The polygenic nature of hypertriglyceridaemia: implications for definition, diagnosis, and management

Identification of tacrolimus-related genes in familial combined hyperlipidemia and development of a diagnostic model using bioinformatics analysis

Background

Clinical observations have revealed that patients undergoing organ transplantation administered tacrolimus often experience abnormal lipid metabolism with serious consequences. Thus, the intricate interplay between tacrolimus and lipid metabolism must be addressed to develop targeted therapeutic interventions. Our ongoing research aims to develop precision medicine approaches that not only alleviate the immediate repercussions for organ transplant patients but also enhance their long-term outcomes. To this end, we investigated the potential genes associated with tacrolimus metabolism in familial combined hyperlipidemia (FCHL) to identify relevant biomarkers of FCHL, develop predictive diagnostic models for hyperlipidemia, and reveal potential therapeutic targets for FCHL.

Methods

Dataset GSE1010 containing information on patients diagnosed with FCHL was obtained from the Gene Expression Omnibus (GEO), and an ensemble of tacrolimus-related genes (TRGs) was retrieved from the GeneCards, STITCH, and Molecular Signatures Database databases. A thorough weighted gene co-expression network analysis was conducted, including a differential expression analysis of the GSE1010 and TRG datasets, to identify intricate patterns of gene co-expression and provide insights on the underlying molecular dynamics within the datasets. Key genes were screened, diagnostic models were constructed, and all genes associated with logFC values were assessed using gene set variation and enrichment analyses. Upregulated genes were identified by a positive logFC (>0) and P < 0.05, while downregulated genes were characterized by a negative logFC (<0) and P < 0.05. These criteria facilitated a more nuanced categorization of gene expression changes within the analyzed datasets. Given tacrolimus's immunosuppressive impact, the gene expression matrix data obtained from dataset GSE1010 was submitted to CIBERSORT to assess immune cell infiltration outcomes. Finally, we examined the regulatory network of screened key genes that interact with RNA-binding proteins, potential drugs, small-molecule compounds, and transcription factors.

Results

We screened 14 statistically significant key genes, built a reliable risk model, and grouped the dataset into categories at high and low risk for hyperlipidemia development. FCHL was linked to memory B and immature B immune cells. The gene set variation analysis revealed two pathways associated with cholesterol homeostasis and the complement system that were closely associated with the potential functions of FCHL and tacrolimus-related differentially expressed genes.

Conclusions

Our research offers a better understanding of FCHL and the TRGs involved in lipid metabolism. Additionally, it provides research directions for identifying potential targets for clinical therapies.

The interaction between circadian syndrome and genetic susceptibility in the risk of incident dementia: A longitudinal cohort study

BACKGROUND

Despite growing interest in circadian disturbances as potential triggers for dementia, the specific impact of circadian syndrome (CircS) on dementia incidence remains poorly understood. Moreover, the role of genetic susceptibility modulating these effects remains to be explored.

METHODS

Dementia-free participants from the UK Biobank cohort were included in the analysis. To evaluate the association between CircS and the incidence of dementia, as well as the modifying influence of genetic susceptibility on this relationship, Cox proportional hazards models were utilized.

RESULTS

During a median follow-up period of 14.55 years, 3,965 incident dementia cases were documented. CircS was found to significantly increased the risk of incident dementia, with a hazard ratio (HR) of 1.401 (95 % confidence interval [CI]: 1.296, 1.516). Compared to a CircS score of ≤3, mild CircS (HR: 1.259, 95 % CI: 1.146-1.383), moderate CircS (HR: 1.667, 95 % CI: 1.461-1.903), and severe CircS (HR: 2.028, 95 % CI: 1.397-2.944) were all significantly associated with an elevated risk of dementia. There were significant multiplicative interactions between CircS and genetic susceptibility (Pinteraction<0.001). Participants with both a high polygenic risk score (PRS) and CircS had the highest risk of incident dementia (HR: 2.551, 95 % CI: 2.169, 3.001), compared to those with a low PRS and no CircS.

CONCLUSIONS

CircS was associated with an increased risk of dementia, which might be aggravated by genetic susceptibility.

Selective peroxisome proliferator-activated receptor-α modulator improves hypertriglyceridemia and muscle quality in patients with chronic kidney disease: A retrospective observational study

BACKGROUND & AIMS

Patients with chronic kidney disease (CKD) often have additional health problems, including sarcopenia and sarcopenic obesity. These conditions involve ectopic fat accumulation within muscles. This ectopic fat deposition reduces muscle quality, leading to weaker muscle strength and poorer physical performance. Persistent hypertriglyceridemia contributes to ectopic fat accumulation. Metabolic abnormalities, including dyslipidemia, are major factors in CKD development. Triglycerides (TG) and muscle quality are thus important factors in CKD management. Recently developed selective peroxisome proliferator-activated receptor α modulator (SPPARMα) hold promises for improving hypertriglyceridemia. However, their effectiveness and impact on muscle quality in CKD patients remain unclear. This study aimed to evaluate the effect of SPPARMα on muscle quality and its efficacy in CKD patients.

METHODS

This retrospective observational study involved CKD patients with dyslipidemia. We included patients who initiated medications for hypertriglyceridemia. We compared changes in lipid profiles, renal function, and muscle quality, assessed by phase angle, over six months between two groups: those receiving this type of medication and those receiving conventional treatment.

RESULTS

Among 245 patients diagnosed with CKD and hypertriglyceridemia, 52 started medications for hypertriglyceridemia. Of these, 26 received SPPARMα, and 26 received conventional lipid-lowering medications (statins, ezetimibe, eicosapentaenoic acid, and fibrates). SPPARMα significantly reduced TG (from 296.8 ± 106.1 to 153.0 ± 86.1, p < 0.001) without affecting glomerular filtration rate or urinary protein levels. Conventional treatment also improved TG (from 261.6 ± 89.5 to 173.6 ± 81.3, p < 0.001). Only patients treated with SPPARMα showed significant improvement in muscle quality. Their phase angle increased from 5.41 ± 0.6 to 5.55 ± 0.6 after six months of treatment (p < 0.05).

CONCLUSIONS

Our study demonstrates that the newly developed SPPARMα significantly lowers TG levels in CKD patients without harming their kidneys. Additionally, only patients treated with SPPARMα showed improvement in muscle quality. These findings suggest that SPPARMα may be a valuable treatment option for CKD patients with dyslipidemia, particularly those with low muscle quality.

Beneficial Effect of Fenofibrate in Combination with Silymarin on Parameters of Hereditary Hypertriglyceridemia-Induced Disorders in an Animal Model of Metabolic Syndrome

Background: Hypertriglyceridemia has serious health risks such as cardiovascular disease, type 2 diabetes mellitus, nephropathy, and others. Fenofibrate is an effective hypolipidemic drug, but its benefits for ameliorating disorders associated with hypertriglyceridemia failed to be proven in clinical trials. Methods: To search for possible causes of this situation and possibilities of their favorable influence, we tested the effect of FF monotherapy and the combination of fenofibrate with silymarin on metabolic disorders in a unique model of hereditary hypertriglyceridemic rats (HHTg). Results: Fenofibrate treatment (100 mg/kg BW/day for four weeks) significantly decreased serum levels of triglyceride, (-77%) and free fatty acids (-29%), the hepatic accumulation of triglycerides, and the expression of genes encoding transcription factors involved in lipid metabolism (Srebf2, Nr1h4. Rxrα, and Slco1a1). In contrast, the hypertriglyceridemia-induced ectopic storage of lipids in muscles, the heart, and kidneys reduced glucose utilization in muscles and was not affected. In addition, fenofibrate reduced the activity of the antioxidant system, including Nrf2 expression (-35%) and increased lipoperoxidation in the liver and, to a lesser extent, in the kidneys and heart. Adding silymarin (micronized form, 600 mg/kg BW/day) to fenofibrate therapy increased the synthesis of glycogen in muscles, (+36%) and reduced hyperinsulinemia (-34%). In the liver, it increased the activity of the antioxidant system, including PON-1 activity and Nrf2 expression, and reduced the formation of lipoperoxides. The beneficial effect of combination therapy on the parameters of oxidative stress and lipoperoxidation was also observed, to a lesser extent, in the heart and kidneys. Conclusions: Our results suggest the potential beneficial use of the combination of FF with SLM in the treatment of hypertriglyceridemia-induced metabolic disorders.

Cross-sectional analysis of non-HDL/HDL cholesterol ratio as a marker for cardiovascular disease risk in middle-aged and older adults: Evidence from the CHARLS study

BACKGROUND

While cardiovascular disease is linked to abnormal lipid metabolism, the relationship between NHHR (non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio), a new lipid metric, and cardiovascular disease in middle-aged and older adults in China is still unclear.

METHODS

This cohort study, based on a population sample, examined the incidence of cardiovascular disease (CVD) events, including stroke and heart disease. It utilized self-reported diagnoses from the study's inception and during Wave 4, involving 9259 participants from the China Health and Retirement Longitudinal Study (CHARLS). The research employed restricted cubic spline models and multivariate logistic regression to investigate possible non-linear relationships. Additionally, subgroup analyses were conducted to assess the influence of socio-demographic factors on the outcomes.

RESULT

During the seven-year follow-up period, 1,139 participants developed CVD, including 742 cases of heart problems and 582 strokes. In Model 3, it was observed that for each unit increase in the highest NHHR group, the risk of developing CVD increased by 98%, the risk of stroke increased by 48%, and the risk of heart problems increased by 115%. Subgroup analyses indicated that this correlation was more pronounced among individuals under 60 years of age and those with hypertension.

CONCLUSIONS

According to the current study, elevated NHHR ratio is an important risk factor for CVD in middle-aged and elderly Chinese. Early intervention in patients with higher NHHR ratios may help to further reduce the incidence of CVD.

Causal relationship between dyslipidemia and diabetic neuropathy: a mendelian randomization study

Some studies have shown an association between dyslipidemia and diabetic neuropathy (DN), but the genetic association has not been clarified. Therefore, the present study aimed to investigate the genetic causal association between dyslipidemia and DN through a Mendelian randomization (MR) approach. Genetic causal associations between total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL), and high-density lipoprotein cholesterol (HDL) and DN were investigated by MR to provide a basis for the prevention and treatment of DN. Significant and independent single-nucleotide polymorphisms (SNPs) identified in genome-wide association studies were selected as instrumental variables (IVs) for MR analysis. Inverse variance weighted (IVW), MR‒Egger regression, weighted median (WME), simple mode (SM), and weighted mode (WM) methods were used to analyze causal associations. Heterogeneity and multiplicity tests were also performed and analyzed using the leave-one-out method to assess the stability of the results. Genetically predicted TC and DN (OR = 0.793, 95% CI = 0.655⁓0.961, P = 0.019) and LDL and DN (OR = 0.842, 95% CI = 0.711⁓0.998, P = 0.049) may be causally associated, but no causal associations were found between TG and DN (OR = 0.837, 95% CI = 0.631⁓1.111, P = 0.221) or between HDL and DN (OR = 1.192, 95% CI = 0.940⁓1.510, P = 0.149). TC and LDL may have genetic causal associations with DN, though no genetic causal associations were found for TG or HDL with DN. However, this study may have several limitations, and further clinical studies are needed to expand the sample size for future validation.

Association between pyrrolizidine alkaloids exposure and risk of abnormal serum indices-Insights from a descriptive cross-sectional study in Yunnan Province

The hazard of pyrrolizidine alkaloids (PAs) has been widely reported in animal studies but rarely in population-based research, especially reports about daily exposure. A single-centre descriptive cross-sectional study was conducted on 552 Lahu Autonomous County residents recruited in 2021. Blood PAs exposure biomarker (pyrrole- protein adduct, PPA) and serum biochemical indices were measured. The prevalence of abnormal serum indices and PAs exposure in this region were elucidated using descriptive analyses. 75 % of Lahu Autonomous County participants were exposed to PAs. PAs exposure risk in males was lower than in females (OR=0.357, 95 % CI: 0.222-0.574), and varied with the ethnicity of Lahu Autonomous County. PPA concentration was positively correlated with serum alanine transaminase (ALT) activity (r=0.6263, P < 0.01) and triglyceride level (r=0.2327, P < 0.01); PAs exposure was positively associated with anbormal serum ALT activity (x2=99.629, P < 0.001; OR=1.428, 95 % CI: 1.293-2.319) and hypertriglyceridemia (x2=15.376, P < 0.001; OR=1.629, 95 % CI: 1.229-2.251). These results suggest that PAs exposure might be a risk factor for serum ALT abnormality and hypertriglyceridemia in the local population. This study conducted the first epidemiological study on PAs exposure in China and established the etiological hypotheses for health issues in Lahu Autonomous County.

Impact of polygenic risk score for triglyceride trajectory and diabetic complications in subjects with type 2 diabetes based on large electronic medical record data from Taiwan: a case control study

BACKGROUND

The prevalence of diabetic dyslipidemia has gradually increased worldwide and individuals with hypertriglyceridemia often have a high polygenic burden of triglyceride (TG)-increasing variants. However, the contribution of genetic variants to dyslipidemia in patients with type 2 diabetes (T2D) remains limited. Therefore, in this study, we aimed to investigate the genetic characteristics of longitudinal changes in TG levels among patients with T2D and summarize the genetic effects of polygenic risk score (PRS) on TG trajectory and risk of diabetic complications.

METHODS

We conducted a case-control study. A total of 11,312 patients with T2D with longitudinal TG and genetic data were identified from a large hospital database in Taiwan. We then performed a genome-wide association study and calculated the relative PRS.

RESULTS

In total, 21 single-nucleotide polymorphisms (SNPs) related to TG trajectory were identified and yielded an area under the receiver operating characteristic curve (ROC) of 0.712 for high TG trajectory risk among Taiwanese patients with T2D. A cumulative genetic effect was observed for high TG trajectory, even when considering the adherence of a lipid-lowering agent in stratified analysis. An increased PRS increases high TG trajectory risk in a logistic regression model (odds ratio = 1.55; 95% confidence interval [CI] = 1.31-1.83 in the validation cohort). The TG-specific PRS was associated with the risk of diabetic microvascular complications, including diabetic retinopathy and nephropathy (with hazard ratios of 1.11 [95% CI = 1.01-1.21, P = 0.027] and 1.05 [95% CI = 1.01-1.1, P = 0.018], respectively).

CONCLUSIONS

This study may contribute to the identification of patients with T2D who are at risk of abnormal TG levels and diabetic microvascular complications using polygenic information.

Multifactorial chylomicronemia: keys to detecting severe forms

Multifactorial chylomicronemia associated with multiple comorbidities, drugs and habits is much more common than familial chylomicronemia, an autosomal recessive disease that can be considered as "rare disease". Like the rest of hypertriglyceridemias, chylomicronemias could be classified as primary or monogenic and secondary in which, on the basis of polygenic predisposition, there is concomitant exposure to multiple triggering factors. In this brief revision, we will review its causes and management as well as the keys to its differential diagnosis of the Multifactorial Chylomicronemia.

Metabolic dysfunction and alcohol-related liver disease (MetALD): Position statement by an expert panel on alcohol-related liver disease

In this position statement, we explore the intricate relationship between alcohol intake and metabolic dysfunction in the context of the 2023 nomenclature update for steatotic liver disease (SLD). Recent and lifetime alcohol use should be accurately assessed in all patients with SLD to facilitate classification of alcohol use in grams of alcohol per week. Alcohol biomarkers (i.e., phosphatidylethanol), use of validated questionnaires (i.e. AUDIT-C [alcohol use disorders identification test consumption]), and collateral information from friends and relatives could help facilitate differentiation between alcohol-related liver disease (ALD) per se and liver disease with both metabolic and alcohol-related components (MetALD). Heavy alcohol use can contribute to cardiometabolic risk factors such as high blood pressure, hypertriglyceridaemia, and hyperglycaemia. As a result, caution should be exercised in the application of only one metabolic dysfunction criterion to diagnose MASLD, as suggested in the 2023 nomenclature document, particularly in individuals exceeding weekly alcohol use thresholds of 140 g for women and 210 g for men. This is particularly important in those individuals with isolated high blood pressure, hypertriglyceridaemia, or hyperglycaemia, where the disease process may be driven by alcohol itself. Additionally, metabolic dysfunction and alcohol use should be reassessed over time, especially after periods of change in risk factor exposure. This approach could ensure a more accurate prognosis and effective management of SLD, addressing both metabolic and alcohol-related factors.

Whole blood gene expression analysis of spontaneous hypertriglyceridemia in dogs suggests an underlying pro-thrombotic process

Hypertriglyceridemia (HTG) is influenced by multiple genetic and environmental factors. Spontaneous, idiopathic HTG is common in the Miniature Schnauzer dog and presumed to have a strong genetic influence in this breed. To define genes that are differentially expressed in dogs with HTG, we performed RNA sequencing on peripheral blood of 13 Miniature Schnauzers with HTG and 18 controls. We identified 110 differentially expressed genes (DEGs). Pathway analysis suggests an ongoing pro-thrombotic, endothelial activation process in dogs with HTG. The gene with the largest fold change (5.4 ± 1.4, Padj = 4.4E-04), SERPINE1, encodes plasminogen activator inhibitor 1 (PAI-1), a known risk factor for atherosclerosis and thrombosis. Other top DEGs, including SHANK3, MMRN1, and FZD7, are involved in endothelial activation. Two of the top DEGs, ARHGAP29 and ARHGAP21, inhibit pro-thrombotic pathways and are potentially protective of disease sequelae. Top DEGs, including SERPINE1 and ARHGAP21, have also been linked to metabolic syndrome or its features (e.g. insulin resistance) in humans and animal models. Our findings indicate that HTG in the Miniature Schnauzer dog has similar features to HTG and metabolic syndrome in humans, highlighting the potential use of the dog as a spontaneous model for further research into the etiology and effects of HTG.

Beyond the Guidelines: Perspectives on Management of Pediatric Patients with Hypertriglyceridemia

PURPOSE OF REVIEW

To provide a comprehensive overview of hypertriglyceridemia (HTG) in youth, identifying gaps in categorizing triglyceride (TG) levels and management strategies, and exploring new therapies for TG reduction.

RECENT FINDINGS

Non-fasting TG levels as important cardiovascular (CV) risk indicators, with HTG's pathophysiology involving genetic and secondary factors affecting TG metabolism. Emerging treatments, including those affecting the lipoprotein lipase complex and inhibiting proteins like apoC3 and ANGPTL3, show promise. The review highlights the need for specific management approaches for youth, the significance of non-fasting TG levels, and the potential of new therapies in reducing CV and pancreatitis risks, advocating for further research on these treatments' efficacy and safety.

Ethnic Diversity and Distinctive Features of Familial Versus Multifactorial Chylomicronemia Syndrome: Insights From the UK FCS National Registry

BACKGROUND

Familial chylomicronemia syndrome (FCS) is a rare autosomal recessive disorder. This study aimed to study the genotype distribution of FCS-causing genes in the United Kingdom, genotype-phenotype correlation, and clinical differences between FCS and multifactorial chylomicronemia syndrome (MCS).

METHODS

The study included 154 patients (FCS, 74; MCS, 80) from the UK FCS national registry and the UK arm of the FCS International Quality Improvement and Service Evaluation Project.

RESULTS

FCS was relatively common in non-Europeans and those with parental consanguinity (P<0.001 for both). LPL variants were more common in European patients with FCS (European, 64%; non-European, 46%), while the genotype was more diverse in non-European patients with FCS. Patients with FCS had a higher incidence compared with patients with MCS of acute pancreatitis (84% versus 60%; P=0.001), recurrent pancreatitis (92% versus 63%; P<0.001), unexplained abdominal pain (84% versus 52%; P<0.001), earlier age of onset (median [interquartile range]) of symptoms (15.0 [5.5-26.5] versus 34.0 [25.2-41.7] years; P<0.001), and of acute pancreatitis (24.0 [10.7-31.0] versus 33.5 [26.0-42.5] years; P<0.001). Adverse cardiometabolic features and their co-occurrence was more common in individuals with MCS compared with those with FCS (P<0.001 for each). Atherosclerotic cardiovascular disease was more prevalent in individuals with MCS than those with FCS (P=0.04). However, this association became nonsignificant after adjusting for age, sex, and body mass index. The prevalence of pancreatic complications and cardiometabolic profile of variant-positive MCS was intermediate between FCS and variant-negative MCS.

CONCLUSIONS

The frequency of gene variant distribution varies based on the ethnic origin of patients with FCS. Patients with FCS are at a higher risk of pancreatic complications while the prevalence of atherosclerotic cardiovascular disease is lower in FCS compared with MCS. Carriers of heterozygous pathogenic variants have an intermediate phenotype between FCS and variant-negative MCS.

Genetic variants in triglyceride metabolism genes among individuals with hypertriglyceridemia in Colombia

BACKGROUND

The genetic substrate of severe hypertriglyceridemia (sHTG) in Latin America is insufficiently understood.

OBJECTIVE

To identify genetic variants in genes related to triglyceride (TG) metabolism among adults with sHTG from Colombia.

METHODS

In individuals with plasma TG≥880 mg/dL at least once in their lifetime, we amplified and sequenced all exons and intron/exon boundaries of the genes LPL, APOC2, APOA5, GPIHBP1 and LMF1. For each variant we ascertained its location, zygosity, allelic frequency and pathogenicity classification according to American College of Medical Genetics (ACMG) criteria.

RESULTS

The study included 166 participants (62 % male, mean age 50), peak TG levels ranged between 894 and 11,000 mg/dL. We identified 92 variants: 19 in LPL, 7 in APOC2, 11 in GPIHBP1, 38 in LMF1, and 17 in APOA5. Eighteen of these variants had not been reported. We identified a new pathogenic variant in LMF1 (c.41C>A; p.Ser14*), a new likely pathogenic variant in LMF1 (c.1527 C > T; p.Pro509=, also expressed as c.1447C>T; p.Gln483*), and a known pathogenic variant in LMF1 (c.779G>A; p.Trp260*). Four participants were heterozygous for variant c.953A>G; p.Asn318Ser in LPL, a known risk factor for hypertriglyceridemia. Participants with variants of unknown significance (VUS) in LMF1 had significantly higher peak TG than those with VUS in other genes. Peak TG were 4317 mg/dL in participants with a history of pancreatitis, and 1769 mg/dL in those without it (p = 0.001).

CONCLUSION

Our study identified variants associated with sHTG among Latinos, and showed that genetic variation in LMF1 may be frequently associated with sHTG in this population.

Pancreatic and cardiometabolic complications of severe hypertriglyceridaemia

PURPOSE OF REVIEW

This review endeavours to explore the aetiopathogenesis and impact of severe hypertriglyceridemia (SHTG) and chylomicronaemia on cardiovascular, and pancreatic complications and summarizes the novel pharmacological options for management.

RECENT FINDINGS

SHTG, although rare, presents significant diagnostic and therapeutic challenges. Familial chylomicronaemia syndrome (FCS), is the rare monogenic form of SHTG, associated with increased acute pancreatitis (AP) risk, whereas relatively common multifactorial chylomicronaemia syndrome (MCS) leans more towards cardiovascular complications. Despite the introduction and validation of the FCS Score, FCS continues to be underdiagnosed and diagnosis is often delayed. Longitudinal data on disease progression remains scant. SHTG-induced AP remains a life-threatening concern, with conservative treatment as the cornerstone while blood purification techniques offer limited additional benefit. Conventional lipid-lowering medications exhibit minimal efficacy, underscoring the growing interest in novel therapeutic avenues, that is, antisense oligonucleotides (ASO) and short interfering RNA (siRNA) targeting apolipoprotein C3 (ApoC3) and angiopoietin-like protein 3 and/or 8 (ANGPTL3/8).

SUMMARY

Despite advancements in understanding the genetic basis and pathogenesis of SHTG, diagnostic and therapeutic challenges persist. The rarity of FCS and the heterogenous phenotype of MCS underscore the need for the development of predictive models for complications and tailored personalized treatment strategies. The establishment of national and international registries is advocated to augment disease comprehension and identify high-risk individuals.

Conditions Associated With Hypertriglyceridemia in Adult Patients in a Tertiary Care Center in Basrah, Iraq

Background Hypertriglyceridemia (HTG) is one of the major modifiable risk factors for the development of several metabolic diseases. Determining the factors associated with HTG is an important step for increasing awareness of the problem and proper planning of health programs for HTG prevention. This study aimed to determine the conditions associated with HTG in adult patients in Basrah, Iraq. Methodology This retrospective study was conducted at Faiha Specialized Diabetes Endocrine and Metabolism Center (FDEMC) in Basra, southern Iraq, in January 2024. The data were retrieved from the center database of 37,133 subjects registered from 2008 to 2023 (16,284, 43.8% males and 20,849, 56.2% females) who attended the FDEMC in Basra due to different reasons. Results The most common causes of HTG were type 2 diabetes mellitus (T2DM) (29,799, 80%), obesity (19,914, 53.63%), and smoking (7,309, 12.68%). The age group of 18-45 years displayed higher triglyceride (TG) levels (281.1 ± 210.1 mg/dL) than other age groups. Furthermore, male patients had higher TG levels than females (288.0 ± 196.3 mg/dL vs. 268.9 ± 165.9 mg/dL). Regarding body mass index, overweight and obese patients had higher mean TG levels (284.4 ± 182.1 mg/dL and 281.7 ± 184.6 mg/dL, respectively). Current and ex-smokers had higher TG levels (305.1 ± 212.2 mg/dL and 283.4 ± 161.3 mg/dL, respectively) than non-smokers (272.5 ± 175.4 mg/dL). Moderate HTG was the most common category encountered in 24,137 patients (65%), followed by mild HTG (12,705, 34.2%). Very few patients had severe (264, 7%) or very severe HTG (27, 0.07%). Male patients had more frequent severe and very severe HTG than females. Conclusions The most common conditions associated with HTG were T2DM, obesity, and smoking. Smoker males were prone to severe and very severe HTG.

Hypertriglyceridemia Results From an Impaired Catabolism of Triglyceride-Rich Lipoproteins in PLIN1-Related Lipodystrophy

BACKGROUND

Pathogenic variants in PLIN1-encoding PLIN1 (perilipin-1) are responsible for an autosomal dominant form of familial partial lipodystrophy (FPL) associated with severe insulin resistance, hepatic steatosis, and important hypertriglyceridemia. This study aims to decipher the mechanisms of hypertriglyceridemia associated with PLIN1-related FPL.

METHODS

We performed an in vivo lipoprotein kinetic study in 6 affected patients compared with 13 healthy controls and 8 patients with type 2 diabetes. Glucose and lipid parameters, including plasma LPL (lipoprotein lipase) mass, were measured. LPL mRNA and protein expression were evaluated in abdominal subcutaneous adipose tissue from patients with 5 PLIN1-mutated FPL and 3 controls.

RESULTS

Patients with PLIN1-mutated FPL presented with decreased fat mass, insulin resistance, and diabetes (glycated hemoglobin A1c, 6.68±0.70% versus 7.48±1.63% in patients with type 2 diabetes; mean±SD; P=0.27). Their plasma triglycerides were higher (5.96±3.08 mmol/L) than in controls (0.76±0.27 mmol/L; P<0.0001) and patients with type 2 diabetes (2.94±1.46 mmol/L, P=0.006). Compared with controls, patients with PLIN1-related FPL had a significant reduction of the indirect fractional catabolic rate of VLDL (very-low-density lipoprotein)-apoB100 toward IDL (intermediate-density lipoprotein)/LDL (low-density lipoprotein; 1.79±1.38 versus 5.34±2.45 pool/d; P=0.003) and the indirect fractional catabolic rate of IDL-apoB100 toward LDL (2.14±1.44 versus 7.51±4.07 pool/d; P=0.005). VLDL-apoB100 production was not different between patients with PLIN1-related FPL and controls. Compared with patients with type 2 diabetes, patients with PLIN1-related FPL also showed a significant reduction of the catabolism of both VLDL-apoB100 (P=0.031) and IDL-apoB100 (P=0.031). Plasma LPL mass was significantly lower in patients with PLIN1-related FPL than in controls (21.03±10.08 versus 55.76±13.10 ng/mL; P<0.0001), although the LPL protein expression in adipose tissue was similar. VLDL-apoB100 and IDL-apoB100 indirect fractional catabolic rates were negatively correlated with plasma triglycerides and positively correlated with LPL mass.

CONCLUSIONS

We show that hypertriglyceridemia associated with PLIN1-related FPL results from a marked decrease in the catabolism of triglyceride-rich lipoproteins (VLDL and IDL). This could be due to a pronounced reduction in LPL availability, related to the decreased adipose tissue mass.

Clinico-Laboratory Profile of Hypertriglyceridemia Thalassemia Syndrome: A Case Series in a Paediatric Tertiary Care Centre

BACKGROUND

Increased hemolysis and repeated blood transfusion trigger oxidative stress resulting in numerous adverse effects in beta-thalassemia patients. Extreme elevation of triglyceride level is a rare clinical entity seen in these patients. It is presumed to be caused due to an increase in oxidative stress and is termed Hypertriglyceridemia Thalassemia Syndrome.

OBJECTIVES

To assess the clinical and laboratory characteristics of beta-thalassemia patients presenting with hypertriglyceridemia and its correlation with the pre-transfusion hemoglobin level.  Methods: This hospital record-based retrospective study was conducted at the Dr B C Roy Post Graduate Institute of Paediatric Sciences, Kolkata, India. The study comprised 12 pediatric beta-thalassemia patients whose plasma appeared milky or chylous during a complete hemogram. Clinical examination and laboratory investigations were done to describe their clinico-laboratory features. A whole exome sequencing was carried out to assess their genetic background. Blood hemoglobin and serum triglyceride estimation was carried out initially and at follow-up to determine any correlation between the two.  Results: Out of 1482 patients, 12 (0.80 %) were diagnosed with Hypertriglyceridemia Thalassemia Syndrome. The median age of presentation was 12.5 months (Q1:10 months, Q3:14 months)., and the pretransfusion hemoglobin was 4.82 ± 1.16 g/dL. The lipid profile showed a triglyceride level of 858.3 ± 198.4 mg/dl and a total cholesterol level of 117.4 ± 16.15 mg/dl. Analysis revealed that the triglyceride levels were negatively correlated with the pretransfusion hemoglobin level (repeated measures correlation (rmcorr) = -0.65, 95% CI [-0.794, -0.425], p < 0.001). A genetic study highlighted c.92+5G>C as the commonest mutation.

CONCLUSION

Hypertriglyceridemia was a rare presentation in transfusion-dependent beta-thalassemia patients. The serum triglyceride level significantly reduced when blood transfusion at regular intervals restored the patient's hemoglobin level.

A significant presence in atherosclerotic cardiovascular disease: Remnant cholesterol: A review

The current first-line treatment for atherosclerotic cardiovascular disease (ASCVD) involves the reduction of a patient's low-density lipoprotein cholesterol (LDL-C) levels through the use of lipid-lowering drugs. However, even when other risk factors such as hypertension and diabetes are effectively managed, there remains a residual cardiovascular risk in these patients despite achieving target LDL-C levels with statins and new lipid-lowering medications. This risk was previously believed to be associated with lipid components other than LDL, such as triglycerides. However, recent studies have unveiled the crucial role of remnant cholesterol (RC) in atherosclerosis, not just triglycerides. The metabolized product of triglyceride-rich lipoproteins is referred to as triglyceride-rich remnant lipoprotein particles, and its cholesterol component is known as RC. Numerous pieces of evidence from epidemiological investigations and genetic studies demonstrate that RC plays a significant role in predicting the incidence of ASCVD. As a novel marker for atherosclerosis prediction, when LDL-C is appropriately controlled, RC should be prioritized for attention and intervention among individuals at high risk of ASCVD. Therefore, reducing RC levels through the use of various lipid-lowering drugs may yield long-term benefits. Nevertheless, routine testing of RC in clinical practice remains controversial, necessitating further research on the treatment of elevated RC levels to evaluate the advantages of reducing RC in patients at high risk of ASCVD.

Clinical characterization and mutation spectrum of patients with hypertriglyceridemia in a German outpatient clinic

BACKGROUND

Severe hypertriglyceridemia (HTG) has predominantly multifactorial causes (MCS). Yet a small subset of patients have the monogenetic form (FCS). It remains a challenge to distinguish patients clinically, since decompensated MCS might mimic FCS´s severity. Aim of the current study was to determine clinical criteria that could sufficiently distinguish both forms as well as to apply the FCS score proposed by Moulin and colleagues.

METHODS

We retrospectively studied 72 patients who presented with severe HTG in our clinic during a time span of seven years and received genetic testing. We classified genetic variants (ACMG-criteria), followed by genetic categorization into MCS or FCS. Clinical data were gathered from the medical records and the FCS score was calculated for each patient.

RESULTS

Molecular genetic screening revealed eight FCS patients and 64 MCS patients. Altogether, we found 13 pathogenic variants of which four have not been described before. The FCS patients showed a significantly higher median triglyceride level compared to the MCS. The FCS score yielded a sensitivity of 75% and a specificity of 93.7% in our cohort, and significantly differentiated between the FCS and MCS group (p<0.001).

CONCLUSIONS

In our cohort we identified several variables that significantly differentiated FCS from MCS. The FCS score performed similar to the original study by Moulin, thereby further validating the discriminatory power of the FCS score in an independent cohort.

Plozasiran (ARO-APOC3) for Severe Hypertriglyceridemia: The SHASTA-2 Randomized Clinical Trial

Importance

Severe hypertriglyceridemia (sHTG) confers increased risk of atherosclerotic cardiovascular disease (ASCVD), nonalcoholic steatohepatitis, and acute pancreatitis. Despite available treatments, persistent ASCVD and acute pancreatitis-associated morbidity from sHTG remains.

Objective

To determine the tolerability, efficacy, and dose of plozasiran, an APOC3-targeted small interfering-RNA (siRNA) drug, for lowering triglyceride and apolipoprotein C3 (APOC3, regulator of triglyceride metabolism) levels and evaluate its effects on other lipid parameters in patients with sHTG.

Design, Setting, and Participants

The Study to Evaluate ARO-APOC3 in Adults With Severe Hypertriglyceridemia (SHASTA-2) was a placebo-controlled, double-blind, dose-ranging, phase 2b randomized clinical trial enrolling adults with sHTG at 74 centers across the US, Europe, New Zealand, Australia, and Canada from May 31, 2021, to August 31, 2023. Eligible patients had fasting triglyceride levels in the range of 500 to 4000 mg/dL (to convert to millimoles per liter, multiply by 0.0113) while receiving stable lipid-lowering treatment.

Interventions

Participants received 2 subcutaneous doses of plozasiran (10, 25, or 50 mg) or matched placebo on day 1 and at week 12 and were followed up through week 48.

Main Outcomes and Measures

The primary end point evaluated the placebo-subtracted difference in means of percentage triglyceride change at week 24. Mixed-model repeated measures were used for statistical modeling.

Results

Of 229 patients, 226 (mean [SD] age, 55 [11] years; 176 male [78%]) were included in the primary analysis. Baseline mean (SD) triglyceride level was 897 (625) mg/dL and plasma APOC3 level was 32 (16) mg/dL. Plozasiran induced significant dose-dependent placebo-adjusted least squares (LS)-mean reductions in triglyceride levels (primary end point) of -57% (95% CI, -71.9% to -42.1%; P < .001), driven by placebo-adjusted reductions in APOC3 of -77% (95% CI, -89.1% to -65.8%; P < .001) at week 24 with the highest dose. Among plozasiran-treated patients, 144 of 159 (90.6%) achieved a triglyceride level of less than 500 mg/dL. Plozasiran was associated with dose-dependent increases in low-density lipoprotein cholesterol (LDL-C) level, which was significant in patients receiving the highest dose (placebo-adjusted LS-mean increase 60% (95% CI, 31%-89%; P < .001). However, apolipoprotein B (ApoB) levels did not increase, and non-high-density lipoprotein cholesterol (HDL-C) levels decreased significantly at all doses, with a placebo-adjusted change of -20% at the highest dose. There were also significant durable reductions in remnant cholesterol and ApoB48 as well as increases in HDL-C level through week 48. Adverse event rates were similar in plozasiran-treated patients vs placebo. Serious adverse events were mild to moderate, not considered treatment related, and none led to discontinuation or death.

Conclusions and Relevance

In this randomized clinical trial of patients with sHTG, plozasiran decreased triglyceride levels, which fell below the 500 mg/dL threshold of acute pancreatitis risk in most participants. Other triglyceride-related lipoprotein parameters improved. An increase in LDL-C level was observed but with no change in ApoB level and a decrease in non-HDL-C level. The safety profile was generally favorable at all doses. Additional studies will be required to determine whether plozasiran favorably modulates the risk of sHTG-associated complications.

Trial Registration

ClinicalTrials.gov Identifier: NCT04720534.

Monogenic hypertriglyceridemia and recurrent pancreatitis in a homozygous carrier of a rare APOA5 mutation: a case report

BACKGROUND

Homozygous mutations in the APOA5 gene constitute a rare cause of monogenic hypertriglyceridemia, or familial chylomicronemia syndrome (FCS). We searched PubMed and identified 16 cases of homozygous mutations in the APOA5 gene. Severe hypertriglyceridemia related to monogenic mutations in triglyceride-regulating genes can cause recurrent acute pancreatitis. Standard therapeutic approaches for managing this condition typically include dietary interventions, fibrates, and omega-3-fatty acids. A novel therapeutic approach, antisense oligonucleotide volanesorsen is approved for use in patients with FCS.

CASE PRESENTATION

We report a case of a 25-years old Afghani male presenting with acute pancreatitis due to severe hypertriglyceridemia up to 29.8 mmol/L caused by homozygosity in APOA5 (c.427delC, p.Arg143Alafs*57). A low-fat diet enriched with medium-chain TG (MCT) oil and fibrate therapy did not prevent recurrent relapses, and volanesorsen was initiated. Volanesorsen resulted in almost normalized triglyceride levels. No further relapses of acute pancreatitis occurred. Patient reported an improve life quality due to alleviated chronic abdominal pain and headaches.

CONCLUSIONS

Our case reports a rare yet potentially life-threatening condition-monogenic hypertriglyceridemia-induced acute pancreatitis. The implementation of the antisense drug volanesorsen resulted in improved triglyceride levels, alleviated symptoms, and enhanced the quality of life.

Hypertriglyceridemia: Molecular and Genetic Landscapes

Lipid disorders represent one of the most worrisome cardiovascular risk factors. The focus on the impact of lipids on cardiac and vascular health usually concerns low-density lipoprotein cholesterol, while the role of triglycerides (TGs) is given poor attention. The literature provides data on the impact of higher plasma concentrations in TGs on the cardiovascular system and, therefore, on the outcomes and comorbidities of patients. The risk for coronary heart diseases varies from 57 to 76% in patients with hypertriglyceridemia. Specifically, the higher the plasma concentrations in TGs, the higher the incidence and prevalence of death, myocardial infarction, and stroke. Nevertheless, the metabolism of TGs and the exact physiopathologic mechanisms which try to explain the relationship between TGs and cardiovascular outcomes are not completely understood. The aims of this narrative review were as follows: to provide a comprehensive evaluation of the metabolism of triglycerides and a possible suggestion for understanding the targets for counteracting hypertriglyceridemia; to describe the inner physiopathological background for the relationship between vascular and cardiac damages derived from higher plasma concentrations in TGs; and to outline the need for promoting further insights in therapies for reducing TGs plasma levels.

Characterizing genetic profiles for high triglyceride levels in U.S. patients of African ancestry

Hypertriglyceridemia (HTG) is a common cardiovascular risk factor characterized by elevated triglyceride (TG) levels. Researchers have assessed the genetic factors that influence HTG in studies focused predominantly on individuals of European ancestry. However, relatively little is known about the contribution of genetic variation of HTG in people of African ancestry (AA), potentially constraining research and treatment opportunities. Our objective was to characterize genetic profiles among individuals of AA with mild-to-moderate HTG and severe HTG versus those with normal TGs by leveraging whole-genome sequencing data and longitudinal electronic health records available in the All of Us program. We compared the enrichment of functional variants within five canonical TG metabolism genes, an AA-specific polygenic risk score for TGs, and frequencies of 145 known potentially causal TG variants between HTG patients and normal TG among a cohort of AA patients (N = 15,373). Those with mild-to-moderate HTG (N = 342) and severe HTG (N ≤ 20) were more likely to carry APOA5 p.S19W (odds ratio = 1.94, 95% confidence interval = [1.48-2.54], P = 1.63 × 10-6 and OR = 3.65, 95% confidence interval: [1.22-10.93], P = 0.02, respectively) than those with normal TG. They were also more likely to have an elevated (top 10%) polygenic risk score, elevated carriage of potentially causal variant alleles, and carry any genetic risk factor. Alternative definitions of HTG yielded comparable results. In conclusion, individuals of AA with HTG were enriched for genetic risk factors compared to individuals with normal TGs.

Triglyceride-rich lipoproteins and cardiovascular diseases

The global prevalence of cardiovascular diseases (CVD) continues to rise steadily, making it a leading cause of mortality worldwide. Atherosclerosis (AS) serves as a primary driver of these conditions, commencing silently at an early age and culminating in adverse cardiovascular events that severely impact patients' quality of life or lead to fatality. Dyslipidemia, particularly elevated levels of low-density lipoprotein cholesterol (LDL-C), plays a pivotal role in AS pathogenesis as an independent risk factor. Research indicates that abnormal LDL-C accumulation within arterial walls acts as a crucial trigger for atherosclerotic plaque formation. As the disease progresses, plaque accumulation may rupture or dislodge, resulting in thrombus formation and complete blood supply obstruction, ultimately causing myocardial infarction, cerebral infarction, and other common adverse cardiovascular events. Despite adequate pharmacologic therapy targeting LDL-C reduction, patients with cardiometabolic abnormalities remain at high risk for disease recurrence, highlighting the importance of addressing lipid risk factors beyond LDL-C. Recent attention has focused on the causal relationship between triglycerides, triglyceride-rich lipoproteins (TRLs), and their remnants in AS risk. Genetic, epidemiologic, and clinical studies suggest a causal relationship between TRLs and their remnants and the increased risk of AS, and this dyslipidemia may be an independent risk factor for adverse cardiovascular events. Particularly in patients with obesity, metabolic syndrome, diabetes, and chronic kidney disease, disordered TRLs and its remnants levels significantly increase the risk of atherosclerosis and cardiovascular disease development. Accumulation of over-synthesized TRLs in plasma, impaired function of enzymes involved in TRLs lipolysis, and impaired hepatic clearance of cholesterol-rich TRLs remnants can lead to arterial deposition of TRLs and its remnants, promoting foam cell formation and arterial wall inflammation. Therefore, understanding the pathogenesis of TRLs-induced AS and targeting it therapeutically could slow or impede AS progression, thereby reducing cardiovascular disease morbidity and mortality, particularly coronary atherosclerotic heart disease.

Olezarsen, Acute Pancreatitis, and Familial Chylomicronemia Syndrome

BACKGROUND

Familial chylomicronemia syndrome is a genetic disorder associated with severe hypertriglyceridemia and severe acute pancreatitis. Olezarsen reduces the plasma triglyceride level by reducing hepatic synthesis of apolipoprotein C-III.

METHODS

In a phase 3, double-blind, placebo-controlled trial, we randomly assigned patients with genetically identified familial chylomicronemia syndrome to receive olezarsen at a dose of 80 mg or 50 mg or placebo subcutaneously every 4 weeks for 49 weeks. There were two primary end points: the difference between the 80-mg olezarsen group and the placebo group in the percent change in the fasting triglyceride level from baseline to 6 months, and (to be assessed if the first was significant) the difference between the 50-mg olezarsen group and the placebo group. Secondary end points included the mean percent change from baseline in the apolipoprotein C-III level and an independently adjudicated episode of acute pancreatitis.

RESULTS

A total of 66 patients underwent randomization; 22 were assigned to the 80-mg olezarsen group, 21 to the 50-mg olezarsen group, and 23 to the placebo group. At baseline, the mean (±SD) triglyceride level among the patients was 2630±1315 mg per deciliter, and 71% had a history of acute pancreatitis within the previous 10 years. Triglyceride levels at 6 months were significantly reduced with the 80-mg dose of olezarsen as compared with placebo (-43.5 percentage points; 95% confidence interval [CI], -69.1 to -17.9; P<0.001) but not with the 50-mg dose (-22.4 percentage points; 95% CI, -47.2 to 2.5; P = 0.08). The difference in the mean percent change in the apolipoprotein C-III level from baseline to 6 months in the 80-mg group as compared with the placebo group was -73.7 percentage points (95% CI, -94.6 to -52.8) and between the 50-mg group as compared with the placebo group was -65.5 percentage points (95% CI, -82.6 to -48.3). By 53 weeks, 11 episodes of acute pancreatitis had occurred in the placebo group, and 1 episode had occurred in each olezarsen group (rate ratio [pooled olezarsen groups vs. placebo], 0.12; 95% CI, 0.02 to 0.66). Adverse events of moderate severity that were considered by a trial investigator at the site to be related to the trial drug or placebo occurred in 4 patients in the 80-mg olezarsen group.

CONCLUSIONS

In patients with familial chylomicronemia syndrome, olezarsen may represent a new therapy to reduce plasma triglyceride levels. (Funded by Ionis Pharmaceuticals; Balance ClinicalTrials.gov number, NCT04568434.).

Characterizing genetic profiles for high triglyceride levels in U.S. patients of African ancestry

Hypertriglyceridemia (HTG) is a common cardiovascular risk factor characterized by elevated circulating triglyceride (TG) levels. Researchers have assessed the genetic factors that influence HTG in studies focused predominantly on individuals of European ancestry (EA). However, relatively little is known about the contribution of genetic variation to HTG in people of AA, potentially constraining research and treatment opportunities; the lipid profile for African ancestry (AA) populations differs from that of EA populations-which may be partially attributable to genetics. Our objective was to characterize genetic profiles among individuals of AA with mild-to-moderate HTG and severe HTG versus those with normal TGs by leveraging whole genome sequencing (WGS) data and longitudinal electronic health records (EHRs) available in the All of Us (AoU) program. We compared the enrichment of functional variants within five canonical TG metabolism genes, an AA-specific polygenic risk score for TGs, and frequencies of 145 known potentially causal TG variants between patients with HTG and normal TG among a cohort of AA patients (N=15,373). Those with mild-to-moderate HTG (N=342) and severe HTG (N≤20) were more likely to carry APOA5 p.S19W (OR=1.94, 95% CI [1.48-2.54], p=1.63×10 -6 and OR=3.65, 95% CI [1.22-10.93], p=0.02, respectively) than those with normal TG. They were also more likely to have an elevated (top 10%) PRS, elevated carriage of potentially causal variant alleles, and carry any genetic risk factor. Alternative definitions of HTG yielded comparable results. In conclusion, individuals of AA with HTG were enriched for genetic risk factors compared to individuals with normal TGs.

Evaluation of apolipoprotein A5 variants: A cohort of patients with severe hypertriglyceridemia from Turkiye

BACKGROUND

This study aims to show the clinical and biochemical features in patients with severe hypertriglyceridemia (HTG) associated with rare variants in the apolipoprotein A-V (APOA5) gene.

MATERIALS AND METHODS

Demographics, blood lipid levels, body mass index (BMI) and APOA5 mutation subtypes were collected from the endocrinology clinic registry and analyzed for a retrospective cohort study of ten patients with severe HTG and APOA5 gene variants.

RESULTS

Of the 10 cases, four were female, and six were male. The median age was 45.0 years (min-max: 21-60 years), the median triglyceride was 2429.5 mg/dL (27.5 mmol/L) (min-max: 1351-4087 mg/dL, 15.3-46.2 mmol/L), and the mean BMI was calculated as 30.4 ± 4.4 kg/m2 (min-max: 24.9-41.0 kg/m2). Four cases had diabetes mellitus (DM); two were on intensive insulin therapy, and two were on basal insulin therapy. The mean hemoglobin A1c was 9.2 ± 1.2 % (min-max: 8.3-11.0 %). Among the study group, eight different APOA5 gene mutations were detected. These variants were heterozygous in 2 patients and homozygous (bi-allelic) in 8 patients. One patient was homozygous for APOA5 p.Ser19Trp, a relatively common polymorphism that is a risk variant for HTG.

CONCLUSION

We report a cohort of patients with biallelic and single copy APOA5 variants, who were diagnosed later in life. Most had secondary factors, such as DM or obesity with increased BMI. Most rare APOA5 variants found in our patients were of uncertain significance. Our results add to the growing evidence that rare variants in certain candidate genes may predispose to developing HTG, together with secondary factors such as obesity. The genetic basis of HTG in many other patients is still unknown and remains the subject of further investigation.

Branched-chain amino acids promote occurrence and development of cardiovascular disease dependent on triglyceride metabolism via activation of the mTOR/SREBP-1/betatrophin pathway

Branched-chain amino acid (BCAA) metabolism is associated with triglyceride (TG) metabolism and the development of cardiovascular disease (CVD). However, the underlying mechanism remains uncertain. This study included 1302 subjects and followed for 4-5 years. A hyperbranched-chain aminoacidemia rat model was induced by high fructose diet (HFTD). The relationship between BCAAs and TG level and its regulatory mechanism was investigated in vitro. As results, as baseline BCAA percentile increased, subjects had higher prevalence and incidence of T2DM, NAFLD, and CVD risk (P < 0.05). In animal model, the accumulation of BCAAs and TG and betatrophin expression were significantly elevated in the HFTD group when comparing with those in the SD group(P < 0.05). Immunofluorescence and Masson's trichrome staining revealed that the area of interstitial fibrosis was significantly increased in the HFTD group compared with control group. Met treatment significantly decreased TG levels and betatrophin expression and reversed myocardial fibrosis (P < 0.05). In vitro, LO2 cells, stimulated with 0.1-5 mM BCAAs, displayed a significant dose-dependent increase in betatrophin expression (P < 0.05). And 5 mM BCAAs stimulation significantly increased the p-mTOR and SREBP-1 expression (P < 0.05). However, this effect could be reversed by using the corresponding inhibitor or siRNAs. In conclusions, BCAAs promote occurrence and development of cardiovascular disease dependent on TG metabolism via activation of the mTOR/SREBP-1/betatrophin pathway. The study provides a new theory for the pathogenesis of CVD caused by amino acid metabolism disorders.

The current state of apolipoprotein E in dyslipidemia

PURPOSE OF REVIEW

Apolipoprotein E (apoE) plays a pivotal role in lipid metabolism in the peripheral circulation and in the brain. This has been recognized for decades; however, the importance of the full spectrum of variation in the APOE gene has been less investigated. This review focusses on current progresses in this field with main focus on apoE in dyslipidemia and vascular disease.

RECENT FINDINGS

Whereas ε4 is the risk increasing allele for Alzheimer disease, ε2 is associated with increased risk for age-related macular degeneration. Rare functional ε2-like variants in APOE have previously been reported to have protective associations for Alzheimer disease but recent findings suggest a simultaneous high risk of age-related macular degeneration, in line with observations for the ε2 allele.

SUMMARY

ApoE plays an important and well established role in dyslipidemia, vascular disease, and dementia. Recent evidence from large general population studies now also suggests that apoE is involved in age-related macular degeneration. ApoE-targeted therapeutics are being developed for multiple purposes; this heralds a promising change in the approach to disease processes involving apoE. The different risk profile for dementia and age-related macular degeneration should, however, be kept in mind when developing drugs targeting mechanisms resembling these variants.

Validation of the familial chylomicronaemia syndrome (FCS) score in an ethnically diverse cohort from UK FCS registry: Implications for diagnosis and differentiation from multifactorial chylomicronaemia syndrome (MCS)

BACKGROUND AND AIMS

Prognosis and management differ between familial chylomicronaemia syndrome (FCS), a rare autosomal recessive disorder, and multifactorial chylomicronaemia syndrome (MCS) or severe mixed hyperlipidaemia. A clinical scoring tool to differentiate these conditions has been devised but not been validated in other populations. The objective of this study was to validate this score in the UK population and identify any additional factors that might improve it.

METHODS

A retrospective validation study was conducted using data from 151 patients comprising 75 FCS and 76 MCS patients. All participants had undergone genetic testing for genes implicated in FCS. Validation was performed by standard methods. Additional variables were identified from clinical data by logistic regression analysis.

RESULTS

At the recommended FCS score threshold ≥10 points, the sensitivity and specificity of the score in the UK population were 96% and 75%, respectively. The receiver operating characteristic (ROC) curve analysis yielded an area under the curve (AUC) of 0.88 (95% CI 0.83-0.94, p < 0.001). This study identified non-European (predominantly South Asian) ethnicity, parental consanguinity, body mass index (BMI) < 25 kg/m2, and recurrent pancreatitis as additional positive predictors, while BMI >30 kg/m2 was found to be a negative predictor for FCS. However, inclusion of additional FCS predictors had no significant impact on performance of standard FCS score.

CONCLUSIONS

Our study validates the FCS score in the UK population to distinguish FCS from MCS. While additional FCS predictors were identified, they did not improve further the score diagnostic performance.

Genetic variation in apolipoprotein A-V in hypertriglyceridemia

PURPOSE OF REVIEW

While biallelic rare APOA5 pathogenic loss-of-function (LOF) variants cause familial chylomicronemia syndrome, heterozygosity for such variants is associated with highly variable triglyceride phenotypes ranging from normal to severe hypertriglyceridemia, often in the same individual at different time points. Here we provide an updated overview of rare APOA5 variants in hypertriglyceridemia.

RECENT FINDINGS

Currently, most variants in APOA5 that are considered to be pathogenic according to guidelines of the American College of Medical Genetics and Genomics are those resulting in premature termination codons. There are minimal high quality functional data on the impact of most rare APOA5 missense variants; many are considered as variants of unknown or uncertain significance. Furthermore, particular common polymorphisms of APOA5 , such as p.Ser19Trp and p.Gly185Cys in Caucasian and Asian populations, respectively, are statistically overrepresented in hypertriglyceridemia cohorts and are sometimes misattributed as being causal for chylomicronemia, when they are merely risk alleles for hypertriglyceridemia.

SUMMARY

Both biallelic and monoallelic LOF variants in APOA5 are associated with severe hypertriglyceridemia, although the biochemical phenotype in the monoallelic state is highly variable and is often exacerbated by secondary factors. Currently, with few exceptions, the principal definitive mechanism for APOA5 pathogenicity is through premature truncation. The pathogenic mechanisms of most missense variants in APOA5 remain unclear and require additional functional experiments or family studies.

Multifactorial chylomicronemia syndrome

PURPOSE OF REVIEW

The aim of this review was to understand the role of multifactorial chylomicronemia syndrome (MFCS) as a cause of severe hypertriglyceridemia; to distinguish it from other causes of severe hypertriglyceridemia; and to provide a rational approach to treatment.

RECENT FINDINGS

There have been advances in understanding the genetic underpinning of MFCS, and a better appreciation as to how to differentiate it from the much rarer familial chylomicronemia syndrome, in which there are substantial differences in the approach to their treatment. New approaches to triglyceride lowering will help reduce the risk of pancreatitis, the major complication of MFCS.

SUMMARY

MCSF is a condition in which plasma triglyceride levels are severely elevated, usually to due exacerbation of common genetic forms of hypertriglyceridemia by secondary causes of hypertriglyceridemia and/or triglyceride-raising drugs. Triglyceride-induced pancreatitis can be prevented by markedly reducing triglyceride levels by treating secondary causes and/or eliminating of triglyceride-raising drugs, and by using triglyceride-lowering drugs, especially fibrates. MFCS also increases cardiovascular disease risk, for which lifestyle measures and drugs are required.

Resolution of Extensive Xanthomas Associated With Severe Hypertriglyceridemia via Modified Therapeutic Plasma Exchange

Severe hypertriglyceridemia can be manifested by xanthomas. Therapeutic plasma exchange (TPE) is an invasive medical procedure that has been documented as a viable approach for severe hypertriglyceridemia when cases would be refractory to conventional therapies. TPE is mainly an optional therapeutic modality for cases of severe acute pancreatitis or preventing the recurrence of pancreatitis. Beyond this clinical application, data are scarce on TPE utilization in managing cutaneous lesions associated with hypertriglyceridemia. We present a case of severe hypertriglyceridemia accompanied by extensive xanthomas of various types and a history of recurrent pancreatitis. After conventional therapy failed, a modified plasmapheresis regimen was used and was able to achieve a fast and marked reduction in the patient's serum triglyceride levels with complete resolution of the extensive cutaneous lesions, providing him a newfound comfort he had not experienced in some time and suggesting the regimen potentially could be considered in the treatment of refractory severe hypertriglyceridemia with debilitating cutaneous complications.

Trends in epidemiology of dyslipidemias in India

Dyslipidemias are the most important coronary artery disease (CAD) risk factor. High total cholesterol and its principal subtypes: low-density lipoprotein (LDL) cholesterol and non-high-density lipoprotein (NHDL) cholesterol are the most important. Epidemiological and Mendelian randomization studies have confirmed role of raised triglycerides and lipoprotein(a). INTERHEART study reported a significant association of raised ApoB/ApoA1, total-, LDL-, and NHDL-cholesterol in South Asians. Prospective Urban Rural Epidemiology (PURE) study identified raised NHDL cholesterol as the most important risk factor. Regional and multisite epidemiological studies in India have reported increasing population levels of total-, LDL-, and NHDL cholesterol and triglycerides. India Heart Watch reported higher prevalence of total and LDL cholesterol in northern and western Indian cities. ICMR-INDIAB study reported regional variations in hypercholesterolemia (≥200 mg/dl) from 4.6 % to 50.3 %, with greater prevalence in northern states, Kerala, Goa, and West Bengal. Non-Communicable Disease Risk Factor Collaboration and Global Burden of Diseases Studies have reported increasing LDL- and NHDL-cholesterol in India. Studies among emigrant Indians in UK and USA have reported higher triglycerides in compared to Caucasians. Identification of regional variations and trends in dyslipidemias need more nationwide surveys. Prospective studies are needed to assess quantum of risk with CAD incidence.

Relation among hypertriglyceridaemia, cardiometabolic disease, and hereditary factors-design and rationale of the Stockholm hyperTRIglyceridaemia REGister study

Aims

Hypertriglyceridaemia (hTG) is associated with atherosclerotic cardiovascular disease, pancreatitis, and non-alcoholic fatty liver disease (NAFLD) in large population-based studies. The understanding of the impact of hereditary hTG and cardiometabolic disease status on the development of hTG and its associated cardiometabolic outcomes is more limited. We aimed to establish a multigenerational cohort to enable studies of the relationship between hTG, cardiometabolic disease and hereditary factors.

Methods and results

The population-based observational Stockholm hyperTRIglyceridaemia REGister (STRIREG) study includes 1 460 184 index individuals who have measured plasma triglycerides in the clinical routine in Region Stockholm, Sweden, between 1 January 2000 and 31 December 2021. The laboratory measurements also included basic haematology, blood lipid panel, liver function tests, and HbA1c. Using the Swedish Multi-Generation register, 2 147 635 parents and siblings to the indexes were identified to form the complete study cohort. Laboratory data from participants were combined with data from several national registers that provided information on the cause of death, medical diagnoses, dispensed medicines, and socioeconomic factors including country of birth, education level, and marital status.

Conclusion

The multi-generational longitudinal STRIREG cohort provides a unique opportunity to investigate different aspects of hTG as well as heredity for other metabolic diseases. Important outcome measures include mortality, cardiovascular mortality, major cardiovascular events, development of incident diabetes, and NAFLD. The STRIREG study will provide a deeper understanding of the impact of hereditary factors and associated cardiometabolic complications.

An Increase in Food Insecurity Correlated with an Increase in Plasma Triglycerides among Latinx Children

BACKGROUND

Food insecurity and metabolic diseases both disproportionately affect Hispanic children. Cross-sectional studies have linked food insecurity with adverse cardiometabolic markers, including elevated plasma triglycerides and glucose concentrations. However, the association between changes in food insecurity and changes in cardiometabolic markers in children remains to be explored. Furthermore, few studies have assessed the impact of school-based nutrition interventions on household food insecurity.

OBJECTIVE

The objectives of this study are to assess the effect of the TX Sprouts intervention on household food insecurity and to examine the association between changes in household food insecurity and changes in cardiometabolic markers over 1 academic year.

METHODS

This secondary analysis used data from TX Sprouts, a cluster-randomized school-based gardening, cooking, and nutrition trial. The study enrolled 3rd-5th-grade students from 16 schools that served primarily (>50%) Hispanic families with low income in Austin, TX. Participants (n = 619) provided household food insecurity data and fasting lipid panels at both baseline and postintervention, ∼9 mo following.

RESULTS

There was no intervention effect on household food insecurity. Independent of the intervention, a 1-point increase in food insecurity, indicative of becoming more food insecure, was associated with a 2.61 mg/dL increase in triglycerides (P = 0.001; 95% CI: 1.04, 4.19) at follow-up. Children who were food insecure at baseline and became food secure at follow-up had a mean 5.05 mg/dL decrease in triglycerides compared with a 7.50 mg/dL increase in triglycerides in children who remained food insecure throughout (95% CI: -23.40, -1.71, P = 0.023). There were no other associations between changes in food insecurity and cardiometabolic markers.

CONCLUSION

Although the intervention did not improve food insecurity, reductions in food insecurity over 9 mo were associated with improved cardiometabolic markers in high-risk children, emphasizing the need for interventions targeting food insecurity. The study is registered at clinicaltrials.gov under NCT02668744 (https://classic.

CLINICALTRIALS

gov/ct2/show/NCT02668744).

Understanding Hypertriglyceridemia: Integrating Genetic Insights

Hypertriglyceridemia is an exceptionally complex metabolic disorder characterized by elevated plasma triglycerides associated with an increased risk of acute pancreatitis and cardiovascular diseases such as coronary artery disease. Its phenotype expression is widely heterogeneous and heavily influenced by conditions as obesity, alcohol consumption, or metabolic syndromes. Looking into the genetic underpinnings of hypertriglyceridemia, this review focuses on the genetic variants in LPL, APOA5, APOC2, GPIHBP1 and LMF1 triglyceride-regulating genes reportedly associated with abnormal genetic transcription and the translation of proteins participating in triglyceride-rich lipoprotein metabolism. Hypertriglyceridemia resulting from such genetic abnormalities can be categorized as monogenic or polygenic. Monogenic hypertriglyceridemia, also known as familial chylomicronemia syndrome, is caused by homozygous or compound heterozygous pathogenic variants in the five canonical genes. Polygenic hypertriglyceridemia, also known as multifactorial chylomicronemia syndrome in extreme cases of hypertriglyceridemia, is caused by heterozygous pathogenic genetic variants with variable penetrance affecting the canonical genes, and a set of common non-pathogenic genetic variants (polymorphisms, using the former nomenclature) with well-established association with elevated triglyceride levels. We further address recent progress in triglyceride-lowering treatments. Understanding the genetic basis of hypertriglyceridemia opens new translational opportunities in the scope of genetic screening and the development of novel therapies.

Molecular genetic testing and measurement of levels of GPIHBP1 autoantibodies in patients with severe hypertriglyceridemia: The importance of identifying the underlying cause of hypertriglyceridemia

BACKGROUND

Severe hypertriglyceridemia can be caused by pathogenic variants in genes encoding proteins involved in the metabolism of triglyceride-rich lipoproteins. A key protein in this respect is lipoprotein lipase (LPL) which hydrolyzes triglycerides in these lipoproteins. Another important protein is glycosylphosphatidylinositol-anchored high density lipoprotein-binding protein 1 (GPIHBP1) which transports LPL to the luminal side of the endothelial cells.

OBJECTIVE

Our objective was to identify a genetic cause of hypertriglyceridemia in 459 consecutive unrelated subjects with levels of serum triglycerides ≥20 mmol/l. These patients had been referred for molecular genetic testing from 1998 to 2021. In addition, we wanted to study whether GPIHBP1 autoantibodies also were a cause of hypertriglyceridemia.

METHODS

Molecular genetic analyses of the genes encoding LPL, GPIHBP1, apolipoprotein C2, lipase maturation factor 1 and apolipoprotein A5 as well as apolipoprotein E genotyping, were performed in all 459 patients. Serum was obtained from 132 of the patients for measurement of GPIHBP1 autoantibodies approximately nine years after molecular genetic testing was performed.

RESULTS

A monogenic cause was found in four of the 459 (0.9%) patients, and nine (2.0%) patients had dyslipoproteinemia due to homozygosity for apolipoprotein E2. One of the 132 (0.8%) patients had GPIHBP1 autoantibody syndrome.

CONCLUSION

Only 0.9% of the patients had monogenic hypertriglyceridemia, and only 0.8% had GPIHBP1 autoantibody syndrome. The latter figure is most likely an underestimate because serum samples were obtained approximately nine years after hypertriglyceridemia was first identified. There is a need to implement measurement of GPIHBP1 autoantibodies in clinical medicine to secure that proper therapeutic actions are taken.

Evaluation of the Needs and Experiences of Patients with Hypertriglyceridemia: Social Media Listening Infosurveillance Study

BACKGROUND

Hypertriglyceridemia is a risk factor for cardiovascular diseases. Internet usage in China is increasing, giving rise to large-scale data sources, especially to access, disseminate, and discuss medical information. Social media listening (SML) is a new approach to analyze and monitor online discussions related to various health-related topics in diverse diseases, which can generate insights into users' experiences and expectations. However, to date, no studies have evaluated the utility of SML to understand patients' cognizance and expectations pertaining to the management of hypertriglyceridemia.

OBJECTIVE

The aim of this study was to utilize SML to explore the disease cognition level of patients with hypertriglyceridemia, choice of intervention measures, and the status quo of online consultations and question-and-answer (Q&A) search platforms.

METHODS

An infosurveillance study was conducted wherein a disease-specific comprehensive search was performed between 2004 and 2020 in Q&A search and online consultation platforms. Predefined single and combined keywords related to hypertriglyceridemia were used in the search, including disease, symptoms, diagnosis, and treatment indicators; lifestyle interventions; and therapeutic agents. The search output was aggregated using an aggregator tool and evaluated.

RESULTS

Disease-specific consultation data (n=69,845) and corresponding response data (n=111,763) were analyzed from 20 data sources (6 Q&A search platforms and 14 online consultation platforms). Doctors from inland areas had relatively high voice volumes and appear to exert a substantial influence on these platforms. Patients with hypertriglyceridemia engaging on the internet have an average level of cognition about the disease and its intervention measures. However, a strong demand for the concept of the disease and "how to treat it" was observed. More emphasis on the persistence of the disease and the safety of medications was observed. Young patients have a lower willingness for drug interventions, whereas patients with severe hypertriglyceridemia have a clearer intention to use drug intervention and few patients have a strong willingness for the use of traditional Chinese medicine.

CONCLUSIONS

Findings from this disease-specific SML study revealed that patients with hypertriglyceridemia in China actively seek information from both online Q&A search and consultation platforms. However, the integrity of internet doctors' suggestions on lifestyle interventions and the accuracy of drug intervention recommendations still need to be improved. Further, a combined prospective qualitative study with SML is required for added rigor and confirmation of the relevance of the findings.

[A case of neonatal-onset type I hyperlipoproteinemia with bloody ascites]

This report presents a case of a male infant, aged 32 days, who was admitted to the hospital due to 2 days of bloody stools and 1 day of fever. Upon admission, venous blood samples were collected, which appeared pink. Blood biochemistry tests revealed elevated levels of triglycerides and total cholesterol. The familial whole genome sequencing revealed a compound heterozygous variation in the LPL gene, with one variation inherited from the father and the other from the mother. The patient was diagnosed with lipoprotein lipase deficiency-related hyperlipoproteinemia. Acute symptoms including bloody stools, fever, and bloody ascites led to the consideration of acute pancreatitis, and the treatment involved fasting, plasma exchange, and whole blood exchange. Following the definitive diagnosis based on the genetic results, the patient was given a low-fat diet and received treatment with fat-soluble vitamins and trace elements, as well as adjustments to the feeding plan. After a 4-week hospitalization, the patient's condition improved and he was discharged. Follow-up showed a decrease in triglycerides and total cholesterol levels. At the age of 1 year, the patient's growth and psychomotor development were normal. This article emphasizes the multidisciplinary diagnosis and treatment of familial hyperlipoproteinemia presenting with symptoms suggestive of acute pancreatitis, including bloody ascites, in the neonatal period.

RNA Interference Therapy Targeting Apolipoprotein C-III in Hypertriglyceridemia

BACKGROUND: Apolipoprotein C-III (APOC3) inhibits triglyceride clearance by reducing lipoprotein lipase–mediated hydrolysis and hepatocyte uptake of triglyceride-rich lipoproteins. ARO-APOC3, a hepatocyte-targeting RNA interference therapeutic, inhibits APOC3 messenger ribonucleic acid expression, lowering triglyceride levels. The objective of this trial was to assess the safety, pharmacodynamic variables, and pharmacokinetic variables of ARO-APOC3 treatment. METHODS: Healthy participants and adults with hypertriglyceridemia were randomly assigned to receive escalating single (day 1) or repeat (days 1 and 29) doses, respectively, of subcutaneous injections of ARO-APOC3 10, 25, 50, or 100 mg or placebo; they were followed up until day 113. Additional cohorts of healthy participants and adults with chylomicronemia received repeat doses of open-label ARO-APOC3. The primary objective was to evaluate the safety and side effect profile of ARO-APOC3. Key secondary and exploratory objectives included pharmacokinetic variables and changes in serum APOC3, triglyceride, and cholesterol levels. RESULTS: Eighty-eight participants received ARO-APOC3 and 24 participants received placebo across double-blind and open-label cohorts. Treatment-emergent adverse events (AEs) of transient, mild to moderate liver transaminase changes occurred in 10 participants: 1 patient receiving ARO-APOC3 25 mg, 5 patients receiving ARO-APOC3 50 mg, and 4 participants receiving ARO-APOC3 100 mg (1 healthy participant and 3 patients with hypertriglyceridemia). These events were asymptomatic, and transaminase levels returned to near baseline by the end of the trial. No AEs related to thrombocytopenia or platelet declines were reported. In the hypertriglyceridemia cohorts, the day 113 mean changes from baseline in APOC3 at the 10-, 25-, 50-, and 100-mg doses were −62.0%, −81.7%, −90.1%, and −94.4%, respectively, compared with −1.6% with placebo. This corresponded to median changes in triglyceride levels of −65.6%, −69.9%, −81.2%, and −81.0% compared with −2.8% with placebo. CONCLUSIONS: In this small trial of short duration, ARO-APOC3 was associated with few AEs and reduced serum levels of APOC3 and triglycerides in healthy participants and patients with hypertriglyceridemia. (Funded by Arrowhead Pharmaceuticals, Inc.; ClinicalTrials.gov number, NCT03783377.)

Metabolic Syndrome: An Overview on Its Genetic Associations and Gene-Diet Interactions

Metabolic syndrome (MetS) is a cluster of cardiometabolic risk factors that includes central obesity, hyperglycemia, hypertension, and dyslipidemias and whose inter-related occurrence may increase the odds of developing type 2 diabetes and cardiovascular diseases. MetS has become one of the most studied conditions, nevertheless, due to its complex etiology, this has not been fully elucidated. Recent evidence describes that both genetic and environmental factors play an important role on its development. With the advent of genomic-wide association studies, single nucleotide polymorphisms (SNPs) have gained special importance. In this review, we present an update of the genetics surrounding MetS as a single entity as well as its corresponding risk factors, considering SNPs and gene-diet interactions related to cardiometabolic markers. In this study, we focus on the conceptual aspects, diagnostic criteria, as well as the role of genetics, particularly on SNPs and polygenic risk scores (PRS) for interindividual analysis. In addition, this review highlights future perspectives of personalized nutrition with regard to the approach of MetS and how individualized multiomics approaches could improve the current outlook.

A protocol for an international, multicenter, prospective, non-interventional observational registry for patients with hypertriglyceridemia

BACKGROUND

In the study on triglyceride-induced pancreatitis (TG-IAP), a core clinical dataset using the Jandhyala method was developed to collect the minimum amount of information for each patient presenting with TG-IAP globally. This approach offered a unified framework for observing multiple populations of TG-IAP patients using the same set of indicators, resulting in a considerably larger and uniform real-world population. It was understood that when this core dataset is implemented in a patient registry it could address the issue of missing data in observational studies and produce higher-quality research. In this paper, the protocol used to design and implement a patient registry for this core dataset to generate real-world evidence from multiple sites is described.

METHOD

The study is designed as an international, multicenter, non-interventional, observational registry that will enroll adult patients with hypertriglyceridemia to collect natural history data on the treatment, progression, and long-term outcomes of hypertriglyceridemia-induced acute pancreatitis. Patients with both hypertriglyceridemia and pancreatitis will be invited to participate in the registry at participating hospitals and centers worldwide.

DISCUSSION

Data from this registry, and others like it, is intended for healthcare providers to optimize clinical decision-making through an enhanced understanding of the variability, progression, and natural history of hypertriglyceridemia as well as the burden of disease.

CONCLUSION

Global epidemiological data on hypertriglyceridemia and its role in acute pancreatitis is limited. Using real-world evidence, this registry, along with others like it, may help healthcare providers understand the variability, progression, natural history, and burden of the disease, and improve the diagnosis and management of HTG and TG-IAP.

Polygenic risk for triglyceride levels in the presence of a high impact rare variant

BACKGROUND

Elevated triglyceride (TG) levels are a heritable and modifiable risk factor for cardiovascular disease and have well-established associations with common genetic variation captured in a polygenic risk score (PRS). In young adulthood, the 22q11.2 microdeletion conveys a 2-fold increased risk for mild-moderate hypertriglyceridemia. This study aimed to assess the role of the TG-PRS in individuals with this elevated baseline risk for mild-moderate hypertriglyceridemia.

METHODS

We studied a deeply phenotyped cohort of adults (n = 157, median age 34 years) with a 22q11.2 microdeletion and available genome sequencing, lipid level, and other clinical data. The association between a previously developed TG-PRS and TG levels was assessed using a multivariable regression model adjusting for effects of sex, BMI, and other covariates. We also constructed receiver operating characteristic (ROC) curves using logistic regression models to assess the ability of TG-PRS and significant clinical variables to predict mild-moderate hypertriglyceridemia status.

RESULTS

The TG-PRS was a significant predictor of TG-levels (p = 1.52E-04), along with male sex and BMI, in a multivariable model (pmodel = 7.26E-05). The effect of TG-PRS appeared to be slightly stronger in individuals with obesity (BMI ≥ 30) (beta = 0.4617) than without (beta = 0.1778), in a model unadjusted for other covariates (p-interaction = 0.045). Among ROC curves constructed, the inclusion of TG-PRS, sex, and BMI as predictor variables produced the greatest area under the curve (0.749) for classifying those with mild-moderate hypertriglyceridemia, achieving an optimal sensitivity and specificity of 0.746 and 0.707, respectively.

CONCLUSIONS

These results demonstrate that in addition to significant effects of sex and BMI, genome-wide common variation captured in a PRS also contributes to the variable expression of the 22q11.2 microdeletion with respect to elevated TG levels.

APOE and vascular disease: Sequencing and genotyping in general population cohorts

BACKGROUND AND AIMS

The apolipoprotein E(APOE) ϵ2/ϵ3/ϵ4 polymorphism plays a central role in lipid metabolism, vascular disease and dementia. The impact of the full range of structural genetic variation in APOE for lipids, lipoproteins and apolipoproteins and for vascular disease in the general population is not known.

METHODS

We systematically sequenced APOE in 10,296 individuals from the Copenhagen City Heart Study and genotyped nine rare variants (frequency≥2/10,296) in 95,227 individuals from the Copenhagen General Population Study. The UK Biobank was used for validation of common APOE variants.

RESULTS

Rare mutations in APOE, predicted to be deleterious, are present in 1 in 257 individuals in the general population. In the meta-analysis, multifactorially adjusted hazard ratios (95% confidence intervals) for ϵ44 and ϵ22 versus ϵ33 were 1.15 (1.04-1.26) and 1.02 (0.83-1.24) for ischemic cerebrovascular disease (ICVD), 1.11 (1.04-1.19) and 0.94 (0.83-1.08) for ischemic heart disease (IHD) and 1.03 (0.89-1.17) and 1.49 (1.20-1.87) for peripheral arterial disease (PAD). A multifactorially and ϵ2/ϵ3/ϵ4 adjusted weighted allele score on the continuous scale including all common and rare structural variants showed that for individuals with genetically predicted high plasma apoE and remnant cholesterol the risk for PAD was increased.

CONCLUSIONS

APOE variants with high apoE, triglycerides, and remnant cholesterol are associated with PAD, whereas common APOE variants with high LDL cholesterol, triglycerides and remnant cholesterol are associated with IHD. APOE variants with low apoE are associated with increased risk of ICVD. These findings highlight that both rare and common structural variations in APOE play a role in vascular disease.

Clinical profile, genetic spectrum and therapy evaluation of 19 Chinese pediatric patients with lipoprotein lipase deficiency

BACKGROUND

Lipoprotein lipase (LPL) deficiency, the most common familial chylomicronemia syndrome (FCS), is a rare autosomal recessive disease characterized by chylomicronemia and severe hypertriglyceridemia (HTG), with limited clinical and genetic characterization.

OBJECTIVE

To describe the manifestations and management of 19 pediatric patients with LPL-FCS.

METHODS

LPL-FCS patients from 2014 to 2022 were divided into low-fat (LF), very-low-fat (VLF) and medium-chain-triglyceride (MCT) groups. Their clinical data were evaluated to investigate the effect of different diets. The genotype-phenotype relationship was assessed. Linear regression comparing long-chain triglyceride (LCT) intake and TG levels was analyzed.

RESULTS

Nine novel LPL variants were identified in 19 LPL-FCS pediatric patients. At baseline, eruptive xanthomas occurred in 3/19 patients, acute pancreatitis in 2/19, splenomegaly in 6/19 and hepatomegaly in 3/19. The median triglyceride (TG) level (30.3 mmol/L) was markedly increased. The MCT group and VLF group with LCT intakes <20 en% (energy percentage) had considerably lower TG levels than the LF group (both p<0.05). The LF group presented with severe HTG and significantly decreased TG levels after restricting LCT intakes to <20 en% (p<0.05). Six infants decreased TG levels to <10 mmol/L by keeping LCT intake <10 en%. TG levels and LCT intake were positively correlated in both patients under 2 years (r=0.84) and those aged 2-9 years (r=0.89). No genotype-phenotype relationship was observed.

CONCLUSIONS

This study broadens the clinical and genetic spectra of LPL-FCS. The primary therapy for LPL-FCS pediatric patients is restricting dietary LCTs to <10 en% or <20 en% depending on different ages. MCTs potentially provide extra energy.

Severe hypertriglyceridemia: Existing and emerging therapies

Severe hypertriglyceridemia (sHTG), defined as a triglyceride (TG) concentration ≥ 500 mg/dL (≥ 5.7 mmol/L) is an important risk factor for acute pancreatitis. Although lifestyle, some medications, and certain conditions such as diabetes may lead to HTG, sHTG results from a combination of major and minor genetic defects in proteins that regulate TG lipolysis. Familial chylomicronemia syndrome (FCS) is a rare disorder caused by complete loss of function in lipoprotein lipase (LPL) or LPL activating proteins due to two homozygous recessive traits or compound heterozygous traits. Multifactorial chylomicronemia syndrome (MCS) and sHTG are due to the accumulation of rare heterozygous variants and polygenic defects that predispose individuals to sHTG phenotypes. Until recently, treatment of sHTG focused on lifestyle interventions, control of secondary factors, and nonselective pharmacotherapies that had modest TG-lowering efficacy and no corresponding reductions in atherosclerotic cardiovascular disease events. Genetic discoveries have allowed for the development of novel pathway-specific therapeutics targeting LPL modulating proteins. New targets directed towards inhibition of apolipoprotein C-III (apoC-III), angiopoietin-like protein 3 (ANGPTL3), angiopoietin-like protein 4 (ANGPTL4), and fibroblast growth factor-21 (FGF21) offer far more efficacy in treating the various phenotypes of sHTG and opportunities to reduce the risk of acute pancreatitis and atherosclerotic cardiovascular disease events.

Hypertriglyceridemia-Associated Pancreatitis: New Concepts and Potential Mechanisms

BACKGROUND

Triglycerides are a major source of energy, while high plasma triglycerides are a risk factor for various diseases and premature death. Severely elevated plasma triglycerides are a well-established cause of acute pancreatitis with high mortality, likely due to the presence of elevated levels of chylomicrons and large very low-density lipoproteins in plasma. As markedly elevated levels of these very large lipoproteins are not generally found in mild to moderate hypertriglyceridemia, this was previously not regarded as a cause or marker of increased risk of acute pancreatitis. However, mild to moderate hypertriglyceridemia may identify individuals who at a later timepoint develop severe hypertriglyceridemia and acute pancreatitis.

CONTENT

We describe measurement of plasma triglycerides and studies on plasma triglycerides and risk of acute pancreatitis. Further, we summarize current European and American guidelines for the prevention of acute pancreatitis and, finally, the potential for future prevention of acute pancreatitis through lowering of plasma triglycerides.

SUMMARY

Recent observational and genetic studies indicate that mild to moderate hypertriglyceridemia is causally related to increased risk of acute pancreatitis, most likely as a marker of future severe hypertriglyceridemia. Current guidelines do not mention individuals with mild to moderate hypertriglyceridemia, even though newer evidence suggests an unmet medical need. Treatment could include plasma triglyceride-lowering therapy targeting the pathway for lipoprotein lipase as the main triglyceride degrading enzyme in plasma. Angiopoietin-like 3 and apolipoproteinC-III are inhibitors of lipoprotein lipase, and blocking of these 2 inhibitors is showing promising results in relation to marked triglyceride-lowering and could perhaps be used to prevent acute pancreatitis in the future.