Comparison of the burden of familial hypercholesterolemia between two cohorts of French Canadians hospitalized 25 years apart for coronary heart disease

BACKGROUND

Familial hypercholesterolemia (FH) is associated with lifelong elevated plasma concentrations of low-density lipoprotein cholesterol (LDL-C) and high risk of premature coronary heart disease (CHD). Clinical recommendations and treatments have emerged to facilitate the management of FH patients. Their impact on the burden of FH is however not well documented.

OBJECTIVE

To compare the burden of FH between patients hospitalized for a CHD event 25 years apart in the French-Canadian founder population.

METHODS

Lipid profiles, cardiovascular risk factors, treatments and FH status of 2,029 patients consecutively hospitalized for an acute CHD event between 2017 and 2022 (2022 Cohort) were compared to those of 2,506 patients with angiographically-confirmed CHD who were admitted between 1995 and 1998 (1998 Cohort).

RESULTS

At the time of admission, 24.6 % of CHD patients had LDL-C levels >5.0 mmol/L in 1998 compared to 1.4 % in 2022, and FH was diagnosed in 9.6 % of patients in the 1998 cohort compared to 5.5 % in 2022 (p<0.001). FH patients hospitalized for a CHD event were older in 2022 than in 1998 (p <0.001). The prevalence of premature CHD requiring a hospitalization significantly decreased from 1998 to 2022 (64.3% vs. 44.1 %, p<0.001). At the moment of admission, 18.2 % of FH patients had LDL-C concentration <2.0 mmol/L in 2022 vs 0 % in 1998 (p <0.001).

CONCLUSIONS

Over 25 years, FH patients tend to be older and contribute to a lower proportion of hospitalizations for CHD in the French-Canadian founder population. Despite significant improvement in diagnosis and treatment, FH management remains however sub-optimal.

Inhibition of Angiopoietin-Like Protein 3 or 3/8 Complex and ApoC-III in Severe Hypertriglyceridemia

PURPOSE OF REVIEW

The role of the inhibition of ANGPTL3 in severe or refractory hypercholesterolemia is well documented, less in severe hyperTG. This review focuses on the preclinical and clinical development of ApoC-III inhibitors and ANGPTL3, 4, and 3/8 complex inhibitors for the treatment of severe or refractory forms of hypertriglyceridemia to prevent cardiovascular disease or other morbidities.

RECENT FINDINGS

APOC3 and ANGPTL3 became targets for drug development following the identification of naturally occurring loss of function variants in families with a favorable lipid profile and low cardiovascular risk. The inhibition of ANGPTL3 covers a broad spectrum of lipid disorders from severe hypercholesterolemia to severe hypertriglyceridemia, while the inhibition of ApoC-III can treat hypertriglyceridemia regardless of the severity. Preclinical and clinical data suggest that ApoC-III inhibitors, ANGPTL3 inhibitors, and inhibitors of the ANGPTL3/8 complex that is formed postprandially are highly effective for the treatment of severe or refractory hypertriglyceridemia. Inhibition of ANGPTL3 or the ANGPTL3/8 complex upregulates LPL and facilitates the hydrolysis and clearance of triglyceride-rich lipoproteins (TRL) (LPL-dependent mechanisms), whereas ApoC-III inhibitors contribute to the management and clearance of TRL through both LPL-dependent and LPL-independent mechanisms making it possible to successfully lower TG in subjects completely lacking LPL (familial chylomicronemia syndrome). Most of these agents are biologicals including monoclonal antibodies (mAb), antisense nucleotides (ASO), small interfering RNA (siRNA), or CRISPR-cas gene editing strategies.

Post-prandial analysis of fluctuations in the platelet count and platelet function in patients with the familial chylomicronemia syndrome

BACKGROUND

The familial chylomicronemia syndrome (FCS) is an ultra rare disease caused by lipoprotein lipase (LPL) deficiency associated with potentially lethal acute pancreatitis risk. Thrombocytopenia (platelet count < 150,000 × 10⁹/L) has been reported in patients with FCS, treated or not with volanesorsen, a second generation APOC3 anti-sense oligonucleotide. Chylomicrons are the lipoproteins delivering fat after a meal and FCS thus has a post-prandial origin. Platelet count and function have not been studied post-prandially in FCS.

OBJECTIVE

To evaluate post-prandial fluctuations in the platelet count (PLC) and functional defects of hemostasis in FCS.

METHODS

PLC, functional defects in hemostasis and hematologic variables were measured up-to 5 h after a meal in 6 homozygotes for FCS causing gene variants (HoLPL), 6 heterozygotes for LPL loss-of-function variants (HeLPL) and 7 normolipidemic controls.

RESULTS

Hourly post-prandial PLC was significantly lower in HoLPL than in controls (P < 0.009). Compared to the other groups, the PLC tended to decrease rapidly (in the first hour) post-meal in HoLPL (P = 0.03) and remained lower than baseline 5-h post-meal (P = 0.02) whereas it tended to slightly increase in normolipidemic controls (P = 0.02). Platelet function was not affected by the prandial status. In HoLPL, post-prandial fluctuations in the PLC positively correlated with the lymphocyte count (P = 0.005) and negatively with neutrophil/lymphocyte ratio (NLR).

CONCLUSION

The PLC decreases post-prandially in FCS (HoLPL), is not associated with changes in functional defects of hemostasis and correlates with the NLR, a marker of acute pancreatitis severity.

Correlation between chylomicronemia diagnosis scores and post-heparin lipoprotein lipase activity

INTRODUCTION

Sustained chylomicronemia is a defect in post-prandial triglyceride management characterized by severe hypertriglyceridemia (triglyceride > 10 mmol/L) due to functional or genetic defects in lipoprotein lipase (LPL)-mediated triglyceride-rich lipoprotein lipolysis. Familial chylomicronemia syndrome (FCS) is a rare mendelian form of chylomicronemia caused by loss-of-function variants in LPL or LPL-related genes. Most individuals with chylomicronemia however present multifactorial chylomicronemia (MCS), in which LPL bio-availability and activity are variable. FCS and MCS differ in terms of clinical characteristics and risk of disease, and diagnosis scoring systems have been proposed to accurately distinguish FCS from MCS.

OBJECTIVE

The aim of this study was to assess the strength of the relationship between plasma post-heparin LPL activity and two published chylomicronemia diagnosis scoring systems.

DESIGN AND METHODS

Post-heparin plasma LPL activity was measured using colorimetric assays in a sample of 29 subjects with sustained chylomicronemia (20 FCS and 9 MCS). Chylomicronemia diagnosis scores were obtained for all subjects using the scoring system A (model A), which integrates apolipoprotein B and free glycerol, a surrogate marker of triglyceride hydrolysis, and the scoring system B (model B). Correlation analyses were conducted to estimate the linear relationship between LPL activity and the two diagnosis scoring systems.

RESULTS

There was a significant (p < 0.001) difference in post-heparin LPL activity between FCS and MCS. Both scoring systems significantly correlated with post-heparin LPL activity (model A: r_s = -0.64, p < 0.001; model B: r_s = -0.54, p = 0.002).

CONCLUSIONS

These result suggest that chylomicronemia diagnosis scoring systems correlate with LPL activity and adequately contribute to distinguish FCS from MCS.

Comparison over 25 years of the burden of familial hypercholesterolemia on hospitalizations for coronary heart disease in a French-Canadian founder population

Background

Over the last 25 years, effective treatments, such as potent statins, ezetimibe and PCSK9 inhibitors have gradually emerged to treat heterozygous familial hypercholesterolemia (FH) and guidelines have been progressively developed internationally to promote FH health surveillance, early diagnosis and optimal clinical management. However, the impact of these measures on the burden of FH is not well documented. Although recent genetic and epidemiological studies suggest that the prevalence of familial hypercholesterolaemia (FH) is approximately twice than initialy expected (1:250) (1), it remains significantly higher among French Canadians (FC) (2,3).

Purpose

To compare over 25 years the management and burden of FH among patients hospitalized for an acute coronary heart disease (CHD) event in a FC founder population with a high prevalence of FH.

Methods

Lipid profiles, cardiovascular risk factors, lipid management and FH status of 2,029 FC patients consecutively hospitalized for an acute CHD event between 2017 and 2022 (2022 Cohort) were compared to those of 2,506 patients with angiographically-confirmed CHD who were admitted between 1995 and 1998 (1998 Cohort) (4). FH status was based on molecular, Simon Broome or FH Canada (5) criteria. Statistical comparisons were made using Chi-square and Student's t-tests for independent samples.

Results

Over a 25-year interval, most patients hospitalized for CHD were men (74.5% in 1998 vs 73.4% in 2022). At the time of admission, 23.0% of CHD patients had LDL-Cholesterol levels &gt;5.0 mmol/L in 1998 compared to 1.3% in 2022 (p&lt;0.001). FH was diagnosed in 9.6% of patients in the 1998 cohort compared to 5.5% in 2022 (p&lt;0.001). Overall, the prevalence of obesity, type 2 diabetes and uncontrolled hypertension tended to be higher in 1998, including in FH (p&lt;0.05). The proportion of FH patients hospitalized for CHD who were treated with a statin or a combination of lipid-lowering agents at the moment of admission was 28.4% in 1998 compared to 61.2% in 2022 (p&lt;0.001). FH patients hospitalized for CHD were significantly older in 2022 than in 1998 (59.03±11.17 vs 50.14±11.32 years; p&lt;0.001). Accordingly, the prevalence of premature CHD requiring an hospitalization significantly decreased from 1998 to 2022 in FH (64.3% vs. 44.1%, p&lt;0.001).

Conclusions

Over a 25-year period, FH patients hospitalized for CHD tend to be older and contribute to a lower proportion of hospitalizations. Despite significant improvement in treatment, FH diagnosis and management remain sub-optimal, even in a founder population where FH represents a significant population burden.

Funding Acknowledgement

Type of funding sources: None.

Palmar striated xanthomas in clinical practice

Introduction

The aim of this study was to assess the occurrence of palmar striated xanthomas (PSX) in a wide spectrum of lipid disorders ranging from very severe hypercholesterolemia (homozygous familial hypercholesterolemia) to very severe hypertriglyceridemia (chylomicronemia).

Methods

This study involved 3,382 dyslipidemic Caucasian adult patients (1,856 men and 1,526 women) seen at the Chicoutimi Hospital Lipid Clinic (Quebec, Canada), covering a wide range of lipid disorders, from severe hypertriglyceridemia to severe hypercholesterolemia. Categorical variables were compared using the Pearson χ2 statistic, whereas univariate analysis of variance (ANOVA) or nonparametric Kruskal-Wallis were used for continuous variables.

Results

A total of 5.1% (173/3382) of the studied patients presented PSX, a majority of them (67.1%) being women. PSX were observed in 18.8% of patients with dysbetalipoproteinemia and also among 14.1% of hypertriglyceridemic patients with partial lipoprotein lipase deficiency, 3.7% of patients with chylomicronemia and in all of those with homozygous familial hypercholesterolemia. Overall, 10.7% of patients with PSX did not meet dysbetalipoproteinemia diagnosis criteria.

Conclusion

According to our study, the PSX prevalence estimate among patients without dysbetalipoproteinemia would be around 10% and they could be observed in a wide spectrum of lipid disorders associated with recurrent or sustained remnant lipoprotein accumulation.

Global perspective of familial hypercholesterolaemia: a cross-sectional study from the EAS Familial Hypercholesterolaemia Studies Collaboration (FHSC)

BACKGROUND

The European Atherosclerosis Society Familial Hypercholesterolaemia Studies Collaboration (FHSC) global registry provides a platform for the global surveillance of familial hypercholesterolaemia through harmonisation and pooling of multinational data. In this study, we aimed to characterise the adult population with heterozygous familial hypercholesterolaemia and described how it is detected and managed globally.

METHODS

Using FHSC global registry data, we did a cross-sectional assessment of adults (aged 18 years or older) with a clinical or genetic diagnosis of probable or definite heterozygous familial hypercholesterolaemia at the time they were entered into the registries. Data were assessed overall and by WHO regions, sex, and index versus non-index cases.

FINDINGS

Of the 61 612 individuals in the registry, 42 167 adults (21 999 [53·6%] women) from 56 countries were included in the study. Of these, 31 798 (75·4%) were diagnosed with the Dutch Lipid Clinic Network criteria, and 35 490 (84·2%) were from the WHO region of Europe. Median age of participants at entry in the registry was 46·2 years (IQR 34·3-58·0); median age at diagnosis of familial hypercholesterolaemia was 44·4 years (32·5-56·5), with 40·2% of participants younger than 40 years when diagnosed. Prevalence of cardiovascular risk factors increased progressively with age and varied by WHO region. Prevalence of coronary disease was 17·4% (2·1% for stroke and 5·2% for peripheral artery disease), increasing with concentrations of untreated LDL cholesterol, and was about two times lower in women than in men. Among patients receiving lipid-lowering medications, 16 803 (81·1%) were receiving statins and 3691 (21·2%) were on combination therapy, with greater use of more potent lipid-lowering medication in men than in women. Median LDL cholesterol was 5·43 mmol/L (IQR 4·32-6·72) among patients not taking lipid-lowering medications and 4·23 mmol/L (3·20-5·66) among those taking them. Among patients taking lipid-lowering medications, 2·7% had LDL cholesterol lower than 1·8 mmol/L; the use of combination therapy, particularly with three drugs and with proprotein convertase subtilisin-kexin type 9 inhibitors, was associated with a higher proportion and greater odds of having LDL cholesterol lower than 1·8 mmol/L. Compared with index cases, patients who were non-index cases were younger, with lower LDL cholesterol and lower prevalence of cardiovascular risk factors and cardiovascular diseases (all p<0·001).

INTERPRETATION

Familial hypercholesterolaemia is diagnosed late. Guideline-recommended LDL cholesterol concentrations are infrequently achieved with single-drug therapy. Cardiovascular risk factors and presence of coronary disease were lower among non-index cases, who were diagnosed earlier. Earlier detection and greater use of combination therapies are required to reduce the global burden of familial hypercholesterolaemia.

FUNDING

Pfizer, Amgen, Merck Sharp & Dohme, Sanofi-Aventis, Daiichi Sankyo, and Regeneron.

Genetic burden linked to founder effects in Saguenay-Lac-Saint-Jean illustrates the importance of genetic screening test availability

The Saguenay–Lac-Saint-Jean (SLSJ) region located in the province of Quebec was settled in the 19th century by pioneers issued from successive migration waves starting in France in the 17th century and continuing within Quebec until the beginning of the 20th century. The genetic structure of the SLSJ population is considered to be the product of a triple founder effect and is characterised by a higher prevalence of some rare genetic diseases. Several studies were performed to elucidate the historical, demographic and genetic background of current SLSJ inhabitants to assess the origins of these rare disorders and their distribution in the population. Thanks to the development of new sequencing technologies, the genes and the variants responsible for the most prevalent conditions were identified. Combined with other resources such as the BALSAC population database, identifying the causal genes and the pathogenic variants allowed to assess the impacts of some of these founder mutations on the population health and to design precision medicine public health strategies based on carrier testing. Furthermore, it stimulated the establishment of many public programmes.

We report here a review and an update of a subset of inherited disorders and founder mutations in the SLSJ region. Data were collected from published scientific sources. This work expands the knowledge about the current frequencies of these rare disorders, the frequencies of other rare genetic diseases in this population, the relevance of the carrier tests offered to the population, as well as the current available treatments and research about future therapeutic avenues for these inherited disorders.

Non-Alcoholic Fatty Liver in Patients with Chylomicronemia

Non-alcoholic fatty liver disease (NAFLD) is frequent in patients with features of the metabolic syndrome (MetS), obesity, or type 2 diabetes. Lipoprotein lipase (LPL) is the main driver of triglyceride (TG) hydrolysis in chylomicrons and very-low density lipoproteins (VLDL). In some patients with MetS, dysfunction of this pathway can lead to plasma TG values > 10 mmol/L (multifactorial chylomicronemia or MCS). Chylomicronemia also characterizes LPL deficiency (LPLD), a rare autosomal recessive disease called familial chylomicronemia syndrome (FCS), which is associated with an increased risk of recurrent pancreatitis. This study aims to investigate the expression of NAFLD, as assessed by transient elastography, in MCS and FCS subjects. Data were obtained from 38 subjects with chylomicronemia; 19 genetically confirmed FCS and 19 sex- and age-matched MCS. All participants underwent liver ultrasonography and stiffness measurement after a 4-h fast using transient elastography (FibroScan®, Echosens, Waltham, MA, USA). NAFLD (controlled attenuation parameter (CAP) > 280 dB/m) was observed in 42.1% of FCS and 73.7% of MCS subjects (p = 0.05). FCS subjects had lower body mass index (BMI) than MCS. Only 25% of FCS subjects with NAFLD had a BMI ≥ 30 compared to 64.3% in MCS (p = 0.004). In FCS, NAFLD occurred even in the presence of very low (≤18 kg/m2) BMI. In both FCS and MCS, CAP was negatively associated with acute pancreatitis risk. In this study, NAFLD was commonly observed in both FCS and MCS subjects and occurred independently of the BMI and fasting glucose values in FCS; NAFLD was associated with a lower occurrence of acute pancreatitis episodes.

Identifying Markers of Cardiovascular Event-Free Survival in Familial Hypercholesterolemia

Familial hypercholesterolemia (FH) is an autosomal dominant trait characterized by elevated low-density lipoprotein-cholesterol (LDL-C) concentrations appearing at birth and is associated with increased risk of premature atherosclerotic cardiovascular disease (CVD). However, in some cases, FH subjects over 70 years of age have surprisingly never experienced any CVD symptoms throughout their entire lives. The objective of this study consists of identifying biological and environmental markers acting as cardioprotective factors and associated with unexpected survival in FH. Upon age and reported cardiovascular events (CVE) stratification, we identified a total of 458 French–Canadian FH subjects with premature reported CVE, and 1297 young adults as well as 24 elderly subjects (≥70 years) who have never reported CVE requiring hospitalization. Logistic regression models were used to depict cardioprotective markers among FH survivors (≥70 years). Regression analyses of the FH cohort showed that female sex (odds ratio (OR) = 12.92 (4.23–39.46); p < 0.0001), high levels of high-density lipoprotein (HDL)-C (OR = 6.76 (2.43–18.79); p = 0.0002) and elevated concentrations of adiponectin (OR = 71.40 (5.20–980.47); p = 0.001) were significant contributory factors in reducing FH-related CVD risk. Notably, female (OR = 11.45 (1.25–105.98); p = 0.031) and high HDL-C (OR = 9.78 (1.75–54.67); p = 0.009) were shown to be significant covariates associated with survival in FH. Non-smoking (OR = 11.73 (4.36–31.56); p < 0.0001) was also identified as an environmental factor associated with CVE-free survival. Based on this configured model of premature CVE occurrence, these results demonstrated that, beyond LDL-C levels, female sex, high HDL-C, elevated adiponectin and non-smoking are important markers that contribute to a reduced risk of CVD and CVE-free survival in FH.

Gene expression profiles of recurrent acute pancreatitis risk in patients with sustained chylomicronemia

A fasting triglyceridemia >10 mmol/L is associated with chylomicronemia (CM) and an increased recurrent acute pancreatitis (RAP) risk. The number of pancreatitis episodes varies significantly between patients with CM. The objective of this study was to investigate gene expression profiles of RAP in patients with CM. A total of 47 CM subjects participated in this study. Prior to the analyses, all patients were divided into three groups covering a wide spectrum of RAP: 0 (n = 21), 1-3 (n = 10) or >4 (n = 16) pancreatitis episodes. Gene expression profiles were compared to those of 15 healthy normolipidemic controls. Differential expression moderated T-tests between studied groups were performed using a linear model of the Bioconductor package Limma. The False discovery rate was controlled using the Benjamini-Hochberg procedure. At a p-value <0.01, a false discovery rate of 5% and a >2-fold change expression significance levels, a set of 41 probes have been found differentially expressed in CM subjects with no pancreatitis, 103 in the CM group with 1 to 3 pancreatitis, and 94 in the group with ≥4 pancreatitis compared to healthy controls. Of the identified annotated probes, 14 are shared by all CM groups; 3 are specific to CM with no pancreatitis; 11 are specific to CM with 1 to 3 pancreatitis, and 17 are specific to CM with ≥4 pancreatitis. Most of the annotated biomarkers are involved in inflammatory, immune, lipoprotein kinetics or signalling biological pathways. These results reveal gene expression signatures of RAP in patients with CM.

Lomitapide for treatment of homozygous familial hypercholesterolemia: The Québec experience

BACKGROUND AND AIMS

Homozygous familial hypercholesterolemia (HoFH) is an orphan disease, most often caused by bi-allelic mutations of the LDLR gene. Patients with HoFH have elevated LDL-C levels >13 mmol/L, tendinous xanthomata and severe, premature atherosclerotic cardiovascular disease (ASCVD). Untreated, most HoFH patients die of ASCVD in youth. New therapeutic modalities include lomitapide, an inhibitor of microsomal triglyceride transfer protein that lowers hepatic LDL-C production. We have recently identified 79 Canadian patients with HoFH. Here, we describe our experience with lomitapide in the province of Quebec, a geographic area known to have a high prevalence of HoFH.

METHODS

This is a retrospective case series of 12 HoFH patients followed at three lipidology centers in the province of Quebec.

RESULTS

Mean age of the patients was 44 ± 18 years; age at time of HoFH diagnosis ranged from 2 to 59 years. All patients were on a statin and ezetimibe 10 mg/day and five patients were treated with LDL apheresis. Treatment with lomitapide reduced LDL-C levels by 38% (intention-to-treat). Intolerable gastrointestinal side effects were observed in 3/12 patients and were the main reason for treatment discontinuation. Three patients tolerated lomitapide at doses ranging between 5 and 30 mg/day without major side effects. Downwards drug titration was necessary in the 6 remaining patients because of gastrointestinal side effects (n = 5) and elevated liver enzymes (n = 1), and 2 of them finally discontinued treatment.

CONCLUSIONS

Lomitapide may be used to further decrease LDL-C in HoFH patients; gastrointestinal side effects and hepatic toxicity may limit adherence.

Association of common gene-smoking interactions with elevated plasma apolipoprotein B concentration

Background

Increased apolipoprotein (apo) B level (hyperapoB) is a strong predictor of cardiovascular disease (CVD), even in patients who achieve recommended LDL-Cholesterol (LDL-C) goals. ApoB level, an important correlate of metabolic syndrome (MetS), is influenced by several gene-environment interactions. Some of them are rare and can explain a large proportion of apoB variance, whereas others more common have variable effects. The aim of this study was to evaluate the association of interaction between smoking and common hyperapoB gene variants (PPARα-L162V, lipoprotein lipase loss-of function mutation, apo e4 allele or apo E2/2 genotype) with plasma apoB concentrations, according to the expression of MetS.

Methods

This study was performed among 1798 subjects. Smoking was defined as non/mild smokers vs. moderate-to-heavy smokers. ApoB levels were determined using nephelometry. Logistic regression models were used to document interactions between smoking habits and the presence of hyperapoB gene variants on the relative odds to exhibit increased plasma apoB concentrations.

Results

Around 29% of individuals with a low-risk lipid profile without MetS component had hyperapoB. Smoking and the presence of hyperapoB gene variants tended to be associated with higher plasma apoB levels even in presence of low-LDL-C. There was a significant interaction (P = 0.04) between the presence of ≥1 gene variants and smoking on the risk to exhibit hyperapoB among subjects with low risk profile in primary prevention.

Conclusions

Combination of life habits assessment and some common genes variants may detect a significant proportion of patients with increased apoB levels, and therefore a higher risk of CVD, who could have been initially perceived as low-risk.

Dissection of Clinical and Gene Expression Signatures of Familial versus Multifactorial Chylomicronemia

Familial chylomicronemia syndrome (FCS) is a rare disorder associated with chylomicronemia (CM) and an increased risk of pancreatitis. Most individuals with CM do not have FCS but exhibit multifactorial CM (MCM), which differs from FCS in terms of risk and disease management. This study aimed to investigate clinical and gene expression profiles of FCS and MCM patients. Anthropometrics, clinical, and biochemical variables were analyzed in 57 FCS and 353 MCM patients. Gene expression analyses were performed in a subsample of 19 FCS, 28 MCM, and 15 normolipidemic controls. Receiver operating characteristic (ROC) curve analyses were performed to analyze the capacity of variables to discriminate FCS from MCM. Sustained fasting triglycerides ≥20 mmol/L (>15 mmol/L with eruptive xanthomas), history of pancreatitis, poor response to fibrates, diagnosis of CM at childhood, body mass index <22 kg/m², and delipidated apolipoprotein B or glycerol levels <0.9 g/L and <0.05 mmol/L, respectively, had an area under the ROC curve ≥0.7. Gene expression analyses identified 142 probes differentially expressed in FCS and 32 in MCM compared with controls. Among them, 13 probes are shared between FCS and MCM; 63 are specific to FCS and 2 to MCM. Most FCS-specific or shared biomarkers are involved in inflammatory, immune, circadian, postprandial metabolism, signaling, docking systems, or receptor-mediated clearance mechanisms. This study reveals differential signatures of FCS and MCM. It opens the door to the identification of key mechanisms of CM expression and potential targets for the development of new treatments.

Calculated Non-HDL Cholesterol Includes Cholesterol in Larger Triglyceride-Rich Lipoproteins in Hypertriglyceridemia

Context

Calculated non–high-density lipoprotein (HDL) cholesterol (non-HDLC) should selectively include cholesterol from atherogenic lipoproteins to be a reliable risk marker of cardiovascular disease. In hypertriglyceridemia (HTG), there is increased abundance of larger and less atherogenic triglyceride-rich lipoproteins (TRL), namely, larger very-low-density lipoproteins (VLDL), and chylomicrons.

Objective

We aim to demonstrate that serum triglyceride (TG) level has a substantial impact on non-HDLC’s ability to represent cholesterol from atherogenic lipoproteins, even though TG is not part of the calculation for non-HDLC.

Design

Analysis of lipid profile data

Settings

Lipid Clinic patient cohort, and Biochemistry Laboratory patient cohort

Patients or Other Participants

7,492 patients in the Lipid Clinic cohort with baseline lipid profiles documented prior to starting lipid-lowering medications and 156,311 lipid profiles from The Ottawa Hospital Biochemistry Laboratory cohort.

Intervention

None

Main Outcome Measure

Our modeling process includes derivation of TG-interval–specific lipoprotein composition factor (LCF) for TRL, which represents the mass ratio of cholesterol to TG in TRL. A high LCF indicates that the TRLs are mainly the cholesterol-rich atherogenic remnant lipoproteins. A low LCF indicates that the TRLs are mainly the TG-rich larger VLDL and chylomicrons.

Results

As serum TG increases, there is progressive decline in the LCF for TRL, which indicates that the calculated non-HDLC level reflects progressive inclusion of cholesterol from larger TRL. This is shown in both cohorts.

Conclusions

Calculated non-HDLC is influenced by TG level. As TG increases, non-HDLC gradually includes more cholesterol from larger TRL, which are less atherogenic than LDL and remnant lipoproteins.

4944The contribution of familial hypercholesterolemia (FH) to premature coronary artery disease decreased by 2-fold between 1998 and 2018 in a founder population with high prevalence of FH

Background

Familial hypercholesterolemia (FH) is an autosomal dominant trait associated with high risk of premature coronary artery disease (CAD). The worldwide prevalence of FH is estimated at 1:250 to 1:500. In certain populations, including French Canadians (FC), the prevalence is significantly higher however. From 1995 to 1998, FH contributed to 9.6% of angiographically proven CAD in a FC founder population, the burden being the highest in men aged <50 years (20.6%). In the past 2 decades, powerful statins, ezetimibe and other low-density lipoprotein-Cholesterol (LDL-C) modulators, such as PCSK9 inhibitors, have been progressively introduced and several FH diagnosis scoring systems or guidelines have been developed and disseminated in order to facilitate FH recognition and management. The impact of these measures on the FH burden is however not documented.

Purpose

To compare the burden of FH twenty years apart in FC patients hospitalized for CAD.

Methods

Lipid profiles, cardiovascular risk factors and FH status of 1,132 FC patients who were hospitalized for a CAD event and who consecutively attended the cardiovascular disease clinic in 2017 and 2018 were compared to those of 2,506 who consecutively presented angiographically proven CAD two decades ago. FH status was based on Simon Broome and FH Canada definitions. In 1998, all consenting CAD patients were also molecularly screened for the most prevalent FH causing mutations in FC. Comparisons between groups were performed using Chi-square and independent samples Student's t-test.

Results

Most patients in both cohorts were males (74.5% vs 73.9% in 1998 vs. 2018, respectively). At admission, mean LDL-C (± SD) was 3.99±1.67 in 1998 vs. 2.22±1.06 in 2018 (p<0.001). The proportion of patients who were treated with a statin or another lipid lowering agent was 32.9% in 1998 compared to 67.6% in 2018 (p<0.001) and the drug regimen was also significantly different. In 1998, 24.6% of patients had LDL-C >5.0 mmol/L at admission compared to 4.2% in 2018. Definite FH was diagnosed in 9.6% of patients in the 1998 cohort compared to 4.7% in the 2018 cohort (p<0.001). FH patients hospitalized for CAD were significantly older in 2018 than in 1998 (56.3±11.3 vs. 49.2±10.9 in men, p=0.001; 61.1±11.8 vs. 53.2±12.3 in women, p=0.02). In the same period, the relative burden of diabetes and other lipid disorders, including high-density lipoprotein dysmetabolism significantly increased (p<0.001).

Conclusions

Over a period of 20 years, in a founder population with a high prevalence of FH, the contribution of FH to hospitalizations for CAD decreased by 2-fold and affected patients now tend to be hospitalized at an older age than 2 decades ago. This suggests that early diagnosis and more effective management of FH in the last 2 decades have contributed to significantly decrease its burden.

Acknowledgement/Funding

ECOGENE-21, Amgen, Sanofi

Pharmacogenomics of statin-related myopathy: Meta-analysis of rare variants from whole-exome sequencing

AIMS

Statin-related myopathy (SRM), which includes rhabdomyolysis, is an uncommon but important adverse drug reaction because the number of people prescribed statins world-wide is large. Previous association studies of common genetic variants have had limited success in identifying a genetic basis for this adverse drug reaction. We conducted a multi-site whole-exome sequencing study to investigate whether rare coding variants confer an increased risk of SRM.

METHODS AND RESULTS

SRM 3-5 cases (N = 505) and statin treatment-tolerant controls (N = 2047) were recruited from multiple sites in North America and Europe. SRM 3-5 was defined as symptoms consistent with muscle injury and an elevated creatine phosphokinase level >4 times upper limit of normal without another likely cause of muscle injury. Whole-exome sequencing and variant calling was coordinated from two analysis centres, and results of single-variant and gene-based burden tests were meta-analysed. No genome-wide significant associations were identified. Given the large number of cases, we had 80% power to identify a variant with minor allele frequency of 0.01 that increases the risk of SRM 6-fold at genome-wide significance.

CONCLUSIONS

In this large whole-exome sequencing study of severe statin-related muscle injury conducted to date, we did not find evidence that rare coding variants are responsible for this adverse drug reaction. Larger sample sizes would be required to identify rare variants with small effects, but it is unclear whether such findings would be clinically actionable.

Placental DNA Methylation Adaptation to Maternal Glycemic Response in Pregnancy

Maternal hyperglycemia during pregnancy is associated with excess fetal growth and adverse perinatal and developmental outcomes. Placental epigenetic maladaptation may underlie these associations. We performed an epigenome-wide association study (>850,000 CpG sites) of term placentas and prenatal maternal glycemic response 2-h post oral glucose challenge at 24-30 weeks of gestation among 448 mother-infant pairs. Maternal 2-h glycemia postload was strongly associated with lower DNA methylation of four CpG sites (false discovery rate [FDR] q <0.05) within the phosphodiesterase 4B gene (PDE4B). Additionally, three other individual CpG sites were differentially methylated relative to maternal glucose response within the TNFRSF1B, LDLR, and BLM genes (FDR q <0.05). DNA methylation correlated with expression of its respective genes in placental tissue at three out of four independent identified loci: PDE4B (r = 0.31, P < 0.01), TNFRSF1B (r = -0.24, P = 0.013), and LDLR (r = 0.32, P < 0.001). In an independent replication cohort (N = 65-108 samples), results were consistent in direction but not significantly replicated among tested CpG sites in PDE4B and TNFRSF1B Our study provides evidence that maternal glycemic response during pregnancy is associated with placental DNA methylation of key inflammatory genes whose expression levels are partially under epigenetic control.

Association study between a polymorphic poly-T repeat sequence in the promoter of the somatostatin gene and metabolic syndrome

Background

Metabolic syndrome is a cluster of factors associated with an increased risk of developing type 2 diabetes mellitus (T2D) and coronary artery disease (CAD). It is a complex disorder resulting from the interaction between various environmental factors and genetic susceptibility. The somatostatin (SST) gene has been shown to regulate a wide range of functions, particularly in energy homeostasis. In addition, low levels of SST have been reported to have effects on the progression of metabolic syndrome components. The aim of this study was therefore to evaluate the association between polymorphic T sequences in the promoter of the SST gene and metabolic syndrome expression.

Methods

We studied 1725 French-Canadian subjects from a founder population selected on the basis of having a positive family history of dyslipidemia, CAD or T2D. The analysis were performed on four groups created according to the poly T polymorphism length in the 5′ flanking promoter region of SST. Anova, Ancova and logistic regression models and Chi 2 analyses were used to evaluate the association between the poly T polymorphisms and metabolic syndrome components expression.

Results

Analyses showed that means, frequencies and odds ratio of metabolic syndrome components expression increase as the number of poly-T repeats in the promoter region of SST increases. Women exhibit more significant differences than men. However, the trends are the same in both genders and differences for most of the components are significant in the entire sample.

Conclusion

Those results suggest that the poly T polymorphisms in the SST promoter region may influence several metabolic processes implicated in metabolic syndrome expression. More analyses are needed to document the mechanisms that could underlie genetic regulation effect of SST on metabolic syndrome components and to clarify its specific role.

Large-scale deletions of the ABCA1 gene in patients with hypoalphalipoproteinemia

Copy-number variations (CNVs) have been studied in the context of familial hypercholesterolemia but have not yet been evaluated in patients with extreme levels of HDL cholesterol. We evaluated targeted, next-generation sequencing data from patients with very low levels of HDL cholesterol (i.e., hypoalphalipoproteinemia) with the VarSeq-CNV^® caller algorithm to screen for CNVs that disrupted the ABCA1, LCAT, or APOA1 genes. In four individuals, we found three unique deletions in ABCA1: a heterozygous deletion of exon 4, a heterozygous deletion that spanned exons 8 to 31, and a heterozygous deletion of the entire ABCA1 gene. Breakpoints were identified with Sanger sequencing, and the full-gene deletion was confirmed by using exome sequencing and the Affymetrix CytoScan HD array. Previously, large-scale deletions in candidate HDL genes had not been associated with hypoalphalipoproteinemia; our findings indicate that CNVs in ABCA1 may be a previously unappreciated genetic determinant of low levels of HDL cholesterol. By coupling bioinformatic analyses with next-generation sequencing data, we can successfully assess the spectrum of genetic determinants of many dyslipidemias, including hypoalphalipoproteinemia.

Selection of individuals for genetic testing for familial hypercholesterolaemia: development and external validation of a prediction model for the presence of a mutation causing familial hypercholesterolaemia

Aims

Familial hypercholesterolaemia (FH) is an autosomal dominant disease that warrants early diagnosis to prevent premature cardiovascular disease (CVD). However, genetic testing to make a definite diagnosis is costly, and careful selection of eligible subjects is important. Unfortunately, accuracy of current diagnostic criteria is poor, especially in young individuals. We therefore developed and validated a model to predict the presence of an FH causing mutation in persons referred by general practitioners.

Methods and results

All participants in the Dutch FH screening programme from 1994 to 2014 were included in the development cohort. The validation cohort consisted of consecutive patients, suspected for FH, attending the outpatient lipid clinic in Saguenay (Quebec) from 1993 to 2014. Cross-sectional data were available on medical history, lipid profile, and DNA analysis. Multivariable logistic regression analysis was used for model development. The primary outcome was the presence of a deleterious FH mutation. The development cohort comprised 26 167 FH patients and 37 939 unaffected relatives. Our final model included age; sex; levels of low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol, and triglycerides; history and age of CVD; use of statins; smoking; alcohol; and presence of hypertension. The area under the receiver operating characteristic curve (AUC) was 85.4% (95% CI: 85.0-85.9). The calibration slope was 1.02 (where 1.00 is optimal). In the validation cohort (1436 FH patients and 1767 unaffected persons), the AUC was 95.4% (95% CI: 94.7-96.1%) and the calibration slope 1.06.

Conclusion

Our model showed good discrimination and calibration. We specifically expect our model to be of added value for young persons set against current diagnostic criteria, since LDL-C and age are now used as continuous predictors. The equation will be available as an online calculator to estimate the probability of the presence of an FH mutation in individual patients. This tool might aid physicians in the decision for referral of patients for molecular testing.

Imputation of Baseline LDL Cholesterol Concentration in Patients with Familial Hypercholesterolemia on Statins or Ezetimibe

BACKGROUND

Familial hypercholesterolemia (FH) is the most frequent genetic disorder seen clinically and is characterized by increased LDL cholesterol (LDL-C) (&gt;95th percentile), family history of increased LDL-C, premature atherosclerotic cardiovascular disease (ASCVD) in the patient or in first-degree relatives, presence of tendinous xanthomas or premature corneal arcus, or presence of a pathogenic mutation in the LDLR, PCSK9, or APOB genes. A diagnosis of FH has important clinical implications with respect to lifelong risk of ASCVD and requirement for intensive pharmacological therapy. The concentration of baseline LDL-C (untreated) is essential for the diagnosis of FH but is often not available because the individual is already on statin therapy.

METHODS

To validate a new algorithm to impute baseline LDL-C, we examined 1297 patients. The baseline LDL-C was compared with the imputed baseline obtained within 18 months of the initiation of therapy. We compared the percent reduction in LDL-C on treatment from baseline with the published percent reductions.

RESULTS

After eliminating individuals with missing data, nonstandard doses of statins, or medications other than statins or ezetimibe, we provide data on 951 patients. The mean ± SE baseline LDL-C was 243.0 (2.2) mg/dL [6.28 (0.06) mmol/L], and the mean ± SE imputed baseline LDL-C was 244.2 (2.6) mg/dL [6.31 (0.07) mmol/L] (P = 0.48). There was no difference in response according to the patient's sex or in percent reduction between observed and expected for individual doses or types of statin or ezetimibe.

CONCLUSIONS

We provide a validated estimation of baseline LDL-C for patients with FH that may help clinicians in making a diagnosis.

Placental lipoprotein lipase DNA methylation alterations are associated with gestational diabetes and body composition at 5 years of age

Gestational diabetes mellitus (GDM) is associated with obesity in childhood. This suggests that consequences of in utero exposure to maternal hyperglycemia extend beyond the fetal development, possibly through epigenetic programming. The aims of this study were to assess whether placental DNA methylation (DNAm) marks were associated with maternal GDM status and to offspring body composition at 5 years old in a prospective birth cohort. DNAm levels were measured in the fetal side of the placenta in 66 samples (24 from GDM mothers) using bisDNA-pyrosequencing. Anthropometric and body composition (bioimpedance) were measured in children at 5 years of age. Mann-Whitney and Spearman tests were used to assess associations between GDM, placental DNAm levels at the lipoprotein lipase (LPL) locus and children's weight, height, body mass index (BMI), body fat, and lean masses at 5 years of age. Weight, height, and BMI z-scores were computed according to the World Health Organization growth chart. Analyses were adjusted for gestational age at birth, child sex, maternal age, and pre-pregnancy BMI. LPL DNAm levels were positively correlated with birth weight z-scores (r = 0.252, P = 0.04), and with mid-childhood weight z-scores (r = 0.314, P = 0.01) and fat mass (r = 0.275, P = 0.04), and negatively correlated with lean mass (r = -0.306, P = 0.02). We found a negative correlation between LPL DNAm and mRNA levels in placenta (r = -0.459; P < 0.001), which highlights the regulation of transcriptional activity by these epivariations. We demonstrated that alterations in fetal placental DNAm levels at the LPL gene locus are associated with the anthropometric profile in children at 5 years of age. These findings support the concept of fetal metabolic programming through epigenetic changes.

Genetic determinants of adiponectin regulation revealed by pregnancy

OBJECTIVE

This study investigated genetic determinants of adiponectin during pregnancy to reveal novel biology of adipocyte regulation.

METHODS

A genome-wide association study was conducted in 1,322 pregnant women from the Hyperglycemia and Adverse Pregnancy Outcome Study with adiponectin measured at ∼28 weeks of gestation. Variants reaching P < 5×10^-5 for de novo genotyping in two replication cohorts (Genetics of Glycemic regulation in Gestation and Growth N = 522; ECOGENE-21 N = 174) were selected.

RESULTS

In the combined meta-analysis, the maternal T allele of rs900400 located on chr3q25 (near LEKR1/CCNL1) was associated with lower maternal adiponectin (β ± standard error [SE] = -0.18 ± 0.03 standard deviation [SD] of adiponectin per risk allele; P = 1.5 ×10^-8 ; N = 2,004; multivariable adjusted models). In contrast, rs900400 showed only nominal association with adiponectin in a large sample of nonpregnant women (β ± SE = -0.012 ± 0.006; P = 0.05; N = 16,678 women from the ADIPOgen consortium). The offspring rs900400 T risk allele was associated with greater neonatal skinfold thickness (β ±SE = 0.19 ± 0.04 SD per risk allele; P = 4.1×10^-8 ; N = 1,489) and higher cord blood leptin (β ± SE = 0.28 ± 0.05 log-leptin per risk allele; P = 8.2 ×10^-9 ; N = 502), but not with cord blood adiponectin (P = 0.23; N = 495). The T allele of rs900400 was associated with higher expression of TIPARP in adipocytes.

CONCLUSIONS

These investigations of adipokines during pregnancy and early life suggest that rs900400 has a role in adipocyte function.

Long-Term Retrospective Analysis of Gene Therapy with Alipogene Tiparvovec and Its Effect on Lipoprotein Lipase Deficiency-Induced Pancreatitis

Alipogene tiparvovec (Glybera) is a gene therapy product approved in Europe under the "exceptional circumstances" pathway as a treatment for lipoprotein lipase deficiency (LPLD), a rare genetic disease resulting in chylomicronemia and a concomitantly increased risk of acute and recurrent pancreatitis, with potentially lethal outcome. This retrospective study analyzed the frequency and severity of pancreatitis in 19 patients with LPLD up to 6 years after a single treatment with alipogene tiparvovec. An independent adjudication board of three pancreas experts, blinded to patient identification and to pre- or post-gene therapy period, performed a retrospective review of data extracted from the patients' medical records and categorized LPLD-related acute abdominal pain events requiring hospital visits and/or hospitalizations based on the adapted 2012 Atlanta diagnostic criteria for pancreatitis. Both entire disease time period data and data from an equal time period before and after gene therapy were analyzed. Events with available medical record information meeting the Atlanta diagnostic criteria were categorized as definite pancreatitis; events treated as pancreatitis but with variable levels of laboratory and imaging data were categorized as probable pancreatitis or acute abdominal pain events. A reduction of approximately 50% was observed in all three categories of the adjudicated post-gene therapy events. Notably, no severe pancreatitis and only one intensive care unit admission was observed in the post-alipogene tiparvovec period. However, important inter- and intraindividual variations in the pre- and post-gene therapy incidence of events were observed. There was no relationship between the posttreatment incidence of events and the number of LPL gene copies injected, the administration of immunosuppressive regimen or the percent triglyceride decrease achieved at 12 weeks (primary end point in the prospective clinical studies). Although a causal relationship cannot be established and despite the limited number of individuals evaluated, results from this long-term analysis suggest that alipogene tiparvovec was associated with a lower frequency and severity of pancreatitis events, and a consequent overall reduction in health care resource use up to 6 years posttreatment.

PPARGC1α gene DNA methylation variations in human placenta mediate the link between maternal hyperglycemia and leptin levels in newborns

Background

Children exposed to gestational diabetes mellitus (GDM) are at a higher risk of developing obesity and type 2 diabetes. This susceptibility might involve brown adipose tissue (BAT), which is suspected to protect against obesity. The objective of this study is to assess whether fetal exposure to maternal hyperglycemia is associated with DNA methylation variations in genes involved in BAT genesis and activation.

Methods

DNA methylation levels at the PRDM16, BMP7, CTBP2, and PPARGC1α gene loci were measured in placenta samples using bisulfite pyrosequencing in E-21 (n = 133; 33 cases of GDM) and the HumanMethylation450 array in Gen3G (n = 172, all from non-diabetic women) birth cohorts. Glucose tolerance was assessed in all women using an oral glucose tolerance test at the second trimester of pregnancy. Participating women were extensively phenotyped throughout pregnancy, and placenta and cord blood samples were collected at birth.

Results

We report that maternal glycemia at the second and third trimester of pregnancy are correlated with variations in DNA methylation levels at PRDM16, BMP7, and PPARGC1α and with cord blood leptin levels. Variations in PRDM16 and PPARGC1α DNA methylation levels were also correlated with cord blood leptin levels. Mediation analyses support that DNA methylation variations at the PPARGC1α gene locus explain 0.8 % of the cord blood leptin levels variance independently of maternal fasting glucose levels (p = 0.05).

Conclusions

These results suggest that maternal glucose in pregnancy could produce variations in DNA methylation in BAT-related genes and that some of these DNA methylation marks seem to mediate the impact of maternal glycemia on cord blood leptin levels, an adipokine regulating body weight.

Electronic supplementary material

The online version of this article (doi:10.1186/s13148-016-0239-9) contains supplementary material, which is available to authorized users.

Epigenetic and genetic variations at the TNNT1 gene locus are associated with HDL-C levels and coronary artery disease

AIM

To assess whether epigenetic and genetic variations at the TNNT1 gene locus are associated with high-density lipoprotein cholesterol (HDL-C) and coronary artery disease (CAD). Patients, materials & methods: TNNT1 DNA methylation and c.-20G>A polymorphism were genotyped in subjects with and without familial hypercholesterolemia (FH).

RESULTS

Lower TNNT1 DNA methylation levels were independently associated with lower HDL-C levels and with the TNNT1 c.-20G>A polymorphism. In FH men, carriers of the TNNT1 c.-20G>A polymorphism had lower HDL-C levels and an increased risk of CAD compared with noncarriers. In non-FH men, a higher TNNT1 DNA methylation level was associated with CAD.

CONCLUSION

These results suggest that TNNT1 genetic and epigenetic variations are associated with HDL-C levels and CAD.

Association between a polymorphic poly-T repeat sequence in the promoter of the somatostatin gene and hypertension

Despite the numerous common pathways connecting blood pressure regulation to somatostatin (SST) metabolism, the SST gene has never been seen as a significant blood pressure modulator. The aim of this study was to evaluate the association between a poly-T repeat sequence (rs34872250) in the promoter of the SST gene and blood pressure, according to the obesity status. We genotyped 1918 French-Canadian subjects from a founder population. Analyses were performed according to the length of the poly-T repeat sequence on both alleles and divided into two groups, the 13/13-13/14 group and the 13/15-13/16 group. The effect of age, gender, body mass index, antihypertensive drugs and diabetic status were considered. Systolic, diastolic and mean blood pressures are significantly higher among the 13/15-13/16 group in the whole sample (P<0.05). Whereas the differences remain significant in women, they turn to be non-significant when men are considered alone. The risk of hypertension is increased in the 13/15-13/16 group, particularly among overweight/obese subjects. Systolic blood pressure is significantly higher among overweight/obese carriers of the 13/15-13/16 alleles in the whole sample (P<0.001), in men (P=0.006) and in women (P=0.002), even after correction for age and antihypertensive drugs. These results suggest that the poly-T repeat sequence polymorphism in the promoter of the SST gene is associated with significant variations of blood pressure and could modulate the risk of hypertension, particularly among women.

Gene-based therapies in lipidology: current status and future challenges

PURPOSE OF REVIEW

Gene-based therapies are designed to modulate gene expression in specific tissues by introducing into cells transgenes, antisense oligonucleotides, RNA interference, microRNAs, or a variety of other oligonucleotide-based compounds and their delivery systems. Several types of gene-based therapies are already available or in clinical development to treat severe lipid-related disorders and associated risk. The review briefly presents the current status and future challenges of these therapies in clinical lipidology, focusing on most advanced and promising agents or mechanisms.

RECENT FINDINGS

Gene-based agents address several unmet medical needs in lipidology such as homozygous familial hypercholesterolemia, familial or multifactorial chylomicronemia, severe hypertriglyceridemia, elevated lipoprotein (a), familial partial lipodystrophy, nonalcoholic fatty liver disease, and hypoalphalipoproteinemia. Most advanced antisense oligonucleotide drugs target apolipoprotein C-III, apolipoprotein (a), angiopoietin-like 3, and diacylglycerol o-acyltransferase-2. Long-term efficacy and safety data are now available for two gene-based agents, mipomersen, approved in the USA for homozygous familial hypercholesterolemia and Glybera, AAV1-LPLS447X gene therapy, conditionally approved in Europe for lipoprotein lipase deficiency.

SUMMARY

Although positive to date, the overall benefit-risk ratio of gene-based therapies is yet to be documented long term across additional patients and conditions. The next generation of such therapies might improve their therapeutic index.

LRP1B, BRD2 and CACNA1D: new candidate genes in fetal metabolic programming of newborns exposed to maternal hyperglycemia

AIM

To assess the associations between gestational diabetes mellitus (GDM) and DNA methylation levels at genes related to energy metabolism.

PATIENTS & METHODS

Ten loci were selected from our recent epigenome-wide association study on GDM. DNA methylation levels were quantified by bisulfite pyrosequencing in 80 placenta and cord blood samples (20 exposed to GDM) from an independent birth cohort (Gen3G).

RESULTS

We did not replicate association between DNA methylation and GDM. However, in normoglycemic women, glucose levels were associated with DNA methylation changes at LRP1B and BRD2 and at CACNA1D and LRP1B gene loci in placenta and cord blood, respectively.

CONCLUSION

These results suggest that maternal glucose levels, within the normal range, are associated with DNA methylation changes at genes related to energy metabolism and previously associated with GDM. Maternal glycemia might thus be involved in fetal metabolic programming.

Antisense Inhibition of Apolipoprotein C-III in Patients with Hypertriglyceridemia

BACKGROUND

Apolipoprotein C-III (APOC3) is a key regulator of plasma triglyceride levels. Elevated triglyceride levels are associated with a risk of adverse cardiovascular events and pancreatitis. ISIS 304801 is a second-generation antisense inhibitor of APOC3 synthesis.

METHODS

We conducted a randomized, double-blind, placebo-controlled, dose-ranging, phase 2 study to evaluate ISIS 304801 in untreated patients with fasting triglyceride levels between 350 mg per deciliter (4.0 mmol per liter) and 2000 mg per deciliter (22.6 mmol per liter) (ISIS 304801 monotherapy cohort), as well as in patients receiving stable fibrate therapy who had fasting triglyceride levels between 225 mg per deciliter (2.5 mmol per liter) and 2000 mg per deciliter (ISIS 304801-fibrate cohort). Eligible patients were randomly assigned to receive either ISIS 304801, at doses ranging from 100 to 300 mg, or placebo, once weekly for 13 weeks. The primary outcome was the percentage change in APOC3 level from baseline.

RESULTS

A total of 57 patients were treated in the ISIS 304801 monotherapy cohort (41 received active agent, and 16 received placebo), and 28 patients were treated in the ISIS 304801-fibrate cohort (20 received active agent, and 8 received placebo). The mean (±SD) baseline triglyceride levels in the two cohorts were 581±291 mg per deciliter (6.6±3.3 mmol per liter) and 376±188 mg per deciliter (4.2±2.1 mmol per liter), respectively. Treatment with ISIS 304801 resulted in dose-dependent and prolonged decreases in plasma APOC3 levels when the drug was administered as a single agent (decreases of 40.0±32.0% in the 100-mg group, 63.8±22.3% in the 200-mg group, and 79.6±9.3% in the 300-mg group, vs. an increase of 4.2±41.7% in the placebo group) and when it was administered as an add-on to fibrates (decreases of 60.2±12.5% in the 200-mg group and 70.9±13.0% in the 300-mg group, vs. a decrease of 2.2±25.2% in the placebo group). Concordant reductions of 31.3 to 70.9% were observed in triglyceride levels. No safety concerns were identified in this short-term study.

CONCLUSIONS

We found that treatment with ISIS 304801 was associated with significant lowering of triglyceride levels, among patients with a broad range of baseline levels, through selective antisense inhibition of APOC3 synthesis. (Funded by Isis Pharmaceuticals; ClinicalTrials.gov number, NCT01529424.).