👤 Ponnal Nambi

Although familial hypercholesterolemia (FH) is a US Centers for Disease Control and Prevention tier 1 condition for genetic testing, the impact of testing on clinical outcomes is unclear. We aimed to assess whether genetic testing alters lipid management in HeartCare participants. For participants with pathogenic/likely pathogenic variants for FH observed at Baylor College of Medicine cardiology clinics, data on laboratory values, medication prescriptions, and diagnoses were collected and compared before and after genetic testing. In the 20 participants with APOB/LDLR variants and complete data, low-density lipoprotein cholesterol (LDL-C) was numerically lower but not significantly different before vs after genetic testing (103 vs 79.5 mg/dL). Sixteen (80%) participants were from the lipid clinic; the majority had a preexisting FH diagnosis. LDL-C levels were numerically lower, and more patients received proprotein convertase subtilisin/kexin type 9 inhibitor prescriptions after genetic testing; however, the difference was not statistically significant. The majority of patients with FH achieved LDL-C <100 mg/dL after genetic testing; however, most patients with APOB/LDLR variants were from the lipid clinic and had been diagnosed with FH by clinical criteria. Show less

Hypertriglyceridemia has been proposed as a risk factor for atherosclerotic cardiovascular disease (ASCVD). Triglycerides (TG) are viewed as a marker for remnant cholesterol in triglyceride-rich lipoproteins, as this remnant cholesterol has been identified as a causal risk factor for ASCVD. The limited number of effective treatments for elevated TG has fueled the search for novel pharmacotherapy options, and multiple medication classes are being explored. Apolipoprotein C3 (APOC3) and angiopoietin-like protein 3 (ANGPTL3) are among the most promising targets. Several novel agents utilizing these pathways, including olezarsen, plozasiran, and zodasiran, are currently under development for the management of elevated TG, with olezarsen approved in 2024 for the management of familial chylomicronemia syndrome. This comprehensive review provides updated insights into the development of novel hypertriglyceridemia treatments. Show less

Extreme hypertriglyceridemia, defined as triglyceride (TG) levels ≥1000 mg/dL, is almost always indicative of chylomicronemia. The current diagnostic approach categorizes individuals with chylomicronemia into familial chylomicronemia syndrome (FCS; prevalence 1-10 per million), caused by the biallelic combination of pathogenic variants that impair the lipolytic action of lipoprotein lipase (LPL), or multifactorial chylomicronemia syndrome (MCS, 1 in 500). A pragmatic framework should emphasize the severity of the phenotype and the risk of complications. Therefore, we endorse the term "persistent chylomicronemia (PC)" defined as TG ≥1000 mg/dL in more than half of the measurements to encompass patients with the highest risk for pancreatitis, regardless of their genetic predisposition. We suggest classification of PC into 4 subtypes: (1) genetic FCS, (2) clinical FCS, (3) PC with "alarm" features, and (4) PC without alarm features. Although patients with FCS most likely have PC, the vast majority with PC do not have genetic FCS. Proposed alarm features are: (a) history of recurrent TG-induced acute pancreatitis, (b) recurrent hospitalizations for severe abdominal pain without another identified cause, (c) childhood pancreatitis, (d) family history of TG-induced pancreatitis, and/or (e) postheparin LPL activity <20% of normal value. Alarm features constitute the strongest risk factors for future acute pancreatitis risk. Patients with PC and alarm features have very high risk of pancreatitis, comparable to that in patients with FCS. Effective, innovative treatments for PC, like apolipoprotein C-III inhibitors, have been developed. Combined with lifestyle modifications, these agents markedly lower TG levels and risk of pancreatitis in the very-high-risk groups, irrespective of the monogenic etiology. Pragmatic definitions, education, and focus on patients with PC, specifically those with alarm features, could help mitigate the risk of acute pancreatitis and other complications. Show less

Extreme hypertriglyceridemia, defined as triglyceride (TG) levels ≥1000 mg/dL, is almost always indicative of chylomicronemia. The current diagnostic approach categorizes individuals with chylomicronemia into familial chylomicronemia syndrome (FCS; prevalence 1-10 per million), caused by the biallelic combination of pathogenic variants that impair the lipolytic action of lipoprotein lipase (LPL), or multifactorial chylomicronemia syndrome (MCS, 1 in 500). A pragmatic framework should emphasize the severity of the phenotype and the risk of complications. Therefore, we endorse the term "persistent chylomicronemia" defined as TG ≥1000 mg/dL in more than half of the measurements to encompass patients with the highest risk for pancreatitis, regardless of their genetic predisposition. We suggest classification of PC into four subtypes: 1) genetic FCS, 2) clinical FCS, 3) PC with "alarm" features, and 4) PC without alarm features. Although patients with FCS most likely have PC, the vast majority with PC do not have genetic FCS. Proposed alarm features are: (a) history of recurrent TG-induced acute pancreatitis, (b) recurrent hospitalizations for severe abdominal pain without another identified cause, (c) childhood pancreatitis, (d) family history of TG-induced pancreatitis, and/or (e) post-heparin LPL activity <20 % of normal value. Alarm features constitute the strongest risk factors for future acute pancreatitis risk. Patients with PC and alarm features have very high risk of pancreatitis, comparable to that in patients with FCS. Effective, innovative treatments for PC, like apoC-III inhibitors, have been developed. Combined with lifestyle modifications, these agents markedly lower TG levels and risk of pancreatitis in the very-high-risk groups, irrespective of the monogenic etiology. Pragmatic definitions, education, and focus on patients with PC specifically those with alarm features could help mitigate the risk of acute pancreatitis and other complications. Show less

Despite statin and antihypertensive therapies, older Americans have high atherosclerotic cardiovascular disease (ASCVD) risk. Novel measures of triglyceride-rich lipoproteins, low-density lipoprotein triglycerides (LDL-TG), and remnant-like particle cholesterol (RLP-C), are associated with ASCVD in middle-aged adults. Polymorphisms in genes encoding angiopoietin-related protein 3 (ANGPTL3) and apolipoprotein C-III (apoC-III), two proteins involved in triglyceride catabolism, are associated with increased risk for hypertriglyceridaemia and ASCVD and are potential therapeutic targets. We examined associations of LDL-TG, RLP-C, apoC-III, and ANGPTL3 levels with ASCVD events in older adults in the Atherosclerosis Risk in Communities (ARIC) study. In 6359 participants (mean age 75.8 ± 5.3 years) followed for ASCVD events [coronary heart disease (CHD) or ischaemic stroke] up to 6 years, associations between LDL-TG, RLP-C, apoC-III, and ANGPTL3 and ASCVD events were assessed using Cox regression. With adjustment for age, sex, and race, RLP-C, LDL-TG, apoC-III, and ANGPTL3 (as continuous variables) were significantly associated with CHD. However, after adjustment for traditional risk factors and lipid-lowering medications, only LDL-TG and ANGPTL3 were significantly associated with ASCVD events [hazard ratio (HR) 1.72, 95% confidence interval (CI) 1.25-2.37 per log unit increase in LDL-TG; HR 1.63, 95% CI 1.17-2.28 per log unit increase in ANGPTL3]. In older adults, LDL-TG, RLP-C, apoC-III, and ANGPTL3 were associated with CHD events in minimally adjusted models; LDL-TG and ANGPTL3 remained independent predictors of ASCVD events with further adjustment. Future studies should assess potential benefit of lowering hepatic apoC-III or ANGPTL3 expression in patients with elevated triglyceride-rich lipoproteins. Show less

The 2013 American College of Cardiology/American Heart Association (ACC/AHA) Cholesterol Management Guideline recommends moderate-intensity to high-intensity statin therapy in eligible patients. To examine adoption of the 2013 ACC/AHA guideline in US cardiology practices. Among 161 cardiology practices, trends in the use of moderate-intensity to high-intensity statin and nonstatin lipid-lowering therapy (LLT) were analyzed before (September 1, 2012, to November 1, 2013) and after (February 1, 2014, to April 1, 2015) publication of the 2013 ACC/AHA guideline among 4 mutually exclusive risk groups within the ACC Practice Innovation and Clinical Excellence Registry. Interrupted time series analysis was used to evaluate for differences in trend in use of moderate-intensity to high-intensity statin and nonstatin LLT use in hierarchical logistic regression models. Participants were a population-based sample of 1 105 356 preguideline patients (2 431 192 patient encounters) and 1 116 472 postguideline patients (2 377 219 patient encounters). Approximately 97% of patients had atherosclerotic cardiovascular disease (ASCVD). Moderate-intensity to high-intensity statin and nonstatin LLT use before and after publication of the 2013 ACC/AHA guideline. Time trend in the use of moderate-intensity to high-intensity statin and nonstatin LLT. In the study cohort, the mean (SD) age was 69.6 (12.1) years among 1 105 356 patients (40.2% female) before publication of the guideline and 70.0 (11.9) years among 1 116 472 patients (39.8% female) after publication of the guideline. Although there was a trend toward increasing use of moderate-intensity to high-intensity statins overall and in the ASCVD cohort, such a trend was already present before publication of the guideline. No significant difference in trend in the use of moderate-intensity to high-intensity statins was observed in other groups. The use of moderate-intensity to high-intensity statin therapy was 62.1% (before publication of the guideline) and 66.6% (after publication of the guideline) in the overall cohort, 62.7% (before publication) and 67.0% (after publication) in the ASCVD cohort, 50.6% (before publication) and 52.3% (after publication) in the cohort with elevated low-density lipoprotein cholesterol levels (ie, ≥190 mg/dL), 52.4% (before publication) and 55.2% (after publication) in the diabetes cohort, and 41.9% (before publication) and 46.9% (after publication) in the remaining group with 10-year ASCVD risk of 7.5% or higher. In hierarchical logistic regression models, there was a significant increase in the use of moderate-intensity to high-intensity statins in the overall cohort (4.8%) and in the ASCVD cohort (4.3%) (P < .01 for slope for both). There was no significant change for other risk cohorts. Nonstatin LLT use remained unchanged in the preguideline and postguideline periods in the hierarchical logistic regression models for all of the risk groups. Adoption of the 2013 ACC/AHA Cholesterol Management Guideline in cardiology practices was modest. Timely interventions are needed to improve guideline-concordant practice to reduce the burden of ASCVD. Show less

C-reactive protein (CRP) is a heritable marker of chronic inflammation that is strongly associated with cardiovascular disease. We sought to identify genetic variants that are associated with CRP levels. We performed a genome-wide association analysis of CRP in 66 185 participants from 15 population-based studies. We sought replication for the genome-wide significant and suggestive loci in a replication panel comprising 16 540 individuals from 10 independent studies. We found 18 genome-wide significant loci, and we provided evidence of replication for 8 of them. Our results confirm 7 previously known loci and introduce 11 novel loci that are implicated in pathways related to the metabolic syndrome (APOC1, HNF1A, LEPR, GCKR, HNF4A, and PTPN2) or the immune system (CRP, IL6R, NLRP3, IL1F10, and IRF1) or that reside in regions previously not known to play a role in chronic inflammation (PPP1R3B, SALL1, PABPC4, ASCL1, RORA, and BCL7B). We found a significant interaction of body mass index with LEPR (P<2.9×10(-6)). A weighted genetic risk score that was developed to summarize the effect of risk alleles was strongly associated with CRP levels and explained ≈5% of the trait variance; however, there was no evidence for these genetic variants explaining the association of CRP with coronary heart disease. We identified 18 loci that were associated with CRP levels. Our study highlights immune response and metabolic regulatory pathways involved in the regulation of chronic inflammation. Show less

A series of 4-(3-biaryl)quinolines with sulfone substituents on the terminal aryl ring (8) was prepared as potential LXR agonists. High affinity LXRbeta ligands with generally modest binding selectivity over LXRalpha and excellent agonist potency in LXR functional assays were identified. Many compounds had LXRbeta binding IC(50) values <10 nM while the most potent had EC(50) values <1.0 nM in an ABCA1 mRNA induction assay in J774 mouse cells with efficacy comparable to T0901317. Sulfone 8a was further evaluated in LDL (-/-) mice and shown to reduce atherosclerotic lesion progression. Show less

A series of quinoline-3-carboxamide containing sulfones was prepared and found to have good binding affinity for LXRbeta and moderate binding selectivity over LXRalpha. The 8-Cl quinoline analog 33 with a high TPSA score, displayed 34-fold binding selectivity for LXRbeta over LXRalpha (LXRbeta IC(50)=16nM), good activity for inducing ABCA1 gene expression in a THP macrophage cell line, desired weak potency in the LXRalpha Gal4 functional assay, and low blood-brain barrier penetration in rat. Show less

A series of cinnolines/quinolines was prepared and it was found that 4-phenyl-cinnoline/quinolines with either a 2',3' or 2',5'-disubstituted benzyloxy moiety or the 1-Me-7-indole methoxy moiety on the meta position of the 4-phenyl ring showed good binding selectivity for LXRbeta over LXRalpha. The LXRbeta binding selective modulators displayed good activity for inducing ABCA1 gene expression in J774 macrophage cell line and poor efficacy in the LXRalpha Gal4 functional assay. 26, 37 and 41 were examined for their ability to induce SREBP-1c gene expression in Huh-7 liver cell line and they were weak partial agonists. Show less

A series of substituted 2-benzyl-3-aryl-7-trifluoromethylindazoles were prepared as LXR modulators. These compounds were partial agonists in transactivation assays when compared to 1 (T0901317) and were slightly weaker with respect to potency and efficacy on LXRalpha than on LXRbeta. Lead compounds in this series 12 (WAY-252623) and 13 (WAY-214950) showed less lipid accumulation in HepG2 cells than potent full agonists 1 and 3 (WAY-254011) but were comparable in efficacy to 1 and 3 with respect to cholesterol efflux in THP-1 foam cells, albeit weaker in potency. Compound 13 reduced aortic lesion area in LDLR knockout mice equivalently to 3 or positive control 2 (GW3965). In a 7-day hamster model, compound 13 showed a lesser propensity for plasma TG elevation than 3, when the compounds were compared at doses in which they elevated ABCA1 and ABCG1 gene expression in duodenum and liver at equal levels. In contrast to results previously published for 2, the lack of TG effect of 13 correlated with its inability to increase liver fatty acid synthase (FAS) gene expression, which was up-regulated 4-fold by 3. These results suggest indazoles such as 13 may have an improved profile for potential use as a therapeutic agent. Show less

LXRs (Liver X Receptor alpha and beta) are nuclear receptors that act as ligand-activated transcription factors. LXR activation causes upregulation of genes involved in reverse cholesterol transport (RCT), including ABCA1 and ABCG1 transporters, in macrophage and intestine. Anti-atherosclerotic effects of synthetic LXR agonists in murine models suggest clinical utility for such compounds. Blood markers of LXR agonist exposure/activity were sought to support clinical development of novel synthetic LXR modulators. Transcript levels of LXR target genes ABCA1 and ABCG1 were measured using quantitative reverse transcriptase/polymerase chain reaction assays (qRT-PCR) in peripheral blood from mice and rats (following a single oral dose) and monkeys (following 7 daily oral doses) of synthetic LXR agonists. LXRalpha, LXRbeta, ABCA1, and ABCG1 mRNA were measured by qRT-PCR in human peripheral blood mononuclear cells (PBMC), monocytes, T- and B-cells treated ex vivo with WAY-252623 (LXR-623), and protein levels in human PBMC were measured by Western blotting. ABCA1/G1 transcript levels in whole-blood RNA were measured using analytically validated assays in human subjects participating in a Phase 1 SAD (Single Ascending Dose) clinical study of LXR-623. A single oral dose of LXR agonists induced ABCA1 and ABCG1 transcription in rodent peripheral blood in a dose- and time-dependent manner. Induction of gene expression in rat peripheral blood correlated with spleen expression, suggesting LXR gene regulation in blood has the potential to function as a marker of tissue gene regulation. Transcriptional response to LXR agonist was confirmed in primates, where peripheral blood ABCA1 and ABCG1 levels increased in a dose-dependent manner following oral treatment with LXR-623. Human PBMC, monocytes, T- and B cells all expressed both LXRalpha and LXRbeta, and all cell types significantly increased ABCA1 and ABCG1 expression upon ex vivo LXR-623 treatment. Peripheral blood from a representative human subject receiving a single oral dose of LXR-623 showed significant time-dependent increases in ABCA1 and ABCG1 transcription. Peripheral blood cells express LXRalpha and LXRbeta, and respond to LXR agonist treatment by time- and dose-dependently inducing LXR target genes. Transcript levels of LXR target genes in peripheral blood are relevant and useful biological indicators for clinical development of synthetic LXR modulators. Show less

A series of potent and binding selective LXRbeta agonists was developed using the previously reported non-selective LXR ligand WAY-254011 as a structural template. With the aid of molecular modeling, it was found that 2,3-diMe-Ph, 2,5-diMe-Ph, and naphthalene substituted quinoline acetic acids (such as quinoline 33, 37, and 38) showed selectivity for LXRbeta over LXRalpha in binding assays. Show less