration of lipoprotein(a) (Lp[a]), a large glycoprotein attached to a low-density lipoprotein-like particle, may be associated with risk of coronary heart disease (CHD) and stroke. OBJECTIVE To assess the relationship of Lp(a) concentration with risk of major vascular and nonvascular outcomes. STUDY SELECTION Long-term prospective studies that recorded Lp(a) concentration and subsequent major vascular morbidity and/or cause-specific mortality published between January 1970 and March 2009 were identified through electronic searches of MEDLINE and other databases, manual searches of reference lists, and discussion with collaborators. DATA EXTRACTION Individual records were provided for each of 126,634 participants in 36 prospective studies. During 1.3 million person-years of follow-up, 22,076 first-ever fatal or nonfatal vascular disease outcomes or nonvascular deaths were recorded, including 9336 CHD outcomes, 1903 ischemic strokes, 338 hemorrhagic strokes, 751 unclassified strokes, 1091 other vascular deaths, 8114 nonvascular deaths, and 242 deaths of unknown cause. Within-study regression analyses were adjusted for within-person variation and combined using meta-analysis. Analyses excluded participants with known preexisting CHD or stroke at baseline. DATA SYNTHESIS Lipoprotein(a) concentration was weakly correlated with several conventional vascular risk factors and it was highly consistent within individuals over several years. Associations of Lp(a) with CHD risk were broadly continuous in shape. In the 24 cohort studies, the rates of CHD in the top and bottom thirds of baseline Lp(a) distributions, respectively, were 5.6 (95% confidence interval [CI], 5.4-5.9) per 1000 person-years and 4.4 (95% CI, 4.2-4.6) per 1000 person-years. The risk ratio for CHD, adjusted for age and sex only, was 1.16 (95% CI, 1.11-1.22) per 3.5-fold higher usual Lp(a) concentration (ie, per 1 SD), and it was 1.13 (95% CI, 1.09-1.18) following further adjustment for lipids and other conventional risk factors. The corresponding adjusted risk ratios were 1.10 (95% CI, 1.02-1.18) for ischemic stroke, 1.01 (95% CI, 0.98-1.05) for the aggregate of nonvascular mortality, 1.00 (95% CI, 0.97-1.04) for cancer deaths, and 1.00 (95% CI, 0.95-1.06) for nonvascular deaths other than cancer. CONCLUSION Under a wide range of circumstances, there are continuous, independent, and modest associations of Lp(a) concentration with risk of CHD and stroke that appear exclusive to vascular outcomes.
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Dirisamer A, Widhalm H, Aldover-Macasaet E, Molzer S, Widhalm K. Elevated Lp(a) with a small apo(a) isoform in children: risk factor for the development of premature coronary artery disease. Acta Paediatr 2008; 97:1653-7. [PMID: 18684164 DOI: 10.1111/j.1651-2227.2008.00979.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND levels of Lp(a) and low-molecular-weight apolipoprotein(a) isoform are strongly associated with the development of early cardiovascular disease. Certain types of apo(a) isoforms in combination with elevated levels of Lp(a) may be important in the determining of premature coronary artery disease. Therefore, we investigated the association of familial history of premature coronary artery disease and apo(a) size and Lp(a) levels in children and adolescents with hypercholesterolemia using a novel method determining apo(a) isoforms. METHODS AND RESULTS Isoforms were classified in six phenotype patterns: S1-S4, B, F and according to their K-IV repeats. Apo(a) isoforms were divided into two groups: low-molecular- and high-molecular apo(a) isoforms. In subjects with double-banded apo(a) isoforms containing a small- and a large-isoform Lp(a) each contribution was based on the intensity of staining of the two bands. The percentage of patients with elevated levels of Lp(a) and a small apo(a) isoform (i.e. elevated small-isoform Lp(a)) was 46% in the risk group and 20% in the control group, p < 0.05. The percentage number of children and adolescents with elevated Lp(a) levels was higher in the risk group, reaching statistical significance (p < 0.05). CONCLUSION Elevated levels of small-isoform Lp(a) might be a strong and independent risk factor for the development of premature coronary artery disease in children and adolescents with hypercholesterolemia.
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Affiliation(s)
- Albert Dirisamer
- Department of Obesity and Lipid Disorder, University of Vienna, Austria
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13
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Association between lipoprotein(a) levels, apo(a) isoforms and family history of premature CAD in young Asian Indians. Clin Biochem 2008; 41:453-8. [DOI: 10.1016/j.clinbiochem.2008.01.016] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2007] [Revised: 01/11/2008] [Accepted: 01/15/2008] [Indexed: 01/17/2023]
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14
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Ebesunun M, Agbedana E, Taylor G, Oladapo O. Plasma lipoprotein (a), homocysteine, and other cardiovascular disease (CVD) risk factors in Nigerians with CVD. Appl Physiol Nutr Metab 2008; 33:282-9. [PMID: 18347683 DOI: 10.1139/h07-186] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Elevated plasma lipoprotein (a) (Lp(a)) and total homocysteine (tHcy) concentrations, as well as fat distributions, are associated with cardiovascular disease (CVD) risk. The purpose of this study was to evaluate plasma Lp(a), tHcy, percentage body fat, anthropometric indices, and blood pressure (BP) and their relationships with each other in well-defined, hospital-based, CVD patients in a Nigerian African community. One hundred seventy patients suffering from hypertensive heart disease, hypertension, ischaemic heart disease, and myocardial infraction with the mean age of 45.3 ± 1.3 years and 58 apparently healthy volunteers with the mean age of 44.8 ±1.2 years were selected. Anthropometric indices and BP were measured. Percentage body fat, body mass index, and waist-to-hip ratio (WHR) were calculated. Plasma Lp(a) and tHcy concentrations were determined. The results showed significant increases in BP, skinfold thickness (SFT) variables, and WHR in all of the CVD patients. Plasma Lp(a) was also significantly increased (p < 0.001), whereas the slight increase in the mean tHcy was not statistically significant. Positive significant correlations were found between systolic BP, triceps, SFT, and percentage body fat (p < 0.01), whereas significant correlations were found between some body composition variables, tHcy, and systolic BP (p < 0.05). Our findings provide supportive evidence for altered plasma Lp(a) concentration in addition to some other traditional CVD risk factors in Nigerians. The role of homocysteine is not well defined.
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Affiliation(s)
- M.O. Ebesunun
- Chemical Pathology, University College Hospital Ibadan, School of Medical Laboratory Science, Ibadan, Oyo 002 234, Nigeria
- Chemical Pathology, College of Medicine, University of Ibadan, Ibadan, Oyo 002 234, Nigeria
- Department of Medicine, College of Medicine, University of Ibadan, Ibadan, Oyo 002 234, Nigeria
| | - E.O. Agbedana
- Chemical Pathology, University College Hospital Ibadan, School of Medical Laboratory Science, Ibadan, Oyo 002 234, Nigeria
- Chemical Pathology, College of Medicine, University of Ibadan, Ibadan, Oyo 002 234, Nigeria
- Department of Medicine, College of Medicine, University of Ibadan, Ibadan, Oyo 002 234, Nigeria
| | - G.O.L. Taylor
- Chemical Pathology, University College Hospital Ibadan, School of Medical Laboratory Science, Ibadan, Oyo 002 234, Nigeria
- Chemical Pathology, College of Medicine, University of Ibadan, Ibadan, Oyo 002 234, Nigeria
- Department of Medicine, College of Medicine, University of Ibadan, Ibadan, Oyo 002 234, Nigeria
| | - O.O. Oladapo
- Chemical Pathology, University College Hospital Ibadan, School of Medical Laboratory Science, Ibadan, Oyo 002 234, Nigeria
- Chemical Pathology, College of Medicine, University of Ibadan, Ibadan, Oyo 002 234, Nigeria
- Department of Medicine, College of Medicine, University of Ibadan, Ibadan, Oyo 002 234, Nigeria
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15
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Enas EA, Chacko V, Senthilkumar A, Puthumana N, Mohan V. Elevated lipoprotein(a)--a genetic risk factor for premature vascular disease in people with and without standard risk factors: a review. Dis Mon 2006; 52:5-50. [PMID: 16549089 DOI: 10.1016/j.disamonth.2006.01.002] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Enas A Enas
- CADI Research Foundation, Lisle, Illinois, USA
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16
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Thompson A, Danesh J. Associations between apolipoprotein B, apolipoprotein AI, the apolipoprotein B/AI ratio and coronary heart disease: a literature-based meta-analysis of prospective studies. J Intern Med 2006; 259:481-92. [PMID: 16629854 DOI: 10.1111/j.1365-2796.2006.01644.x] [Citation(s) in RCA: 217] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVES To assess associations of circulating levels of apolipoprotein (apo) AI, apoB and the apoB/AI ratio (apoB/A) with risk of incident coronary heart disease (CHD). DESIGN Literature-based meta-analysis of prospective studies. DATA SOURCES Prospective studies in essentially general populations that reported on associations between apoAI, apoB or apoB/A and first incident CHD outcomes. Studies were identified by computer-based searches and by manual searches of the relevant literature. RESULTS Data from 23 relevant studies were identified. For apoAI, with 6333 CHD cases in 21 studies, comparison of individuals in the bottom third with those in the top third of baseline values yielded a combined relative risk of 1.62 (95% confidence interval: 1.43-1.83), i.e. an inverse association. For apoB, a combined analysis of 6320 CHD cases from 19 studies gave a relative risk of 1.99 (1.65-2.39) for a comparison of individuals in the top third versus those in the bottom third of baseline values. For apoB/A, with 3730 CHD cases from seven studies, a comparison of individuals in the top third versus the bottom third of baseline values gave a combined relative risk of 1.86 (1.55-2.22). These associations were somewhat stronger following correction for within-person variations in apolipoprotein levels. There was evidence of heterogeneity amongst the published studies, but it was only partly explained by available study-level characteristics. CONCLUSIONS The present quantitative review suggests the existence of moderately strong associations between baseline levels of each of apoAI, apoB, and apoB/A and risk of CHD. More detailed analysis, perhaps based on individual participant data from prospective studies, could help to overcome several limitations in the present review and to clarify any relevance of these apolipoproteins to disease prediction and aetiology.
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Affiliation(s)
- A Thompson
- Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK
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17
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Longenecker JC, Klag MJ, Marcovina SM, Liu YM, Jaar BG, Powe NR, Fink NE, Levey AS, Coresh J. High Lipoprotein(a) Levels and Small Apolipoprotein(a) Size Prospectively Predict Cardiovascular Events in Dialysis Patients. J Am Soc Nephrol 2005; 16:1794-802. [PMID: 15800123 DOI: 10.1681/asn.2004110922] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Lipoprotein(a) [Lp(a)] levels are increased in dialysis patients, suggesting that they may play a role in the elevated atherosclerotic cardiovascular disease (ASCVD) risk in this population. Few prospective studies of Lp(a) level, apolipoprotein(a) [apo(a)] size, and ASCVD have been performed in the dialysis population. An inception cohort of 833 incident dialysis patients were followed prospectively. Baseline Lp(a) was measured by apo(a) size-independent ELISA and apo(a) size by Western blot after SDS-agarose gel electrophoresis. A combined prospective nonfatal and fatal ASCVD end point included myocardial infarction, coronary revascularization, cerebrovascular accident, carotid endarterectomy, peripheral revascularization, gangrene, or limb amputation. Survival analyses were performed with adjustment for baseline demographics, comorbid conditions, ASCVD risk factors, albumin, lipids, and C-reactive protein. Median follow-up was 27.4 mo, with 297 ASCVD events, 130 non-ASCVD deaths, and seven losses to follow-up over 1649 person-years. In multivariate Cox regression models, both high Lp(a) concentration (>/=53 nmol/L) and low molecular weight (LMW) apo(a) isoforms (</=22 Kringle-IV repeats) predicted ASCVD events (relative hazard [RH] = 1.38, P = 0.02; RH = 1.58, P < 0.0005, respectively). In models that included both Lp(a) concentration and apo(a) size, only apo(a) size remained associated with ASCVD. Among those with both LMW apo(a) and Lp(a) level >123 nmol/L, the relative hazard (RH) of ASCVD was 1.73 (P < 0.0005), compared with high molecular weight apo(a) and Lp(a) level <123 nmol/L. No interactions by age, race, gender, diabetes, or ASCVD were present. Both LMW apo(a) size and high Lp(a) level predict ASCVD risk in dialysis patients, but the association of ASCVD with LMW isoforms is stronger than the association with high Lp(a) concentration.
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18
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Calmarza P, Cordero J, Santos V, Vella JC. Apolipoprotein(a) isoforms in infarcted men under 60 years old. Clin Biochem 2005; 37:911-8. [PMID: 15369723 DOI: 10.1016/j.clinbiochem.2003.06.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2003] [Accepted: 06/28/2003] [Indexed: 11/28/2022]
Abstract
OBJECTIVE The aim of this study was to compare the Lp(a) concentration and the frequency distribution of the apo(a) isoforms of a myocardial infarcted male group under 60 years old and a group of healthy subjects (controls). METHODS A total of 111 infarcted men and 99 men free from disease were enrolled in this study. Lp(a) concentrations were measured by a commercial available rate nephelometry method, and apolipoprotein(a) isoform analysis was performed by sodium dodecyl sulfate (SDS) polyacrilamide gel electrophoresis (PAGE) and immunoblotting. RESULTS Infarcted patients had higher Lp(a) concentrations (0.33 +/- 0.36 g/l) than noninfarcted subjects did (0.19 +/- 0.22 g/l), and these differences were significant (P = 0.001). Infarcted patients have also shown a greater proportion of elevated (> or = 0.30 g/l) Lp(a) concentrations 37.8% than controls 20.2% (P < 0.01). The distributions of apo(a) phenotypes for patients with myocardial infarction and controls were remarkably different (P < 0.001), and the proportions of smaller isoforms were significantly different by chi-square analysis (P < 0.01). CONCLUSIONS Infarcted patients under 60 years old display higher Lp(a) concentrations and a significantly higher proportion of low molecular weight apolipoprotein(a) isoforms than controls.
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Affiliation(s)
- Pilar Calmarza
- Hospital General Yagüe., Avda. del Cid no. 96, 09005 Burgos, Spain.
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19
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Kronenberg F. Epidemiology, pathophysiology and therapeutic implications of lipoprotein(a) in kidney disease. Expert Rev Cardiovasc Ther 2004; 2:729-43. [PMID: 15350174 DOI: 10.1586/14779072.2.5.729] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Chronic kidney disease is associated with a tremendously increased risk for cardiovascular disease. Traditional risk factors for cardiovascular disease, however, show a diminished predictive power in these patients compared with the general population. This review provides an overview of lipoprotein(a), which is considered a nontraditional risk factor. The characteristic genetic and nongenetic changes of lipoprotein(a) in kidney disease are discussed and set into the context of risk prediction. In particular, genetically determined apolipoprotein(a) polymorphism is a powerful risk predictor for cardiovascular disease and total mortality in these patients. Finally, the limited interventional strategies available to lower lipoprotein(a) are considered.
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Affiliation(s)
- Florian Kronenberg
- Department of Medical Biology and Human Genetics, Innsbruck Medical University, Schöpfstr. 41, A-6020 Innsbruck, Austria.
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20
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Rifai N, Ma J, Sacks FM, Ridker PM, Hernandez WJL, Stampfer MJ, Marcovina SM. Apolipoprotein(a) size and lipoprotein(a) concentration and future risk of angina pectoris with evidence of severe coronary atherosclerosis in men: The Physicians' Health Study. Clin Chem 2004; 50:1364-71. [PMID: 15155542 DOI: 10.1373/clinchem.2003.030031] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND The relationship of lipoprotein (a) [Lp(a)] concentrations with risk of coronary heart disease needs clarification, especially for threshold values for increased risk and for possible interactions with LDL-cholesterol concentrations and apolipoprotein (a) [apo(a)] size polymorphism. This study was designed to examine the ability of baseline Lp(a) concentration and apo(a) size to predict future severe angina pectoris in apparently healthy men. METHODS Baseline Lp(a) concentration and apo(a) size were determined in 195 men who subsequently developed angina and in 195 men who remained free of cardiovascular disease for 5 years. RESULTS Cases had higher median Lp(a) concentrations than did controls (30.6 vs 22.5 nmol/L; P = 0.02). Lp(a) concentration was predictive of angina [relative risk (RR) from lowest to highest quintiles: 1.0, 1.5, 1.0, 1.8, and 2.6; P for trend = 0.015]. The increased risk was approximately 4-fold (95% confidence interval, 1.4- to 11-fold) among men who had Lp(a) above the 95th percentile (>158 nmol/L). Men with Lp(a) concentrations in the highest quintile and LDL-cholesterol concentrations >1600 mg/L had a 12-fold increased risk (95% confidence interval, 1.5- to 43-fold). Small apo(a) size isoforms also significantly predicted risk of angina (RR for lowest quintile = 4.1; P for trend = 0.004). When the independent effect of Lp(a) concentration and apo(a) size was assessed by including them in the same multivariate model, only the association between apo(a) size and risk remained significant. CONCLUSIONS High Lp(a) predicts risk of angina, and the risk is substantially increased with high concomitant LDL-cholesterol. Small apo(a) size predicts angina with greater strength and independence than Lp(a) concentration.
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Affiliation(s)
- Nader Rifai
- Department of Laboratory Medicine, Children's Hospital and Harvard Medical School, Boston, MA 02115, USA.
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21
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Kronenberg F, Lingenhel A, Lhotta K, Rantner B, Kronenberg MF, König P, Thiery J, Koch M, von Eckardstein A, Dieplinger H. The apolipoprotein(a) size polymorphism is associated with nephrotic syndrome. Kidney Int 2004; 65:606-12. [PMID: 14717931 DOI: 10.1111/j.1523-1755.2004.00418.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND The atherogenic serum lipoprotein(a) [Lp(a)] is significantly elevated in patients with nephrotic syndrome. The underlying mechanism for this elevation is poorly understood. METHODS We investigated in 207 patients with nondiabetic nephrotic syndrome and 274 controls whether the apolipoprotein(a) [apo(a)] kringle-IV repeat polymorphism explains the elevated Lp(a) levels in these patients. RESULTS Patients showed a tremendous elevation of Lp(a) concentrations when compared to controls (mean 60.4 vs. 20.0 mg/dL and median 29.8 vs. 6.4 mg/dL, P < 0.0001). Primary and secondary causes contributed to this elevation. The primary causes became apparent by a markedly elevated number of low-molecular-weight apo(a) phenotypes which are usually associated with high Lp(a) levels. This frequency was 35.7% in patients compared to only 24.8% in controls (P= 0.009). In addition, secondary causes by the pathogenetic mechanisms of the nephrotic syndrome itself resulted in a different increase of Lp(a) in the various apo(a) isoform groups. Based on the measured Lp(a) concentrations in each subject, we calculated separately the Lp(a) concentrations arising from the two expressed isoforms by estimating the relative proportion of the two serum isoforms in the sodium dodecyl sulfate (SDS) agarose gel electrophoresis. Low-molecular-weight isoforms were associated with 40% to 75% elevated Lp(a) concentrations when compared to matched isoforms from controls. High-molecular-weight apo(a) isoforms showed 100% to 500% elevated Lp(a) levels compared to matched isoforms from controls. The severity of the nephrotic syndrome as well as the degree of renal impairment did not influence the Lp(a) concentrations. CONCLUSION The tremendously increased Lp(a) levels in nephrotic syndrome ar caused by primary genetic as well as disease-related mechanisms.
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Affiliation(s)
- Florian Kronenberg
- Institute of Medical Biology and Human Genetics, University of Innsbruck, Innsbruck,
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22
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Averina M, Nilssen O, Brenn T, Brox J, Arkhipovsky VL, Kalinin AG. Factors behind the Increase in Cardiovascular Mortality in Russia: Apolipoprotein AI and B Distribution in the Arkhangelsk Study 2000. Clin Chem 2004; 50:346-54. [PMID: 14684620 DOI: 10.1373/clinchem.2003.023853] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
AbstractBackground: Cardiovascular mortality is markedly higher in Russia than in Western Europe and the US. Little is known about indicators of atherosclerotic risk in the Russian population. To our knowledge, this is the first study of apolipoprotein (apo) AI and B in Russia based on the WHO-IFCC standard.Methods: We measured apo AI and B by immunoturbidimetric assay in 3694 men and women from Arkhangelsk, Russia, in 1999–2000.Results: The age-related distribution of apo B was similar to that in other countries, whereas the apo AI profile was different. For men ≥20 years, apo AI was considerably higher than in studies from other countries. Women had also relatively high apo AI concentrations, although the difference was not as pronounced as in men. The apo AI concentration was positively associated with age and lifestyle variables such as alcohol consumption and physical activity, and negatively associated with body mass index and self-reported myocardial infarction. γ-Glutamyltransferase was positively associated with apo AI in both sexes.Conclusions: The apparently favorable apolipoprotein profiles contrast with official death statistics indicating high cardiovascular mortality in Russia. High apo AI might indicate excessive alcohol consumption.
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Affiliation(s)
- Maria Averina
- Institute of Community Medicine, Medical Faculty, University of Tromsø, N-9037 Tromsø, Norway.
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Abstract
BACKGROUND As compared with what is known about predictors of vascular events in middle-aged persons, less is known about these events in the elderly. Lp(a) lipoprotein, which plays an important part in atherothrombogenesis, has been associated with an increased risk of vascular disease. We investigated this relation among older U.S. adults. METHODS In a prospective study of 5888 community-dwelling older adults (65 years of age or older) in the United States, 2375 women and 1597 men who were free of vascular disease provided base-line serum samples for analysis for levels of Lp(a) lipoprotein. These 3972 subjects were followed for a median of 7.4 years to evaluate the development of stroke and to track deaths from vascular causes and all causes. The men and women were divided into quintile groups according to the Lp(a) lipoprotein level at base line. RESULTS Using Cox proportional-hazards models, we determined the risk associated with each quintile level of Lp(a) lipoprotein, with the lowest quintile serving as the reference group. As compared with those in the lowest quintile, men in the highest quintile had three times the unadjusted risk of stroke (relative risk, 3.00; 95 percent confidence interval, 1.59 to 5.65), almost three times the risk of death associated with vascular events (relative risk, 2.54; 95 percent confidence interval, 1.59 to 4.08), and nearly twice the risk of death from all causes (relative risk, 1.76; 95 percent confidence interval, 1.31 to 2.36). Adjustment for age; sex; the levels of total cholesterol, low-density lipoprotein cholesterol, and triglycerides; carotid-wall thickness; smoking status; the presence or absence of diabetes and systolic and diastolic hypertension; body-mass index; and other traditional risk factors had little effect on the final assessments. Similar analyses for women, which also included adjustment for estrogen use or nonuse, revealed no such relation. CONCLUSIONS Among older adults in the United States, an elevated level of Lp(a) lipoprotein is an independent predictor of stroke, death from vascular disease, and death from any cause in men but not in women. These data support the use of Lp(a) lipoprotein levels in predicting the risk of these events in older men.
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Affiliation(s)
- Abraham A Ariyo
- Center for Cardiovascular Disease Prevention and Intervention, HeartMasters, Dallas, TX 75212, USA.
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Geethanjali FS, Luthra K, Lingenhel A, Kanagasaba-Pathy AS, Jacob J, Srivastava LM, Vasisht S, Kraft HG, Utermann G. Analysis of the apo(a) size polymorphism in Asian Indian populations: association with Lp(a) concentration and coronary heart disease. Atherosclerosis 2003; 169:121-30. [PMID: 12860258 DOI: 10.1016/s0021-9150(03)00143-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Most studies aiming to detect associations of genetic variation with common complex diseases, e.g. coronary heart disease (CHD) have been performed in populations with a western lifestyle but it is unclear whether associations detected in one geographic group exist also in others. We here have determined lipoprotein(a) levels and apo(a) K-IV-2 repeat genotypes in CHD patients (N=254) and controls (N=480) from two Asian Indian populations (Tamil Nadu and New Delhi). In both populations and also in the pooled dataset median Lp(a) levels were significantly elevated in the patients (27.4 mg/dl) compared with the controls (17.6 mg/dl). Apo(a) K-IV-2 allele frequencies were not different between the CHD patients and controls and thus did not explain the increased Lp(a) levels in CHD patients. Contrary to what has recently been observed in Black and White men short (K-IV<or=22) alleles associated with high Lp(a) concentration were not overrepresented in the patients. Rather, short (K-IV<or=22), intermediate (K-IV 23-29) and long (K-IV>or=30) apo(a) alleles were all associated with higher Lp(a) levels in the patients. Accordingly relative risk (estimated as odds ratio) for CHD rose continuously with increasing Lp(a) but was independent of apo(a) allele length. Together with previous studies our results indicate that the relation between apo(a) genotypes, Lp(a) levels, and CHD may be heterogeneous across ethnic groups and that it depends on the genetic architecture of the Lp(a) trait in a given population whether an association of K-IV-2 repeat length with CHD exists or not.
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Affiliation(s)
- F S Geethanjali
- Institute of Medical Biology and Human Genetics, University of Innsbruck, 6020 Innsbruck, Austria
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Longenecker JC, Coresh J, Marcovina SM, Powe NR, Levey AS, Giaculli F, Fink NE, Klag MJ. Lipoprotein(a) and prevalent cardiovascular disease in a dialysis population: The Choices for Healthy Outcomes in Caring for ESRD (CHOICE) study. Am J Kidney Dis 2003; 42:108-16. [PMID: 12830462 DOI: 10.1016/s0272-6386(03)00413-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
BACKGROUND Levels of lipoprotein(a) [Lp(a)], an atherogenic lipoprotein, are elevated in patients with end-stage renal disease and inversely related to the size of apolipoprotein(a) [apo(a)], a glycoprotein bound to Lp(a). We studied the association of Lp(a) level and apo(a) size with prevalent atherosclerotic cardiovascular disease (ASCVD) in 871 incident dialysis patients (261 blacks, 565 whites, 45 other). METHODS Lp(a) was measured by an apo(a) size-independent enzyme-linked immunoassay; and apo(a) size was measured by sodium dodecyl sulfate-agarose gel electrophoresis. Prevalent ASCVD, derived from medical records, was defined as coronary heart disease or cerebral or peripheral vascular disease. Adjustment variables included age, sex, race, dialysis modality, diabetes, serum creatinine level, albumin level, and low-density lipoprotein cholesterol level. RESULTS ASCVD prevalence was 58%. Median Lp(a) levels for those with compared with those without ASCVD were 38 versus 35 nmol/L for whites (P = 0.49) and 100 versus 74 nmol/L for blacks, respectively (P = 0.35). Lp(a) level was associated with ASCVD among those younger than 60 years (odds ratio [OR] for +1 interquartile range of Lp(a), 1.5; P = 0.02), but not among those 60 years and older (OR, 1.0; P = 0.82; P(interaction) by age, 0.08). ORs were 1.3 for all whites (P = 0.03) and 1.1 for all blacks (P = 0.87; P(interaction)by race = 0.53). ORs of ASCVD were 1.7 for whites younger than 60 years (P = 0.01) and 1.2 for blacks younger than 60 years (P = 0.77; P(interaction) by race = 0.42). No association between apo(a) isoform size and ASCVD was present. CONCLUSION In an incident dialysis cohort, Lp(a) level was associated with prevalent ASCVD among whites younger than 60 years, but not among blacks or those older than 60 years. Apo(a) isoform size was not associated with prevalent ASCVD. These data suggest that baseline ASCVD is unlikely to strongly confound the potential associations of Lp(a) level and prospectively ascertained ASCVD among incident dialysis patients.
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Gazzaruso C, Garzaniti A, Falcone C, Puija A, Geroldi D, Giordanetti S, Fratino P. Lipoprotein(a), apolipoprotein(a) polymorphism and restenosis after intracoronary stent placement in Type 2 diabetic patients. J Diabetes Complications 2003; 17:135-40. [PMID: 12738397 DOI: 10.1016/s1056-8727(02)00192-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The relationship between lipoprotein(a) [Lp(a)] and restenosis after intracoronary stent implantation has never been analysed in diabetic patients. The aim of the present prospective study was to evaluate whether Lp(a) levels and apolipoprotein(a) [apo(a)] phenotypes are predictors of restenosis after elective stent implantation in Type 2 diabetic patients with de novo lesions of coronary arteries. We recruited 102 Type 2 diabetic patients with a new lesion successfully treated with elective placement of one or two Palmaz-Schatz stents. Follow-up angiography was scheduled at 6 months or earlier if clinically indicated. Seven patients were lost to the follow up. Among 95 patients enrolled, restenosis was present in 37 (38.9%) and absent in 58 (61.1%). The restenosis group showed Lp(a) levels higher than the nonrestenosis group (25.1+/-14.4 vs. 21.3+/-14.6 mg/dl), but the difference was not significant. The restenosis group had a percentage of subjects with at least one apo(a) isoform of low molecular weight (MW) significantly greater than the nonrestenosis group (75.7% vs. 55.1%; P<.05). A multiple logistic regression analysis showed that presence of multivessel disease (risk relative [RR]: 5.83; 95% confidence interval [CI]: 1.21-28.15; P<.05) was the only predictor of restenosis after stent placement in diabetic patients. Lp(a) and apo(a) polymorphisms did not enter the model as predictive variables. Our study shows that the presence of multivessel disease is a predictor of restenosis after intracoronary stent implantation in diabetic patients. On the contrary, Lp(a) and apo(a) polymorphisms do not appear to be reliable markers of restenosis in patients with Type 2 diabetes mellitus.
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Affiliation(s)
- Carmine Gazzaruso
- Diabetes Center, Internal Medicine Unit, Department of Internal Medicine and Medical Therapeutics, IRCCS Maugeri Foundation Hospital, University of Pavia, Via Ferrata 8, 27100 Pavia, Italy.
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Alaoui M, Merle C, Garnotel R, Jolly D, Durlach V, Gillery P. Study of apo(a) length polymorphism and lipoprotein(a) concentrations in subjects with single or double apo(a) isoforms. Clin Chem Lab Med 2003; 41:634-9. [PMID: 12812260 DOI: 10.1515/cclm.2003.096] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Cardiovascular risk is associated with high lipoprotein(a) (Lp(a)) concentrations and low molecular weight apolipoprotein(a) (apo(a)) isoforms. We studied the relationship between these two biological parameters, particularly in subjects expressing two apo(a) isoforms. Plasma Lp(a) was measured by immunonephelometry in 530 unrelated Caucasian patients at high cardiovascular risk, and apo(a) size determined by immunoblotting using a recombinant standard. Two, one, or no apo(a) isoforms were detected in 258, 270, and 2 subjects, respectively. Lp(a) concentrations showed a non-Gaussian distribution, being higher in the 'double band' than in the 'single band' group (median 0.42 vs. 0.11 g/l, p < 0.0005). Apo(a) size distribution was bimodal, with two frequency peaks at 18 kringles (K) and 27 K. Small size apo(a) isoforms were more frequently found in the 'double band' group, where major isoforms were of lower size than minor isoforms (median 20 vs. 27 K). Regression analysis showed that apo(a) gene length accounted for 33% of Lp(a) variation, with a threshold effect at 20 K, no correlation being found over this value. The minor apo(a) isoform did not significantly influence Lp(a) concentration. These data confirm the relationship between apo(a) size and Lp(a) concentration and suggest that the assessment of cardiovascular risk should take into account the threshold effect at 20 K and the absence of influence of the minor apo(a) isoform.
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Affiliation(s)
- Mariam Alaoui
- Laboratory of Biochemistry, Robert Debré Hospital, CHU of Reims, Reims, France
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Abstract
Lipoprotein(a) is a cholesterol-enriched lipoprotein, consisting of a covalent linkage joining the unique and highly polymorphic apolipoprotein(a) to apolipoprotein B100, the main protein moiety of low-density lipoproteins. Although the concentration of lipoprotein(a) in humans is mostly genetically determined, acquired disorders might influence synthesis and catabolism of the particle. Raised concentration of lipoprotein(a) has been acknowledged as a leading inherited risk factor for both premature and advanced atherosclerosis at different vascular sites. The strong structural homologies with plasminogen and low-density lipoproteins suggest that lipoprotein(a) might represent the ideal bridge between the fields of atherosclerosis and thrombosis in the pathogenesis of vascular occlusive disorders. Unfortunately, the exact mechanisms by which lipoprotein(a) promotes, accelerates, and complicates atherosclerosis are only partially understood. In some clinical settings, such as in patients at exceptionally low risk for cardiovascular disease, the potential regenerative and antineoplastic properties of lipoprotein(a) might paradoxically counterbalance its athero-thrombogenicity, as attested by the compatibility between raised plasma lipoprotein(a) levels and longevity.
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Affiliation(s)
- Giuseppe Lippi
- Istituto di Chimica e Microscopia Clinica, Dipartimento di Scienze Morfologiche e Biomediche, Università degli Studi di Verona, Verona, Italy
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Gazzaruso C, Garzaniti A, Falcone C, Geroldi D, Turpini C, Fratino P. Restenosis after intracoronary stent placement: can apolipoprotein(a) polymorphism play a role? Int J Cardiol 2003; 87:91-8. [PMID: 12468059 DOI: 10.1016/s0167-5273(02)00202-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND The relationship between lipoprotein(a) and restenosis after intracoronary stent implantation has been analysed by two specific studies, but the role of apoliprotein(a) polymorphism was not considered. The aim of the present prospective study was to evaluate whether lipoprotein(a) levels and apolipoprotein(a) phenotypes are predictors of restenosis after elective stent implantation in patients with de novo lesions of coronary arteries. METHODS We recruited 182 patients with a new lesion successfully treated with elective placement of one or two Palmaz-Schatz stents. Follow-up angiography was scheduled at 6 months or earlier if clinically indicated. Nine patients were lost to the follow up. Among 173 patients enrolled, restenosis was present in 52 (30.0%) and absent in 121 (70.0%). RESULTS Lipoprotein(a) levels were higher in the restenosis than in the nonrestenosis group (29.5+/-17.2 versus 27.4+/-20.2 mg/dl), even if the difference did not attain statistical significance (P=0.067). The restenosis group had a percentage of subjects with at least one apolipoprotein(a) isoform of low molecular weight significantly greater than the nonrestenosis group (82.7 versus 66.9%; P=0.035). A multiple logistic regression analysis showed that multiple stenting (RR: 4.01; CI 95%: 1.65-13.91; P=0.004), presence of diabetes (RR: 3.96; CI 95%: 1.67-9.37; P=0.002) and presence of multivessel disease (RR: 2.71; CI 95%: 1.19-6.16; P=0.017) were predictors of restenosis after stent placement. Lipoprotein(a) and apolipoprotein(a) polymorphism did not enter the model as predictive variables. CONCLUSIONS Our study confirms that multiple stenting, diabetes and multivessel disease are powerful predictors of restenosis after intracoronary stent implantation. On the contrary, lipoprotein(a) and apolipoprotein(a) polymorphism do not appear to be reliable markers of restenosis in patients with stent implantation.
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Affiliation(s)
- Carmine Gazzaruso
- Internal Medicine Unit, IRCCS Maugeri Foundation Hospital, Department of Internal Medicine and Medical Therapeutics, University of Pavia, Via Ferrata 8, 27100 Pavia, Italy.
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Kronenberg F, Mündle M, Längle M, Neyer U. Prevalence and progression of peripheral arterial calcifications in patients with ESRD. Am J Kidney Dis 2003; 41:140-8. [PMID: 12500231 DOI: 10.1053/ajkd.2003.50033] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND Peripheral arterial calcifications are seen frequently in patients with end-stage renal disease (ESRD). However, prevalence and progression, as well as contributing factors, never were investigated in an unselected incident cohort of dialysis patients. METHODS We investigated 155 patients with ESRD at the beginning of dialysis therapy and followed them up prospectively during the first year of either hemodialysis (n = 106) or peritoneal dialysis treatment (n = 49). The prevalence and progression of arterial calcifications during the first year were graded by a single radiologist on standardized plain radiographs of the pelvis and calves. Findings were analyzed in relation to sex, age, diabetes mellitus, dialysis modality, total and high-density lipoprotein cholesterol levels, lipoprotein(a) (Lp[a]) level, apolipoprotein(a) kringle-IV repeat polymorphism, calcium level, phosphorus level, intact parathyroid hormone level, and homocysteine level. RESULTS Patients with peripheral arterial calcifications at the start of renal replacement therapy (RRT) (n = 104) were significantly older (P < 0.001), had diabetes more often (P < 0.001), and had greater Lp(a) concentrations (P = 0.03) and a trend to greater total cholesterol concentrations. Patients with progression of calcifications during the first year of RRT had significantly greater homocysteine levels (P = 0.036). Logistic regression analysis showed that patients without calcifications either at the beginning or after 1 year of RRT were younger (P = 0.01) and had significantly lower homocysteine (P = 0.004) and Lp(a) levels (P = 0.03) and less frequently had diabetes mellitus (P = 0.04). CONCLUSION Our observations suggest that the prevalence of peripheral arterial calcifications in patients with ESRD is related to age, diabetes mellitus, and Lp(a) and homocysteine levels. Progression of arterial calcifications might be related to high plasma homocysteine concentrations.
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Affiliation(s)
- Florian Kronenberg
- Institute of Medical Biology and Human Genetics, University of Innsbruck, Austria.
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Longenecker JC, Klag MJ, Marcovina SM, Powe NR, Fink NE, Giaculli F, Coresh J. Small apolipoprotein(a) size predicts mortality in end-stage renal disease: The CHOICE study. Circulation 2002; 106:2812-8. [PMID: 12451008 DOI: 10.1161/01.cir.0000038946.91899.bb] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND The high mortality rate in end-stage renal disease has engendered interest in nontraditional atherosclerotic cardiovascular disease (ASCVD) risk factors that are more prevalent in end-stage renal disease, such as elevated lipoprotein(a) [Lp(a)] levels. Previous studies suggest that high Lp(a) levels and small apolipoprotein(a) [apo(a)] isoform size are associated with ASCVD, but none have investigated the relationship between Lp(a) level, apo(a) size, and mortality. METHODS AND RESULTS An inception cohort of 864 incident dialysis patients was followed prospectively. Lp(a) was measured by an apo(a) size-independent ELISA and apo(a) size by Western blot after SDS-agarose gel electrophoresis. Comorbid conditions were determined by medical record review. Time to death was ascertained through dialysis clinic and Health Care Financing Administration follow-up. Survival analyses were performed with adjustment for baseline demographic, comorbid conditions, albumin, and lipids. Median follow-up was 33.7 months, with 346 deaths, 162 transplantations, and 10 losses to follow-up during 1999 person-years of follow-up. Cox regression analysis showed no association between Lp(a) level and mortality. However, an association between small apo(a) isoform size and mortality was found (hazard ratio, 1.36; P=0.004) after adjusting for age, race, sex, comorbidity score, cause of renal disease, and congestive heart failure. The association was somewhat lower in white patients (hazard ratio 1.34; P=0.019) than in black patients (1.69; P=0.04). No interaction by age, race, sex, diabetes, ASCVD, or Lp(a) level was present. CONCLUSIONS Small apo(a) size, but not Lp(a) level, independently predicts total mortality risk in dialysis patients.
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Gazzaruso C, Garzaniti A, Giordanetti S, Falcone C, De Amici E, Geroldi D, Fratino P. Assessment of asymptomatic coronary artery disease in apparently uncomplicated type 2 diabetic patients: a role for lipoprotein(a) and apolipoprotein(a) polymorphism. Diabetes Care 2002; 25:1418-24. [PMID: 12145244 DOI: 10.2337/diacare.25.8.1418] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE In patients with uncomplicated diabetes, there is low probability of finding significant coronary artery disease (CAD) by noninvasive tests. Therefore, screening for its presence is not justified, and it is important to find reliable predictors of silent CAD to identify patients with uncomplicated diabetes for further screening. The relationship between lipoprotein(a) [Lp(a)], apolipoprotein(a) [apo(a)] polymorphism, and silent CAD has never been studied. We investigated the association of Lp(a) and apo(a) polymorphism with angiographically documented asymptomatic CAD in type 2 diabetic patients without evident complications. RESEARCH DESIGN AND METHODS A total of 1,323 diabetic patients without any clinical and electrocardiographic evidence of CAD were evaluated. Of 121 patients with highly positive results of exercise electrocardiography (ECG) (n = 30) or positive results on exercise thallium scintigraphy (n = 91), 103 subjects showed angiographically documented CAD (CAD group). Of 1,106 patients with negative results on exercise ECG, 103 subjects without CAD (NO CAD group) were selected and matched by age, gender, and duration of diabetes to patients in the CAD group. In patients in the NO CAD group, results of exercise ECG, 48-h ambulatory ECG, and stress echocardiography were negative for CAD. RESULTS The CAD group had higher Lp(a) levels (21.7 +/- 17.7 vs. 15.2 +/- 19.0 mg/dl; P = 0.0093) than the NO CAD group, and a percentage of subjects had at least one small apo(a) isoform (68.9 vs. 29.1%; P = 0.0000) higher than the NO CAD group. Logistic regression analysis showed that apo(a) phenotypes (odds ratio [OR] 8.13, 95% CI 3.65-21.23), microalbuminuria (5.38, 2.44-11.88), smoking (2.72, 1.31-5.64), and Lp(a) levels (2.41, 1.15-5.03) were predictors of asymptomatic CAD. CONCLUSIONS Our investigation reports the first evidence of an independent association of Lp(a) and apo(a) polymorphism with asymptomatic CAD. This suggests that Lp(a) levels and apo(a) phenotypes could be used together with other risk factors as markers of asymptomatic CAD in patients with diabetes.
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Affiliation(s)
- Carmine Gazzaruso
- Internal Medicine Unit, Diabetes Center, IRCCS Maugeri Foundation Hospital, Department of Internal Medicine and Medical Therapeutics, University of Pavia, Pavia, Italy.
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Cantin B, Lamarche B, Després JP, Dagenais GR. Does correction of the friedewald formula using lipoprotein(a) change our estimation of ischemic heart disease risk? The Quebec Cardiovascular Study. Atherosclerosis 2002; 163:261-7. [PMID: 12052472 DOI: 10.1016/s0021-9150(02)00034-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
BACKGROUND LDL-cholesterol is usually calculated using the Friedewald formula. This calculation method does not take into account the presence of Lp(a), which is associated with LDL-cholesterol. Dahlen has suggested that the Friedewald formula should be modified to account for Lp(a) associated cholesterol. This study was undertaken to determine if correction of the Friedewald formula would result in a better evaluation of ischemic heart disease (IHD) risk. METHODS 2222 men free from IHD were prospectively followed for 5 years for the appearance of myocardial infarction, coronary insufficiency or coronary death. At the baseline evaluation all had a complete fasting lipid profile which included Lp(a) determinations. LDL-cholesterol levels were calculated from total cholesterol, total triglycerides and HDL-cholesterol using the Friedewald formula and also using the Dahlen modification of the Friedewald formula. RESULTS During the follow-up there were 89 first IHD events. Both types of LDL-cholesterol calculations showed that the last tertile of the LDL-cholesterol distribution in comparison to the first tertile, doubles the relative risk (RR: 2.15; 95% confidence limits: 1.23-3.75) using the Friedewald formula (RR: 2.18; 95% confidence limits: 1.25-3.81) using the Dahlen modification. Lp(a) levels were not an independent predictor of IHD risk. CONCLUSION Modification of the Friedewald formula to account for Lp(a) levels does not improve our evaluation of IHD risk.
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Luc G, Bard JM, Arveiler D, Ferrieres J, Evans A, Amouyel P, Fruchart JC, Ducimetiere P. Lipoprotein (a) as a predictor of coronary heart disease: the PRIME Study. Atherosclerosis 2002; 163:377-84. [PMID: 12052486 DOI: 10.1016/s0021-9150(02)00026-6] [Citation(s) in RCA: 158] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The association of an elevated level of lipoprotein (a) (Lp(a)) with the development of coronary heart disease (CHD) remains controversial. Lp(a) was investigated as a CHD risk factor in the PRIME Study, a prospective cohort study which included 9133 French and Northern Irish men aged 50-59 at entry, without a history of CHD and not on hypolipidaemic drugs. During a follow-up of 5 years, 288 subjects experienced at least one CHD event (myocardial infarction (MI), coronary death, angina pectoris). Lp(a) was measured by immunoassay in all subjects on fresh plasma obtained at entry. Traditional cardiovascular risk factors such as low-density lipoproteins (LDL)-cholesterol, HDL-cholesterol, triglycerides, the presence of diabetes, hypertension or smoking were determined. Logistic regression analysis was used to evaluate Lp(a) level as a CHD risk factor after controlling for the other risk factors. In addition, its possible interaction with LDL- and HDL-cholesterol levels was investigated. Lp(a) appeared a significant risk factor (P<0.0006) in the whole cohort without between-population interaction, even if the association was not statistically significant in the Belfast sample. The relative risk (RR) of CHD events in subjects with Lp(a) levels in the highest quartile was 1.5 times that of subjects in the lowest quartile (RR: 1.56; 95% confidence intervals (CIs): 1.10-2.21). A high Lp(a) level was a risk for MI, coronary death and angina pectoris. A significant interaction term between Lp(a) and LDL-cholesterol levels, however, was found. The relative CHD risk associated with a Lp(a) level > or =33 mg/dl in comparison with Lp(a) <33 mg/dl increasing gradually from 0.82 (95% CI: 0.28-2.44) in men with LDL-cholesterol in the lowest quartile (<121 mg/dl) to 1.58 (95% CI: 1.06-2.40) in the highest quartile (>163 mg/dl). In conclusion, Lp(a) increased the risk for MI and angina pectoris, especially in men with a high LDL-cholesterol level. This study which analyzed Lp(a) level using a measurement independent of apolipoprotein (a) size on fresh plasma, has confirmed utility of Lp(a) as a predictor of CHD.
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Affiliation(s)
- Gérald Luc
- Department of Atherosclerosis, INSERM UR545, Pasteur Institute of Lille, 1, rue du Professeur Calmette, France and University Lille II, France.
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Kang C, Dominguez M, Loyau S, Miyata T, Durlach V, Anglés-Cano E. Lp(a) particles mold fibrin-binding properties of apo(a) in size-dependent manner: a study with different-length recombinant apo(a), native Lp(a), and monoclonal antibody. Arterioscler Thromb Vasc Biol 2002; 22:1232-8. [PMID: 12117743 DOI: 10.1161/01.atv.0000021144.87870.c8] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Small-sized apolipoprotein(a) [apo(a)] isoforms with high antifibrinolytic activity are frequently found in cardiovascular diseases, suggesting a role for apo(a) size in atherothrombosis. To test this hypothesis, we sought to characterize the lysine (fibrin)-binding function of isolated apo(a) of variable sizes. METHODS AND RESULTS Recombinant apo(a) [r-apo(a)] preparations consisting of 10 to 34 kringles and a monoclonal antibody that neutralizes the lysine-binding function were produced and used in parallel with lipoprotein(a) [Lp(a)] particles isolated from plasma in fibrin-binding studies. All r-apo(a) preparations displayed similar affinity and specificity for lysine residues on fibrin regardless of size (K(d) 3.6+/-0.3 nmol/L) and inhibited the binding of plasminogen with a similar intensity (IC50 16.8+/-5.4 nmol/L). In contrast, native Lp(a) particles displayed fibrin affinities that were in inverse relationship with the apo(a) kringle number. Thus, a 15-kringle apo(a) separated from Lp(a) and a 34-kringle r-apo(a) displayed an affinity for fibrin that was higher than that in the corresponding particles (K(d) 2.5 versus 10.5 nmol/L and K(d) 3.8 versus 541 nmol/L, respectively). However, fibrin-binding specificity of the r-apo(a) preparations and the Lp(a) particles was efficiently neutralized (IC50 0.07 and 4 nmol/L) by a monoclonal antibody directed against the lysine-binding function of kringle IV-10. CONCLUSIONS Our data indicate that fibrin binding is an intrinsic property of apo(a) modulated by the composite structure of the Lp(a) particle.
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Affiliation(s)
- Chantal Kang
- INSERM U460, Faculté de Médecine Xavier Bichat, Paris, France
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Martín S, Pedro-Botet J, Joven J, Simó JM, Ladona MG, Pavesi M, Rubiés-Prat J. Heterozygous apolipoprotein (a) status and protein expression as a risk factor for premature coronary heart disease. THE JOURNAL OF LABORATORY AND CLINICAL MEDICINE 2002; 139:181-7. [PMID: 11944029 DOI: 10.1067/mlc.2002.121770] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Exactly how apolipoprotein a [APO(a)] isoform size affects the degree of cardiovascular risk associated with high lipoprotein a [LP(a)] levels is not fully understood. Using a sodium dodecyl sulfate-agarose APO(a) & LP(a) phenotyping method, we assessed the role of APO(a) size heterogeneity according to the number of kringle 4 repeats and the differential APO(a) protein expression in 91 male Spanish patients with premature coronary heart disease (CHD) compared with 99 healthy Spanish men. CHD patients had significantly increased median plasma LP(a) levels (0.31 g/L) and a higher percentage of subjects with LP(a) levels of 0.30 g/L or greater (51%) than controls (0.15 g/L and 23%, respectively). Patients with the double-band phenotype had significantly higher plasma LP(a) levels (median 0.37 g/L) compared with those expressing a single-band phenotype (median 0.20 g/L; P =.018) and with their corresponding controls (median 0.15 g/L; P <.001). The double-band phenotype and LP(a) values of 0.30 g/L or greater had a significant association with CHD (odds ratio [OR] 6.47, 95% confidence interval [CI] 2.51-16.7), stronger than that observed for the entire group (OR 4.19, 95% CI 1.97-8.90). The adjusted OR for the APO(a) protein pattern that equally expressed both isoforms indicates an independent association with premature CHD (OR 3.33; 95% CI 1.08-10.3). These results suggest that APO(a) phenotyping might be used in subjects with hyperlipoproteinemia a as a powerful marker to assess the risk of premature CHD because heterozygous status, mainly when both isoforms are equally expressed, is associated with higher cardiovascular risk.
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Affiliation(s)
- Silvia Martín
- Unitat de Lípids i Epidemiologia Cardiovascular and Departament de Farmacologia, Institut Municipal d'Investigació Mèdica, Barcelona, Spain
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Császár A, Füst G, Nagy B, Szalai C, Karádi I, Duba J, Prohászka Z, Horváth L, Dieplinger H. The association of serum lipoprotein(a) levels, apolipoprotein(a) size and (TTTTA)(n) polymorphism with coronary heart disease. Clin Chim Acta 2001; 309:45-51. [PMID: 11408005 DOI: 10.1016/s0009-8981(01)00500-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND The association between lipoprotein(a) levels, apolipoprotein(a) size and the (TTTTA)(n) polymorphism which is located in the 5' non-coding region of the apo(a) gene was studied in 263 patients with severe coronary heart disease and 97 healthy subjects. METHODS Lp(a) levels were measured by ELISA, apo(a) isoform size was determined by SDS-agarose gel electrophoresis, and analysis of the (TTTTA)(n) was carried out by PCR. For statistical calculation, both groups were divided into low (at least one apo(a) isoform with < or = 22 Kringle IV) and high (both isoforms with >22 KIV) apo(a) isoform sizes, and into low number (<10 in both alleles) and high number of (> or =10 at least one allele) TTTTA repeats. RESULTS Lp(a) levels were higher (P=0.007), apo(a) isoforms size < or =22 KIV and TTTTA repeats > or = 10 were more frequent (P=0.007 and 0.01) in cases than in controls. Lp(a) levels were found to be increased with low apo(a) weight in both groups (both P<0.0001). In multivariate logistic regression analysis, only the Lp(a) levels (P=0.005) and (TTTTA)(n) polymorphism (P=0.002) were found to be significantly associated with CHD. CONCLUSION Nevertheless, these results indicate that in CHD patients the (TTTTA)(n) polymorphism has an effect on Lp(a) levels which is independent of the apo(a) size.
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Gazzaruso C, Garzaniti A, Falcone C, Geroldi D, Finardi G, Fratino P. Association of lipoprotein(a) levels and apolipoprotein(a) phenotypes with coronary artery disease in Type 2 diabetic patients and in non-diabetic subjects. Diabet Med 2001; 18:589-94. [PMID: 11553191 DOI: 10.1046/j.1464-5491.2001.00536.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIMS We investigated whether in Type 2 diabetic patients lipoprotein(a) (Lp(a)) levels and apolipoprotein(a) (apo(a)) polymorphism are associated with angiographically documented coronary artery disease (CAD). We also examined whether there are differences in the distributions of Lp(a) levels and apo(a) phenotypes between CAD patients with and without diabetes. METHODS A hundred and seven diabetic patients with CAD, 274 diabetic patients without CAD, 201 non-diabetic patients with CAD, and 358 controls were enrolled. RESULTS Diabetic patients with CAD showed Lp(a) levels (21.2 +/- 17.7 vs. 15.1 +/- 17.8 mg/dl; P = 0.0018) and a percentage of subjects with at least one apo(a) isoform of low molecular weight (MW) (67.2% vs. 27.7%; P = 0.0000) significantly greater than diabetic patients without CAD. Multivariate analysis showed that in diabetic patients Lp(a) levels and apo(a) phenotypes were significantly associated with CAD; odds ratios (ORs) of high Lp(a) levels for CAD were 2.17 (1.28-3.66), while ORs of the presence of at least one apo(a) isoform of low MW were 5.35 (3.30-8.60). Lp(a) levels (30.2 +/- 23.7 vs. 21.2 +/- 17.7 mg/dl; P = 0.0005) and the percentage of subjects with at least one apo(a) isoform of low MW (87.0% vs. 67.2%; P = 0.0001) were significantly higher in CAD patients without than in those with diabetes. CONCLUSIONS Our data suggest that Lp(a) levels and apo(a) phenotypes are independently associated with CAD in Type 2 diabetic patients; thus both these parameters may be helpful in selecting diabetic subjects at high genetic cardiovascular risk. However, Lp(a) levels and apo(a) polymorphism seem to be cardiovascular risk factors less important in diabetic than in non-diabetic subjects. Diabet. Med. 18, 589-594 (2001)
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Affiliation(s)
- C Gazzaruso
- IRCCS Maugeri Foundation Hospital, Section of Internal Medicine, Diabetes Centre, Pavia, Italy.
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39
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Massy ZA. Importance of homocysteine, lipoprotein (a) and non-classical cardiovascular risk factors (fibrinogen and advanced glycation end-products) for atherogenesis in uraemic patients. Nephrol Dial Transplant 2001; 15 Suppl 5:81-91. [PMID: 11073279 DOI: 10.1093/ndt/15.suppl_5.81] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Z A Massy
- Division of Nephrology, CH Beauvais and INSERM U507, Necker Hospital, Paris, France
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40
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Sharp DS, Burchfiel CM, Rodriguez BL, Sharrett AR, Sorlie PD, Marcovina SM. Apolipoprotein A-1 predicts coronary heart disease only at low concentrations of high-density lipoprotein cholesterol: an epidemiological study of Japanese-Americans. INTERNATIONAL JOURNAL OF CLINICAL & LABORATORY RESEARCH 2001; 30:39-48. [PMID: 10984131 DOI: 10.1007/s005990070032] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Conventional epidemiological and clinical studies of apolipoprotein A-1 and high-density lipoprotein-cholesterol have demonstrated, when examined jointly, that high-density lipoprotein is a better predictor of coronary heart disease. This strategy does not take into account known lipid metabolic relationships. A statistical approach that takes into account apolipoprotein A-1 being a constituent of the high-density lipoprotein particle is more appropriate. Among 1,177 Japanese-American men of the Honolulu Heart Program cohort free of disease at baseline (1980-1982), 182 new coronary heart disease cases developed over a 12-year follow-up period. After removing the linear relationship with high-density lipoprotein-cholesterol, a relative measure of apoliprotein A-1 concentration was derived. Based on joint conditions of "low" and "high" relative apoliprotein A-1 concentration and < or =40 and >40 mg/dl for the high-density lipoprotein-cholesterol distribution, four groupings were created. Among relative joint groupings of high/< or =40, low/< or =40, high/>40, and low/>40, respectively, the 12-year coronary heart disease incidence varied from 28.6, 18.2, 8.3, to 11.7 cases per 1,000 person-years. A test of statistical interaction was significant (P=0.028). Additional analyses revealed coronary heart disease cases were more likely among men with triglycerides > 190 mg/dl. Observed patterns of relationships among relative apoliprotein A-1 level, high-density lipoprotein cholesterol, and triglycerides with incident coronary heart disease are consistent with patterns noted in clinical, laboratory, and transgenic animal research more capable of elucidating mechanisms of disease causation. This epidemiological study suggests similar mechanisms may be operating at a population level, and may contribute to the public health burden of coronary heart disease.
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Affiliation(s)
- D S Sharp
- Epidemiology and Biometry Program, Division of Epidemiology and Clinical Applications, National Heart, Lung, and Blood Institute, Bethesda, Maryland, USA
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41
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Paultre F, Pearson TA, Weil HF, Tuck CH, Myerson M, Rubin J, Francis CK, Marx HF, Philbin EF, Reed RG, Berglund L. High levels of Lp(a) with a small apo(a) isoform are associated with coronary artery disease in African American and white men. Arterioscler Thromb Vasc Biol 2000; 20:2619-24. [PMID: 11116062 DOI: 10.1161/01.atv.20.12.2619] [Citation(s) in RCA: 128] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Elevated levels of lipoprotein(a) [Lp(a)] and the presence of small isoforms of apolipoprotein(a) [apo(a)] have been associated with coronary artery disease (CAD) in whites but not in African Americans. Because of marked race/ethnicity differences in the distribution of Lp(a) levels across apo(a) sizes, we tested the hypothesis that apo(a) isoform size determines the association between Lp(a) and CAD. We related Lp(a) levels, apo(a) isoforms, and the levels of Lp(a) associated with different apo(a) isoforms to the presence of CAD (>/=50% stenosis) in 576 white and African American men and women. Only in white men were Lp(a) levels significantly higher among patients with CAD than in those without CAD (28.4 versus 16.5 mg/dL, respectively; P:=0.004), and only in this group was the presence of small apo(a) isoforms (<22 kringle 4 repeats) associated with CAD (P:=0.043). Elevated Lp(a) levels (>/=30 mg/dL) were found in 26% of whites and 68% of African Americans, and of those, 80% of whites but only 26% of African Americans had a small apo(a) isoform. Elevated Lp(a) levels with small apo(a) isoforms were significantly associated with CAD (P:<0.01) in African American and white men but not in women. This association remained significant after adjusting for age, diabetes mellitus, smoking, hypertension, HDL cholesterol, LDL cholesterol, and triglycerides. We conclude that elevated levels of Lp(a) with small apo(a) isoforms independently predict risk for CAD in African American and white men. Our study, by determining the predictive power of Lp(a) levels combined with apo(a) isoform size, provides an explanation for the apparent lack of association of either measure alone with CAD in African Americans. Furthermore, our results suggest that small apo(a) size confers atherogenicity to Lp(a).
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Affiliation(s)
- F Paultre
- Department of Medicine, Columbia University, New York, NY 10032, USA
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Abstract
BACKGROUND -Studies of the association between the plasma concentration of lipoprotein(a) [Lp(a)] and coronary heart disease (CHD) have reported apparently conflicting findings. We report a meta-analysis of the prospective studies with at least 1 year of follow-up published before 2000. METHODS AND RESULTS The following information was abstracted for each study: geographical location of study, size, type of cohort (population-based or selected because of previous disease), mean age, follow-up duration, blood storage temperature and duration, assay methods, degree of adjustment for potential confounders, and relationship of baseline Lp(a) measurement with subsequent CHD risk. There were 5436 deaths from CHD or nonfatal myocardial infarctions during a weighted mean follow-up of 10 years in the 27 eligible studies. Comparison of individuals in the top third of baseline plasma Lp(a) measurements with those in the bottom third in each study yielded a combined risk ratio of 1.6 (95% CI 1.4 to 1.8, 2P:<0.00001), with similar findings when the analyses were restricted to the 18 studies of general populations (combined risk ratio 1.7, 95% CI 1.4 to 1.9; 2P:<0. 00001). Despite differences among studies in blood storage techniques and assay methods, there was no significant heterogeneity among the results from the 18 population-based studies or among those from the 9 studies of patients with previous disease. Lp(a) was only weakly correlated with classical vascular risk factors, and adjustment for those that had been recorded made little difference to the reported risk ratios. CONCLUSIONS These prospective studies demonstrate a clear association between Lp(a) and CHD, but further studies are needed to determine the extent to which this is causal.
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Affiliation(s)
- J Danesh
- Clinical Trial Service Unit and Epidemiological Studies Unit, Nuffield Department of Clinical Medicine, University of Oxford, Radcliffe Infirmary, Oxford, UK
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43
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Kronenberg F, Kuen E, Ritz E, Junker R, König P, Kraatz G, Lhotta K, Mann JFE, Müller GA, Neyer U, Riegel W, Riegler P, Schwenger V, VON Eckardstein A. Lipoprotein(a) serum concentrations and apolipoprotein(a) phenotypes in mild and moderate renal failure. J Am Soc Nephrol 2000; 11:105-115. [PMID: 10616846 DOI: 10.1681/asn.v111105] [Citation(s) in RCA: 163] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
High lipoprotein(a) (Lp(a)) serum concentrations and the underlying apolipoprotein(a) (apo(a)) phenotypes are risk factors for cardiovascular disease in the general population as well as in patients with renal disease. Lp(a) concentrations are markedly elevated in patients with end-stage renal disease. However, nothing is known about the changes of Lp(a) depending on apo(a) size polymorphism in the earliest stages of renal impairment. In this study, GFR was measured by iohexol technique in 227 non-nephrotic patients with different degrees of renal impairment and was then correlated with Lp(a) serum concentrations stratified according to low (LMW) and high (HMW) molecular weight apo(a) phenotypes. Lp(a) increased significantly with decreasing GFR. Such an increase was dependent on apo(a) phenotype. Only renal patients with HMW apo(a) phenotypes expressed higher median Lp(a) concentrations, i.e., 6.2 mg/dl at GFR >90 ml/min per 1.73 m2, 14.2 at GFR 45 to 90 ml/min per 1.73 m2, and 18.0 mg/dl at GFR <45 ml/min per 1.73 m2. These values were markedly different when compared with apo(a) phenotype-matched control subjects who had a median level of 4.4 mg/dl (ANOVA, linear relationship, P < 0.001). In contrast, no significant differences were observed at different stages of renal function in patients with LMW apo(a) phenotypes when compared with phenotype-matched control subjects. The elevation of Lp(a) was independent of the type of primary renal disease and was not related to the concentration of C-reactive protein. Multiple linear regression analysis found that the apo(a) phenotype and GFR were significantly associated with Lp(a) levels. Non-nephrotic-range proteinuria modified the association between GFR and Lp(a) levels. In summary, an increase of Lp(a) concentrations, compared with apo(a) phenotype-matched control subjects, is seen in non-nephrotic patients with primary renal disease even in the earliest stage when GFR is not yet subnormal. This change is found only in subjects with HMW apo(a) phenotypes, however.
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Affiliation(s)
- Florian Kronenberg
- Institute of Medical Biology and Human Genetics, University of Innsbruck, Austria
| | - Erich Kuen
- Institute of Medical Biology and Human Genetics, University of Innsbruck, Austria
| | - Eberhard Ritz
- Department of Internal Medicine, Division of Nephrology, Ruperto-Carola-University, Heidelberg, Germany
| | - Ralf Junker
- Institute of Clinical Chemistry and Laboratory Medicine and Institute of Arteriosclerosis Research, University of Münster, Germany
| | - Paul König
- Innsbruck University Hospital, Department of Clinical Nephrology, Innsbruck, Austria
| | - Günter Kraatz
- Department of Internal Medicine A, Ernst-Moritz-Arndt-University, Greifswald, Germany
| | - Karl Lhotta
- Innsbruck University Hospital, Department of Clinical Nephrology, Innsbruck, Austria
| | | | - Gerhard A Müller
- Department of Nephrology and Rheumatology, Georg-August-University, Göttingen, Germany
| | - Ulrich Neyer
- Feldkirch Hospital, Department of Nephrology, Feldkirch, Austria
| | - Werner Riegel
- Medizinische Universitätskliniken des Saarlandes, Innere Medizin IV, Homburg/Saar, Germany
| | - Peter Riegler
- Bozen Hospital, Division of Nephrology and Hemodialysis, Bozen, Italy
| | - Vedat Schwenger
- Department of Internal Medicine, Division of Nephrology, Ruperto-Carola-University, Heidelberg, Germany
| | - Arnold VON Eckardstein
- Institute of Clinical Chemistry and Laboratory Medicine and Institute of Arteriosclerosis Research, University of Münster, Germany
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Tate JR, Berg K, Couderc R, Dati F, Kostner GM, Marcovina SM, Rifai N, Sakurabayashi I, Steinmetz A. International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) Standardization Project for the Measurement of Lipoprotein(a). Phase 2: selection and properties of a proposed secondary reference material for lipoprotein(a). Clin Chem Lab Med 1999; 37:949-58. [PMID: 10616748 DOI: 10.1515/cclm.1999.140] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The International Federation of Clinical Chemistry and Laboratory Medicine Working Group for the Standardization of Lipoprotein(a) Assays has initiated a project to select a secondary reference material for lipoprotein(a) that can standardize the measurement of this lipoprotein. Most of the analytical problems with lipoprotein(a) assays are due to apolipoprotein(a) kringle 4 type 2 reactive antibodies and values being expressed in mg/l mass units rather than as nmol/l of apolipoprotein(a) particles. In Phase 2, four manufactured materials were compared for analytical performance, commutability properties and method harmonization in 27 lipoprotein(a) test systems. Results of precision and linearity testing were comparable for all materials whereas testing for the harmonization effect resulted in an among-assay coefficient of variation for corrected lipoprotein(a) values of between 11% and 22%. The material that gave maximum harmonization achieved a variation of < 8% for 18 immunonephelometric and immunoturbidimetric assay systems. It can be hypothesized that this residual variation in part takes into account the inaccuracy of lipoprotein(a) measurement due to apolipoprotein(a) size polymorphism. On the basis of acceptable analytical performance, maximal harmonization effect and documented stability, a lyophilized material has been selected as the common calibrator for lipoprotein(a) to be used in a value transfer procedure by diagnostic companies.
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Affiliation(s)
- J R Tate
- Department of Chemical Pathology, Princess Alexandra Hospital, Brisbane, Australia
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45
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Marcovina SM, Koschinsky ML. Lipoprotein(a) concentration and apolipoprotein(a) size: A synergistic role in advanced atherosclerosis? Circulation 1999; 100:1151-3. [PMID: 10484533 DOI: 10.1161/01.cir.100.11.1151] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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46
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Kronenberg F, Kronenberg MF, Kiechl S, Trenkwalder E, Santer P, Oberhollenzer F, Egger G, Utermann G, Willeit J. Role of lipoprotein(a) and apolipoprotein(a) phenotype in atherogenesis: prospective results from the Bruneck study. Circulation 1999; 100:1154-60. [PMID: 10484534 DOI: 10.1161/01.cir.100.11.1154] [Citation(s) in RCA: 198] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Experimental studies have suggested both atherogenic and thrombogenic properties of lipoprotein(a) [Lp(a)], depending on Lp(a) plasma concentrations and varying antifibrinolytic capacity of apolipoprotein(a) [apo(a)] isoforms. Epidemiological studies may contribute to assessment of the relevance of these findings in the general population. METHODS AND RESULTS This study prospectively investigated the association between Lp(a) plasma concentrations, apo(a) phenotypes, and the 5-year progression of carotid atherosclerosis assessed by high-resolution duplex ultrasound in a random sample population of 826 individuals. We differentiated early atherogenesis (incident nonstenotic atherosclerosis) from advanced (stenotic) stages in atherosclerosis that originate mainly from atherothrombotic mechanisms. Lp(a) plasma concentrations predicted the risk of early atherogenesis in a dose-dependent fashion, with this association being confined to subjects with LDL cholesterol levels above the population median (3.3 mmol/L). Apo(a) phenotypes were distributed similarly in subjects with and without early carotid atherosclerosis. In contrast, apo(a) phenotypes of low molecular weight emerged as one of the strongest risk predictors of advanced stenotic atherosclerosis, especially when associated with high Lp(a) plasma concentrations (odds ratio, 6.4; 95% CI, 2.8 to 14. 9). CONCLUSIONS Lp(a) is one of the few risk factors capable of promoting both early and advanced stages of atherogenesis. Lp(a) plasma concentrations predicted the risk of early atherogenesis synergistically with high LDL cholesterol. Low-molecular-weight apo(a) phenotypes with a putatively high antifibrinolytic capacity in turn emerged as one of the leading risk conditions of advanced stenotic stages of atherosclerosis.
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Affiliation(s)
- F Kronenberg
- Institute of Medical Biology and Human Genetics, University of Innsbruck, Austria.
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Saku K, Zhang B, Liu R, Shirai K, Arakawa K. Associations among serum lipoprotein(a) levels, apolipoprotein(a) phenotypes, and myocardial infarction in patients with extremely low and high levels of serum lipoprotein(a). JAPANESE CIRCULATION JOURNAL 1999; 63:659-65. [PMID: 10496479 DOI: 10.1253/jcj.63.659] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A high serum lipoprotein(a) [Lp(a)] level, which is genetically determined by apolipoprotein(a) [apo(a)] size polymorphism, is an independent risk factor for coronary atherosclerosis. However, the associations among Lp(a) levels, apo(a) phenotypes, and myocardial infarction (MI) have not been studied. Patients with MI (cases, n = 101, M/F: 86/15, age: 62+/-10y) and control subjects (n = 92, M/F: 53/39, age: 58+/-14y) were classified into quintile groups (Groups I to V) according to Lp(a) levels. Apo(a) isoform phenotyping was performed by a sensitive, high-resolution technique using sodium dodecyl sulfate-agarose/gradient polyacrylamide gel electrophoresis (3-6%), which identified 26 different apo(a) phenotypes, including a null type. Groups with higher Lp(a) levels (Groups II, III, and V) had higher percentages of MI patients than that with the lowest Lp(a) levels (Group I) (54%, 56%, or 75% vs. 32%, p<0.05). Groups with different Lp(a) levels had different frequency distributions of apo(a) isoprotein phenotypes: Groups II, III, IV, and V, which had increasing Lp(a) levels, had increasingly higher percentages of smaller isoforms (A1-A4, A5-A9) and decreasingly lower percentages of large isoforms (A10-A20, A21-A25) compared to Group I. An apparent inverse relationship existed between Lp(a) and the apo(a) phenotype. Subjects with the highest Lp(a) levels (Group V) had significantly (p<0.05) higher serum levels of total cholesterol, apo B, and Lp(a). Patients with MI and the controls had different distributions of apo(a) phenotypes: i.e., more small isoforms and more large size isoforms, respectively (A1-A4/A5-A9/A10-A20/A21-A25: 35.7%/27.7%/20.8%/15.8% and 22.8%/23.9%/29.4%/23.9%, respectively). Lp(a) (parameter estimate +/- standard error: 0.70+/-0.20, Wald chi2 = 12.4, p = 0.0004), apo(a) phenotype (-0.43+/-0.15, Wald chi2 = 8.17, p = 0.004), High-density lipoprotein-cholesterol, apo A-I, and apo B were significantly associated with MI after adjusting for age, gender, and conventional risk factors, as assessed by a univariate logistic regression analysis. The association between Lp(a) and MI was independent of the apo(a) phenotype, but the association between the apo(a) phenotype and MI was not independent of Lp(a), as assessed by a multivariate logistic regression analysis. This association was not influenced by other MI- or Lp(a)-related lipid variables. These results suggest that apo(a) phenotype contributes to, but does not completely explain, the increased Lp(a) levels in MI. A stepwise logistic regression analysis with and without Lp(a) in the model identified Lp(a) and the apo(a) phenotype as significant predictors for MI, respectively.
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Affiliation(s)
- K Saku
- Department of Internal Medicine, Fukuoka University School of Medicine, Japan.
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Brazier L, Tiret L, Luc G, Arveiler D, Ruidavets JB, Evans A, Chapman J, Cambien F, Thillet J. Sequence polymorphisms in the apolipoprotein(a) gene and their association with lipoprotein(a) levels and myocardial infarction. The ECTIM Study. Atherosclerosis 1999; 144:323-33. [PMID: 10407493 DOI: 10.1016/s0021-9150(98)00333-5] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Lp(a) concentrations are largely determined by apo(a) isoform size, but several studies have shown that apo(a) isoforms could not entirely explain the increase of Lp(a) levels observed in patients with coronary heart disease (CHD). Since up to 90% of the variance in Lp(a) levels has been suggested to be attributable to the apo(a) locus, the hypothesis that polymorphisms of the apo(a) gene other than size could contribute to the increase of Lp(a) levels in CHD patients must be considered. This hypothesis was tested in the ECTIM Study comparing 594 patients with myocardial infarction and 682 control subjects in Northern Ireland and France. In addition to apo(a) phenotyping, five previously described polymorphisms of the apo(a) gene were genotyped: a (TTTTA)n repeat at position -1400 from the ATG, a G/A at -914, a C/T at -49, a G/A at -21 and a Met/Thr affecting amino acid 4168. As reported earlier [Parra HJ, Evans AE, Cambou JP, Amouyel P, Bingham A, McMaster D, Schaffer P, Douste-Blazy P, Luc G, Richard JL, Ducimetiere P, Fruchart JC, Cambien F. A case-control study of lipoprotein particles in two populations at contrasting risk for coronary heart disease. The ECTIM study. Arterioscler Thromb 1992; 12:701-707], mean Lp(a) levels were higher in cases than in controls (20.7 vs 14.6 mg/dl in Belfast, 17.2 vs 8.9 mg/dl in France, P < 0.001 for case-control and population differences). In the present study, mean apo(a) isoform size differed significantly between cases and controls (25.7 vs 26.6 kr in Belfast, 25.9 vs 27.4 kr in France, P < 0.001 for case-control and P = 0.13 for population difference). After adjustment for apo(a) isoforms, Lp(a) levels remained significantly higher in cases than in controls (difference, 4.6 mg/dl; P < 0.001). Genotype and allele frequencies did not differ significantly between cases and controls for any of the five polymorphisms studied. The five polymorphisms were in strong linkage disequilibrium and had a combined heterozygosity of 0.83. In multivariate regression analysis adjusted for apo(a) isoforms, only the (TTTTA)n polymorphism was significantly associated with Lp(a) levels; it explained 4.5% of Lp(a) variability in cases and 3.1% in controls. The Lp(a) case/control difference was not reduced after taking into account the (TTTTA)n effect. We conclude that the increase of Lp(a) levels observed in MI cases, and which was not directly attributable to apo(a) size variation, was not related to the five polymorphisms of the apo(a) gene considered.
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Affiliation(s)
- L Brazier
- Institut National de la Santé et de la Recherche Médicale, Unité U321, Lipoprotéines et Athérogénèse, Hôpital de la Pitié, 83 Boulevard de l'Hôpital, Paris, France
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49
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Kronenberg F, Neyer U, Lhotta K, Trenkwalder E, Auinger M, Pribasnig A, Meisl T, König P, Dieplinger H. The low molecular weight apo(a) phenotype is an independent predictor for coronary artery disease in hemodialysis patients: a prospective follow-up. J Am Soc Nephrol 1999; 10:1027-36. [PMID: 10232689 DOI: 10.1681/asn.v1051027] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Patients with end-stage renal disease treated by hemodialysis have a tremendous risk for cardiovascular complications that cannot be explained by traditional atherosclerosis risk factors. Lipoprotein(a) (Lp(a)), a risk factor for these complications in the general population, is significantly elevated in these patients. In this study, it was determined whether Lp(a) and/or the genetically determined apo(a) phenotype are risk predictors for the development of coronary artery disease in these patients. A cohort of 440 unselected hemodialysis patients were followed for a period of 5 yr independent of the cause of renal disease, duration of preceding treatment, and the preexistence of coronary artery disease at study entry. Coronary events defined as definite myocardial infarction, percutaneous transluminal coronary angioplasty, aortocoronary bypass, or a stenosis >50% in the coronary angiography were the main outcome measure. Sixty-six (15%) of the 440 patients suffered a coronary event during follow-up. In univariate analysis, patients with events were significantly older and showed a trend to lower HDL cholesterol concentrations, and higher apolipoprotein B and Lp(a) concentrations without reaching significance. Apo(a) phenotypes of low molecular weight, however, were significantly more frequent in patients with compared to those without events (43.9% versus 21.9%, P<0.001). The other lipids, lipoproteins, and apolipoproteins were similar in both groups. Multiple Cox proportional hazards regression analysis found age and the apo(a) phenotype to be the best predictors for coronary events during the observation period, independent of whether patients with a preexisting coronary artery disease or an age >65 yr at the study entry or both were excluded from the analysis. Diabetes mellitus was a risk factor only in presence of a low molecular weight apo(a) phenotype. The genetically determined apo(a) phenotype is a strong and independent predictor for coronary events in hemodialysis patients. Apo(a) phenotyping might be helpful to identify hemodialysis patients at high risk for coronary artery disease.
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Affiliation(s)
- F Kronenberg
- Institute of Medical Biology and Human Genetics, University of Innsbruck, Austria.
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Rainwater DL, McMahan CA, Malcom GT, Scheer WD, Roheim PS, McGill HC, Strong JP. Lipid and apolipoprotein predictors of atherosclerosis in youth: apolipoprotein concentrations do not materially improve prediction of arterial lesions in PDAY subjects. The PDAY Research Group. Arterioscler Thromb Vasc Biol 1999; 19:753-61. [PMID: 10073983 DOI: 10.1161/01.atv.19.3.753] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We compared serum lipid and apolipoprotein predictors of atherosclerosis in cases from the multicenter study, Pathobiological Determinants of Atherosclerosis in Youth (PDAY). The lipid measures included HDL cholesterol (HDL-C) and non-HDL-C, and the apolipoprotein measures included concentrations of apoA1, apoB, and Lp(a), and sizes of the apo(a) proteins. We tested whether the apolipoprotein measures predicted atherosclerotic lesions as well as the more traditional lipid measures. We estimated extent of lesions as fatty streaks or raised lesions (fibrous plaques, complicated or calcified lesions) in 3 sites: thoracic aorta, abdominal aorta, and right coronary artery. Neither apoA1 nor apoB measures were as strongly or consistently correlated with extent of lesions as the corresponding lipid measure (HDL-C and non-HDL-C, respectively). Beyond the basic model that included sex, age, race, smoking status, hypertension, and the lipid measures, apoA1 and apoB added only an average 1.3% increased explanatory ability to the model, whereas HDL-C plus non-HDL-C added an average 2.5%. The results suggest that the traditional lipid measures are more useful than apolipoprotein measures for detecting young persons at high risk of precocious atherosclerosis. Because of large racial differences, the two Lp(a)-related measures, Lp(a) concentrations and apo(a) size, were evaluated in blacks and whites separately. Under these circumstances, neither of the Lp(a)-related measures was strongly or consistently correlated with extent of lesions.
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Affiliation(s)
- D L Rainwater
- Southwest Foundation for Biomedical Research, University of Texas Health Science Center, San Antonio, TX, USA
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