What is type I hyperlipoproteinemia?
Dietary therapy is the only available treatment for Type I hyperlipoproteinemia. In other forms of chylomicronemia (Type V hyperlipoproteinemia, e.g., severe Type V), fat restriction often is successful in lowering triglyceride levels to a safe range. The need to maintain a very-low-fat intake at all times must be emphasized.
Which medications are used in the treatment of hyperlipoproteinemia?
Apr 09, 2022 · WhatsApp. Answer. Type I hyperlipoproteinemia is the best-characterized genetic cause of hypertriglyceridemia and is caused by a deficiency or defect in either the enzyme lipoprotein lipase or its ...
What are the indications for secondary hyperlipoproteinemia?
The authors summarize the physiological role of lipoprotein(a), causes and treatment of elevated lipoprotein(a) level, and the association between lipoprotein(a) and cardiovascular diseases. Orv ...
When is niacin indicated in the treatment of hypertriglyceridemia?
Which of the following statements best summarizes the dietary treatment of hyperlipoproteinemia? asked Jan 11, 2016 in Nursing by Hannah. nutrition-diet-therapy; An LDL level of _____ mg/dL is considered desirable. asked Dec 23, 2021 in Nutritional Science by Face_Off. advanced-nutrition;
What is primary hyperlipoproteinemia?
It is convenient to classify primary hyperlipoproteinemias that are associated with plasma triglyceride elevations into two categories, depending on the concentration of serum triglycerides. These are distinct hypertriglyceridemia (triglyceride level > 500 mg/dL) and borderline hypertriglyceridemia (triglyceride level 250 to 500 mg/dL).
Why is it important to determine the degree to which age-related increases in plasma triglyceride levels are
For example, it would seem important to determine the degree to which age-related increases in plasma triglyceride levels are a function of obesity. The second need is to evaluate the impact of commonly used drugs (such as antihypertensives) on plasma lipid and lipoprotein distribution in population studies.
What type of hyperlipidemia is mildly elevated?
One genetic form of hyperlipidemia in which triglyceride levels can be mildly elevated is familial combined lipidemia. Affected persons of one family can have various lipoprotein phenotypes--Type IV (increased VLDL), Type IIA (increased low-density lipoproteins [LDLs]), or Type IIB (increased VLDL and LDL).
How do lipoproteins affect atherogenesis?
The pathogenetic mechanisms by which triglyceride-rich lipoproteins may influence atherogenesis have received little research attention in the past and research efforts should be intensified in the future. A few of the important research directions include: 1 Does the process of VLDL degradation at the level of the artery wall generate products that contribute to atherogenesis (cholesterol, free fatty acids, lysophospholipids)? 2 What is the importance of abnormal lipoprotein levels in the pathogenesis of human atherosclerosis? 3 Do the heterogeneous properties of VLDL particles (reactivity with cell-surface receptors, apolipoprotein content, or distribution) determine their atherogenicity? 4 Using appropriate animal models, what interactions can be found among the characteristics of the triglyceride-rich lipoproteins, smoking, and the development of atherosclerosis in the coronary and peripheral arteries? Attempts to establish interactions between smoking and diet-induced hyperbetalipoproteinemia proved inconclusive when using experimental animals have been negative. Clinical evidence suggests that the association between smoking and increased concentrations of the triglyceride-rich lipoproteins may be stronger. 5 There is need to develop colonies of experimental animals with hypertriglyceridemia.
What is the normal triglyceride level?
The triglyceride levels in this category range between 250 and 500 mg/dL. Five to 10 percent of adult Americans have triglyceride levels in this range. In the absence of elevated serum cholesterol levels (in the individual or family members), other risk factors for heart disease, or premature cardiovascular disease in other family members, there is no evidence for increased cardiovascular risk; specific triglyceride-lowering therapy seems unnecessary. If the person has other major risk factors, such as hypertension, smoking, or obesity, vigorous attempts to modify these factors should be undertaken.
How many people have triglycerides?
Probably fewer than 1 in 1,000 persons have triglyceride levels of more than 500 mg/dL. Opinion is divided as to whether such levels are associated with increased risk for cardiovascular disease in the absence of other risk factors, but triglyceride levels should be reduced in any event to prevent pancreatitis.
What are the diseases associated with high triglycerides?
Similarly, many diseases associated with high triglyceride levels, such as diabetes mellitus, chronic renal disease, and certain primary hyperlipidemias, are associated with an increase in risk for cardiovascular disease.
What is the second hit of dysbetalipoproteinemia?
That is, a secondary cause of hyperlipidemia , “second hit,” must be present for the dysbetalipoproteinemia to develop. In addition, the patient may be taking medications, such as protease inhibitors or tricyclic antidepressants, that exacerbate hyperlipidemia.
Where is lipoprotein lipase found?
The enzyme is found in the endothelial cells of capillaries and can be released into the plasma by heparin. Lipoprotein lipase is essential for the metabolism of chylomicrons and VLDL, transforming them into their respective remnants. Apo C-II, an apolipoprotein present in both chylomicrons and VLDL, acts as a cofactor in the action ...
What is the genetic cause of hypertriglyceridemia?
Answer. Type I hyperlipoproteinemia is the best-characterized genetic cause of hypertriglyceridemia and is caused by a deficiency or defect in either the enzyme lipoprotein lipase or its cofactor, apo C-II. Lipoprotein lipase hydrolyzes triglycerides in chylomicrons and very low-density lipoprotein (VLDL), releasing free fatty acids.
What is the apo C II?
Apo C-II, an apolipoprotein present in both chylomicrons and VLDL, acts as a cofactor in the action of lipoprotein lipase. The above pathway is affected by other genetic disorders, particularly type 1 or type 2 diabetes, because lipoprotein lipase requires insulin for full activity. That is, a secondary cause of hyperlipidemia, ...
What is the difference between type I and type V hyperlipoproteinemia?
Both type I and type V hyperlipoproteinemia are characterized by severe hypertriglyceridemia due to an increase in chylomicrons. Type I hyperlipoproteinemia is caused by a decisive abnormality of the lipoprotein lipase (LPL)- apolipoprotein C-II system , whereas the cause of type V hyperlipoproteinemia is more complicated and more closely related to acquired environmental factors. Since the relationship of hypertriglyceridemia with atherosclerosis is not as clear as that of hypercholesterolemia, and since type I and V hyperlipoproteinemia are relatively rare, few guidelines for their diagnosis and treatment have been established; however, type I and V hyperlipoproteinemia are clinically important as underlying disorders of acute pancreatitis, and appropriate management is necessary to prevent or treat such complications. Against such a background, here we propose guidelines primarily concerning the diagnosis and management of type I and V hyperlipoproteinemia in Japanese.
What are the causes of lipid physiology?
The causes of these lipid abnormalities can be acquired, most commonly due to obesity, or genetic, as is the case in familial hypercholesterolemia. This chapter discusses normal lipid physiology, general screening guidelines, as well as the diagnosis, presentation, and management of disorders of HDL, LDL, and triglyceride metabolism.
What are the lipid abnormalities?
There are a variety of lipid abnormalities that include genetic disorders, such as primary hyperlipoproteinemias, and abnormalities that come as a result of systemic disorders such as liver disease and hypothyroidism, among others. The common vector for these disorders is their possible association with a high risk of cardiovascular disease. However, although these conditions may be inconspicuous when it comes to systemic manifestations, they may present with skin symptoms such as xanthomas. Although some types of xanthomas may be very common with a rather controversial association to hyperlipidemia (e.g. xanthelasmas), the presence of other types of xanthomas (i.e. palmar xanthomas) may be pathognomonic for certain pathologies. Therefore it is very important for dermatologists to be able to recognize these types of skin manifestations and follow appropriate diagnostic and therapeutic approaches that may not only involve the cutaneous disorders but also referral to a cardiologist for cardiovascular risk assessment and administration of lipid lowering medications. In this chapter basic information on lipid metabolism is conveyed, while a description of xanthomas and hyperlipidemias and their association with cardiovascular comorbidity is also provided.
What is apoc II?
Apolipoprotein C-II (apoC-II) is a small exchangeable apolipoprotein found on triglyceride-rich lipoproteins (TRL), such as chylomicrons (CM) and very low-density lipoproteins (VLDL), and on high-density lipoproteins (HDL), particularly during fasting. ApoC-II plays a critical role in TRL metabolism by acting as a cofactor of lipoprotein lipase (LPL), the main enzyme that hydrolyses plasma triglycerides (TG) on TRL. Here, we present an overview of the role of apoC-II in TG metabolism, emphasizing recent novel findings regarding its transcriptional regulation and biochemistry. We also review the 24 genetic mutations in the APOC2 gene reported to date that cause hypertriglyceridemia (HTG). Finally, we describe the clinical presentation of apoC-II deficiency and assess the current therapeutic approaches, as well as potential novel emerging therapies.
What is a familial chylomicronaemia?
Familial chylomicronaemia syndrome (FCS) is a rare, inherited disorder characterised by impaired clearance of triglyceride (TG)-rich lipoproteins from plasma, leading to severe hypertriglyceridaemia (HTG) and a markedly increased risk of acute pancreatitis. It is due to the lack of lipoprotein lipase (LPL) function, resulting from recessive loss of function mutations in the genes coding LPL or its modulators. A large overlap in the phenotype between FCS and multifactorial chylomicronaemia syndrome (MCS) contributes to the inconsistency in how patients are diagnosed and managed worldwide, whereas the incidence of acute hypertriglyceridaemic pancreatitis is more frequent in FCS. A panel of European experts provided guidance on the diagnostic strategy surrounding FCS and proposed an algorithm-based diagnosis tool for identification of these patients, which can be readily translated into practice. Features included in this FCS score comprise: severe elevation of plasma TGs (fasting TG levels >10 mmol/L [885 mg/dL] on multiple occasions), refractory to standard TG-lowering therapies, a young age at onset, the lack of secondary factors (except for pregnancy and oral oestrogens) and a history of episodes of acute pancreatitis. Considering 53 FCS patients from three cohorts and 52 MCS patients from three cohorts, the overall sensitivity of the FCS score (≥10) was 88% (95% confidence interval [CI]: 0.76, 0.97) with an overall specificity of 85% (95% CI: 0.75, 0.94). Receiver operating characteristic curve area was 0.91. Pragmatic clinical scoring, by standardising diagnosis, may help differentiate FCS from MCS, may alleviate the need for systematic genotyping in patients with severe HTG and may help identify high-priority candidates for genotyping.
What is HTG in medical terms?
Hypertriglyceridemia (HTG) is a commonly encountered medical condition defined by elevated fasting plasma triglyceride (TG) levels. The degree of elevation may range from mild to severe, with clinical features ranging from asymptomatic to increased vascular disease susceptibility to life-threatening pancreatitis. While numerous nongenetic secondary factors play a strong contributory role, a genetic component is frequently present in patients who clinically express HTG. Purely monogenic or Mendelian HTG – for example autosomal recessive chylomicronemia – is exceedingly rare and results from bi-allelic mutations affecting lipolysis. The pool of patients with more common polygenic HTG has an increased frequency of heterozygous large-effect rare variants in LPL (lipoprotein lipase) and related genes, together with a high burden of small-effect common polymorphisms, although any particular variant is not definitively causative in this condition. Hypertriglyceridemia (HTG) ranges from mild to severe, with the role of genetic determinants increasing with a more severe clinical presentation.One definition proposes that plasma triglyceride (TG) levels in mild-to-moderate HTG are between 2.0 and 9.9 mmol L−1 (175 and 885 mg dL−1), while in severe HTG, levels exceed 10 mmol L−1 (885 mg dL−1).A gamut of secondary factors can contribute to clinical expression of HTG.Clinical consequences of HTG range from increased vascular disease risk to visible lipid eruptions on the skin to life-threatening pancreatitis, depending on the affected species of lipoprotein particles and associated disturbances.Monogenic chylomicronemia is an extreme and rare form of severe HTG that results from bi-allelic mutations in LPL, APOC2, APOA5, LMF1, or GPIHBP1 genes.Most other HTG cases have a polygenic basis: this patient pool harbours an assortment of genetic variants, including a high burden of rare heterozygous large-effect variants and common small-effect variants.
How is genetic information used to treat diseases?
The use of genetic information to explore and treat diseases is ever-expanding, varying from the use of classical approaches for monogenetic disorders to the growing genome-wide association studies to understand more complex traits. In hypertriglyceridemia, development has progressed rapidly. We have now observed the use of genetic information to treat monogenetic disorders using gene therapy, which, for the first time, has been implemented successfully in human subjects. In addition, antisense oligonucleotide therapy in mice and more recently, in humans, has been demonstrated to lower triglyceride levels. In polygenetic disease, the use of large-scale genome-wide association studies has changed our perception of the underlying phenotypes, demonstrating a large overlap in common genetic determinants. This information is translated to understanding reactions to drug therapy, but also in relation to environment interaction. Finally, the use of genetics for predicting cardiovascular disease risk is being continuously studied, although clinical application appears to still be far along the road ahead.
