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.

Medium-chain fatty acids modify macrophage expression of metabolic and inflammatory genes in a PPAR ß/δ-dependent manner.

There is great interest on medium chain fatty acids (MCFA) for cardiovascular health. We explored the effects of MCFA on the expression of lipid metabolism and inflammatory genes in macrophages, and the extent to which they were mediated by the nuclear receptor peroxisome proliferator-activated receptor beta/delta (PPAR ß/δ). J774A.1 murine macrophages were exposed to octanoate or decanoate as MCFA, a long-chain fatty acid control (palmitate), or the PPAR ß/δ agonist GW501516, with or without lipopolysaccharide (LPS) stimulation, and with or without an siRNA-induced knockdown of PPAR ß/δ. MCFA increased the expression of Plin2, encoding a lipid-droplet associated protein with anti-inflammatory effects in macrophages, in a partially PPAR ß/δ-dependent manner. Both MCFA stimulated expression of the cholesterol efflux pump ABCA1, more pronouncedly under LPS stimulation and in the absence of PPAR ß/δ. Octanoate stimulated the expression of Pltp, encoding a phospholipid transfer protein that aids ABCA1 in cellular lipid efflux. Only palmitate increased expression of the proinflammatory genes Il6, Tnf, Nos2 and Mmp9. Non-stimulated macrophages exposed to MCFA showed less internalization of fluorescently labeled lipoproteins. MCFA influenced the transcriptional responses of macrophages favoring cholesterol efflux and a less inflammatory response compared to palmitate. These effects were partially mediated by PPAR ß/δ.

Severe hypertriglyceridemia secondary to splice-site and missense variants in LMF1 in three patients from Ecuador.

Rare pathogenic variants in the LMF1 gene, which encodes lipase maturation factor 1, are a minor cause of familial chylomicronemia syndrome (FCS) and severe hypertriglyceridemia. In this report we present three adult patients, all of them born and raised in Quito, Ecuador, with severe hypertriglyceridemia secondary to biallelic LMF1 variants. In two of the three cases (patients 1 and 3), the presentation was acute pancreatitis secondary to plasma triglycerides well above 10 mmol/L. The other case (patient 2) was a sibling of one of the initial patients, who was asymptomatic but markedly hypertriglyceridemic. Next-generation sequencing revealed a homozygous splice-site variant in exon 6 of LMF1 in patients 1 and 2 (c.897G>A, p.Gln299=), and a homozygous missense variant in exon 2 of LMF1 in patient 3 (c.233T>C, p.Leu78Pro). The finding of two disease-causing variants in three patients from the same location raises the question of whether LMF1 may be a more prevalent cause of severe hypertriglyceridemia among Latin-American patients.

Social inequalities shape diet composition among urban Colombians: The Colombian Nutritional Profiles cross-sectional study.

OBJECTIVE: To explore the influence of socioeconomic position on habitual dietary intake in Colombian cities. DESIGN: We conducted a cross-sectional, population-based study in five Colombian cities. Dietary intake was assessed with a 157-item semi-quantitative food frequency questionnaire previously developed for the Colombian population. Nutrient analysis was performed using national and international food composition tables. Socioeconomic position was assessed with two indicators: a government-defined, asset-based, household-level index called socioeconomic stratum (SES) and, among adults, highest educational level attained. SETTING: The five main urban centers of Colombia: Bogotá, Medellin, Barranquilla, Cali and Bucaramanga. PARTICIPANTS: Probabilistic, multistage sample of 1865 participants (n=1491 for analyses on education). RESULTS: For both sexes, increasing SES was associated with a lower consumption of energy (p-trend <0.001 in both sexes), carbohydrates (p-trend ˂0.001 in both sexes), sodium (p-trend=0.005 in males, <0.001 in females), saturated fatty acids (p-trend <0.001 in both sexes) and among females, cholesterol (p-trend=0.002). More educated men consumed significantly less energy and carbohydrates (p-trend=0.036 and ˂0.001, respectively). Among men, intake of trans fats increased monotonically with educational level, being 21% higher among college graduates relative to those with only elementary education (p-trend=0.023). Among women, higher educational level was associated with higher MUFA intake (p-trend=0.027). CONCLUSIONS: SES and educational level are strong correlates of the usual diet of urban Colombians. Economically deprived and less educated segments of society display dietary habits that make them vulnerable to chronic diseases and should be the primary target of public health nutrition policies.

[Familial chylomicronemia]. / Quilomicronemia familiar.

Familial chylomicronemia is a disease in which a genetic mutation affects the ability of the organism to metabolize triglycerides bound to lipoproteins, causing extremely high plasma triglycerides and associated consequences. The most frequent complication is acute pancreatitis, which may lead to multiorganic failure or pancreatic insufficiency. Familial chylomicronemia also exerts a profound negative impact on quality of life, social relationships and professional development. The gene most frequently affected is lipoprotein lipase-1 gene (LPL), the enzyme in charge of hydrolyzing circulating triglycerides for tissue uptake. Mutations in other genes regulating maturation, transport or polymerization (eg. APOC2, APOAV, LMF-1, GPIHBP-1) of lipoprotein lipase-1, may also be involved. However, in about 30% of patients the causal variant is not identified. Familial chylomicronemia should be suspected in patients with severe hypertriglyceridemia with poor response to conventional treatment, or accompanied by eruptive xanthomas, lipemia retinalis or abdominal pain. The availability of risk scores and genetic tests should facilitate its opportune detection and management. Nutritional therapy is based on a very-low-fat diet with adequate supply of lipid-soluble vitamins and essential fatty acids, plus avoidance of alcohol consumption. Current pharmacological treatment may include fibrates and omega-3 fatty acids but prioritizes biotechnological agents targeting the molecular disturbances of the disease. These include an antisense oligonucleotide against apoC-III (volanesorsen), a monoclonal antibody against angiopoietin-like protein-3 (evinacumab), and other agents currently in development.

La quilomicronemia familiar es una condición en que una mutación genética altera la capacidad de metabolizar los triglicéridos que viajan en las lipoproteínas, causando elevación extrema de triglicéridos plasmáticos y complicaciones asociadas. La complicación más frecuente es la pancreatitis, que puede llevar a falla multiorgánica o insuficiencia pancreática. La quilomicronemia familiar también afecta la calidad de vida, las relaciones sociales y el desarrollo profesional. El gen más frecuentemente afectado en la quilomicronemia familiar es el de lipoproteína lipasa-1 (LPL), enzima que hidroliza triglicéridos circulantes para su captación tisular. Mutaciones en genes (como APOC2, APOAV, LMF-1, GPIHBP-1) que codifican para proteínas que regulan la maduración, transporte o polimerización de lipoproteína lipasa-1, también pueden estar involucradas. Sin embargo, en cerca del 30% de los pacientes no se encuentra la variante causal. La quilomicronemia familiar debe sospecharse en casos de hipertrigliceridemia extrema, resistente al tratamiento convencional, o que se acompaña de xantomas eruptivos, lipemia retinalis o dolor abdominal. La disponibilidad de escalas de riesgo y pruebas genéticas deben promover la detección oportuna. La nutrición se basa en una dieta muy baja en grasa con adecuada suplencia de vitaminas liposolubles y ácidos grasos esenciales, además de evitar el consumo de alcohol. Si bien el tratamiento farmacológico incluye fibratos y ácidos grasos omega 3, el enfoque actual privilegia agentes biotecnológicos dirigidos a los defectos moleculares propios de la enfermedad. Ello incluye un oligonucleótido antisentido dirigido contra apoC-III (volanesorsen), un anticuerpo monoclonal contra la proteína similar a angiopoietina tipo 3 (evinacumab), y otros compuestos en desarrollo.

Quilomicronemia familiar / Familial chylomicronemia

Resumen La quilomicronemia familiar es una condición en que una mutación genética altera la capacidad de metabolizar los triglicéridos que viajan en las lipoproteínas, causando elevación extrema de triglicéridos plasmáticos y complicaciones asociadas. La complicación más frecuente es la pancreatitis, que puede llevar a falla multiorgánica o insuficiencia pancreática. La quilomicronemia familiar también afecta la calidad de vida, las relaciones sociales y el desarrollo profesional. El gen más frecuentemente afectado en la quilomicronemia familiar es el de lipoproteína lipasa-1 (LPL), enzima que hidroliza triglicéridos circulantes para su captación tisular. Mutaciones en genes (como APOC2, APOAV, LMF-1, GPIHBP-1) que codifican para proteínas que regulan la maduración, transporte o polimerización de lipoproteína lipasa-1, también pueden estar involucradas. Sin embargo, en cerca del 30% de los pacientes no se encuentra la variante causal. La quilomicronemia familiar debe sospecharse en casos de hipertrigliceridemia extrema, resistente al tratamiento convencional, o que se acompaña de xantomas eruptivos, lipemia retinalis o dolor abdominal. La disponibilidad de escalas de riesgo y pruebas genéticas deben promover la detección oportuna. La nutrición se basa en una dieta muy baja en grasa con adecuada suplencia de vitaminas liposolubles y ácidos grasos esenciales, además de evitar el consumo de alcohol. Si bien el tratamiento farmacológico incluye fibratos y ácidos grasos omega 3, el enfoque actual privilegia agentes biotecnológicos dirigidos a los defectos moleculares propios de la enfermedad. Ello incluye un oligonucleótido antisentido dirigido contra apoC-III (volanesorsen), un anticuerpo monoclonal contra la proteína similar a angiopoietina tipo 3 (evinacumab), y otros compuestos en desarrollo.

Abstract Familial chylomicronemia is a disease in which a genetic mutation affects the ability of the organism to metabolize triglycerides bound to lipoproteins, causing extremely high plasma triglycerides and associated consequences. The most frequent complication is acute pancreatitis, which may lead to multiorganic failure or pancreatic insufficiency. Familial chylomicronemia also exerts a profound negative impact on quality of life, social relationships and professional development. The gene most frequently affected is lipoprotein lipase-1 gene (LPL), the enzyme in charge of hydrolyzing circulating triglycerides for tissue uptake. Mutations in other genes regulating maturation, transport or polymerization (eg. APOC2, APOAV, LMF-1, GPIHBP-1) of lipoprotein lipase-1, may also be involved. However, in about 30% of patients the causal variant is not identified. Familial chylomicronemia should be suspected in patients with severe hypertriglyceridemia with poor response to conventional treatment, or accompanied by eruptive xanthomas, lipemia retinalis or abdominal pain. The availability of risk scores and genetic tests should facilitate its opportune detection and management. Nutritional therapy is based on a very-low-fat diet with adequate supply of lipid-soluble vitamins and essential fatty acids, plus avoidance of alcohol consumption. Current pharmacological treatment may include fibrates and omega-3 fatty acids but prioritizes biotechnological agents targeting the molecular disturbances of the disease. These include an antisense oligonucleotide against apoC-III (volanesorsen), a monoclonal antibody against angiopoietin-like protein-3 (evinacumab), and other agents currently in development.

Impact of a Formulation Containing Unusual Polyunsaturated Fatty Acids, Trace Elements, Polyphenols and Plant Sterols on Insulin Resistance and Associated Disturbances.

INTRODUCTION: To evaluate the effect of a lipid-based formulation containing unusual polyunsaturated fatty acids, trace elements, polyphenols and plant sterols on insulin resistance and its associated disturbances among adults at risk of diabetes. METHODS: This was an 8-week, three-arm, open-label randomized clinical trial. We studied individuals aged ≥ 18 years old with diabetes risk given by a body mass index ≥ 25 kg/m2 or a FinnRisc score ≥ 13/20. Participants were randomly assigned to receive: 7 ml sunflower oil (control group), 3.5 ml of the study formulation + 3.5 ml of sunflower oil (low-dose group) or 7 ml of study formulation (high-dose group). RESULTS: We randomized 25 individuals. After one withdrawal in the high-dose group, the study sample comprised nine patients in the control, nine in the low-dose and six in the high-dose groups. The insulin sensitivity increased significantly and in a dose-dependent fashion, up to 10% in the high-dose group. At week 8 the low-dose group exhibited lower glycemic excursions during the oral glucose tolerance test (OGTT), especially 1 h after the glucose challenge (32 mg/dl or 23% lower vs. control group). The incremental area under the glucose curve in the OGTT was 17.1% lower in the low-dose group vs. the control group. Waist circumference increased in the control group, remained constant in the low-dose group and decreased in the high-dose group. C-reactive protein decreased in both formulation groups, up to 50% in the high-dose group. Participants in the formulation groups exhibited increased secretion of GLP-1 and plasma irisin at week 8 vs. the control group. CONCLUSION: The formulation induced favorable changes in insulin sensitivity, glucose tolerance, abdominal obesity and inflammation. These effects and their durability will need to be assessed in larger studies. TRIAL REGISTRATION: NCT03512665. FUNDING: Team Foods Colombia.

Post-Liver Transplantation Diabetes Mellitus: A Review of Relevance and Approach to Treatment.

Post-liver transplantation diabetes mellitus (PLTDM) develops in up to 30% of liver transplant recipients and is associated with increased risk of mortality and multiple morbid outcomes. PLTDM is a multicausal disorder, but the main risk factor is the use of immunosuppressive agents of the calcineurin inhibitor (CNI) family (tacrolimus and cyclosporine). Additional factors, such as pre-transplant overweight, nonalcoholic steatohepatitis and hepatitis C virus infection, may further increase risk of developing PLTDM. A diagnosis of PLTDM should be established only after doses of CNI and steroids are stable and the post-operative stress has been overcome. The predominant defect induced by CNI is insulin secretory dysfunction. Plasma glucose control must start immediately after the transplant procedure in order to improve long-term results for both patient and transplant. Among the better known antidiabetics, metformin and DPP-4 inhibitors have a particularly benign profile in the PLTDM context and are the preferred oral agents for long-term management. Insulin therapy is also an effective approach that addresses the prevailing pathophysiological defect of the disorder. There is still insufficient evidence about the impact of newer families of antidiabetics (GLP-1 agonists, SGLT-2 inhibitors) on PLTDM. In this review, we summarize current knowledge on the epidemiology, pathogenesis, course of disease and medical management of PLTDM.