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BACKGROUND: Familial chylomicronemia syndrome is a genetic disorder associated with severe hypertriglyceridemia and severe acute pancreatitis. Olezarsen reduces the plasma triglyceride level by reducing hepatic synthesis of apolipoprotein C-III. METHODS: In a phase 3, double-blind, placebo-controlled trial, we randomly assigned patients with genetically identified familial chylomicronemia syndrome to receive olezarsen at a dose of 80 mg or 50 mg or placebo subcutaneously every 4 weeks for 49 weeks. There were two primary end points: the difference between the 80-mg olezarsen group and the placebo group in the percent change in the fasting triglyceride level from baseline to 6 months, and (to be assessed if the first was significant) the difference between the 50-mg olezarsen group and the placebo group. Secondary end points included the mean percent change from baseline in the apolipoprotein C-III level and an independently adjudicated episode of acute pancreatitis. RESULTS: A total of 66 patients underwent randomization; 22 were assigned to the 80-mg olezarsen group, 21 to the 50-mg olezarsen group, and 23 to the placebo group. At baseline, the mean (±SD) triglyceride level among the patients was 2630±1315 mg per deciliter, and 71% had a history of acute pancreatitis within the previous 10 years. Triglyceride levels at 6 months were significantly reduced with the 80-mg dose of olezarsen as compared with placebo (-43.5 percentage points; 95% confidence interval [CI], -69.1 to -17.9; P<0.001) but not with the 50-mg dose (-22.4 percentage points; 95% CI, -47.2 to 2.5; P = 0.08). The difference in the mean percent change in the apolipoprotein C-III level from baseline to 6 months in the 80-mg group as compared with the placebo group was -73.7 percentage points (95% CI, -94.6 to -52.8) and between the 50-mg group as compared with the placebo group was -65.5 percentage points (95% CI, -82.6 to -48.3). By 53 weeks, 11 episodes of acute pancreatitis had occurred in the placebo group, and 1 episode had occurred in each olezarsen group (rate ratio [pooled olezarsen groups vs. placebo], 0.12; 95% CI, 0.02 to 0.66). Adverse events of moderate severity that were considered by a trial investigator at the site to be related to the trial drug or placebo occurred in 4 patients in the 80-mg olezarsen group. CONCLUSIONS: In patients with familial chylomicronemia syndrome, olezarsen may represent a new therapy to reduce plasma triglyceride levels. (Funded by Ionis Pharmaceuticals; Balance ClinicalTrials.gov number, NCT04568434.).
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Apolipoproteína C-III , Hiperlipoproteinemia Tipo I , Pancreatitis , Triglicéridos , Humanos , Pancreatitis/tratamiento farmacológico , Masculino , Femenino , Método Doble Ciego , Apolipoproteína C-III/sangre , Persona de Mediana Edad , Adulto , Triglicéridos/sangre , Hiperlipoproteinemia Tipo I/tratamiento farmacológico , Hiperlipoproteinemia Tipo I/sangre , Hiperlipoproteinemia Tipo I/complicaciones , Enfermedad Aguda , Oligonucleótidos/uso terapéutico , Oligonucleótidos/efectos adversos , Anciano , Hipertrigliceridemia/tratamiento farmacológico , Hipertrigliceridemia/sangre , Adulto JovenRESUMEN
BACKGROUND: Angiopoietin-like 3 (ANGPTL3) inhibits lipoprotein and endothelial lipases and hepatic uptake of triglyceride-rich lipoprotein remnants. ANGPTL3 loss-of-function carriers have lower levels of triglycerides, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, and non-HDL cholesterol and a lower risk of atherosclerotic cardiovascular disease than noncarriers. Zodasiran is an RNA interference (RNAi) therapy targeting expression of ANGPTL3 in the liver. METHODS: We conducted a double-blind, placebo-controlled, dose-ranging phase 2b trial to evaluate the safety and efficacy of zodasiran in adults with mixed hyperlipidemia (fasting triglyceride level of 150 to 499 mg per deciliter and either an LDL cholesterol level of ≥70 mg per deciliter or a non-HDL cholesterol level of ≥100 mg per deciliter). Eligible patients were randomly assigned in a 3:1 ratio to receive subcutaneous injections of zodasiran (50, 100, or 200 mg) or placebo on day 1 and week 12 and were followed through week 36. The primary end point was the percent change in the triglyceride level from baseline to week 24. RESULTS: A total of 204 patients underwent randomization. At week 24, substantial mean dose-dependent decreases from baseline in ANGPTL3 levels were observed with zodasiran (difference in change vs. placebo, -54 percentage points with 50 mg, -70 percentage points with 100 mg, and -74 percentage points with 200 mg), and significant dose-dependent decreases in triglyceride levels were observed (difference in change vs. placebo, -51 percentage points, -57 percentage points, and -63 percentage points, respectively) (P<0.001 for all comparisons). Other differences in change from baseline as compared with placebo included the following: for non-HDL cholesterol level, -29 percentage points with 50 mg, -29 percentage points with 100 mg, and -36 percentage points with 200 mg; for apolipoprotein B level, -19 percentage points, -15 percentage points, and -22 percentage points, respectively; and for LDL cholesterol level, -16 percentage points, -14 percentage points, and -20 percentage points, respectively. We observed a transient elevation in glycated hemoglobin levels in patients with preexisting diabetes who received the highest dose of zodasiran. CONCLUSIONS: In patients with mixed hyperlipidemia, zodasiran was associated with significant decreases in triglyceride levels at 24 weeks. (Funded by Arrowhead Pharmaceuticals; ARCHES-2 ClinicalTrials.gov number, NCT04832971.).
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BACKGROUND: Heterozygous familial hypercholesterolemia (FH) is among the most common genetic conditions worldwide that affects ≈ 1 in 300 individuals. FH is characterized by increased levels of low-density lipoprotein cholesterol (LDL-C) and increased risk of coronary artery disease (CAD), but there is a wide spectrum of severity within the FH population. This variability in expression is incompletely explained by known risk factors. We hypothesized that genome-wide genetic influences, as represented by polygenic risk scores (PRSs) for cardiometabolic traits, would influence the phenotypic severity of FH. METHODS: We studied individuals with clinically diagnosed FH (n=1123) from the FH Canada National Registry, as well as individuals with genetically identified FH from the UK Biobank (n=723). For all individuals, we used genome-wide gene array data to calculate PRSs for CAD, LDL-C, lipoprotein(a), and other cardiometabolic traits. We compared the distribution of PRSs in individuals with clinically diagnosed FH, genetically diagnosed FH, and non-FH controls and examined the association of the PRSs with the risk of atherosclerotic cardiovascular disease. RESULTS: Individuals with clinically diagnosed FH had higher levels of LDL-C, and the incidence of atherosclerotic cardiovascular disease was higher in individuals with clinically diagnosed compared with genetically identified FH. Individuals with clinically diagnosed FH displayed enrichment for higher PRSs for CAD, LDL-C, and lipoprotein(a) but not for other cardiometabolic risk factors. The CAD PRS was associated with a risk of atherosclerotic cardiovascular disease among individuals with an FH-causing genetic variant. CONCLUSIONS: Genetic background, as expressed by genome-wide PRSs for CAD, LDL-C, and lipoprotein(a), influences the phenotypic severity of FH, expanding our understanding of the determinants that contribute to the variable expressivity of FH. A PRS for CAD may aid in risk prediction among individuals with FH.
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LDL-Colesterol , Enfermedad de la Arteria Coronaria , Predisposición Genética a la Enfermedad , Estudio de Asociación del Genoma Completo , Hiperlipoproteinemia Tipo II , Lipoproteína(a) , Herencia Multifactorial , Fenotipo , Sistema de Registros , Humanos , Hiperlipoproteinemia Tipo II/genética , Hiperlipoproteinemia Tipo II/sangre , Hiperlipoproteinemia Tipo II/diagnóstico , Hiperlipoproteinemia Tipo II/epidemiología , Femenino , Masculino , Persona de Mediana Edad , LDL-Colesterol/sangre , Enfermedad de la Arteria Coronaria/genética , Enfermedad de la Arteria Coronaria/epidemiología , Enfermedad de la Arteria Coronaria/sangre , Enfermedad de la Arteria Coronaria/diagnóstico , Medición de Riesgo , Lipoproteína(a)/sangre , Lipoproteína(a)/genética , Adulto , Anciano , Canadá/epidemiología , Reino Unido/epidemiología , Índice de Severidad de la Enfermedad , Factores de Riesgo , Estudios de Casos y Controles , Biomarcadores/sangre , IncidenciaRESUMEN
BACKGROUND: Pediatric patients with homozygous familial hypercholesterolemia (HoFH) have an increased risk of atherosclerotic cardiovascular disease and difficulty meeting low-density lipoprotein cholesterol (LDL-C) goals. In this post hoc analysis, we evaluated pooled safety and efficacy data from 3 studies in pediatric patients with HoFH treated with the PCSK9 (proprotein convertase subtilisin/kexin type 9) monoclonal antibody inhibitor evolocumab. METHODS: Patients with HoFH aged 10 to 17 years received treatment with open-label evolocumab 420 mg subcutaneously monthly or biweekly in the TAUSSIG, RAMAN, or HAUSER-OLE clinical studies. All patients received background statins with or without ezetimibe. Study duration ranged from 12 to 260 weeks. The primary end point was treatment-emergent adverse events per 100 patient-years. Efficacy end points were changes from baseline to week 12 in lipids and PCSK9. RESULTS: Of the 39 patients in the pooled analysis, 69.2% were males, median age was 13.0 years, and 79.5% (31/39) had genotyped HoFH with LDLR pathogenic variants. Overall, median exposure to evolocumab was 18.2 (Q1, Q3: 3.0, 18.5) months. Treatment-emergent adverse events with an exposure-adjusted patient incidence rate of ≥5% were upper respiratory tract infection (6.6%), influenza (5.2%), and acne (5.0%) per 100 patient-years. Exposure-adjusted patient incidence of serious treatment-emergent adverse events was 13.3% per 100 patient-years. Excluding 4 patients receiving lipoprotein apheresis, week 12 median percentage change from baseline in LDL-C was -2.9% (Q1, Q3: -21.7, 1.5); however, 42.9% (15/35) of patients achieved ≥15% reduction in LDL-C from baseline. Residual LDLR (LDL receptor) activity was not associated with a reduction in LDL-C. CONCLUSIONS: In this pooled data analysis from 3 studies in pediatric patients with HoFH, evolocumab was well tolerated, with no new safety signals reported. These safety findings are consistent with findings from previous studies of evolocumab. Patients showed marked variability in LDL-C reduction. Results from this pooled analysis support guidelines suggesting a trial of PCSK9 inhibitor therapy regardless of estimated residual LDLR function. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01624142, NCT03403374, and NCT02624869.
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Anticuerpos Monoclonales Humanizados , Anticolesterolemiantes , LDL-Colesterol , Homocigoto , Hiperlipoproteinemia Tipo II , Inhibidores de PCSK9 , Adolescente , Niño , Femenino , Humanos , Masculino , Factores de Edad , Anticuerpos Monoclonales/efectos adversos , Anticuerpos Monoclonales/uso terapéutico , Anticuerpos Monoclonales Humanizados/efectos adversos , Anticuerpos Monoclonales Humanizados/uso terapéutico , Anticolesterolemiantes/uso terapéutico , Anticolesterolemiantes/efectos adversos , Biomarcadores/sangre , LDL-Colesterol/sangre , Quimioterapia Combinada , Ezetimiba/uso terapéutico , Ezetimiba/efectos adversos , Predisposición Genética a la Enfermedad , Inhibidores de Hidroximetilglutaril-CoA Reductasas/efectos adversos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Hiperlipoproteinemia Tipo II/sangre , Hiperlipoproteinemia Tipo II/tratamiento farmacológico , Hiperlipoproteinemia Tipo II/genética , Hiperlipoproteinemia Tipo II/diagnóstico , Fenotipo , Proproteína Convertasa 9/genética , Inhibidores de Serina Proteinasa/efectos adversos , Inhibidores de Serina Proteinasa/uso terapéutico , Factores de Tiempo , Resultado del Tratamiento , Estudios Clínicos como AsuntoRESUMEN
PURPOSE OF REVIEW: While biallelic rare APOA5 pathogenic loss-of-function (LOF) variants cause familial chylomicronemia syndrome, heterozygosity for such variants is associated with highly variable triglyceride phenotypes ranging from normal to severe hypertriglyceridemia, often in the same individual at different time points. Here we provide an updated overview of rare APOA5 variants in hypertriglyceridemia. RECENT FINDINGS: Currently, most variants in APOA5 that are considered to be pathogenic according to guidelines of the American College of Medical Genetics and Genomics are those resulting in premature termination codons. There are minimal high quality functional data on the impact of most rare APOA5 missense variants; many are considered as variants of unknown or uncertain significance. Furthermore, particular common polymorphisms of APOA5 , such as p.Ser19Trp and p.Gly185Cys in Caucasian and Asian populations, respectively, are statistically overrepresented in hypertriglyceridemia cohorts and are sometimes misattributed as being causal for chylomicronemia, when they are merely risk alleles for hypertriglyceridemia. SUMMARY: Both biallelic and monoallelic LOF variants in APOA5 are associated with severe hypertriglyceridemia, although the biochemical phenotype in the monoallelic state is highly variable and is often exacerbated by secondary factors. Currently, with few exceptions, the principal definitive mechanism for APOA5 pathogenicity is through premature truncation. The pathogenic mechanisms of most missense variants in APOA5 remain unclear and require additional functional experiments or family studies.
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Hiperlipoproteinemia Tipo I , Hipertrigliceridemia , Humanos , Apolipoproteína A-V/genética , Variación Genética , Heterocigoto , Hiperlipoproteinemia Tipo I/genética , Hipertrigliceridemia/genética , Hipertrigliceridemia/patología , Polimorfismo Genético , Triglicéridos/genéticaRESUMEN
Elevated low-density lipoprotein cholesterol (LDL-C) is a major causal factor for atherosclerotic cardiovascular disease (ASCVD), the leading cause of mortality worldwide. Statins are the recommended first-line lipid-lowering therapy (LLT) for patients with primary hypercholesterolemia and established ASCVD, with LLT intensification recommended in the substantial proportion of patients who do not achieve levels below guideline-recommended LDL-C thresholds with statin treatment alone. The proprotein convertase subtilisin/kexin type 9 inhibitor monoclonal antibody evolocumab has demonstrated significant LDL-C reductions of > 60% in the clinical trial and open-label extension settings, with LDL-C reductions observed early post-evolocumab initiation and maintained long term, during up to 8.4 years of follow-up. Evolocumab therapy, when added to a statin, also conferred a significant reduction in major cardiovascular (CV) events, including a 20% reduction in the composite of CV death, myocardial infarction (MI), or stroke. The absolute benefits were enhanced among various patient types at high and very high risk for secondary ASCVD (e.g., with recent MI, multiple events or peripheral artery disease). Importantly, evolocumab treatment resulted in incremental CV risk reductions during the extended follow-up, including a 23% reduction in CV mortality and no apparent LDL-C level below which there is no further CV risk reduction. Hence, the evolocumab clinical data support the need for early and significant LDL-C lowering, especially in vulnerable ASCVD patients, in order to derive the greatest benefit in the long term. Importantly, evolocumab had no impact on any treatment emergent adverse events apart from a small increase in local injection site reactions. A growing body of real-world evidence (RWE) for evolocumab in heterogeneous populations is consistent with the trial data, including robust LDL-C reductions below guideline-recommended thresholds, a favourable safety profile even at the lowest levels of LDL-C achieved, and a high treatment persistence rate of > 90%. Altogether, this review highlights findings from 50 clinical trials and RWE studies in > 51,000 patients treated with evolocumab, to demonstrate the potential of evolocumab to address the healthcare gap in LDL-C reduction and secondary prevention of ASCVD in a variety of high- and very high-risk patients.
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INTRODUCTION: Apolipoprotein E E4 allele (APOE E4) and slow gait are independently associated with cognitive impairment and dementia. However, it is unknown whether their coexistence is associated with poorer cognitive performance and its underlying mechanism in neurodegenerative diseases. METHODS: Gait speed, APOE E4, cognition, and neuroimaging were assessed in 480 older adults with neurodegeneration. Participants were grouped by APOE E4 presence and slow gait. Mediation analyses were conducted to determine if brain structures could explain the link between these factors and cognitive performance. RESULTS: APOE E4 carriers with slow gait had the lowest global cognitive performance and smaller gray matter volumes compared to non-APOE E4 carriers with normal gait. Coexistence of APOE E4 and slow gait best predicted global and domain-specific poorer cognitive performances, mediated by smaller gray matter volume. DISCUSSION: Gait slowness in APOE E4 carriers with neurodegenerative diseases may indicate extensive gray matter changes associated with poor cognition. HIGHLIGHTS: APOE E4 and slow gait are risk factors for cognitive decline in neurodegenerative diseases. Slow gait and smaller gray matter volumes are associated, independently of APOE E4. Worse cognition in APOE E4 carriers with slow gait is explained by smaller GM volume. Gait slowness in APOE E4 carriers indicates poorer cognition-related brain changes.
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Apolipoproteína E4 , Enfermedades Neurodegenerativas , Humanos , Anciano , Apolipoproteína E4/genética , Enfermedades Neurodegenerativas/genética , Genotipo , Cognición , Marcha , Apolipoproteínas E/genéticaRESUMEN
INTRODUCTION: We investigated the effect of perivascular spaces (PVS) volume on speeded executive function (sEF), as mediated by white matter hyperintensities (WMH) volume and plasma glial fibrillary acidic protein (GFAP) in neurodegenerative diseases. METHODS: A mediation analysis was performed to assess the relationship between neuroimaging markers and plasma biomarkers on sEF in 333 participants clinically diagnosed with Alzheimer's disease/mild cognitive impairment, frontotemporal dementia, or cerebrovascular disease from the Ontario Neurodegenerative Disease Research Initiative. RESULTS: PVS was significantly associated with sEF (c = -0.125 ± 0.054, 95% bootstrap confidence interval [CI] [-0.2309, -0.0189], p = 0.021). This effect was mediated by both GFAP and WMH. DISCUSSION: In this unique clinical cohort of neurodegenerative diseases, we demonstrated that the effect of PVS on sEF was mediated by the presence of elevated plasma GFAP and white matter disease. These findings highlight the potential utility of imaging and plasma biomarkers in the current landscape of therapeutics targeting dementia. HIGHLIGHTS: Perivascular spaces (PVS) and white matter hyperintensities (WMH) are imaging markers of small vessel disease. Plasma glial fibrillary protein acidic protein (GFAP) is a biomarker of astroglial injury. PVS, WMH, and GFAP are relevant in executive dysfunction from neurodegeneration. PVS's effect on executive function was mediated by GFAP and white matter disease.
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INTRODUCTION: We investigated whether novel plasma biomarkers are associated with cognition, cognitive decline, and functional independence in activities of daily living across and within neurodegenerative diseases. METHODS: Glial fibrillary acidic protein (GFAP), neurofilament light chain (NfL), phosphorylated tau (p-tau)181 and amyloid beta (Aß)42/40 were measured using ultra-sensitive Simoa immunoassays in 44 healthy controls and 480 participants diagnosed with Alzheimer's disease/mild cognitive impairment (AD/MCI), Parkinson's disease (PD), frontotemporal dementia (FTD) spectrum disorders, or cerebrovascular disease (CVD). RESULTS: GFAP, NfL, and/or p-tau181 were elevated among all diseases compared to controls, and were broadly associated with worse baseline cognitive performance, greater cognitive decline, and/or lower functional independence. While GFAP, NfL, and p-tau181 were highly predictive across diseases, p-tau181 was more specific to the AD/MCI cohort. Sparse associations were found in the FTD and CVD cohorts and for Aß42/40 . DISCUSSION: GFAP, NfL, and p-tau181 are valuable predictors of cognition and function across common neurodegenerative diseases, and may be useful in specialized clinics and clinical trials.
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Enfermedad de Alzheimer , Enfermedades Cardiovasculares , Disfunción Cognitiva , Demencia Frontotemporal , Enfermedades Neurodegenerativas , Humanos , Actividades Cotidianas , Péptidos beta-Amiloides , Ontario , Cognición , Biomarcadores , Proteínas tauRESUMEN
INTRODUCTION: Familial chylomicronemia syndrome (FCS) is a rare autosomal recessive condition. Effective treatment is important as patients are at risk for severe and potentially fatal acute pancreatitis. We review recent developments in pharmacologic treatment for FCS, namely biological inhibitors of apolipoprotein (apo) C-III and angiopoietin-like protein 3 (ANGPTL3). AREAS COVERED: FCS follows a biallelic inheritance pattern in which an individual inherits two pathogenic loss-of-function alleles of one of the five causal genes - LPL (in 60-80% of patients), GPIHBP1, APOA5, APOC2, and LMF1 - leading to the absence of lipolytic activity. Patients present from childhood with severely elevated triglyceride (TG) levels >10 mmol/L. Most patients with severe hypertriglyceridemia do not have FCS. A strict low-fat diet is the current first-line treatment, and existing lipid-lowering therapies are minimally effective in FCS. Apo C-III inhibitors are emerging TG-lowering therapies shown to be efficacious and safe in clinical trials. ANGPTL3 inhibitors, another class of emerging TG-lowering therapies, have been found to require at least partial lipoprotein lipase activity to lower plasma TG in clinical trials. ANGPTL3 inhibitors reduce plasma TG in patients with multifactorial chylomicronemia but not in patients with FCS who completely lack lipoprotein lipase activity. EXPERT OPINION: Apo C-III inhibitors currently in development are promising treatments for FCS.
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Proteína 3 Similar a la Angiopoyetina , Hiperlipoproteinemia Tipo I , Humanos , Hiperlipoproteinemia Tipo I/genética , Hiperlipoproteinemia Tipo I/tratamiento farmacológico , Hiperlipoproteinemia Tipo I/terapia , Apolipoproteína C-III/genética , Apolipoproteína C-III/antagonistas & inhibidores , Hipolipemiantes/uso terapéutico , Lipoproteína Lipasa/genética , Proteínas Similares a la Angiopoyetina/antagonistas & inhibidores , Proteínas Similares a la Angiopoyetina/genética , Dieta con Restricción de Grasas , Receptores de LipoproteínaRESUMEN
Atherosclerotic cardiovascular disease (ASCVD) is a significant health challenge, and apolipoprotein B (ApoB)-containing lipoproteins are increasingly recognized as central to its progression. Initially labelled as the "low-density lipoprotein hypothesis," our understanding of the etiology of ASCVD has evolved into the "ApoB principle," which highlights the causal and consistent role of all ApoB lipoproteins in ASCVD development. We review the large body of data from genetic studies, to epidemiologic studies, to clinical trials that support this foundational principle. We also provide an overview of the recommendations from guideline committees across the globe on dyslipidemia management and compare these with recent Canadian guidelines. With a few key differences, recent guidelines worldwide provide largely concordant recommendations for diagnosing and managing dyslipidemia with general consensus regarding the need for optimal control of low-density lipoprotein cholesterol and ApoB-containing lipoproteins to prevent cardiovascular events and improve patient care.
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Dislipidemias , Guías de Práctica Clínica como Asunto , Humanos , Dislipidemias/sangre , Dislipidemias/diagnóstico , Dislipidemias/terapia , Apolipoproteínas B/sangre , Aterosclerosis/prevención & control , Conducta de Reducción del Riesgo , Enfermedades Cardiovasculares/prevención & control , Canadá/epidemiología , LDL-Colesterol/sangre , Hipolipemiantes/uso terapéuticoRESUMEN
Lipoprotein(a) (Lp[a]) is an low-density lipoprotein (LDL)-like particle in which apolipoprotein (apo) B is covalently bound to a plasminogen-like molecule called apo(a). A High level of Lp(a) has been demonstrated to be an independent, causal, and prevalent risk factor for atherosclerotic cardiovascular disease (ASCVD), as well as aortic valve disease, through mechanisms that promote atherogenesis, inflammation, and thrombosis. With reliable and accessible assays, Lp(a) level has been established to be associated linearly with the risk for ASCVD. The 2021 Canadian Cardiovascular Society Dyslipidemia Guidelines recommend measuring an Lp(a) level once in a person's lifetime as part of the initial lipid screening. The aim of this review is to provide an update and overview of the utility and application of Lp(a) level in the assessment and treatment of adults at risk for ASCVD, consistent with this guideline recommendation.
La lipoprotéine(a), ou Lp(a), est une lipoprotéine de basse densité dans laquelle l'apolipoprotéine B est liée de manière covalente à une molécule semblable au plasminogène, l'apolipoprotéine(a). On a démontré qu'un taux élevé de Lp(a) est un facteur de risque indépendant, causal et fréquent d'athérosclérose cardiovasculaire (ASCV) et de valvulopathie aortique, en raison de mécanismes qui favorisent l'athérogénèse, l'inflammation et la thrombose. Des épreuves fiables et accessibles ont permis d'établir que le taux de Lp(a) était associé de façon linéaire à un risque d'ASCV. Dans ses lignes directrices de 2021 sur la prise en charge de la dyslipidémie, la Société cardiovasculaire du Canada recommande de mesurer le taux de Lp(a) une fois au cours de la vie d'une personne, dans le cadre du dépistage initial des lipides. Le présent article vise à fournir une mise à jour et un compte rendu de l'utilité et de l'application du taux de Lp(a) dans l'évaluation et le traitement des adultes présentant un risque d'ASCV, conformément à cette recommandation issue des lignes directrices.
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Background: Low density lipoprotein (LDL) and Lipoprotein (Lp)(a) are proatherogenic apolipoprotein (apo) B-containing members of the non-high-density lipoprotein (non-HDL) family of particles. Elevated plasma levels of LDL cholesterol (C), non-HDL-C, and apo B are defining features of heterozygous familial hypercholesterolemia (HeFH), but reports of elevated plasma Lp(a) concentration are inconsistent. Methods: We performed retrospective chart reviews of 256 genetically characterized patients with hypercholesterolemia and 272 control subjects from the Lipid Genetics Clinic at University Hospital in London, Ontario. We evaluated pairwise correlations between plasma levels of Lp(a) and those of LDL-C, non-HDL-C and apo B. Results: Mean Lp(a) levels were not different between individuals with hypercholesterolemia and control subjects. No correlations were found between Lp(a) and LDL-C or non-HDL-C levels in controls or patients with hypercholesterolemia; all r values < 0.079 and all P values > 0.193. Borderline weak correlations between Lp(a) and apo B were identified in patients r = 0.103; P = 0.112) and controls (r = 0.175; P = 0.005). Results were similar across genotypic subgroups. Conclusions: Lp(a) levels are independent of LDL-C and non-HDL-C; in particular Lp(a) levels are not increased in patients with hypercholesterolemia and molecularly proven HeFH. Apo B was only weakly associated with Lp(a). Elevated Lp(a) does not cause FH in our clinic patients. Genetic variants causing HeFH that raise LDL-C do not affect Lp(a), confirming that these lipoproteins are metabolically distinct. Lp(a) cannot be predicted from LDL-C and must be determined separately to evaluate its amplifying effect on atherosclerotic risk in patients with hypercholesterolemia.
Introduction: Les lipoprotéines de faible densité (LDL) et les lipoprotéines (Lp)(a) sont des éléments contenant des apolipoprotéines (apo)B proathérogènes de la famille des particules non à lipoprotéines de haute densité (non-HDL). Des concentrations plasmatiques élevées de cholestérol LDL, de cholestérol non-HDL et d'apoB sont des caractéristiques déterminantes de l'hypercholestérolémie familiale de type hétérozygote (HFHe), mais les documents qui portent sur les concentrations plasmatiques élevées de Lp(a) sont contradictoires. Méthodes: Nous avons effectué des revues rétrospectives de dossiers de 256 patients ayant les caractéristiques génétiques de l'hypercholestérolémie, et 272 témoins de la clinique de dyslipidémies génétiques de l'Hôpital universitaire de London, en Ontario. Nous avons évalué les corrélations par paires entre les concentrations plasmatiques de Lp(a) et celles du cholestérol LDL, du cholestérol non-HDL et de l'apoB. Résultats: Les concentrations moyennes de Lp(a) n'étaient pas différentes entre les individus atteints d'hypercholestérolémie et les témoins. Aucune corrélation n'a été observée entre les concentrations de Lp(a) et de cholestérol LDL ou de cholestérol nonHDL des témoins ou des patients atteints d'hypercholestérolémie ; toutes valeurs r < 0,079 et toutes valeurs P > 0,193. Nous avons relevé des corrélations limites faibles entre les concentrations de Lp(a) et d'apoB chez les patients r = 0,103 ; P = 0,112) et les témoins (r = 0,175 ; P = 0,005). Les résultats étaient similaires dans tous les sous-groupes génotypiques. Conclusions: Les concentrations de Lp(a) sont indépendantes des concentrations de cholestérol LDL et de cholestérol nonHDL ; notamment les concentrations de Lp(a) n'augmentent pas chez les patients atteints d'hypercholestérolémie et de HFHe moléculairement prouvée. L'apoB n'était que faiblement associée aux concentrations de Lp(a). Les concentrations élevées de Lp(a) ne causaient pas la HF chez les patients de notre clinique. Les variants génétiques causant la HFHe qui font augmenter les concentrations de cholestérol LDL n'affectent pas les concentrations de Lp(a), ce qui confirme que ces lipoprotéines sont distinctes sur le plan métabolique. Puisqu'on ne peut prédire les concentrations de Lp(a) à partir des concentrations de cholestérol LDL, elles doivent être déterminées séparément pour évaluer leur effet amplificateur sur le risque athérosclérotique des patients atteints d'hypercholestérolémie.
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Background and aims: Severe hypertriglyceridemia (HTG), defined as plasma triglyceride (TG) concentration > 10 mmol/L, is relatively uncommon, and its implications for atherosclerotic cardiovascular disease (ASCVD) risk remain somewhat unclear. We evaluated the association between severe HTG and carotid intima-media thickness (IMT), a marker for ASCVD. Methods: We studied three clinical cohorts: 88 patients with severe HTG (mean TG level 20.6 mmol/L), 271 patients with familial hypercholesterolemia (FH) as a contrast group, and 70 normolipidemic controls. Carotid IMT was measured using standardized ultrasound imaging. Statistical analysis was conducted using one-way analysis of variance (ANOVA) to compare mean IMT values, analysis of covariance (ANCOVA) to adjust for confounding variables, specifically age and sex, as well as Spearman pairwise correlation analysis between variables. Results: Unadjusted mean carotid IMT was greater in severe HTG and FH groups compared to controls, however, this was no longer significant for severe HTG after adjustment for age and sex. In contrast, adjusted carotid IMT remained significantly different between the FH and control groups. Conclusions: Our findings suggest that extreme TG elevations in severe HTG patients are not significantly associated with carotid IMT, in contrast to the increased IMT seen in FH patients. These findings add perspective to the complex relationship between severe HTG and ASCVD risk.
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BACKGROUND: Computational variant effect predictors offer a scalable and increasingly reliable means of interpreting human genetic variation, but concerns of circularity and bias have limited previous methods for evaluating and comparing predictors. Population-level cohorts of genotyped and phenotyped participants that have not been used in predictor training can facilitate an unbiased benchmarking of available methods. Using a curated set of human gene-trait associations with a reported rare-variant burden association, we evaluate the correlations of 24 computational variant effect predictors with associated human traits in the UK Biobank and All of Us cohorts. RESULTS: AlphaMissense outperformed all other predictors in inferring human traits based on rare missense variants in UK Biobank and All of Us participants. The overall rankings of computational variant effect predictors in these two cohorts showed a significant positive correlation. CONCLUSION: We describe a method to assess computational variant effect predictors that sidesteps the limitations of previous evaluations. This approach is generalizable to future predictors and could continue to inform predictor choice for personal and clinical genetics.