👤 René R Sevag Packard

Circulating apoB-containing lipoproteins fall into three principal categories- low-density lipoproteins (LDLs), triglyceride-rich lipoproteins (TRLs) and lipoprotein(a) [Lp(a)]. These three different lipoproteins are all causally related to atherosclerotic cardiovascular disease (ASCVD) and together account for the full spectrum of apoB-related atherogenic risk. They vary substantially in metabolic and kinetic properties, size and lipid composition and may affect the atherosclerotic pathogenic process differently. Indeed, genetic evidence indicates that TRLs and Lp(a) are several-fold more atherogenic per particle than LDL in terms of ASCVD risk. On the other hand, Lp(a) and TRLs are typically much less abundant than LDL. How should these countervailing factors be balanced to understand their net contribution to risk? In this review, we summarize the evidence relating to the atherogenicity of LDLs, TRLs and Lp(a) and explore the implications for risk stratification and therapeutic strategies. We argue that LDL lowering will remain the cornerstone of apoB-related risk reduction, but eradication of residual risk necessitates combination therapies targeting TRLs and/or Lp(a) in addition to LDL. Show less

LDL-C and non-HDL-C do not fully capture coronary heart disease (CHD) risk attributed to all apoB-containing lipoproteins. Use of apolipoprotein B (apoB) as a marker of total atherogenic particle number improves risk prediction, but risk may still be underestimated when triglyceride-rich lipoproteins (TRL/remnants) and lipoprotein(a) [Lp(a)] are elevated. The aim was to formulate a new metric-risk-weighted apoB (RW-apoB)-designed to capture risk from LDL, TRL/remnants, and Lp(a) in a single number. Based on previously published estimates of the relative atherogenicity of LDL, TRL/remnant, and Lp(a) particles, RW-apoB was developed (using UK Biobank data) as an atherogenicity-weighted apoB-sum calculated as: RW-apoB = 11.65×TG(mmol/L) + 0.215×lipoprotein(a)(nmol/L) + 0.736×apoB(mg/dL). Assigning RW-apoB to individuals substantially reclassified their risk status. Compared with ranking by measured apoB, 52% of individuals were up- or down-ranked by ≥10 percentiles. About one-third of those in the top RW-apoB quintile-with elevated TRL and Lp(a) and a CHD event rate of 5.4%-were misclassified as lower risk by apoB. Conversely, individuals in the top measured apoB quintile but with low TRL and Lp(a) had a lower event rate (3.9%) and were correctly down-ranked. RW-apoB improved risk prediction, significantly increasing Harrell's C-index relative to apoB (P < .0001). In statin-treated subjects, RW-apoB was potentially a better index of residual risk. RW-apoB consistently outperformed apoB as a risk predictor in Cox models across the UK Biobank and three other large population cohorts. RW-apoB represents not only particle number but also accounts for the higher atherogenicity of TRL and Lp(a). It offers clinically meaningful improvements in CHD risk stratification. Show less

Apolipoprotein C-III (apoC-III) has emerged as a pivotal regulator of triglyceride metabolism and a key factor in cardiovascular risk. This review explores the physiological and pathological roles of apoC-III, focusing on kinetic mechanisms, genetic data, and the therapeutic potential of targeting apoC-III. Loss-of-function mutations in APOC3 significantly lower plasma triglyceride levels and coronary heart disease risk, validating apoC-III as a therapeutic target. Kinetic studies indicate that increased hepatic secretion of apoC-III raises triglyceride levels, particularly in individuals with type 2 diabetes. Beyond lipid metabolism, apoC-III promotes lipoprotein retention and amplifies arterial inflammation. Novel inhibitors, such as antisense oligonucleotides targeting APOC3, have been shown to markedly reduce plasma apoC-III and triglyceride concentrations in both preclinical and clinical studies. Genetic and mechanistic evidence together establish the inhibition of apoC-III as a promising strategy for patients at high risk of persistent hypertriglyceridemia and cardiovascular disease. ApoC-III not only controls lipid metabolism but also exerts direct pro-atherogenic and pro-inflammatory effects, supporting its role as a multifaceted therapeutic target in cardiometabolic medicine. Show less

Apolipoprotein B-containing triglyceride-rich lipoproteins (TRLs) -chylomicrons, very low-density lipoproteins (VLDL), their remnants, and intermediate-density lipoproteins (IDL) - are recognised as key contributors to atherosclerotic cardiovascular disease (ASCVD). On a per particle basis, genetic and clinical evidence indicates that TRL/remnants exhibit a greater atherogenic potential than LDL and evidence points to this being mediated by enhanced arterial wall retention of TRLs, the pro-inflammatory actions of their constituent apolipoproteins and cargo of cholesterol and bioactive lipids, and their capacity to induce endothelial dysfunction. Despite the strong association between plasma triglyceride levels and ASCVD, TRL-lowering trials have produced inconsistent, often negative results. The answer to this conundrum, as explored here, likely lies in the complexity of TRL structure, composition and metabolism, and in the dynamic influence that TRLs have on the properties of LDL, the most abundant atherogenic lipoprotein. The substantial heterogeneity in the TRL/remnant/IDL spectrum means that these particles present a wide range of potentially pathogenic factors to the artery wall in the form of major and minor lipids and a variety of surface apolipoproteins. Significant gaps exist in our knowledge: how are TRL remodelled during their lifetime in the bloodstream to become cholesterol-enriched lipoproteins; which are the most relevant TRL subspecies or TRL constituents, that initiate and progress the formation of atherosclerotic lesions; and what are the prime targets for effective intervention. Critical to the design of future triglyceride-lowering prevention trials will be the development of superior biomarkers of TRL/remnant atherogenicity and the development of a precision medicine approach to ASCVD prevention. Show less

Apolipoprotein C-III (apoC-III) is an important regulator of triglyceride (TG) metabolism and a target for intervention. The present study examined the effects of gain-of-function (GOF) variants in APOC3 on apolipoprotein B kinetics to understand further how changes in the synthesis of this apolipoprotein impact triglyceride-rich lipoprotein (TRL) metabolism. Two groups of subjects were recruited by population screening, 9 carriers of known APOC3 GOF variants and 9 age-, sex- and BMI-matched non-carriers. The kinetics of TRL were determined using stable isotope tracers of apoprotein and triglyceride metabolism in a non-steady-state protocol involving administration of a fat-rich meal. APOC3 GOF carriers had 47 % higher plasma apoC-III levels compared to non-carriers (P = 0.022) and higher production rates for the apolipoprotein. Post-prandial response (total area-under-curve) for plasma TG was 108 % greater in GOF carriers compared to non-carriers (P = 0.002) due specifically to higher levels of VLDL APOC3 GOF carriers showed specific alterations in TRL metabolism (compared to matched non-carriers), namely slower lipolysis and delayed clearance of VLDL Show less

Apolipoprotein B (apoB) is the main structural protein of LDLs, triglyceride-rich lipoproteins and lipoprotein(a), and is crucial for their formation, metabolism and atherogenic properties. In this Review, we present insights into the role of apoB-containing lipoproteins in atherogenesis, with an emphasis on the mechanisms leading to plaque initiation and growth. LDL, the most abundant cholesterol-rich lipoprotein in plasma, is causally linked to atherosclerosis. LDL enters the artery wall by transcytosis and, in vulnerable regions, is retained in the subendothelial space by binding to proteoglycans via specific sites on apoB. A maladaptive response ensues. This response involves modification of LDL particles, which promotes LDL retention and the release of bioactive lipid products that trigger inflammatory responses in vascular cells, as well as adaptive immune responses. Resident and recruited macrophages take up modified LDL, leading to foam cell formation and ultimately cell death due to inadequate cellular lipid handling. Accumulation of dead cells and cholesterol crystallization are hallmarks of the necrotic core of atherosclerotic plaques. Other apoB-containing lipoproteins, although less abundant, have substantially greater atherogenicity per particle than LDL. These lipoproteins probably contribute to atherogenesis in a similar way to LDL but might also induce additional pathogenic mechanisms. Several targets for intervention to reduce the rate of atherosclerotic lesion initiation and progression have now been identified, including lowering plasma lipoprotein levels and modulating the maladaptive responses in the artery wall. Show less

Triglyceride-rich lipoproteins (TRLs) and remnants are established causal risk factors for coronary heart disease (CHD). APOC3 gene-silencing agents reduce TRL/remnant concentrations but the consequent quantitative effect on CHD risk is not yet defined. We used a polygenic score (PGS)-based model to investigate if the degree of TRL/remnant reduction seen on APOC3 silencing would lead to a meaningful reduction in CHD risk. A TRL/remnant-specific PGS was used to select two groups (each >4,150 individuals) from the UK Biobank. CHD event rates were compared between the group with the highest PGS with genetically higher TRL/remnant levels (mimicking placebo) and the group with the lowest PGS with lower levels (mimicking APOC3 silencing). Compared with the high PGS group, the low PGS group had lower plasma triglycerides (-34%), TRL/remnant cholesterol (-22.5%), non-HDL cholesterol (-7.5%) and apolipoprotein B (-6.0%), with a small reduction in LDL cholesterol (-3.9%) and a 15.3% increase in HDL cholesterol. These differences were similar to those seen with APOC3 silencing agents, but with about a third of the absolute effect size. The low PGS group had a 28% lower lifetime CHD event rate (HR = 0.72, 95% CI:0.56-0.91). Extrapolating to a 5-year trial, an APOC3 silencing agent achieving a 16-23 mg/dL decrease in TRL/remnant cholesterol is predicted to reduce CHD risk by approximately 25%. Based on our genetic modelling, the degree of TRL/remnant lowering seen on APOC3 silencing would produce a meaningful CHD risk reduction of around 25 % over a 5-year outcomes trial. Show less

Triglyceride-rich lipoproteins and remnants (TRL/remnants) have a causal, but not yet quantified, relationship with coronary heart disease (CHD): myocardial infarction plus revascularization. The authors sought to estimate TRL/remnant per-particle atherogenicity, investigate causal relationships with inflammation, and determine whether differences in the atherogenicity of TRL/remnants and low-density lipoprotein (LDL) impact the causal association of non-high-density lipoprotein cholesterol (non-HDL-C) with CHD. Single nucleotide polymorphisms (SNPs) (N = 1,357) identified by genome-wide association in the UK Biobank were ranked into 10 clusters according to the effect on TRL/remnant-C vs LDL-C. Mendelian randomization analysis was used to estimate for each SNP cluster CHD ORs per 10 mg/dL apolipoprotein B (apoB) and per 0.33 mmol/L non-HDL-cholesterol, and to evaluate association of TRL/remnants with biomarkers of systemic inflammation. SNPs in cluster 1 predominantly affected LDL-C, whereas SNPs in cluster 10 predominantly affected TRL/remnant-C. CHD risk per genetically predicted increase in apoB and in non-HDL-C rose across clusters. ORs per 10 mg/dL higher apoB was 1.15 (95% CI: 1.11-1.19) in cluster 1 vs 1.70 (95% CI: 1.52-1.90) in cluster 10. Comparing ORs between these TRL/remnant-predominant and LDL-predominant clusters, we estimated that TRL/remnants were at least 3.9 (95% CI: 2.8-5.4) times more atherogenic than LDL on a per-particle basis. For non-HDL-C, CHD ORs per 0.33 mmol/L rose from 1.15 (95% CI: 1.11-1.19) for cluster 1 to 1.40 (95% CI: 1.30-1.50) for cluster 10. TRL/remnants exhibited causal relationships with inflammation, but this did not explain their greater atherogenicity. TRL/remnants are about 4 times more atherogenic than LDL. Variation in the causal association of non-HDL-C with CHD indicates that adjustment for percentage TRL/remnant-C may be needed for accurate risk prediction. Show less

The availability of pharmacological approaches able to effectively reduce circulating LDL cholesterol (LDL-C) has led to a substantial reduction in the risk of atherosclerosis-related cardiovascular disease (CVD). However, a residual cardiovascular (CV) risk persists in treated individuals with optimal levels of LDL-C. Additional risk factors beyond LDL-C are involved, and among these, elevated levels of triglycerides (TGs) and TG-rich lipoproteins are causally associated with an increased CV risk. Apolipoprotein C-III (apoC-III) is a key regulator of TG metabolism and hence circulating levels through several mechanisms including the inhibition of lipoprotein lipase activity and alterations in the affinity of apoC-III-containing lipoproteins for both the hepatic receptors involved in their removal and extracellular matrix in the arterial wall. Genetic studies have clarified the role of apoC-III in humans, establishing a causal link with CVD and showing that loss-of-function mutations in the APOC3 gene are associated with reduced TG levels and reduced risk of coronary heart disease. Currently available hypolipidaemic drugs can reduce TG levels, although to a limited extent. Substantial reductions in TG levels can be obtained with new drugs that target specifically apoC-III; these include two antisense oligonucleotides, one small interfering RNA and an antibody. Show less

BackgroundApolipoprotein C-III (apoC-III) is a regulator of triglyceride (TG) metabolism, and due to its association with risk of cardiovascular disease, is an emergent target for pharmacological intervention. The impact of substantially lowering apoC-III on lipoprotein metabolism is not clear.MethodsWe investigated the kinetics of apolipoproteins B48 and B100 (apoB48 and apoB100) in chylomicrons, VLDL1, VLDL2, IDL, and LDL in patients heterozygous for a loss-of-function (LOF) mutation in the APOC3 gene. Studies were conducted in the postprandial state to provide a more comprehensive view of the influence of this protein on TG transport.ResultsCompared with non-LOF variant participants, a genetically determined decrease in apoC-III resulted in marked acceleration of lipolysis of TG-rich lipoproteins (TRLs), increased removal of VLDL remnants from the bloodstream, and substantial decrease in circulating levels of VLDL1, VLDL2, and IDL particles. Production rates for apoB48-containing chylomicrons and apoB100-containing VLDL1 and VLDL2 were not different between LOF carriers and noncarriers. Likewise, the rate of production of LDL was not affected by the lower apoC-III level, nor were the concentration and clearance rate of LDL-apoB100.ConclusionThese findings indicate that apoC-III lowering will have a marked effect on TRL and remnant metabolism, with possibly significant consequences for cardiovascular disease prevention.Trial registrationClinicalTrials.gov NCT04209816 and NCT01445730.FundingSwedish Heart-Lung Foundation, Swedish Research Council, ALF grant from the Sahlgrenska University Hospital, Novo Nordisk Foundation, Sigrid Juselius Foundation, Helsinki University Hospital Government Research funds, Finnish Heart Foundation, and Finnish Diabetes Research Foundation. Show less

'Genome-first' approaches to analyzing rare variants can reveal new insights into human biology and disease. Because pathogenic variants are often rare, new discovery requires aggregating rare coding variants into 'gene burdens' for sufficient power. However, a major challenge is deciding which variants to include in gene burden tests. Pathogenic variants in MYBPC3 and MYH7 are well-known causes of hypertrophic cardiomyopathy (HCM), and focusing on these 'positive control' genes in a genome-first approach could help inform variant selection methods and gene burdening strategies for other genes and diseases. Integrating exome sequences with electronic health records among 41 759 participants in the Penn Medicine BioBank, we evaluated the performance of aggregating predicted loss-of-function (pLOF) and/or predicted deleterious missense (pDM) variants in MYBPC3 and MYH7 for gene burden phenome-wide association studies (PheWAS). The approach to grouping rare variants for these two genes produced very different results: pLOFs but not pDM variants in MYBPC3 were strongly associated with HCM, whereas the opposite was true for MYH7. Detailed review of clinical charts revealed that only 38.5% of patients with HCM diagnoses carrying an HCM-associated variant in MYBPC3 or MYH7 had a clinical genetic test result. Additionally, 26.7% of MYBPC3 pLOF carriers without HCM diagnoses had clear evidence of left atrial enlargement and/or septal/LV hypertrophy on echocardiography. Our study shows the importance of evaluating both pLOF and pDM variants for gene burden testing in future studies to uncover novel gene-disease relationships and identify new pathogenic loss-of-function variants across the human genome through genome-first analyses of healthcare-based populations. Show less

Cardiovascular disease (CVD) is the leading cause of death globally. It is well-established based on evidence accrued during the last three decades that high plasma concentrations of cholesterol-rich atherogenic lipoproteins are causatively linked to CVD, and that lowering these reduces atherosclerotic cardiovascular events in humans (1-9). Historically, most attention has been on low-density lipoproteins (LDL) since these are the most abundant atherogenic lipoproteins in the circulation, and thus the main carrier of cholesterol into the artery wall. However, with the rise of obesity and insulin resistance in many populations, there is increasing interest in the role of triglyceride-rich lipoproteins (TRLs) and their metabolic remnants, with accumulating evidence showing they too are causatively linked to CVD. Plasma triglyceride, measured either in the fasting or non-fasting state, is a useful index of the abundance of TRLs and recent research into the biology and genetics of triglyceride heritability has provided new insight into the causal relationship of TRLs with CVD. Of the genetic factors known to influence plasma triglyceride levels variation in Show less

Apolipoprotein C-III (apoC-III) is known to inhibit lipoprotein lipase (LPL) and function as an important regulator of triglyceride metabolism. In addition, apoC-III has also more recently been identified as an important risk factor for cardiovascular disease. This review summarizes the mechanisms by which apoC-III induces hypertriglyceridemia and promotes atherogenesis, as well as the findings from recent clinical trials using novel strategies for lowering apoC-III. Genetic studies have identified subjects with heterozygote loss-of-function (LOF) mutations in APOC3, the gene coding for apoC-III. Clinical characterization of these individuals shows that the LOF variants associate with a low-risk lipoprotein profile, in particular reduced plasma triglycerides. Recent results also show that complete deficiency of apoC-III is not a lethal mutation and is associated with very rapid lipolysis of plasma triglyceride-rich lipoproteins (TRL). Ongoing trials based on emerging gene-silencing technologies show that intervention markedly lowers apoC-III levels and, consequently, plasma triglyceride. Unexpectedly, the evidence points to apoC-III not only inhibiting LPL activity but also suppressing removal of TRLs by LPL-independent pathways. Available data clearly show that apoC-III is an important cardiovascular risk factor and that lifelong deficiency of apoC-III is cardioprotective. Novel therapies have been developed, and results from recent clinical trials indicate that effective reduction of plasma triglycerides by inhibition of apoC-III might be a promising strategy in management of severe hypertriglyceridemia and, more generally, a novel approach to CHD prevention in those with elevated plasma triglyceride. Show less

To investigate how apolipoprotein C-III (apoC-III) metabolism is altered in subjects with type 2 diabetes, whether the perturbed plasma triglyceride concentrations in this condition are determined primarily by the secretion rate or the removal rate of apoC-III, and whether improvement of glycaemic control using the glucagon-like peptide-1 analogue liraglutide for 16 weeks modifies apoC-III dynamics. Postprandial apoC-III kinetics were assessed after a bolus injection of [5,5,5- Improved glycaemic control by liraglutide therapy for 16 weeks significantly reduced apoC-III secretion rate (561 ± 198 vs. 652 ± 196 mg/d, P = 0.03) and apoC-III levels (10.0 ± 3.8 vs. 11.7 ± 4.3 mg/dL, P = 0.035) in subjects with type 2 diabetes. Change in apoC-III secretion rate was significantly associated with the improvement in indices of glucose control (r = 0.67; P = 0.009) and change in triglyceride area under the curve (r = 0.59; P = 0.025). In line with this, the apoC-III secretion rate was higher in subjects with type 2 diabetes compared with BMI-matched non-diabetic subjects (676 ± 208 vs. 505 ± 174 mg/d, P = 0.042). The results reveal that the secretion rate of apoC-III is associated with elevation of triglyceride-rich lipoproteins in subjects with type 2 diabetes, potentially through the influence of glucose homeostasis on the production of apoC-III. Show less

Genome-wide association studies (GWAS) have identified >250 loci for body mass index (BMI), implicating pathways related to neuronal biology. Most GWAS loci represent clusters of common, noncoding variants from which pinpointing causal genes remains challenging. Here we combined data from 718,734 individuals to discover rare and low-frequency (minor allele frequency (MAF) < 5%) coding variants associated with BMI. We identified 14 coding variants in 13 genes, of which 8 variants were in genes (ZBTB7B, ACHE, RAPGEF3, RAB21, ZFHX3, ENTPD6, ZFR2 and ZNF169) newly implicated in human obesity, 2 variants were in genes (MC4R and KSR2) previously observed to be mutated in extreme obesity and 2 variants were in GIPR. The effect sizes of rare variants are ~10 times larger than those of common variants, with the largest effect observed in carriers of an MC4R mutation introducing a stop codon (p.Tyr35Ter, MAF = 0.01%), who weighed ~7 kg more than non-carriers. Pathway analyses based on the variants associated with BMI confirm enrichment of neuronal genes and provide new evidence for adipocyte and energy expenditure biology, widening the potential of genetically supported therapeutic targets in obesity. Show less

Redox active ultrafine particles (UFP, d < 0.2 μm) promote vascular oxidative stress and atherosclerosis. Notch signaling is intimately involved in vascular homeostasis, in which forkhead box O1 (FOXO1) acts as a co-activator of the Notch activation complex. We elucidated the importance of FOXO1/Notch transcriptional activation complex to restore vascular regeneration after UFP exposure. In a zebrafish model of tail injury and repair, transgenic Tg(fli1:GFP) embryos developed vascular regeneration at 3 days post amputation (dpa), whereas UFP exposure impaired regeneration (p < 0.05, n = 20 for control, n = 28 for UFP). UFP dose dependently reduced Notch reporter activity and Notch signaling-related genes (Dll4, JAG1, JAG2, Notch1b, Hey2, Hes1; p < 0.05, n = 3). In the transgenic Tg(tp1:GFP; flk1:mCherry) embryos, UFP attenuated endothelial Notch activity at the amputation site (p < 0.05 vs. wild type [WT], n = 20). A disintegrin and metalloproteinase domain-containing protein 10 (ADAM10) inhibitor or dominant negative (DN)-Notch1b messenger RNA (mRNA) disrupted the vascular network, whereas notch intracellular cytoplasmic domain (NICD) mRNA restored the vascular network (p < 0.05 vs. WT, n = 20). UFP reduced FOXO1 expression, but not Master-mind like 1 (MAML1) or NICD (p < 0.05, n = 3). Immunoprecipitation and immunofluorescence demonstrated that UFP attenuated FOXO1-mediated NICD pull-down and FOXO1/NICD co-localization, respectively (p < 0.05, n = 3). Although FOXO1 morpholino oligonucleotides (MOs) attenuated Notch activity, FOXO1 mRNA reversed UFP-mediated reduction in Notch activity to restore vascular regeneration and blood flow (p < 0.05 vs. WT, n = 5). Innovation and Conclusion: Our findings indicate the importance of the FOXO1/Notch activation complex to restore vascular regeneration after exposure to the redox active UFP. Antioxid. Redox Signal. 28, 1209-1223. Show less

There is a critical gap in our knowledge of the mechanisms that govern interactions between daily life experiences (e.g., stress) and metabolic diseases, despite evidence that stress can have profound effects on cardiometabolic health. Apolipoprotein A-IV (apoA-IV) is a protein found in chylomicrons (lipoprotein particles that transport lipids throughout the body) where it participates in lipid handling and the regulation of peripheral metabolism. Moreover, apoA-IV is expressed in brain regions that regulate energy balance including the arcuate nucleus. Given that both peripheral and central metabolic processes are important modulators of hypothalamic-pituitary-adrenocortical (HPA) axis activity, the present work tests the hypothesis that apoA-IV activity affects stress responses. As emerging data suggests that apoA-IV actions can vary with background strain, we also explore the strain-dependence of apoA-IV stress regulation. These studies assess HPA axis, metabolic (hyperglycemia), and anxiety-related behavioral responses to psychogenic stress in control (wildtype) and apoA-IV-deficient (KO) mice on either the C57Bl/6J (C57) or 129×1/SvJ (129) background strain. The results indicate that apoA-IV KO increases post-stress corticosterone and anxiety-related behavior specifically in the 129 strain, and increases stress-induced hyperglycemia exclusively in the C57 strain. These data support the hypothesis that apoA-IV is a novel factor that limits stress reactivity in a manner that depends on genetic background. An improved understanding of the complex relationship among lipid homeostasis, stress sensitivity, and genetics is needed to optimize the development of personalized treatments for stress- and metabolism-related diseases. Show less

Some cholesteryl ester transfer protein (CETP) inhibitors lower low-density lipoprotein cholesterol (LDL-C) levels without reducing cardiovascular events, suggesting that the clinical benefit of lowering LDL-C may depend on how LDL-C is lowered. To estimate the association between changes in levels of LDL-C (and other lipoproteins) and the risk of cardiovascular events related to variants in the CETP gene, both alone and in combination with variants in the 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) gene. Mendelian randomization analyses evaluating the association between CETP and HMGCR scores, changes in lipid and lipoprotein levels, and the risk of cardiovascular events involving 102 837 participants from 14 cohort or case-control studies conducted in North America or the United Kingdom between 1948 and 2012. The associations with cardiovascular events were externally validated in 189 539 participants from 48 studies conducted between 2011 and 2015. Differences in mean high-density lipoprotein cholesterol (HDL-C), LDL-C, and apolipoprotein B (apoB) levels in participants with CETP scores at or above vs below the median. Odds ratio (OR) for major cardiovascular events. The primary analysis included 102 837 participants (mean age, 59.9 years; 58% women) who experienced 13 821 major cardiovascular events. The validation analyses included 189 539 participants (mean age, 58.5 years; 39% women) with 62 240 cases of coronary heart disease (CHD). Considered alone, the CETP score was associated with higher levels of HDL-C, lower LDL-C, concordantly lower apoB, and a corresponding lower risk of major vascular events (OR, 0.946 [95% CI, 0.921-0.972]) that was similar in magnitude to the association between the HMGCR score and risk of major cardiovascular events per unit change in levels of LDL-C (and apoB). When combined with the HMGCR score, the CETP score was associated with the same reduction in LDL-C levels but an attenuated reduction in apoB levels and a corresponding attenuated nonsignificant risk of major cardiovascular events (OR, 0.985 [95% CI, 0.955-1.015]). In external validation analyses, a genetic score consisting of variants with naturally occurring discordance between levels of LDL-C and apoB was associated with a similar risk of CHD per unit change in apoB level (OR, 0.782 [95% CI, 0.720-0.845] vs 0.793 [95% CI, 0.774-0.812]; P = .79 for difference), but a significantly attenuated risk of CHD per unit change in LDL-C level (OR, 0.916 [95% CI, 0.890-0.943] vs 0.831 [95% CI, 0.816-0.847]; P < .001) compared with a genetic score associated with concordant changes in levels of LDL-C and apoB. Combined exposure to variants in the genes that encode the targets of CETP inhibitors and statins was associated with discordant reductions in LDL-C and apoB levels and a corresponding risk of cardiovascular events that was proportional to the attenuated reduction in apoB but significantly less than expected per unit change in LDL-C. The clinical benefit of lowering LDL-C levels may therefore depend on the corresponding reduction in apoB-containing lipoprotein particles. Show less

Our goal was to determine whether genetic variation at genes affecting statin metabolism or targets of statin therapy would influence low density lipoprotein (LDL) cholesterol lowering with pravastatin, baseline heart disease, or cardiac endpoints on trial. We examined associations of single nucleotide polymorphisms (SNPs) at the liver X receptor alpha (LXRA, rs12221497), and the solute carrier organic anion transporter (SLCO1B1, rs4149056 and rs2306283) gene loci with these variables. We studied 5411 participants in PROSPER (PROspective Study of Pravastatin in the Elderly at Risk) (mean age 75.3 years), who had been randomized to pravastatin 40 mg/day or placebo and were followed for a mean of 3.2 years. No relationships between genetic variation at the LXRA gene locus with statin induced LDL lowering response or other parameters were noted. Both the SLCO1B1 rs4149056 (valine for alanine at 174) and the rs2306283 (asparagine for aspartic acid at 130) SNPs affect the amino acid sequence of the SLCO1B1 gene product. No effect of the rs2306283 SNP on any of the variables was noted. However the presence of the rs4149056 SNP was associated with significantly less LDL cholesterol lowering response to pravastatin (wildtype, 71.5% of the population, -37.0%; heterozygotes, 25.8% of the population, -36.0%; and homozygotes, 2.7% of the population, -31.8%, p=0.003 at 6 months, and p=0.022 at 12 months). Our data indicate that the presence of the rs4149056 non-synonymous SNP at the SLCO1B1 gene locus can significantly decrease the pravastatin induced LDL cholesterol lowering response. Show less