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Tasdighi E, Adhikari R, Almaadawy O, Leucker TM, Blaha MJ. LP(a): Structure, Genetics, Associated Cardiovascular Risk, and Emerging Therapeutics. Annu Rev Pharmacol Toxicol 2024; 64:135-157. [PMID: 37506332 DOI: 10.1146/annurev-pharmtox-031023-100609] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/30/2023]
Abstract
Lipoprotein(a) [Lp(a)] is a molecule bound to apolipoprotein(a) with some similarity to low-density lipoprotein cholesterol (LDL-C), which has been found to be a risk factor for cardiovascular disease (CVD). Lp(a) appears to induce inflammation, atherogenesis, and thrombosis. Approximately 20% of the world's population has increased Lp(a) levels, determined predominantly by genetics. Current clinical practices for the management of dyslipidemia are ineffective in lowering Lp(a) levels. Evolving RNA-based therapeutics, such as the antisense oligonucleotide pelacarsen and small interfering RNA olpasiran, have shown promising results in reducing Lp(a) levels. Phase III pivotal cardiovascular outcome trials [Lp(a)HORIZON and OCEAN(a)] are ongoing to evaluate their efficacy in secondary prevention of major cardiovascular events in patients with elevated Lp(a). The future of cardiovascular residual risk reduction may transition to a personalized approach where further lowering of either LDL-C, triglycerides, or Lp(a) is selected after high-intensity statin therapy based on the individual risk profile and preferences of each patient.
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Affiliation(s)
- Erfan Tasdighi
- Ciccarone Center for the Prevention of Cardiovascular Disease, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA;
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Rishav Adhikari
- Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Omar Almaadawy
- Department of Medicine, MedStar Union Memorial Hospital, Baltimore, Maryland, USA
| | - Thorsten M Leucker
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Michael J Blaha
- Ciccarone Center for the Prevention of Cardiovascular Disease, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA;
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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Lan NSR, Chan DC, Pang J, Fegan PG, Yeap BB, Rankin JM, Schultz CJ, Watts GF, Bell DA. Lipoprotein(a) in Patients With Type 2 Diabetes and Premature Coronary Artery Disease in the Coronary Care Unit. Heart Lung Circ 2020; 30:734-740. [PMID: 33191140 DOI: 10.1016/j.hlc.2020.09.932] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 08/25/2020] [Accepted: 09/17/2020] [Indexed: 02/03/2023]
Abstract
INTRODUCTION Lipoprotein(a) [Lp(a)] and diabetes are independently associated with premature coronary artery disease (pCAD). However, there is an inverse relationship between Lp(a) concentration and type 2 diabetes (T2D) risk. We examine whether Lp(a) distribution in patients with pCAD differs between those with or without T2D, and whether elevated Lp(a) is associated with pCAD in patients with T2D. METHODS Lp(a) concentration was measured in consecutive acute coronary syndrome (ACS) patients in two coronary care units (study one: ACS with or without diabetes, study two: ACS and diabetes). Elevated Lp(a) mass concentration was defined as ≥0.5 g/L and pCAD where CAD was diagnosed age <60 years. The association between elevated Lp(a) and pCAD was assessed using logistic regression. RESULTS Of 449 patients, 233 (51.9%) had pCAD and 278 (61.9%) had T2D. In patients with pCAD, those with T2D had a significantly lower median Lp(a) concentration (0.13 g/L versus 0.27 g/L, p=0.004). In patients with T2D, elevated Lp(a) was significantly associated with pCAD (OR 2.419, 95% CI 1.513-3.867, p<0.001). After adjusting for gender, smoking, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol and triglycerides, elevated Lp(a) remained significantly associated with pCAD (OR 2.895, 95% CI 1.427-5.876, p=0.003) in patients with T2D. CONCLUSIONS In coronary care patients with pCAD, patients with T2D had lower Lp(a) concentrations than those without T2D. Despite this, elevated Lp(a) remained predictive of pCAD in patients with T2D. Measurement of Lp(a) should be considered in younger adults with T2D to identify who may benefit from earlier preventative therapies to reduce pCAD burden.
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Affiliation(s)
- Nick S R Lan
- Department of Endocrinology and Diabetes, Fiona Stanley Hospital, Perth, WA, Australia; Department of Cardiology, Fiona Stanley Hospital, Perth, WA, Australia.
| | - Dick C Chan
- Medical School, The University of Western Australia, Perth, WA, Australia
| | - Jing Pang
- Medical School, The University of Western Australia, Perth, WA, Australia
| | - P Gerry Fegan
- Department of Endocrinology and Diabetes, Fiona Stanley Hospital, Perth, WA, Australia; Medical School, Curtin University, Perth, WA, Australia
| | - Bu B Yeap
- Department of Endocrinology and Diabetes, Fiona Stanley Hospital, Perth, WA, Australia; Medical School, The University of Western Australia, Perth, WA, Australia
| | - James M Rankin
- Department of Cardiology, Fiona Stanley Hospital, Perth, WA, Australia
| | - Carl J Schultz
- Medical School, The University of Western Australia, Perth, WA, Australia; Departments of Internal Medicine and Cardiology, Royal Perth Hospital, Perth, WA, Australia
| | - Gerald F Watts
- Medical School, The University of Western Australia, Perth, WA, Australia; Departments of Internal Medicine and Cardiology, Royal Perth Hospital, Perth, WA, Australia
| | - Damon A Bell
- Medical School, The University of Western Australia, Perth, WA, Australia; Departments of Internal Medicine and Cardiology, Royal Perth Hospital, Perth, WA, Australia; Department of Clinical Biochemistry, PathWest Laboratory Medicine WA, Royal Perth and Fiona Stanley Hospitals, Perth, WA, Australia; Department of Biochemistry, Clinipath Pathology, Perth, WA, Australia
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Ueland T, Kleveland O, Michelsen AE, Wiseth R, Damås JK, Holven KB, Aukrust P, Gullestad L, Yndestad A, Halvorsen B. Serum lipoprotein(a) is not modified by interleukin-6 receptor antagonism or associated with inflammation in non-ST-elevation myocardial infarction. Int J Cardiol 2018; 274:348-350. [PMID: 29961573 DOI: 10.1016/j.ijcard.2018.06.093] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 06/02/2018] [Accepted: 06/21/2018] [Indexed: 12/11/2022]
Abstract
BACKGROUND The IL-6 receptor antagonist tocilizumab has been shown to attenuate the proatherogenic lipoprotein a [Lp(a)] in rheumatoid arthritis. We evaluated if a single dose of tocilizumab reduced Lp(a) in patients with non-ST-elevation myocardial infarction (NSTEMI). METHODS Lp(a) was assessed by immunoassay (n = 117 patients) at 7 consecutive time-points between day 1 and 3 and at 3 and 6 months follow-up. RESULTS Tocilizumab did not affect Lp(a) at any time-point during the study and was not associated with cardiovascular risk factors. CONCLUSIONS Short-time inhibition of IL-6 with tocilizumab in patients with NSTEMI did not influence Lp(a) levels.
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Affiliation(s)
- Thor Ueland
- Research Institute of Internal Medicine, Oslo University Hospital Rikshospitalet, Norway; Institute of Clinical Medicine, Oslo University Hospital Rikshospitalet, Norway; K.G. Jebsen TREC, University of Tromsø, Tromsø, Norway.
| | - Ola Kleveland
- Clinic of Cardiology, St. Olavs Hospital, Norway; Department of Circulation and Medical Imaging, Norwegian University of Science and Technology NTNU, Trondheim, Norway
| | - Annika E Michelsen
- Research Institute of Internal Medicine, Oslo University Hospital Rikshospitalet, Norway; Institute of Clinical Medicine, Oslo University Hospital Rikshospitalet, Norway
| | - Rune Wiseth
- Clinic of Cardiology, St. Olavs Hospital, Norway; Department of Circulation and Medical Imaging, Norwegian University of Science and Technology NTNU, Trondheim, Norway
| | - Jan Kristian Damås
- Centre of Molecular Inflammation Research, Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology NTNU, Trondheim, Norway
| | - Kirsten B Holven
- Norwegian National Advisory Unit on Familial Hypercholesterolemia, Department of Endocrinology, Morbid Obesity, and Preventive Medicine, Norway; Department of Nutrition, Faculty of Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Pål Aukrust
- Research Institute of Internal Medicine, Oslo University Hospital Rikshospitalet, Norway; Institute of Clinical Medicine, Oslo University Hospital Rikshospitalet, Norway; Section of Clinical Immunology and Infectious Diseases, Oslo University Hospital Rikshospitalet, Norway; K.G. Jebsen TREC, University of Tromsø, Tromsø, Norway
| | - Lars Gullestad
- Institute of Clinical Medicine, Oslo University Hospital Rikshospitalet, Norway; Department of Cardiology, Oslo University Hospital Rikshospitalet, Norway; KG Jebsen Center for Cardiac Research, University of Oslo and Center for Heart Failure Research, Oslo University Hospital, Norway
| | - Arne Yndestad
- Research Institute of Internal Medicine, Oslo University Hospital Rikshospitalet, Norway; Institute of Clinical Medicine, Oslo University Hospital Rikshospitalet, Norway; KG Jebsen Center for Cardiac Research, University of Oslo and Center for Heart Failure Research, Oslo University Hospital, Norway
| | - Bente Halvorsen
- Research Institute of Internal Medicine, Oslo University Hospital Rikshospitalet, Norway; Institute of Clinical Medicine, Oslo University Hospital Rikshospitalet, Norway
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Sultan S, Dowling M, Kirton A, DeVeber G, Linds A, Elkind MSV. Dyslipidemia in Children With Arterial Ischemic Stroke: Prevalence and Risk Factors. Pediatr Neurol 2018; 78:46-54. [PMID: 29229232 PMCID: PMC5776751 DOI: 10.1016/j.pediatrneurol.2017.09.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 09/27/2017] [Accepted: 09/29/2017] [Indexed: 12/15/2022]
Abstract
BACKGROUND Risk factors for pediatric stroke are poorly understood and require study to improve prevention. Total cholesterol and triglyceride values peak to near-adult levels before puberty, a period of increased stroke incidence. The role of lipids in childhood arterial ischemic stroke has been minimally investigated. METHODS We performed a cross-sectional analysis of lipid and Lp(a) concentrations in children with arterial ischemic stroke in the International Pediatric Stroke Study to compare the prevalence of dyslipidemia and high- or low-ranking lipid values in our dataset with reported population values. We analyzed sex, body mass index, race, ethnicity, family history, and stroke risk factors for associations with dyslipidemia, high non-high-density lipoprotein cholesterol, and hypertriglyceridemia. RESULTS Compared with the National Health and Nutrition Examination Survey, a higher proportion of children ≥5 years with arterial ischemic stroke had dyslipidemia (38.4% versus 21%), high total cholesterol (10.6% versus 7.4%), high non-high-density lipoprotein cholesterol (23.1% versus 8.4%), and low high-density lipoprotein cholesterol (39.8% versus 13.4%). The lipid values that corresponded to one standard deviation above the mean (84th percentile) in multiple published national studies generally corresponded to a lower ranking percentile in children aged five years or older with arterial ischemic stroke. Dyslipidemia was more likely associated with an underweight, overweight, or obese body mass index compared with a healthy weight. Ethnic background and an acute systemic illness were also associated with abnormal lipids. CONCLUSIONS Dyslipidemia and hypertriglyceridemia may be more prevalent in children with arterial ischemic stroke compared with stroke-free children.
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Affiliation(s)
- Sally Sultan
- Department of Pediatrics, Columbia University Medical Center, New York, New York.
| | - Michael Dowling
- Department of Pediatrics and Neurology & Neurotherapeutics, Division of Pediatric Neurology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-9063
| | - Adam Kirton
- Calgary Pediatric Stroke Program, Alberta Children’s Hospital Research Institute, University of Calgary, 2888 Shaganappi Trail NW, Calgary, Alberta, Canada
| | - Gabrielle DeVeber
- Division of Neurology and Labatt Family Heart Centre, Department of Pediatrics, Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada
| | - Alexandra Linds
- Children's Stroke Program, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, 686 Bay St. 12-9840, Toronto, ON
| | - Mitchell S. V. Elkind
- Department of Neurology, College of Physicians and Surgeons, Columbia University, 710 W 168th Street, NI-642, New York, NY 10032
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Patel P, Davies T, Madira W, Gupta P. Serum lipoprotein(a) concentrations do not change significantly in the immediate seven-day period post myocardial infarction. Ann Clin Biochem 2014; 52:502-5. [PMID: 25344455 DOI: 10.1177/0004563214559221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/20/2014] [Indexed: 11/16/2022]
Abstract
BACKGROUND Lipoprotein(a) is an independent predictor of cardiovascular disease and its variability after myocardial infarction was assessed in this study. METHODS Lipoprotein(a) was analysed by a size insensitive latex immunoturbidimetric end point assay in samples from days 0 to 7 in 31 patients admitted with myocardial infarction. RESULTS Median lipoprotein(a) changed by -0.9%, -0.1% and 9.6% on days 1, 2-3 and 4-7, respectively, and was not statistically significant. Median total cholesterol reduced by 8.7%, 9.1%, 14.5% and C-reactive protein increased by 68.4%, 510%, 502% over days 1, 2-3, 4-7, respectively. CONCLUSIONS Unlike total cholesterol and C-reactive protein, lipoprotein(a) does not demonstrate significant variability for up to seven days after myocardial infarction and measurements made during this period after myocardial infarction are physiologically meaningful.
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Affiliation(s)
- Prashanth Patel
- Department of Chemical Pathology, University Hospitals of Leicester NHS Trust, Leicester, UK
| | - Timothy Davies
- Department of Chemical Pathology, University Hospitals of Leicester NHS Trust, Leicester, UK
| | - Webster Madira
- Department of Chemical Pathology, University Hospitals of Leicester NHS Trust, Leicester, UK
| | - Pankaj Gupta
- Department of Chemical Pathology, University Hospitals of Leicester NHS Trust, Leicester, UK
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Sultan SM, Schupf N, Dowling MM, Deveber GA, Kirton A, Elkind MSV. Review of lipid and lipoprotein(a) abnormalities in childhood arterial ischemic stroke. Int J Stroke 2013; 9:79-87. [PMID: 24148253 DOI: 10.1111/ijs.12136] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
National organizations recommend cholesterol screening in children to prevent vascular disease in adulthood. There are currently no recommendations for cholesterol and lipoprotein (a) testing in children who experience an arterial ischemic stroke. While dyslipidemia and elevated lipoprotein (a) are associated with ischemic stroke in adults, the role of atherosclerotic risk factors in childhood arterial ischemic stroke is not known. A review of the literature was performed from 1966 to April 2012 to evaluate the association between childhood arterial ischemic stroke and dyslipidemia or elevated lipoprotein (a). Of 239 citations, there were 16 original observational studies in children (with or without neonates) with imaging-confirmed arterial ischemic stroke and data on cholesterol or lipoprotein (a) values. Three pairs of studies reported overlapping subjects, and two were eliminated. Among 14 studies, there were data on cholesterol in 7 and lipoprotein (a) in 10. After stroke, testing was performed at >three-months in nine studies, at ≤three-months in four studies, and not specified in one study. There were five case-control studies: four compared elevated lipoprotein (a) and one compared abnormal cholesterol in children with arterial ischemic stroke to controls. A consistent positive association between elevated lipoprotein (a) and stroke was found [Mantel-Haenszel OR 4·24 (2·94-6·11)]. There was no association in one study on total cholesterol, and a positive association in one study on triglycerides. The literature suggests that elevated lipoprotein (a) may be more likely in children with arterial ischemic stroke than in control children. The absence of confirmatory study on dyslipidemia should be addressed with future research.
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Affiliation(s)
- Sally M Sultan
- Neurologic Institute, Department of Neurology, Columbia University Medical Center, New York, NY, USA
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7
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Rigal M, Ruidavets JB, Viguier A, Petit R, Perret B, Ferrieres J, Larrue V. Lipoprotein (a) and risk of ischemic stroke in young adults. J Neurol Sci 2007; 252:39-44. [PMID: 17113602 DOI: 10.1016/j.jns.2006.10.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2006] [Revised: 06/26/2006] [Accepted: 10/04/2006] [Indexed: 11/29/2022]
Abstract
UNLABELLED Lipoprotein (a) [Lp(a)] is a LDL-particle linked to apoprotein (a) [apo(a)]. High Lp(a) plasma level is a risk factor for coronary heart disease and, in older men, for ischemic stroke. The role of Lp(a) as a risk factor for ischemic stroke in young adults is uncertain. METHODS Lp(a) concentration was prospectively measured in 100 consecutive patients with acute ischemic stroke (58 men and 42 women) aged 18-55 years, and in 100 controls matched for age and gender. RESULTS The distribution of Lp(a) concentration was skewed toward the highest and median tertiles in male patients. In multivariate logistic regression analyses adjusting on classical risk factors for ischemic stroke and lipid variables, Lp(a) concentration in the highest and medium tertiles compared with the lowest tertile was significantly associated with ischemic stroke in men (OR 3.55, 95% CI 1.33-9.48, p = 0.012), but was not in women (OR 0.42, 95% CI 0.14-1.26, p = 0.12). Although large vessel atherosclerosis was more common in men than in women, there were no differences in Lp(a) concentration according to the cause of ischemic stroke. CONCLUSION Among subjects aged 18-55 years, a slightly elevated Lp(a) concentration was strongly and independently associated with ischemic stroke in men, but not in women. Further studies are required to elucidate the mechanisms underlying this gender-specific association.
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Affiliation(s)
- M Rigal
- EA 2049 and Department of Neurology, Hôpital Rangueil 31059 Toulouse, France
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Abstract
Lipoprotein (a) [Lp(a)], is present only in humans, Old World nonhuman primates, and the European hedgehog. Lp(a) has many properties in common with low-density lipoprotein (LDL) but contains a unique protein, apo(a), which is structurally different from other apolipoproteins. The size of the apo(a) gene is highly variable, resulting in the protein molecular weight ranging from 300 to 800 kDa; this large variation may be caused by neutral evolution in the absence of any selection advantage. Apo(a) influences to a major extent metabolic and physicochemical properties of Lp(a), and the size polymorphism of the apo(a) gene contributes to the pronounced heterogeneity of Lp(a). There is an inverse relationship between apo(a) size and Lp(a) levels; however, this pattern is complex. For a given apo(a) size, there is a considerable variation in Lp(a) levels across individuals, underscoring the importance to assess allele-specific Lp(a) levels. Further, Lp(a) levels differ between populations, and blacks have generally higher levels than Asians and whites, adjusting for apo(a) sizes. In addition to the apo(a) size polymorphism, an upstream pentanucleotide repeat (TTTTA(n)) affects Lp(a) levels. Several meta-analyses have provided support for an association between Lp(a) and coronary artery disease, and the levels of Lp(a) carried in particles with smaller size apo(a) isoforms are associated with cardiovascular disease or with preclinical vascular changes. Further, there is an interaction between Lp(a) and other risk factors for cardiovascular disease. The physiological role of Lp(a) is unknown, although a majority of studies implicate Lp(a) as a risk factor.
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Affiliation(s)
- Lars Berglund
- Department of Medicine, University of California, Davis, UCD Medical Center, 4150 V Street, Suite G400, Sacramento, CA 95817, USA.
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Khovidhunkit W, Kim MS, Memon RA, Shigenaga JK, Moser AH, Feingold KR, Grunfeld C. Effects of infection and inflammation on lipid and lipoprotein metabolism: mechanisms and consequences to the host. J Lipid Res 2004; 45:1169-96. [PMID: 15102878 DOI: 10.1194/jlr.r300019-jlr200] [Citation(s) in RCA: 1012] [Impact Index Per Article: 50.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Infection and inflammation induce the acute-phase response (APR), leading to multiple alterations in lipid and lipoprotein metabolism. Plasma triglyceride levels increase from increased VLDL secretion as a result of adipose tissue lipolysis, increased de novo hepatic fatty acid synthesis, and suppression of fatty acid oxidation. With more severe infection, VLDL clearance decreases secondary to decreased lipoprotein lipase and apolipoprotein E in VLDL. In rodents, hypercholesterolemia occurs attributable to increased hepatic cholesterol synthesis and decreased LDL clearance, conversion of cholesterol to bile acids, and secretion of cholesterol into the bile. Marked alterations in proteins important in HDL metabolism lead to decreased reverse cholesterol transport and increased cholesterol delivery to immune cells. Oxidation of LDL and VLDL increases, whereas HDL becomes a proinflammatory molecule. Lipoproteins become enriched in ceramide, glucosylceramide, and sphingomyelin, enhancing uptake by macrophages. Thus, many of the changes in lipoproteins are proatherogenic. The molecular mechanisms underlying the decrease in many of the proteins during the APR involve coordinated decreases in several nuclear hormone receptors, including peroxisome proliferator-activated receptor, liver X receptor, farnesoid X receptor, and retinoid X receptor. APR-induced alterations initially protect the host from the harmful effects of bacteria, viruses, and parasites. However, if prolonged, these changes in the structure and function of lipoproteins will contribute to atherogenesis.
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Affiliation(s)
- Weerapan Khovidhunkit
- Division of Endocrinology and Metabolism, Department of Medicine, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Bangkok, Thailand
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Saely CH, Marte T, Drexel H. Lp(a) lipoprotein, vascular disease, and mortality in the elderly. N Engl J Med 2004; 350:1150-2; author reply 1150-2. [PMID: 15014191 DOI: 10.1056/nejm200403113501117] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Horváth L, Császár A, Falus A, Dieplinger H, Horváth A, Puskás E, Halm G, Bányai A, Pálóczi K, László E, Kalabay L, Romics L, Füst G. IL-6 and lipoprotein(a) [LP(a)] concentrations are related only in patients with high APO(a) isoforms in monoclonal gammopathy. Cytokine 2002; 18:340-3. [PMID: 12160523 DOI: 10.1006/cyto.2002.1044] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have investigated the influence of apo(a) genetics on the relationship between interleukin (IL)-6, and lipoprotein (a) [Lp(a)] levels in 154 patients with monoclonal gammopathy and 189 healthy subjects. No significant differences in Lp(a) levels and distribution of subjects with different sizes of apo(a) isoforms were found between patients and healthy controls. Relationship between IL-6 and Lp(a) levels was strongly dependent on the size of apo(a) isoforms. In patients with high-size apo(a) isoforms Lp(a) levels positively correlated (r=0.475, P=0.0007) to IL-6 concentrations, whereas no correlation was found in patients with low apo(a) isoforms. Our present finding may provide a plausible explanation for the contradictory findings about the acute phase protein nature of Lp(a).
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Affiliation(s)
- Laura Horváth
- 3rd Department of Medicine, Faculty of Medicine, Semmelweis University Budapest, Hungary
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Korte W, Greiner J, Feldges A, Riesen WF. Increased lipoprotein(a) levels are not a steady prothrombotic defect. Blood 2001; 98:1993-4. [PMID: 11565543 DOI: 10.1182/blood.v98.6.1993] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Abstract
High plasma concentrations of lipoprotein (a) [Lp(a)] are now considered a major risk factor for atherosclerosis and cardiovascular disease. This effect of Lp(a) may be related to its composite structure, a plasminogen-like inactive serine-proteinase, apoprotein (a) [apo(a)], which is disulfide-linked to the apoprotein B100 of an atherogenic low-density lipoprotein (LDL) particle. Apo(a) contains, in addition to the protease region and a copy of kringle 5 of plasminogen, a variable number of copies of plasminogen-like kringle 4, giving rise to a series of isoforms. This structural homology endows Lp(a) with the capacity to bind to fibrin and to membrane proteins of endothelial cells and monocytes, and thereby inhibits binding of plasminogen and plasmin formation. This mechanism favors fibrin and cholesterol deposition at sites of vascular injury and impairs activation of transforming growth factor-beta (TGF-beta) that may result in migration and proliferation of smooth muscle cells into the vascular intima. It is currently accepted that this effect of Lp(a) is linked to its concentration in plasma, and an inverse relationship between apo(a) isoform size and Lp(a) concentrations that is under genetic control has been documented. Recently, it has been shown that inhibition of plasminogen binding to fibrin by apo(a) from homozygous subjects is also inversely associated with isoform size. These findings suggest that the structural polymorphism of apo(a) is not only inversely related to the plasma concentration of Lp(a), but also to a functional heterogeneity of apo(a) isoforms. Based on these pathophysiological findings, it can be proposed that the predictive value of Lp(a) as a risk factor for vascular occlusive disease in heterozygous subjects would depend on the relative concentration of the isoform with the highest affinity for fibrin.
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Affiliation(s)
- A de la Peña-Díaz
- Departamento de Hematología, Instituto Nacional de Cardiología Ignacio Chávez, México, D.F., Mexico
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Wityk RJ, Kittner SJ, Jenner JL, Hebel JR, Epstein A, Wozniak MA, Stolley PD, Stern BJ, Sloan MA, Price TR, McCarter RJ, Macko RF, Johnson CJ, Earley CJ, Buchholz DW, Schaefer EJ. Lipoprotein (a) and the risk of ischemic stroke in young women. Atherosclerosis 2000; 150:389-96. [PMID: 10856531 DOI: 10.1016/s0021-9150(99)00388-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND AND PURPOSE lipoprotein (a) (lp (a)) is a lipid-containing particle similar to LDL which has been found in atherosclerotic plaque. The role of lp (a) in ischemic stroke remains controversial, but some studies suggest lp (a) is particularly important as a risk factor for stroke in young adults. We investigated the role of lp (a) as a risk factor for stroke in young women enrolled in the Stroke Prevention in Young Women Study. METHODS subjects were participants in a population-based, case-control study of risk factors for ischemic stroke in young women. Cases were derived from surveillance of 59 regional hospitals in the central Maryland, Washington DC, Pennsylvania and Delaware area. Lp (a) was measured in 110 cases and 216 age-matched controls. Demographics, risk factors, and stroke subtype were determined by interview and review of medical records. RESULTS lp (a) values were higher in blacks than whites, but within racial groups, the distribution of lp (a) values was similar between cases and controls. After adjustment for age, race, hypertension, diabetes, cigarette smoking, coronary artery disease, total cholesterol and HDL cholesterol, the odds ratio for an association of lp (a) and stroke was 1.36 (95% CI 0.80-2.29). There was no dose-response relationship between lp (a) quintile and stroke risk. Among stroke subtypes, only lacunar stroke patients had significantly elevated lp (a) values compared to controls. CONCLUSIONS we found no association of lp (a) with stroke in a population of young women with ischemic stroke. Small numbers of patients limit conclusions regarding risk in ischemic stroke subtypes, but we could not confirm previous suggestions of an association of lp (a) with atherosclerotic stroke in young adults.
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Affiliation(s)
- R J Wityk
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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Christensen B, Landaas S, Stensvold I, Djurovic S, Retterstøl L, Ringstad J, Berg K, Thelle DS. Whole blood folate, homocysteine in serum, and risk of first acute myocardial infarction. Atherosclerosis 1999; 147:317-26. [PMID: 10559518 DOI: 10.1016/s0021-9150(99)00202-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
High level of total homocysteine (tHcy) is a risk factor for coronary artery disease (CAD), but the mechanism is not known. The serum concentration of tHcy, total cholesterol, high density lipoprotein cholesterol (HDL-C), and apolipoprotein A-I (apo A-I) and the concentration of folate in whole blood were measured in 107 patients with first acute myocardial infarction (MI) and 103 controls. The level of whole blood folate was lower and that of tHcy higher in cases than in controls. An increase of 50 nmol/l whole blood folate was associated with an OR for MI of 0.75, and an increase of 5 micromol/l tHcy with an OR for MI of 1.57. Correlations were observed between the levels of whole blood folate and tHcy and between whole blood folate and alcohol intake, and in MI cases, between tHcy, HDL-C, and apo A-I as well as between HDL-C and alcohol intake. The number of cigarette smokers was higher among cases than controls. In smokers, the level of tHcy was higher and that of whole blood folate lower than in non-smokers. After adjustment for smoking, the whole blood folate and tHcy-associated risks of MI became non-significant. We conclude that smoking may affect folate status and tHcy level adversely. The risk of MI in smokers may at least partly be attributed to hyperhomocysteinemia or low folate.
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Affiliation(s)
- B Christensen
- Department of Medical Genetics, Ullevâl University Hospital, N-0407, Oslo, Norway
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Peynet J, Beaudeux JL, Woimant F, Flourié F, Giraudeaux V, Vicaut E, Launay JM. Apolipoprotein(a) size polymorphism in young adults with ischemic stroke. Atherosclerosis 1999; 142:233-9. [PMID: 9920527 DOI: 10.1016/s0021-9150(98)00232-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
High serum lipoprotein(a) (Lp(a)) concentration which is largely determined by genetic factors, mainly the apolipoprotein(a) (apo(a)) polymorphism, is associated with ischemic cerebrovascular disease. The aim of this study was to investigate whether apo(a) size was associated with acute ischemic stroke in young adults for which causal factors often remain undetermined. Lipid parameters, Lp(a) concentration and apo(a) isoform size distribution were determined in 90 young patients (37.4+/-8.7 years) with acute cerebral ischemia, and compared to those of control subjects with similar age and sex ratio. Apo(a) size was expressed as its apparent number of kringle 4 (Kr 4) repeats. Serum Lp(a) concentrations were significantly higher in patients than in controls (median values: 0.18 vs. 0.07 g/l, P=0.009) and were as expected inversely related to the number of kringle 4 repeats in both controls (r2=-0.61, P < 0.001) and patients (r2=-0.56, P < 0.001). However there was no difference in the apo(a) isoform size distributions between the two groups (median isoform size: 27 vs. 27 Kr 4, P=0.25). Lp(a) levels were increased as well in patients with size apo(a) isoform < or = 22 Kr 4 as in those with isoforms > 25 Kr 4. Multivariate analysis showed that apo(a) phenotype did not appear as a risk factor for cerebrovascular infarction. Thus, our results indicate that serum Lp(a) was significantly increased in young people with ischemic stroke but fail to reveal a role of small-sized apo(a) isoforms in the occurrence of this event. They suggest that other factors, genetic or environmental in nature, than the apo(a) size contribute to increase the serum Lp(a) concentrations in these young patients.
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Affiliation(s)
- J Peynet
- Service de Biochimie et de Biologie Moléculaire, Hôpital Lariboisière, Paris, France.
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Bernard DR, Langlois MR, Delanghe JR, De Buyzere ML. Evolution of haptoglobin concentration in serum during the early phase of acute myocardial infarction. EUROPEAN JOURNAL OF CLINICAL CHEMISTRY AND CLINICAL BIOCHEMISTRY : JOURNAL OF THE FORUM OF EUROPEAN CLINICAL CHEMISTRY SOCIETIES 1997; 35:85-8. [PMID: 9056748 DOI: 10.1515/cclm.1997.35.2.85] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Haptoglobin (Hp) is a haemoglobin-binding acute phase protein with three genetic types: Hp 1-1, Hp 2-1, Hp 2-2. We investigated 45 patients during the first 48 hours of acute myocardial infarction, and studied determinant factors and clinical correlates. Upon hospital admission, serum haptoglobin concentration was increased (1.95 +/- 0.94 g/l, mean +/- SD, P < 0.001) versus the reference population (0.97 +/- 0.46 g/l, n = 107), independent of haptoglobin type: 1.84 +/- 0.64 g/l (Hp 1-1, n = 11) (P < 0.01), 1.98 +/- 0.79 g/l (Hp 2-1, n = 25) (P < 0.001), 1.98 +/- 1.58 g/l (Hp 2-2, n = 9) (P < 0.001). Moreover, during the first hours of hospitalization, a temporal lowering of haptoglobin was observed suggesting acute haemolysis, independent of the haptoglobin type. Minimal serum haptoglobin was reached 9.6 +/- 5.8 hours after admission. The amplitude of the haptoglobin decrease correlated with initial serum haptoglobin (r = 0.78) and was more pronounced (P < 0.05) in men (0.53 +/- 0.57 g/l) than in women (0.18 +/- 0.17 g/l). Decrease of serum haptoglobin did not correlate with infarct size (based on creatine kinase-MB release). Out of the other acute phase proteins measured upon admission, only C-reactive protein was significantly increased (P < 0.05). During the next 36 hours, haptoglobin increased as a result of the acute phase response to myocardial injury. Our findings suggest that acute myocardial infarction is also preceded by an acute phase response, characterized by an initial high haptoglobin and followed by a temporal haptoglobin decrease due to haemolysis.
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Affiliation(s)
- D R Bernard
- Laboratorium Klinische Scheikunde, Universitair Ziekenhuis Gent, Belgium
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Aull S, Lalouschek W, Schnider P, Sinzinger H, Uhl F, Zeiler K. Dynamic changes of plasma lipids and lipoproteins in patients after transient ischemic attack or minor stroke. Am J Med 1996; 101:291-8. [PMID: 8873491 DOI: 10.1016/s0002-9343(96)00199-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
PURPOSE Only few data are available concerning variations of lipids and lipoproteins in the acute stage after ischemic cerebrovascular events. It was the aim of this study to investigate whether the lipid and lipoprotein levels obtained in the first few days after a transient ischemic attack (TIA) or a minor stroke (MS) actually reflect "correct' values or "changed' (ie, false low) values, as in patients after acute myocardial infarction. PATIENTS AND METHODS Total cholesterol (TC), HDL-cholesterol (HDL-C), LDL-cholesterol (LDL-C), and triglyceride (TG) levels of 37 unselected patients with TIA or MS were determined within 12-48 hours (Group A) or within 49-168 hours (Group B) after the acute event. After a mean observation period of 15.3 months, all patients were re-examined; the results were compared with those of the baseline evaluation. RESULTS At the time of the baseline evaluation, TC and LDL-C levels of Group B patients were significantly lower than Group A levels. At the end of the observation period, however, Group A and Group B patients did not differ with regard to all four parameters. In comparison with the baseline examination, the values of Group A patients had not changed. In Group B patients, however, TC, HDL-C, LDL-C, and TG levels had significantly increased. CONCLUSION Our results strongly suggest that lipid and lipoprotein levels of patients with TIA or MS should be assessed within a maximum of 48 hours after the acute event. If the examination cannot be performed within that period, the determination of reliable values is possible only after several weeks or months.
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Affiliation(s)
- S Aull
- Neurological Clinic, University of Vienna, Austria
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Abstract
The plasma protein binding of drugs has been shown to have significant effects on numerous aspects of clinical pharmacokinetics and pharmacodynamics. In many clinical situations, measurement of the total drug concentration does not provide the needed information concerning the unbound fraction of drug in plasma which is available for distribution, elimination, and pharmacodynamic action. Thus, accurate determination of unbound plasma drug concentrations is essential in the therapeutic monitoring of drugs. Many methodologies are available for determining the extent of plasma protein binding of drugs, however, in the clinical evaluation of drug therapy, equilibrium dialysis and ultrafiltration are the most routinely utilised methods. Both of these methods have been proven to be experimentally sound and to yield adequate protein binding data. Furthermore, the characterisation of the interactions between drug and protein molecules is essential for the assessment of the pharmacokinetic implications of drug-protein binding. Protein binding parameters which characterise the affinity of the drug-protein association, the number of classes of binding sites, the number of binding sites per class or protein and the binding capacity are useful for predicting unbound drug concentrations. Simple graphical methods have often been used to obtain protein binding parameters, but these methods have limitations and are not useful for drugs with more than 1 class of binding site. Therefore, the fitting of protein binding models which characterise the drug-protein binding interaction for experimental data is the preferred method of calculating binding parameters. Using the appropriate model, values for binding parameters are typically estimated by using nonlinear least-squares regression analysis.
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Affiliation(s)
- J D Wright
- Department of Pharmaceutics, College of Pharmacy, University of Georgia, Athens, USA
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