Triglycerides, hypertension, and smoking predict cardiovascular disease in dysbetalipoproteinemia.

BACKGROUND: Dysbetalipoproteinemia (DBL) is an autosomal recessive lipid disorder associated with a reduced clearance of remnant lipoproteins and is associated with an increased cardiovascular disease (CVD) risk. The genetic cause of DBL is apoE2 homozygosity in 90% of cases. However, a second metabolic hit must be present to precipitate the disease. However, no study has investigated the predictors of CVD, peripheral artery disease and coronary artery disease in a large cohort of patients with DBL. OBJECTIVE: The objectives of this study were to describe the clinical characteristics of a DBL cohort and to identify the predictors of CVD, peripheral artery disease, and coronary artery disease in this population. METHODS: The inclusion criteria included age ≥ 18 years, apoE2/E2, triglycerides (TG) > 135 mg/dL and VLDL-C/plasma TG ratio > 0.30. RESULTS: We studied 221 adult DBL patients, of which 51 (23%) had a history of CVD. We identified 3 independent predictors of CVD, namely hypertension (OR 5.68, 95% CI 2.13-15.16, P = .001), pack year of smoking (OR 1.03, 95% CI 1.01-1.05, P = .01) and TG tertile (OR 1.82, 95% CI 1.09-3.05, P = .02). The CVD prevalence was 51% in patients with hypertension and 18% in those without hypertension (P = .00001), and 30% in the highest TG tertile vs 15% in the lowest tertile (P = .04). Similarly, the CVD prevalence was higher in heavy smokers compared with nonsmokers (36% vs 13%, P = .006). CONCLUSION: Hypertension, smoking, and TG are independently associated with CVD risk in patients with DBL. Aggressive treatment should be initiated in patients with DBL because of the increased risk of CVD.

Familial dysbetalipoproteinemia: an underdiagnosed lipid disorder.

PURPOSE OF REVIEW: To review pathophysiological, epidemiological and clinical aspects of familial dysbetalipoproteinemia; a model disease for remnant metabolism and remnant-associated cardiovascular risk. RECENT FINDINGS: Familial dysbetalipoproteinemia is characterized by remnant accumulation caused by impaired remnant clearance, and premature cardiovascular disease. Most familial dysbetalipoproteinemia patients are homozygous for apolipoprotein ε2, which is associated with decreased binding of apolipoprotein E to the LDL receptor. Although familial dysbetalipoproteinemia is an autosomal recessive disease in most cases, 10% is caused by autosomal dominant mutations. Of people with an ε2ε2 genotype 15% develops familial dysbetalipoproteinemia, which is associated with secondary risk factors, such as obesity and insulin resistance, that inhibit remnant clearance by degradation of the heparan sulfate proteoglycan receptor. The prevalence of familial dysbetalipoproteinemia ranges from 0.12 to 0.40% depending on the definition used. Clinical characteristics of familial dysbetalipoproteinemia are xanthomas and mixed hyperlipidemia (high total cholesterol and triglycerides); the primary lipid treatment goal in familial dysbetalipoproteinemia is non-HDL-cholesterol; and treatment consists of dietary therapy and treatment with statin and fibrate combination. SUMMARY: Familial dysbetalipoproteinemia is a relatively common, though often not diagnosed, lipid disorder characterized by mixed hyperlipidemia, remnant accumulation and premature cardiovascular disease, which should be treated with dietary therapy and statin and fibrate combination.

Vascular risk factors, vascular disease, lipids and lipid targets in patients with familial dysbetalipoproteinemia: a European cross-sectional study.

BACKGROUND: Familial dysbetalipoproteinemia (FD), also known as type III hyperlipoproteinemia, is a genetic dyslipidemia characterized by elevated very low density lipoprotein (VLDL) and chylomicron remnant particles that confers increased risk of cardiovascular disease (CVD). The objective of this study was to evaluate the prevalence of vascular risk factors, CVD, lipid values, treatment and lipid targets in patients with FD across Europe. METHODS: This cross-sectional study was performed in 305 patients with FD from seven academic hospitals in four European countries. Information was collected from clinical records. RESULTS: Patients mean (±standard deviation) age was 60.9±14.4 years, 201 (66%) were male, 69 (23%) had diabetes mellitus (DM) and 87 (29%) had a prior history of CVD. Mean body mass index was 28.5±5.0 kg/m2. Lipid-lowering medication was used by 227 (74%) patients (27% usual dose (theoretical low-density lipoprotein cholesterol (LDL-C) reduction≤40%) and 46% intensive dose (theoretical LDL-C reduction>40%)). Non high-density lipoprotein cholesterol (non-HDL-C) levels below treatment target (<3.3 mmol/L) were present in 123 (40%) patients and 163 patients (53%) had LDL-C levels below target (<2.5 mmol/L). No significant determinants were found for having non-HDL-C levels below target, while a prior history of CVD (OR 1.90, 95%CI 1.05-3.47) and presence of DM (OR 2.00, 95%CI 1.08-3.70) were associated with having LDL-C levels below treatment target. CONCLUSION: The majority of FD patients had non-HDL-C levels above the treatment target of 3.3 mmol/L. Intensive dose lipid-lowering medication was used by only half of the patients, leaving them at increased cardiovascular risk.

Indicaciones de la combinación de pravastatina y fenofibrato según el nivel de riesgo cardiovascular. Situaciones clínicas habituales / Indications for the combination of pravastatin and fenofibrate according to the cardiovascular risk level. Common clinical situations

En la diabetes, el síndrome metabólico, algunas dislipemias familiares, la patología isquémica de origen ateromatoso y la insuficiencia renal es común la existencia de una dislipemia mixta, es decir, un exceso de colesterol y de triglicéridos, asociado o no a un déficit de colesterol unido a lipoproteínas de alta densidad (cHDL). Estas situaciones clínicas se relacionan con un alto o muy alto riesgo cardiovascular y en ellas es conveniente lograr un control global de las alteraciones del metabolismo lipídico, tanto con referencia al exceso de colesterol vehiculizado por las lipoproteínas aterogénicas (colesterol unido a lipoproteínas de baja densidad [cLDL] y colesterol no-HDL), como al exceso de triglicéridos y al déficit de colesterol transportado por las lipoproteínas antiaterogénicas (cHDL). Para conseguir dicho control global, además de corregir las posibles causas de dislipemia secundaria, mejorar los hábitos de vida y utilizar un fármaco de la familia de las estatinas, con frecuencia es necesario asociar un fármaco de la familia de los fibratos. Esta asociación se ha mostrado eficaz y segura en el control global de la dislipemia y la prevención cardiovascular en los pacientes de alto riesgo, y en la población diabética ha demostrado un efecto favorable frente a la microangiopatía, tanto a nivel de la retina como del glomérulo renal. En los pacientes con insuficiencia renal moderada, el uso de los fibratos es controvertido y existen notables discrepancias sobre las recomendaciones emitidas por distintos organismos y consensos de expertos

In diabetes, metabolic syndrome, some types of familial dyslipidemia, ischemic pathology of atheromatous origin and renal failure, the presence of mixed dyslipidemia is common. In other words, there is an excess of cholesterol and triglycerides, associated or not with HDL-c deficiency. Theseclinical conditions are associated with high to very high cardiovascular risk. It is appropriate when treating these conditions to achieve an overall control of lipid metabolism abnormalities, in terms of excess cholesterol carried by atherogenic lipoproteins (LDL-c and non-HDL-c) and triglyceride excess and deficit of HDL-c. To achieve this overall control is necessary to correct the potential causes of secondary dyslipidemia, improve lifestyle habits and use a drug from the statin family, and it is often necessary to combine a drug from the fibrate family. This combination has been shown to be effective and safe in the overall control of dyslipidemia and the cardiovascular risk prevention in patients at high risk. This combination has been shown to have a favorable eff ect in the population with diabetes and microangiopathy, both in the retina and in the glomerulus. For patients with moderate renal failure, the use of fibrates is controversial, and there are marked disagreements between the recommendations issued by various organizations and expert consensus groups

[Familial type III hyperlipoproteinemia].

Familial type III hyperlipoproteinemia(HLP) is characterized by increased plasma triglyceride(TG) and plasma remnant lipoproteins(chyromicron remnants and VLDL remnants i.e. IDL). Remnants predispose affected subjects to premature or accelerated atherosclerosis. Clinical features of type III HLP with apo E2/2 genotype are examined in 26 Japanese patients. Mean levels of plasma TG, total cholesterol, LDL cholesterol and remnant cholesterol(RLP-C) were 374, 256, 74 and 49 mg/dL, respectively. High plasma RLP-C levels above 30 mg/dL and high plasma RLP-C/plasma TG ratio above 0.1 are very useful for diagnosis of type III HLP. Fifty-four point two percent of the patients had diabetes mellitus and 66.2 % of the patients had metabolic syndrome. Diabetes and obesity contribute to the occurrence of type III HLP with apo E2/2 genotype in Japan. Coronary heart disease(CHD) occurred in 41.7% of the patients. Type III HLP is strongly associated with atherosclerosis in Japan.

Type III hyperlipoproteinemia with xanthomas and multiple myeloma.

BACKGROUND: Type III hyperlipoproteinemia usually results from an inherited defect in the composition of apolipoprotein E and is associated with atherosclerosis. An acquired form of the type III phenotype may rarely be associated with myeloma and immunoglobulin-lipoprotein complexes. OBSERVATION: We present the case of a 72-year-old man with a history of well-controlled, unclassified hypercholesterolemia and hypertriglyceridemia, without evidence of atherosclerotic disease. He subsequently developed refractory dyslipidemia, palmar crease, and tuberous xanthomas. Type III hyperlipoproteinemia was confirmed, and nonclassic defective apolipoprotein E. Common secondary causes of hyperlipidemia were ruled out. A workup for malignancy revealed monoclonal IgA gammopathy. Immunostaining confirmed IgA antibodies complexed to the patient's very low-density lipoprotein (VLDL) fraction, causing gross impairment of VLDL metabolism. Conventional therapy for type III hyperlipoproteinemia was attempted but ineffective. Thus, chemotherapy was initiated for his myeloma, with subsequent lowering of his IgA, cholesterol, and triglyceride levels, and improvement of his xanthomas. CONCLUSION: There are several unusual features to this case. Planar xanthomas can be associated with myelomas, but usually in the setting of normal lipids. Type III hyperlipoproteinemias are not usually refractory to standard therapy and are only rarely associated with IgA myeloma. IgA antibodies complexed to the patient's VLDL caused gross impairment of VLDL metabolism. The patient's apolipoprotein E genotype (heterozygote E2/E3) is not typical for expression of the heritable type III phenotype (homozygote E2/E2). These features support a causal relationship between this patient's multiple myeloma and type III hyperlipoproteinemia rather than two independent, coexistent conditions.

Apolipoprotein epsilon 2/3 genotype and type III hyperlipoproteinemia among Taiwanese.

BACKGROUND: Type III hyperlipoproteinemia (HLP) is a genetic disorder of lipid metabolism in humans that predisposes affected subjects to the premature development of atherosclerosis. Most type III HLP occurs in homozygous carriers of apolipoprotein (apo) E2. The aims of this study were to determine the frequencies of different apo E genotypes in type III HLP in Taiwanese and to assess the possibility of apo E mutants in these patients. MATERIALS AND METHODS: Four hundred and seven patients with hyperlipoproteinemia were recruited. Electrophoresis, apo E genotyping and sequencing were performed. RESULTS: Of the 407 hyperlipoproteinemia, 8 were identified as type III HLP. In contrast to reports of high apo epsilon 2/2 genotype prevalence, only two of the type III HLP subjects were of the apo epsilon 2/2 genotype (25%). Fifty percent of the type III HLP were of apo epsilon 2/3 genotype. This observation was further reflected in a lower frequency of the epsilon 2 allele (0.563) and higher epsilon 3 allele (0.375) frequency. No rare apo E variant was found by direct sequencing. CONCLUSION: The most common genotype of type III HLP in Taiwan was apo epsilon 2/3 instead of apo epsilon 2/2.

Expression of type III hyperlipoproteinemia in apolipoprotein E2 (Arg158 --> Cys) homozygotes is associated with hyperinsulinemia.

Type III hyperlipoproteinemia (HLP) is mainly found in homozygous carriers of apolipoprotein E2 (apoE2, Arg158-->Cys). Only a small percentage (< 5%) of these apoE2 homozygotes develops hyperlipidemia, indicating that additional environmental and genetic factors contribute to the expression of type III HLP. In the present study, first, the prevalence of type III HLP among apoE2 homozygotes was estimated in a Dutch population sample of 8888 participants. Second, 68 normocholesterolemic and 162 hypercholesterolemic apoE2 homozygotes (type III HLP patients) were collected to investigate additional factors influencing type III HLP expression. In the Dutch population sample, apoE2 homozygosity occurred with a frequency of 0.6% (57 of 8888 individuals). Among the 57 E2/2 subjects, 10 type III HLP patients were identified (prevalence 18%). Comparison of normocholesterolemic E2/2 subjects and type III HLP patients showed that the latter had a significantly increased body mass index (25.6 +/- 4.0 versus 26.9 +/- 3.8 kg/m(2), respectively; P=0.03) and prevalence of hyperinsulinemia (26% versus 63%, respectively; P<0.001). Multiple linear regression analysis demonstrated that most of the variability in type III HLP expression can be explained by fasting insulin levels (partial correlation coefficient approximately 0.50, P<0.001). In contrast to men, apoE2 homozygous women aged > or = 50 years had significantly higher plasma lipid levels than their counterparts aged < 50 years. These data demonstrate that the expression of type III HLP in E2/2 subjects is elicited to a large extent by hyperinsulinemia. In addition, in female apoE2 homozygotes, the expression increases with age; this increase is most likely due to the loss of estrogen production.

Apo E variants in patients with type III hyperlipoproteinemia.

Type III hyperlipoproteinemia (HLP III) is characterized by the reduced catabolism and accumulation of chylomicron and very low density lipoprotein (VLDL) remnants. Most HLP III patients are homozygous for the apolipoprotein E2 (Cys112, Cys158) allele; however, several other mutations at this gene locus have been associated with this HLP. In order to assess the presence of rare apo E variants in our population, we have examined apo E phenotypes by isoelectric focusing (IEF) and genotypes by restriction enzyme analysis of polymerase chain reaction (PCR) amplified DNA in 15 patients with HLP III. Lack of concordance between these two methods was observed in 11 subjects (73.3%). DNA sequencing analysis of the receptor binding domain of the apo E gene in the 11 HLP III patients with discrepancies demonstrated the presence of six carriers of the epsilon 3(Arg136-->Ser) allele and three carriers of the epsilon 2(Gly127-->Asp) allele. Five HLP III patients were apo E2/E2 using IEF, but only 2 of them were epsilon 2 homozygous using PCR. Two patients were E3/E3 homozygous with normal DNA sequence in the low density lipoprotein receptor binding domain of apo E. In conclusion, our results show that a number of different apo E genotypes are associated with HLP III in this population. More specifically, mutations at positions 127 and 136 might be frequent in Spain and occur in patients with HLP III.

Type III hyperlipoproteinaemia in a black patient. A case report.

A Black male aged 55 years presented with xanthomatosis on the elbows, buttocks and knees. The fasting serum cholesterol (10,62 mmol/l) and triglyceride levels (8,85 mmol/l) were elevated. The refrigerator test revealed a diffuse lactescence with a faint chylomicron layer. The very low density lipoprotein (VLDL) cholesterol and triglyceride levels were also elevated, with a VLDL cholesterol-to-VLDL triglyceride ratio of 0,37 and a VLDL cholesterol-to-serum triglyceride ratio of 0,45. Electrophoresis of the serum revealed a broad beta-band and the VLDL isolated exhibited beta mobility. After exclusion of secondary causes a diagnosis of primary type III hyperlipoproteinaemia was made.