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1.
Eur Heart J ; 45(27): 2410-2418, 2024 Jul 12.
Article in English | MEDLINE | ID: mdl-38700053

ABSTRACT

BACKGROUND AND AIMS: Despite growing evidence that apolipoprotein B (apoB) is the most accurate marker of atherosclerotic cardiovascular disease (ASCVD) risk, its adoption in clinical practice has been low. This investigation sought to determine whether low-density lipoprotein cholesterol (LDL-C), non-high-density lipoprotein cholesterol (HDL-C), and triglycerides are sufficient for routine cardiovascular care. METHODS: A sample of 293 876 UK Biobank adults (age: 40-73 years, 42% men), free of cardiovascular disease, with a median follow-up for new-onset ASCVD of 11 years was included. Distribution of apoB at pre-specified levels of LDL-C, non-HDL-C, and triglycerides was examined graphically, and 10-year ASCVD event rates were compared for high vs. low apoB. Residuals of apoB were constructed after regressing apoB on LDL-C, non-HDL-C, and log-transformed triglycerides and used as predictors in a proportional hazards regression model for new-onset ASCVD adjusted for standard risk factors, including HDL-C. RESULTS: ApoB was highly correlated with LDL-C and non-HDL-C (Pearson's r = .96, P < .001 for both) but less so with log triglycerides (r = .42, P < .001). However, apoB ranges necessary to capture 95% of all observations at pre-specified levels of LDL-C, non-HDL-C, or triglycerides were wide, spanning 85.8-108.8 md/dL when LDL-C 130 mg/dL, 88.3-112.4 mg/dL when non-HDL-C 160 mg/dL, and 67.8-147.4 md/dL when triglycerides 115 mg/dL. At these levels (±10 mg/dL), 10-year ASCVD rates for apoB above mean + 1 SD vs. below mean - 1 SD were 7.3 vs. 4.0 for LDL-C, 6.4 vs. 4.6 for non-HDL-C, and 7.0 vs. 4.6 for triglycerides (all P < .001). With 19 982 new-onset ASCVD events on follow-up, in the adjusted model, residual apoB remained statistically significant after accounting for LDL-C and HDL-C (hazard ratio 1.06, 95% confidence interval 1.0-1.07), after accounting for non-HDL-C and HDL-C (hazard ratio 1.04, 95% confidence interval 1.03-1.06), and after accounting for triglycerides and HDL-C (hazard ratio 1.13, 95% confidence interval 1.12-1.15). None of the residuals of LDL-C, non-HDL-C, or of log triglycerides remained significant when apoB was included in the model. CONCLUSIONS: High variability of apoB at individual levels of LDL-C, non-HDL-C, and triglycerides coupled with meaningful differences in 10-year ASCVD rates and significant residual information contained in apoB for prediction of new-onset ASCVD events demonstrate that LDL-C, non-HDL-C, and triglycerides are not adequate proxies for apoB in clinical care.


Subject(s)
Apolipoproteins B , Biomarkers , Cholesterol, LDL , Triglycerides , Humans , Triglycerides/blood , Middle Aged , Female , Male , Aged , Adult , Cholesterol, LDL/blood , Biomarkers/blood , Apolipoproteins B/blood , Cholesterol, HDL/blood , Cardiovascular Diseases/prevention & control , Cardiovascular Diseases/blood , Cardiovascular Diseases/epidemiology
2.
Curr Opin Cardiol ; 39(1): 49-53, 2024 01 01.
Article in English | MEDLINE | ID: mdl-37934698

ABSTRACT

PURPOSE OF REVIEW: Some experts and consensus groups continue to argue that apolipoprotein B (apoB) should not be introduced broadly into clinical care. But, too often, the present approach to clinical care is not succeeding. An important reason for this failure, we believe, is that the conventional approach limits what the expert clinician can accomplish and is too complex, confusing, and contradictory for primary care physicians to apply effectively in their practise. RECENT FINDINGS: There are four major reasons that apoB should be measured routinely in clinical care. First, apoB is a more accurate marker of cardiovascular risk than LDL-C or non-HDL-C. Second, the measurement of apoB is standardized whereas the measurements of LDL-C and non-HDL-C are not. Third, with apoB and a conventional lipid panel, all the lipid phenotypes can be simply and accurately distinguished. This will improve the care of the expert. Fourth, apoB, as the single measure to evaluate the success of therapy, would simplify the process of care for primary care physicians. SUMMARY: By introducing apoB broadly into clinical care, the process of care will be improved for both the expert and the primary care physician, and this will improve the outcomes of care.


Subject(s)
Apolipoproteins B , Cardiovascular Diseases , Cholesterol , Humans , Cholesterol, HDL , Cholesterol, LDL , Lipoproteins , Cardiovascular Diseases/drug therapy
3.
Curr Opin Lipidol ; 34(6): 259-266, 2023 12 01.
Article in English | MEDLINE | ID: mdl-37773930

ABSTRACT

PURPOSE OF REVIEW: The triglyceride-rich apoB lipoprotein particles make up a minority of the apoB particles in plasma. They vary in size, in lipid, and in protein content. Most are small enough to enter the arterial wall and therefore most are atherogenic. But how important a contribution TRL particles make to the total risk created by the apoB lipoproteins remains controversial. A recent Mendelian randomization analysis determined that the cardiovascular risk related to the cholesterol within these apoB particles--the TRL cholesterol--was greater than--and independent of--the risk related to apoB. If correct, these observations have major clinical significance. RECENT FINDINGS: Accordingly, we have analyzed these results in detail. In our view, the independent strength of the association between TRL cholesterol and apoB with cardiovascular risk seems inconsistent with the biological connections between apoB and cholesterol as integral and highly correlated constituents of apoB particles. These results are also inconsistent with other lines of evidence such as the results of the fibrate randomized clinical trials. Moreover, we are also concerned with other aspects of the analysis. SUMMARY: We do not regard the issue as settled. However, this enquiry has led us to a fuller understanding of the determinants of the cholesterol content of the TRL apoB particles and the complex processing of cholesterol amongst the plasma lipoproteins.


Subject(s)
Cardiovascular Diseases , Humans , Cardiovascular Diseases/genetics , Risk Factors , Cholesterol/metabolism , Lipoproteins , Triglycerides , Apolipoproteins B , Heart Disease Risk Factors
4.
J Proteome Res ; 22(5): 1455-1465, 2023 05 05.
Article in English | MEDLINE | ID: mdl-37053489

ABSTRACT

The most abundant proteins on high-density lipoproteins (HDLs), apolipoproteins A-I (APOA1) and A-II (APOA2), are determinants of HDL function with 15 and 9 proteoforms (chemical-structure variants), respectively. The relative abundance of these proteoforms in human serum is associated with HDL cholesterol efflux capacity, and cholesterol content. However, the association between proteoform concentrations and HDL size is unknown. We employed a novel native-gel electrophoresis technique, clear native gel-eluted liquid fraction entrapment electrophoresis (CN-GELFrEE) paired with mass spectrometry of intact proteins to investigate this association. Pooled serum was fractionated using acrylamide gels of lengths 8 and 25 cm. Western blotting determined molecular diameter and intact-mass spectrometry determined proteoform profiles of each fraction. The 8- and 25 cm experiments generated 19 and 36 differently sized HDL fractions, respectively. The proteoform distribution varied across size. Fatty-acylated APOA1 proteoforms were associated with larger HDL sizes (Pearson's R = 0.94, p = 4 × 10-7) and were approximately four times more abundant in particles larger than 9.6 nm than in total serum; HDL-unbound APOA1 was acylation-free and contained the pro-peptide proAPOA1. APOA2 proteoform abundance was similar across HDL sizes. Our results establish CN-GELFrEE as an effective lipid-particle separation technique and suggest that acylated proteoforms of APOA1 are associated with larger HDL particles.


Subject(s)
Apolipoproteins , Lipoproteins, HDL , Humans , Particle Size , Lipoproteins, HDL/metabolism , Apolipoprotein A-I , Cholesterol/metabolism , Blotting, Western , Cholesterol, HDL
5.
Clin Chem ; 69(1): 48-55, 2023 01 04.
Article in English | MEDLINE | ID: mdl-36331823

ABSTRACT

BACKGROUND: We examined the interplay of apolipoprotein B (apoB) and LDL particle size, approximated by the LDL-cholesterol (LDL-C)/apoB ratio, on the risk of new-onset coronary heart disease (CHD). METHODS: Participants without cardiovascular disease from the UK Biobank (UKB; n = 308 182), the Women's Health Study (WHS; n = 26 204), and the Framingham Heart Study (FHS; n = 2839) were included. Multivariable Cox models were used to assess the relationship between apoB and LDL-C/apoB ratio and incidence of CHD (14 994 events). Our analyses were adjusted for age, sex (except WHS), HDL-cholesterol (HDL-C), systolic blood pressure, antihypertensive treatment, diabetes, and smoking. RESULTS: In all 3 studies, there was a strong positive correlation between apoB and LDL-C (correlation coefficients r = 0.80 or higher) and a weak inverse correlation of apoB with LDL-C/apoB ratio (-0.28 ≤ r ≤ -0.14). For all 3 cohorts, CHD risk was higher for higher levels of apoB. Upon multivariable adjustment, the association between apoB and new-onset CHD remained robust and statistically significant in all 3 cohorts with hazard ratios per 1 SD (95% CI): 1.24 (1.22-1.27), 1.33 (1.20-1.47), and 1.24 (1.09-1.42) for UKB, WHS, and FHS, respectively. However, the association between LDL-C/apoB and CHD was statistically significant only in the FHS cohort: 0.78 (0.64-0.94). CONCLUSIONS: Our analysis confirms that apoB is a strong risk factor for CHD. However, given the null association in 2 of the 3 studies, we cannot confirm that cholesterol-depleted LDL particles are substantially more atherogenic than cholesterol-replete particles. These results lend further support to routine measurement of apoB in clinical care.


Subject(s)
Coronary Disease , Humans , Female , Cholesterol, LDL , Particle Size , Coronary Disease/epidemiology , Coronary Disease/etiology , Apolipoproteins B , Cholesterol , Risk Factors , Cholesterol, HDL
6.
J Lipid Res ; 63(12): 100299, 2022 12.
Article in English | MEDLINE | ID: mdl-36272600

ABSTRACT

The cumulative exposure to apolipoprotein B (apoB)-containing lipoproteins in the blood during early adult life is a central determinant of atherosclerotic cardiovascular disease risk. To date, the patterns and rates of change in apoB through early adult life have not been described. Here, we used NMR to measure apoB concentrations in up to 3055 Coronary Artery Risk Development in Young Adults (CARDIA) Study participants who attended the years 2 (Y2), 7 (Y7), 15 (Y15), 20 (Y20), and 30 (Y30) exams. We examined individual-level spaghetti plots of apoB change, and we calculated average annualized rate of apoB concentration change during follow-up. We used multivariable linear regression models to assess the associations between CARDIA participant characteristics and annualized rates of apoB change. Male sex, higher measures of adiposity, lower HDL-C, lower Healthy Eating Index, and higher blood pressures were observed more commonly in individuals with higher apoB level at Y2 and Y20. Inter- and intra-individual variation in apoB concentration over time was substantial-while the mean (SD) rate of change was 0.52 (1.0) mg/dl/year, the range of annualized rates of change was -6.26 to +9.21 mg/dl/year. At baseline, lower first apoB measurement, female sex, White race, lower BMI, and current tobacco use were associated with apoB increase. We conclude that the significant variance in apoB level over time and the modest association between baseline measures and rates of apoB change suggest that the ability to predict an individual's future apoB serum concentrations, and thus their cumulative apoB exposure, after a one-time assessment in young adulthood is low.


Subject(s)
Apolipoproteins B , Coronary Vessels , Young Adult , Humans , Male , Female , Adult , Risk Factors , Heart , Obesity
7.
Int J Mol Sci ; 23(16)2022 Aug 20.
Article in English | MEDLINE | ID: mdl-36012684

ABSTRACT

Cholesteryl ester transfer protein (CETP) facilitates the exchange of cholesteryl esters and triglycerides (TG) between high-density lipoprotein (HDL) particles and TG-rich, apolipoprotein (apo) B-containing particles. Initially, these compounds were developed to raise plasma HDL cholesterol (HDL-C) levels, a mechanism that was previously thought to lower the risk of atherosclerotic cardiovascular disease (ASCVD). More recently, the focus changed and the use of pharmacologic CETP inhibitors to reduce low-density lipoprotein cholesterol (LDL-C), non-HDL-C and apoB concentrations became supported by several lines of evidence from animal models, observational investigations, randomized controlled trials and Mendelian randomization studies. Furthermore, a cardiovascular outcome trial of anacetrapib demonstrated that CETP inhibition significantly reduced the risk of major coronary events in patients with ASCVD in a manner directly proportional to the substantial reduction in LDL-C and apoB. These data have dramatically shifted the attention on CETP away from raising HDL-C instead to lowering apoB-containing lipoproteins, which is relevant since the newest CETP inhibitor, obicetrapib, reduces LDL-C by up to 51% and apoB by up to 30% when taken in combination with a high-intensity statin. An ongoing cardiovascular outcome trial of obicetrapib in patients with ASCVD is expected to provide further evidence of the ability of CETP inhibitors to reduce major adverse cardiovascular events by lowering apoB. The purpose of the present review is to provide an up-to-date understanding of CETP inhibition and its relationship to ASCVD risk reduction.


Subject(s)
Atherosclerosis , Hydroxymethylglutaryl-CoA Reductase Inhibitors , Animals , Apolipoproteins B/metabolism , Cholesterol Ester Transfer Proteins/metabolism , Cholesterol, HDL/metabolism , Cholesterol, LDL , Triglycerides
8.
Curr Opin Lipidol ; 32(4): 226-230, 2021 08 01.
Article in English | MEDLINE | ID: mdl-33870931

ABSTRACT

PURPOSE OF REVIEW: The 2019 European Society of Cardiology/European Atherosclerosis Society Guidelines concluded that apolipoprotein B (apoB) was a more accurate measure of cardiovascular risk and a better guide to the adequacy of lipid lowering than low-density lipoprotein cholesterol (LDL-C) or non-high-density lipoprotein cholesterol (HDL-C). Also, they stated that apoB can be measured more accurately than LDL-C or non-HDL-C. This strong endorsement of the central role of apoB contrasts with the limited endorsement of apoB by the 2018 American College of Cardiology/American Heart Association Multisociety Guidelines. Nevertheless, both retained LDL-C as the primary metric to guide statin/ezetimibe/Proprotein convertase subtilisin/kexin type 9 (PCSK9) therapy. RECENT FINDINGS: This essay will review the most important recent advances in knowledge about apoB with particular emphasis on the results of Mendelian randomization studies and a new discordance analysis in subjects on statin therapy. We will also lay out why using LDL-C to guide the adequacy of lipid lowering therapy represents an interpretive error of the results of the statin/ezetimibe/PCSK9 inhibitor randomized clinical trials and therefore why apoB should be the primary metric to guide statin/ezetimibe/PCSK9 therapy. SUMMARY: There is now a robust body of evidence demonstrating the superiority of apoB over LDL-C and non-HDL-C as a clinical marker of cardiovascular risk. LDL-C is not the appropriate marker to assess the benefits of statin/ezetimibe/PCSK9 therapy.


Subject(s)
Apolipoproteins B , Cardiovascular Diseases , Hypolipidemic Agents , Cardiovascular Diseases/diagnosis , Cardiovascular Diseases/drug therapy , Humans , Hydroxymethylglutaryl-CoA Reductase Inhibitors , Mendelian Randomization Analysis
9.
Circulation ; 142(9): 827-837, 2020 09.
Article in English | MEDLINE | ID: mdl-32700572

ABSTRACT

BACKGROUND: Lipid-lowering recommendations for prevention of atherosclerotic cardiovascular disease rely principally on estimated 10-year risk. We sought to determine the optimal time for initiation of lipid lowering in younger adults as a function of expected 30-year benefit. METHODS: Data from 3148 National Health and Nutrition Examination Survey (2009-2016) participants, age 30 to 59 years, not eligible for lipid-lowering treatment recommendation under the most recent US guidelines, were analyzed. We estimated the absolute and relative impact of lipid lowering as a function of age, age at initiation, and non-high-density lipoprotein cholesterol (HDL-C) level on the expected rates of atherosclerotic cardiovascular disease over the succeeding 30 years. We modeled expected risk reductions based on shorter-term effects observed in statin trials (model A) and longer-term benefits based on Mendelian randomization studies (model B). RESULTS: In both models, potential reductions in predicted 30-year atherosclerotic cardiovascular disease risk were greater with older age and higher non-HDL-C level. Immediate initiation of lipid lowering (ie, treatment for 30 years) in 40- to 49-year-old patients with non-HDL-C ≥160 mg/dL would be expected to reduce their average predicted 30-year risk of 17.1% to 11.6% (model A; absolute risk reduction [ARR], 5.5%) or 6.5% (model B; ARR 10.6%). Delaying lipid lowering by 10 years (treatment for 20 years) would result in residual 30-year risk of 12.7% (A; ARR 4.4) or 9.9% (B; ARR 7.2%) and delaying by 20 years (treatment for 10 years) would lead to expected mean residual risk of 14.6% (A; ARR 2.6%) or 13.9% (B; ARR 3.2%). The slope of the achieved ARR as a function of delay in treatment was also higher with older age and higher non-HDL-C level. CONCLUSIONS: Substantial reduction in expected atherosclerotic cardiovascular disease risk in the next 30 years is achievable by intensive lipid lowering in individuals in their 40s and 50s with non-HDL-C ≥160 mg/dL. For many, the question of when to start lipid lowering might be more relevant than whether to start lipid lowering.


Subject(s)
Atherosclerosis/blood , Atherosclerosis/prevention & control , Cholesterol, HDL/blood , Hydroxymethylglutaryl-CoA Reductase Inhibitors/administration & dosage , Models, Cardiovascular , Primary Prevention , Adult , Female , Humans , Male , Middle Aged
10.
Circulation ; 139(13): 1603-1611, 2019 03 26.
Article in English | MEDLINE | ID: mdl-30586759

ABSTRACT

BACKGROUND: To optimize preventive strategies for coronary heart disease (CHD), it is essential to understand and appropriately quantify the contribution of its key risk factors. Our objective was to compare the associations of key modifiable CHD risk factors-specifically lipids, systolic blood pressure (SBP), diabetes mellitus, and smoking-with incident CHD events based on their prognostic performance, attributable risk fractions, and treatment benefits, overall and by age. METHODS: Pooled participant-level data from 4 observational cohort studies sponsored by the National Heart, Lung, and Blood Institute were used to create a cohort of 22 626 individuals aged 45 to 84 years who were initially free of cardiovascular disease. Individuals were followed for 10 years from baseline evaluation for incident CHD. Proportional hazards regression was used to estimate metrics of prognostic model performance (likelihood ratio, C index, net reclassification, discrimination slope), hazard ratios, and population attributable fractions for SBP, non-high-density lipoprotein cholesterol (non-HDL-C), diabetes mellitus, and smoking. Expected absolute risk reductions for antihypertensive and lipid-lowering treatment were assessed. RESULTS: Age, sex, and race capture 63% to 80% of the prognostic performance of cardiovascular risk models. In contrast, adding either SBP, non-HDL-C, diabetes mellitus, or smoking to a model with other risk factors increases the C index by only 0.004 to 0.013. However, primordial prevention could have a substantial effect as demonstrated by population attributable fractions of 28% for SBP≥130 mm Hg and 17% for non-HDL-C≥130 mg/dL. Similarly, lowering the SBP of all individuals to <130 mm Hg or lowering low-density lipoprotein cholesterol by 30% would be expected to lower a baseline 10-year CHD risk of 10.7% to 7.0 and 8.0, respectively (absolute risk reductions: 3.7% and 2.7%, respectively). Prognostic performance decreases with age (C indices for age groups 45-54, 55-64, 65-74, 75-84 are 0.75, 0.72, 0.66, and 0.62, respectively), whereas absolute risk reductions increase (SBP: 1.1%, 2.3%, 5.4%, 10.3%, respectively; non-HDL-C: 1.1%, 2.0%, 3.7%, 5.9%, respectively). CONCLUSIONS: Although individual modifiable CHD risk factors contribute only modestly to prognostic performance, our models indicate that eliminating or controlling these individual factors would lead to substantial reductions in total population CHD events. Metrics used to judge importance of risk factors should be tailored to the research objectives.


Subject(s)
Blood Pressure , Cholesterol, HDL/blood , Cholesterol, LDL/blood , Coronary Disease/blood , Coronary Disease/physiopathology , Aged , Aged, 80 and over , Coronary Disease/epidemiology , Diabetes Mellitus/blood , Diabetes Mellitus/epidemiology , Diabetes Mellitus/physiopathology , Female , Humans , Male , Middle Aged , Risk Factors
11.
Curr Cardiol Rep ; 22(8): 67, 2020 06 19.
Article in English | MEDLINE | ID: mdl-32562186

ABSTRACT

PURPOSE OF REVIEW: Guidelines propose using non-HDL cholesterol or apolipoprotein (apo) B as a secondary treatment target to reduce residual cardiovascular risk of LDL-targeted therapies. This review summarizes the strengths, weaknesses, opportunities, and threats (SWOT) of using apoB compared with non-HDL cholesterol. RECENT FINDINGS: Non-HDL cholesterol, calculated as total-HDL cholesterol, includes the assessment of remnant lipoprotein cholesterol, an additional risk factor independent of LDL cholesterol. ApoB is a direct measure of circulating numbers of atherogenic lipoproteins, and its measurement can be standardized across laboratories worldwide. Discordance analysis of non-HDL cholesterol versus apoB demonstrates that apoB is the more accurate marker of cardiovascular risk. Baseline and on-treatment apoB can identify elevated numbers of small cholesterol-depleted LDL particles that are not reflected by LDL and non-HDL cholesterol. ApoB is superior to non-HDL cholesterol as a secondary target in patients with mild-to-moderate hypertriglyceridemia (175-880 mg/dL), diabetes, obesity or metabolic syndrome, or very low LDL cholesterol < 70 mg/dL. When apoB is not available, non-HDL cholesterol should be used to supplement LDLC.


Subject(s)
Apolipoproteins B , Cardiovascular Diseases , Cholesterol , Cholesterol, HDL , Cholesterol, LDL , Humans , Lipoproteins
13.
Arterioscler Thromb Vasc Biol ; 38(1): 262-265, 2018 01.
Article in English | MEDLINE | ID: mdl-29122815

ABSTRACT

OBJECTIVE: To reanalyze data from recent randomized trials of statins to assess whether the benefits and risks of statins are mediated primarily via their LDL-C (low-density lipoprotein cholesterol) lowering effects or via other mechanisms. APPROACH AND RESULTS: We adapted Egger regression, a technique frequently used in Mendelian randomization studies to detect genetic pleiotropy, to reanalyze the available randomized control trial data of statin therapy. For cardiovascular end points, each 1 mmol/L change in LDL-C with statin therapy was associated with a hazard ratio of 0.77 (95% confidence interval, 0.71-0.84) with an intercept that was indistinguishable from zero (intercept, -0.0032; [95% confidence interval, -0.090 to 0.084]; P=0.94), indicating no pleiotropy. For incident diabetes mellitus, a 1 mmol/L change in LDL-C with statin therapy was associated with a hazard ratio of 1.07 (95% confidence interval, 0.99-1.16) and an intercept nondistinguishable from zero (intercept, -0.015; [95% confidence interval, -0.30 to 0.27]; P=0.91), again indicating no pleiotropy. CONCLUSIONS: Our reanalysis of the randomized control trial data using Egger regression adds to the existing evidence that the cardiovascular benefits of statins and their association with incident diabetes mellitus are mediated primarily, if not entirely, via their LDL-C lowering properties rather than by any pleiotropic effects.


Subject(s)
Cardiovascular Diseases/drug therapy , Cholesterol, LDL/blood , Diabetes Mellitus/drug therapy , Dyslipidemias/drug therapy , Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use , Biomarkers/blood , Cardiovascular Diseases/blood , Cardiovascular Diseases/diagnosis , Cardiovascular Diseases/epidemiology , Diabetes Mellitus/blood , Diabetes Mellitus/diagnosis , Diabetes Mellitus/epidemiology , Dyslipidemias/blood , Dyslipidemias/diagnosis , Dyslipidemias/epidemiology , Evidence-Based Medicine , Humans , Incidence , Primary Prevention/methods , Randomized Controlled Trials as Topic , Regression Analysis , Risk Factors , Secondary Prevention/methods , Treatment Outcome
14.
J Lipid Res ; 59(7): 1266-1275, 2018 07.
Article in English | MEDLINE | ID: mdl-29769239

ABSTRACT

Triglycerides are the conventional tool to measure VLDLs, whereas LDL cholesterol (LDL-C) is the conventional tool to measure LDLs. Multiple epidemiological studies, including a series of genetically based analyses, have demonstrated that cardiovascular risk is related to triglycerides independently of LDL-C, and this has led to a series of new therapeutic agents designed specifically to reduce plasma triglycerides. The triglyceride hypothesis posits that increased levels of triglycerides increase cardiovascular risk and decreasing plasma triglycerides decreases cardiovascular risk. In this work, we will examine the validity of the triglyceride hypothesis by detailing the biological complexities associated with hypertriglyceridemia, the genetic epidemiological evidence in favor of hypertriglyceridemia, the evidence from the fibrate randomized clinical trials relating triglycerides and clinical outcomes, and the completeness of the evidence from the initial studies of novel mutations and the therapeutic agents based on these mutations that lower triglycerides. Because of the multiple metabolic links between VLDL and LDL, we will try to demonstrate that measuring triglycerides and LDL-C alone are inadequate to document the lipoprotein profile. We will try to demonstrate that apoB must be measured, as well as triglycerides and cholesterol, to have an accurate estimate of lipoprotein status.


Subject(s)
Cardiovascular Diseases/epidemiology , Cardiovascular Diseases/metabolism , Hypertriglyceridemia/epidemiology , Hypertriglyceridemia/metabolism , Apolipoproteins B/metabolism , Cardiovascular Diseases/genetics , Cardiovascular Diseases/therapy , Humans , Hypertriglyceridemia/genetics , Hypertriglyceridemia/therapy , Lipoproteins/metabolism , Risk Factors
15.
J Proteome Res ; 17(6): 2156-2164, 2018 06 01.
Article in English | MEDLINE | ID: mdl-29649363

ABSTRACT

Top-down proteomics (TDP) allows precise determination/characterization of the different proteoforms derived from the expression of a single gene. In this study, we targeted apolipoprotein A-I (ApoA-I), a mediator of high-density-lipoprotein cholesterol efflux (HDL-E), which is inversely associated with coronary heart disease risk. Absolute ApoA-I concentration and allelic variation only partially explain interindividual HDL-E variation. Therefore, we hypothesize that differences in HDL-E are associated with the abundances of different ApoA-I proteoforms. Here, we present a targeted TDP methodology to characterize ApoA-I proteoforms in serum samples and compare their abundances between individuals. We characterized 18 ApoA-I proteoforms using selected-ion monitoring coupled to electron-transfer dissociation mass spectrometry. We then compared the abundances of these proteoforms between two groups of four participants, representing the individuals with highest and lowest HDL-E values within the Chicago Healthy Aging Study ( n = 420). Six proteoforms showed significantly ( p < 0.0005) higher intensity in high HDL-E individuals: canonical ApoA-I [fold difference (fd) = 1.17], carboxymethylated ApoA-I (fd = 1.24) and, with highest difference, four fatty acylated forms: palmitoylated (fd = 2.16), oleoylated (fd = 2.08), arachidonoylated (fd = 2.31) and one bearing two modifications: palmitoylation and truncation (fd = 2.13). These results demonstrate translational potential for targeted TDP in revealing, with high sensitivity, associations between interindividual proteoform variation and physiological differences underlying disease risk.


Subject(s)
Apolipoprotein A-I/blood , Lipoproteins, HDL/metabolism , Proteomics/methods , Aged , Biological Transport , Cholesterol/metabolism , Female , Humans , Male , Mass Spectrometry/methods , Precision Medicine , Protein Processing, Post-Translational , Specimen Handling
17.
CMAJ ; 195(47): E1644-E1645, 2023 Dec 03.
Article in French | MEDLINE | ID: mdl-38049165
18.
Nephrology (Carlton) ; 23(1): 69-74, 2018 Jan.
Article in English | MEDLINE | ID: mdl-27718506

ABSTRACT

AIM: This study aims to describe the variability of pre-dialysis troponin values in stable haemodialysis patients and compare the performance of single versus fluctuating or persistently elevated troponins in predicting a composite of mortality and cardiac arrest, myocardial infarction or stroke. METHODS: A total of 128 stable ambulatory chronic haemodialysis patients were enrolled. Pre-dialysis troponin I was measured for three consecutive months. The patients were followed for 1 year. A troponin elevation (>0.06 µg/L) was considered high risk, and patients were classified into three risk groups: (i) patients who had normal troponin levels on all three measurements; (ii) patients with at least one elevated and one normal troponin value; and (iii) patients with elevated troponin values on all measurements. RESULTS: A total of 81 patients had all three troponin values in the normal range; 29 had fluctuating values; 18 had all three values elevated. Twenty-seven deaths or composite events were observed: eight in the first risk group, 10 in the second and nine in the third. Persistently elevated and fluctuating troponin values were associated with higher mortality and cardiovascular event rate. Serial troponin measurement had a higher sensitivity for the composite outcome than single troponin measurement when either fluctuating or persistently elevated values were considered to confer high risk. CONCLUSION: Most haemodialysis patients do not have elevated troponin levels at baseline. Troponin levels that remain elevated or fluctuate are associated with worse outcomes. A serial troponin measurement strategy is associated with better sensitivity and higher negative predictive value compared with single troponin measurement.


Subject(s)
Cardiovascular Diseases/blood , Cardiovascular Diseases/mortality , Renal Dialysis/mortality , Renal Insufficiency, Chronic/therapy , Troponin/blood , Aged , Aged, 80 and over , Biomarkers/blood , Cardiovascular Diseases/diagnosis , Female , Heart Arrest/blood , Heart Arrest/diagnosis , Heart Arrest/mortality , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Myocardial Infarction/blood , Myocardial Infarction/diagnosis , Myocardial Infarction/mortality , Predictive Value of Tests , Proportional Hazards Models , Prospective Studies , Renal Dialysis/adverse effects , Renal Insufficiency, Chronic/diagnosis , Renal Insufficiency, Chronic/mortality , Risk Factors , Stroke/blood , Stroke/diagnosis , Stroke/mortality , Time Factors , Treatment Outcome , Up-Regulation
20.
Circulation ; 133(16): 1574-81, 2016 Apr 19.
Article in English | MEDLINE | ID: mdl-26945047

ABSTRACT

BACKGROUND: Current guidelines recommend statins in the primary prevention of cardiovascular disease on the basis of predicted cardiovascular risk without directly considering the expected benefits of statin therapy based on the available randomized, controlled trial evidence. METHODS AND RESULTS: We included 2134 participants representing 71.8 million American residents potentially eligible for statins in primary prevention from the National Health and Nutrition Examination Survey for the years 2005 to 2010. We compared statin eligibilities using 2 separate approaches: a 10-year risk-based approach (≥7.5% 10-year risk) and an individualized benefit approach (ie, based on predicted absolute risk reduction over 10 years [ARR10] ≥2.3% from randomized, controlled trial data). A risk-based approach led to the eligibility of 15.0 million (95% confidence interval, 12.7-17.3 million) Americans, whereas a benefit-based approach identified 24.6 million (95% confidence interval, 21.0-28.1 million). The corresponding numbers needed to treat over 10 years were 21 (range, 9-44) and 25 (range, 9-44). The benefit-based approach identified 9.5 million lower-risk (<7.5% 10-year risk) Americans not currently eligible for statin treatment who had the same or greater expected benefit from statins (≥2.3% ARR10) compared with higher-risk individuals. This lower-risk/acceptable-benefit group includes younger individuals (mean age, 55.2 versus 62.5 years; P<0.001 for benefit based versus risk based) with higher low-density lipoprotein cholesterol (140 versus133 mg/dL; P=0.01). Statin treatment in this group would be expected to prevent an additional 266 508 cardiovascular events over 10 years. CONCLUSIONS: An individualized statin benefit approach can identify lower-risk individuals who have equal or greater expected benefit from statins in primary prevention compared with higher-risk individuals. This approach may help develop guideline recommendations that better identify individuals who meaningfully benefit from statin therapy.


Subject(s)
Cardiovascular Diseases/diagnosis , Cardiovascular Diseases/prevention & control , Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use , Nutrition Surveys , Precision Medicine/methods , Primary Prevention/methods , Adult , Aged , Female , Humans , Male , Middle Aged , Randomized Controlled Trials as Topic/methods
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