Dysbetalipoproteinemia Is Associated With Increased Risk of Coronary and Peripheral Vascular Disease.

CONTEXT: Dysbetalipoproteinemia (DBL) is a disorder in which remnant lipoproteins accumulate in the plasma due to a genetic apolipoprotein E dysfunction in conjunction with the presence of secondary metabolic factors. An increased risk of both coronary and peripheral vascular disease (PVD) has been observed in these patients in retrospective studies. OBJECTIVE: The primary objective was to compare the incidence of atherosclerotic cardiovascular disease (ASCVD) and PVD in a cohort of patients with DBL compared with normolipidemic controls. As a secondary objective, the incidence of ASCVD and PVD was compared between patients with DBL and patients with familial hypercholesterolemia (FH). METHODS: A total of 221 patients with DBL, 725 patients with FH, and 1481 normolipidemic controls were included in the study. The data were obtained by review of medical records. RESULTS: In patients with DBL, there was an overall excess risk of PVD (hazard ratio [HR] 13.58, 95% CI 4.76-38.75) and ASCVD (HR 3.55, 95% CI 2.17-5.83) (P < .0001) when compared with normolipidemic controls. When compared with patients with FH, an increased risk of PVD (HR 3.89, 95% CI 1.20-12.55, P = .02) was observed in patients with DBL. CONCLUSION: We demonstrated that the risks of ASCVD and PVD in DBL are >3-fold and >13-fold higher, respectively, than normolipidemic controls. Furthermore, the risk of PVD is ∼4-fold higher in DBL than in FH. Adequate screening of DBL is imperative to improve the clinical care of these patients by preventing the development of ASCVD.

Prospective Registry Study of Primary Dyslipidemia (PROLIPID): Rationale and Study Design.

INTRODUCTION: Primary dyslipidemias are inherited disorders in plasma lipoprotein metabolism that lead to serious cardiovascular and other complications. The Japanese Ministry of Health, Labor and Welfare (MHLW) covers medical expenses, under the Research Program on Rare and Intractable Diseases, for homozygous familial hypercholesterolemia (FH), familial chylomicronemia, sitosterolemia, cerebrotendinous xanthomatosis, lecithin:cholesterol acyltransferase deficiency, Tangier disease, and abetalipoproteinemia. Apolipoprotein A1 deficiency, heterozygous FH, and type III hyperlipoproteinemia are covered by the MHLW Pediatric Chronic Disease Program. Heterozygous FH and type III hyperlipoproteinemia are also important for their relatively common prevalence and, accordingly, high impact on Japanese public health by significant contribution to the overall prevalence of cardiovascular diseases. Therefore, a systemic survey of these diseases is mandatory to estimate their actual situation, such as prevalence, clinical manifestations, and prognoses among the Japanese population. The impact of these rare and intractable diseases on cardiovascular and other complications will likely be higher among Japanese people than other ethnicities because the general Japanese population has many cardioprotective aspects. The current study intends to conduct a multicenter registry of these diseases to assess their demographics and clinical features comprehensively. METHODS AND ANALYSIS: The Prospective Registry Study of Primary Dyslipidemia is a registry-based prospective, observational, multicenter cohort study in Japan, enrolling patients who fulfill the Japanese clinical criteria of the primary dyslipidemias listed above, from 26 participating institutes from August 2015 to March 2023. A total of 1,000 patients will be enrolled in the study and followed for 10 years. Clinical parameters are collected, including physical and laboratory findings, genetic analysis, drugs, lifestyle management, and clinical events, especially cardiovascular events. The primary endpoint of this study is the new onset of cardiovascular disease and acute pancreatitis, and the secondary endpoint is death from any causes. ETHICS AND DISSEMINATION: This study complies with the Declaration of Helsinki, the Ethical Guidelines for Medical and Health Research Involving Human Subjects, and all other applicable laws and guidelines in Japan. The institutional review boards have approved this study protocol at all participating institutes. The final results are to be published at appropriate international conferences and in peer-reviewed journals.

Case of familial hyperlipoproteinemia type III hypertriglyceridemia induced acute pancreatitis: Role for outpatient apheresis maintenance therapy.

Hypertriglyceridemic pancreatitis (HTGP) accounts for up to 10% of acute pancreatitis presentations in non-pregnant individuals and is the third most common cause of acute pancreatitis after alcohol and gallstones. There are a number of retrospective studies and case reports that have suggested a role for apheresis and insulin infusion in the acute inpatient setting. We report a case of HTGP in a male with hyperlipoproteinemia type III who was treated successfully with insulin and apheresis on the initial inpatient presentation followed by bi-monthly outpatient maintenance apheresis sessions for the prevention of recurrent HTGP. We also reviewed the literature for the different inpatient and outpatient management modalities of HTGP. Given that there are no guidelines or randomized clinical trials that evaluate the outpatient management of HTGP, this case report may provide insight into a possible role for outpatient apheresis maintenance therapy.

Primary hypertriglyceridemia in children and adolescents.

Primary disorders of lipid metabolism causing hypertriglyceridemia (HyperTG) result from genetic defects in triglyceride synthesis and metabolism. With the exception of lipoprotein lipase deficiency, these primary HyperTG disorders usually present in adulthood. However, some are unmasked earlier by precipitating factors, such as obesity and insulin resistance, and can be diagnosed in adolescence. Physical findings may be present and can include eruptive, palmer, or tuberoeruptive xanthomas. Triglyceride levels are very high to severe and can occur in the absence or the presence of other lipid abnormalities. Each of the causes of HyperTG is associated with an increased risk to develop recurrent pancreatitis and some may increase the risk of premature cardiovascular disease. Adoption of a healthy lifestyle that includes a low-fat diet, optimizing body weight, smoking avoidance/cessation, and daily physical activity is the first line of therapy. Pharmacologic therapies are available and can be beneficial in select disorders. Here, we review the causes of primary HyperTG in children and adolescents, discuss their clinical presentation and associated complications including the risk of pancreatitis and premature cardiovascular disease, and conclude with management and novel therapies currently in development. The goal of this article is to provide a useful resource for clinicians who may encounter primary HyperTG in the pediatric population.

Dysbetalipoproteinemia: an extreme disorder of remnant metabolism.

PURPOSE OF REVIEW: Lipoprotein metabolism and the role of apolipoprotein E in the pathogenesis of dysbetalipoproteinemia. RECENT FINDINGS: Remnant lipoproteins, modulated by lifestyle and genetic factors, are atherogenic. Dysbetalipoproteinemia could be viewed as a monogenic disorder of remnant metabolism. SUMMARY: Elevated plasma triglyceride and cholesterol concentrations (mixed hyperlipidemias) are commonly encountered and dysbetaliproteinemia should be considered in this setting. Dysbetalipoproteinemia (remnant clearance disease, Fredrickson type III hyperlipidemia) is an uncommon dyslipoproteinemia related to mutations in apolipoprotein E that disrupt the clearance of remnants of triglyceride-rich lipoproteins; it may be overlooked because xanthomata of the skin and/or tendons occur in a minority of patients. The diagnosis ideally requires the demonstration of remnant lipoprotein accumulation and a genetic cause. Genotyping for apolipoprotein E2 may not prove the diagnosis as it may be associated with low plasma lipid values. The recent association of remnant lipoproteins with atherosclerosis along with many factors that modulate remnant lipoprotein metabolism underscores the importance of recognising dysbetalipoproteinemia as an extreme state of remnant lipoprotein accumulation. Although there may be some differences between remnants in the general population and dysbetalipoproteinemia, it is clear that remnants promote atherosclerosis. Current treatment strategies are adequate but new strategies could also be of benefit in dysbetalipoproteinemia.

Lipid-associated rheumatologic syndromes.

Rheumatologic manifestations of hyperlipidemia and lipid-associated arthritis are rarely seen in the rheumatologist's office. On the other hand, a rheumatologist may be the clinician who identifies and initiates proper therapy for disorders related to hyperlipidemia when the musculoskeletal manifestations of these syndromes are recognized. In this article both the joint and tendon manifestations are reviewed, including the lesser known lipid liquid crystal form of arthritis. The relationship between gout and hyperuricemia is briefly discussed, as are the autoimmune manifestations of lipid-lowering therapy.

[Connections between apolipoprotein E genotypes and the development of cardiovascular diseases]. / Az apolipoprotein E genotípusok összefüggése cardiovascularis betegségek kialakulásával.

Elevated plasma lipid level is one of the main risk factors for cardiovascular diseases, which are considered to be primary causes of death. Apolipoprotein E plays a part in the lipid transport in the blood, thus polimophisms of that affect the lipid composition of the plasma. The three most common alleles of apolipoprotein E are e2, e3, e4. Out of the two non-wild type alleles, the e2 and e4, the latter was shown to play a role in the development of cardiovascular diseases and Alzheimer's disease. Some studies mention the e2/e2 homozygote genotype as one of the causes of hyperlipoproteinemia type III. Besides lipid metabolism, apolipoprotein E also influences the manifestation of cardiovascular diseases through other biochemical pathways, therefore it is essential to explore the molecular background of these metabolic pathways.

Xanthomata and diabetes in an adolescent with familial dysbetalipoproteinemia 9 yr after valproate-induced pancreatitis.

A 14-yr-old girl presented with eruptive xanthomata and hypertriglyceridemia. This rare presentation led to diagnoses of diabetes and familial dysbetalipoproteinemia. Type 1 diabetes is a common childhood illness often presenting in adolescence. However, this patient's past medical history revealed valproate-induced severe acute pancreatitis with necrosis at the age of 5 yr. Diabetes, in this case, developed 9 yr later as a result of inadequate pancreatic tissue to support increasing insulin requirements during growth and adolescence. Diabetes was discovered only after the appearance of cutaneous eruptive xanthomata, which appeared due to the previously undiagnosed genetic dyslipidemia. Although the relationship between xanthomata, hypertriglyceridemia, and diabetes may be well known in adults, in children, xanthomata are very rarely the presenting feature of diabetes of any cause. The patient was treated with insulin which induced rapid resolution of hypertriglyceridemia and gradual disappearance of xanthomata. This case acknowledges the rarity of diabetes presenting with xanthomata in adolescence, highlights the importance of searching for an underlying dyslipidemia in such a case, and presents diabetes as a long-term complication of acute pancreatitis in children.

Correlation of atherosclerosis between different topographic sites is highly dependent on the type of hyperlipidemia.

There is a surprising paucity of studies that provide quantitative correlative data on the extent of atherosclerosis between different topographic sites. The impact of cardiovascular risk factors is dependent on the vascular bed, which underlies site-selective effects on progression of atherosclerosis. Therefore, the intraindividual correlation of atherosclerosis between different topographic sites may be dependent on the specific cardiovascular risk profile. The focused objective of the current study is to evaluate whether the correlation of the extent of atherosclerosis between different topographic sites is dependent on the type of hyperlipidemia. Atherosclerosis was quantified at four different topographic locations in the aorta of rabbits with type II or type III hyperlipidemia. Correlation coefficients and semi-partial correlation coefficients adjusted for plasma lipoproteins and sex were determined to compare the degree of atherosclerosis at different topographic sites. Semi-partial correlations adjusted for total plasma cholesterol, plasma triglycerides, and sex of the intima/media ratio between different topographic sites were highly dependent on the type of hyperlipidemia. E.g., the semi-partial correlation coefficient between the intima/media ratio at the level of the ascending aorta and at the level of the descending thoracic aorta was 0.87 (p < 0.0001) in the model of type II hyperlipidemia and was only 0.10 (p = NS) in the model of type III hyperlipidemia. This divergent pattern was also observed for other intersite correlations. Semi-partial Pearson correlation coefficients were very similar to unadjusted Pearson correlation coefficients. Correlation of atherosclerosis between different topographic sites may vary importantly in relation to the type of hyperlipidemia.

A dynamic model of calcific nodule destabilization in response to monocyte- and oxidized lipid-induced matrix metalloproteinases.

Vulnerable plaque remains clinically undetectable, and there is no accepted in vitro model. We characterize the calcific nodules produced by calcifying vascular cells (CVC) in ApoE-null mice, demonstrating increased destabilization of cultured nodules in the presence of oxidized low-density lipoprotein (oxLDL) and monocytes under pulsatile shear stress. CVC implanted in the subcutaneous space of hyperlipidemic mice produced nodules revealing features of calcific atherosclerotic plaque including a fibrous cap, cholesterol clefts, thin shoulder, lipids, and calcium mineral deposits. CVC nodules seeded in the pulsatile flow channel (τ(avg) = 23 dyn/cm(2), ∂τ/∂t = 71 dyn·cm(-2)·s(-1)) underwent deformation and destabilization. Computational fluid dynamics revealed distinct shear force profiles on the nodules. Presence of oxLDL or monocytic THP-1 cells significantly increased the numbers of nodules destabilized from the substrate. Both oxLDL and THP-1 increased matrix metalloproteinase (MMP) activity in CVC. The MMP inhibitor GM6001 significantly reversed oxLDL- and THP-1-induced nodule destabilization, whereas overexpression of MMP-9 increased destabilization. These findings demonstrate that CVC-derived nodules resembled calcific atherosclerotic plaque and were destabilized in the presence of active lipids and monocytes via induction of MMPs.

Disappearance of angina pectoris by lipid-lowering in type III hyperlipoproteinemia.

Type III hyperlipoproteinemia is a rare familial disease characterized by marked elevations of serum cholesterol and triglyceride levels caused by an accumulation of remnant lipoproteins in apolipoprotein E2/E2 homozygotes. It is associated with an increased risk for premature atherosclerotic vascular disease. A 55-year-old woman was diagnosed as having type III hyperlipoproteinemia on the basis of skin lesions, serum lipid levels, lipid electrophoresis, and apolipoprotein E genotyping and stable angina pectoris on the basis of typical symptoms and treadmill exercise electrocardiographic results. After 1 year of combination therapy with atorvastatin and fenofibrate, skin xanthomata disappeared, leaving minimal remnants. In addition, there was no exertional chest pain, and treadmill exercise electrocardiographic results were negative. This finding was confirmed by coronary computed tomographic angiography. This case suggests that proper medical therapy can induce the regression of uncomplicated coronary lesions in type III hyperlipoproteinemia.

Improved plasma lipids and body weight in overweight/obese patients with type III hyperlipoproteinemia after 4 weeks on a low glycemic diet.

BACKGROUND & AIM: The optimal diet for type III hyperlipoproteinemia is unknown. We examined blood lipids and body weight following low or high glycemic index diets in comparison with a lipid-lowering diet. MATERIALS AND METHODS: Sixteen overweight/obese men completed a cross-over study where they followed a standard lipid-lowering diet, a high and a low glycemic index diet, each lasting 4 weeks. Measurements were obtained at the end of each diet intervention. RESULTS: The lipid-lowering diet reduced significantly LDL cholesterol, and apolipoprotein B by 24%, and 17%, whereas high glycemic index increased LDL cholesterol with 21%. The low glycemic index diet reduced (p<0.05) total and LDL cholesterol and apolipoprotein B compared with the lipid-lowering diet. A moderate weight loss (p<0.05) was achieved after the lipid-lowering diet compared with baseline: 1.4 (-3.6-0.2; median, 95% CI) kg and similar to that after high glycemic index diet. A low glycemic index diet resulted in 2.4 (-3.9-1.4) kg weight loss compared with the high glycemic index diet (p<0.05). CONCLUSION: A low glycemic index diet may be superior to that of a standard lipid-lowering diet in type III hyperlipoproteinemia.

[Orange skin and xanthomas associated with lycopenaemia in a setting of type III dyslipoproteinemia]. / Coloration orangée des téguments et des xanthomes au cours d'une lycopénémie associée à une dyslipoprotéinémie de type III.

BACKGROUND: Type III hyperlipoproteinaemia (HLP) is a rare form of dyslipidaemia characterized by skin lesions such as palmar crease xanthoma and tuberous xanthomas. To our knowledge, there have been no previous reports of yellow-orange discoloration of the skin and xanthomas associated with this disease. CASE REPORT: A 61-year-old woman consulted for palmar crease xanthoma and tuberous xanthomas of the elbows with odd yellow-orange discoloration. Laboratory investigations demonstrated type-III HLP and a high serum lycopene level. After 14 weeks of lipid-lowering treatment, the xanthomas and discoloration showed improvement. In addition, lipid levels and serum lycopene had returned to normal. DISCUSSION: All cases of lycopenaemia reported in the literature followed excessive ingestion of lycopene in foods. We describe the first case of lycopenaemia with orange discoloration of xanthomas following raised serum lycopene but not involving excessive dietary intake. Type-III HLP was doubtless instrumental in the physiopathogenesis of these orange lesions.

The role of the long-term follow-up clinic in discovering new emerging late effects in adult survivors of childhood cancer.

Our understanding of late effects in long-term survivors of childhood cancer is continually evolving as significant numbers of survivors are entering middle to later adulthood. Effects of conventional treatment on premature aging are being recognized, as are long-term effects of newer therapies. Clinicians in long-term follow-up clinics are in a unique position to monitor for recognized late effects and to be alert to signs and symptoms of late effects that have not been previously reported in the pediatric cancer literature. This article presents 2 young adult survivors who displayed subtle signs of impaired cerebral blood flow due to carotid artery stenosis many years after being treated with neck irradiation. When the first patient presented nearly a decade ago in the clinic with symptoms, premature carotid artery disease was not a radiation-related late effect that had been reported previously in survivors of childhood cancer. These cases are used to illustrate the key role of long-term follow-up clinics in identifying new and emerging treatment-related late effects and underscore the importance of lifetime surveillance and the need for collaboration between pediatric and adult health care providers.

Lipoprotein glomerulopathy-like disease in a patient with type III hyperlipoproteinemia due to apolipoprotein E2 (Arg158 Cys)/3 heterozygosity.

A 77-year-old woman developed nephrotic syndrome associated with type III hyperlipoproteinemia (III HLP) and increased apolipoprotein E (apo E). Apo E analysis disclosed E2/E3 heterozygosity in phenotypic and genotypic expressions, without any other mutations. A renal biopsy showed intraluminal and subendothelial thrombus-like deposits in the dilated capillary loops of the glomerulus that stained positive for lipids and apo E. Electron microscopy revealed tiny granular particles in the capillary lumina, as well as between the glomerular basement membrane and the endothelial cells. It was therefore concluded that III HLP associated with apo E2/E3 heterozygosity could induce lipoprotein glomerulopathy-like disease and nephrotic syndrome.