Apolipoprotein E polymorphism--a risk factor for metabolic syndrome.

BACKGROUND: Metabolic syndrome is closely related to several disturbances in lipid and lipoprotein metabolism. The aim of this study was to determine the association between apolipoprotein E (apoE) genotypes and the risk of metabolic syndrome and/or coronary heart disease complications. METHODS: The study included 279 subjects divided into three groups: 1) control subjects, 2) metabolic syndrome patients, and 3) obese patients with coronary heart disease. All subjects were characterized by body mass index, and plasma levels of glucose, triglycerides, cholesterol, high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C). ApoE genotypes were identified by PCR-restriction fragment length polymorphism using genomic DNA. RESULTS: Statistical analysis of plasma parameters showed that subjects in groups 2 and 3 had higher levels of triglycerides and lower levels of HDL-C compared to group 1. The frequencies of apoE genotypes determined in this Romanian population (65% for E3/3, 19.6% for E4/3, 9.5% for E3/2, 4.1% for E2/2, 0.6% for E4/4, 1.3% for E4/2) were in agreement with those reported for other Caucasian populations. The distribution of apoE alleles indicated a higher frequency of epsilon4 in groups 2 and 3. There was a higher frequency of the apoE4/3 genotype in groups 2 and 3, which was significantly correlated with higher levels of triglycerides and lower levels of HDL-C. CONCLUSIONS: Correlations of apoE genotypes with these markers indicate that the epsilon4 allele is an independent risk factor for metabolic syndrome.     

Common genetic variants that relate to disorders of lipid transport in Spanish subjects with premature coronary artery disease

Fifteen common polymorphic variants at six loci (apolipoproteins AI, B, CIII and E, hepatic lipase and lipoprotein lipase) involved in plasma lipid transport have been studied in 210 northern Spanish men, of whom 98 had proven coronary artery disease. The other 112 men were clinically free from coronary artery disease and acted as controls. The genotypes were investigated for relationships with plasma lipid and lipoprotein levels, as well as for the presence of coronary artery disease. As expected, the mean levels of plasma triacylglycerols (triglycerides) and lipoprotein (a) and the number of smokers were significantly higher in the disease group, and high-density lipoprotein (HDL)-cholesterol was significantly lower. Surprisingly, plasma cholesterol and low-density lipoprotein cholesterol were not different between the two groups. With regard to the common mutations, plasma triacylglycerol levels were related to the HindIII variants of lipoprotein lipase (P<0.05), to the apolipoprotein CIII variant (C3175G in exon 4) and to the apolipoprotein AI XmnI polymorphisms (P<0.05 and P<0.02 respectively). The apolipoprotein E variants were related to plasma cholesterol (P<0.05), HDL-cholesterol (P<0.02), plasma triacylglycerols (P<0.05) and the triacylglycerol/HDL ratio (P<0.01). Only the three-codon insertion/deletion variants of the apolipoprotein B signal peptide region discriminated between the two groups with or without arterial disease (P=0.02). The possible functional effects of these common mutations are discussed.     

Effect of APOE genotype on lipid levels in patients with coronary heart disease during a 3-week inpatient rehabilitation program

It has been suggested that the apolipoprotein E (APOE) genotype modifies the effect of dietary and pharmacological interventions for lowering lipid levels. We wanted to determine whether APOE genotyping information would be useful in making lipid-lowering treatment decisions in clinical practice. We included 981 patients with coronary heart disease (CHD) enrolled in an inpatient 3-week standardized rehabilitation program. Of these, 555 (57%) patients received continued statin therapy and 232 (24%) patients received newly initiated statin therapy. Dietary intervention was part of the program only for 194 (20%) patients. Total cholesterol (TC) and low-density lipoprotein cholesterol (LDLC) levels decreased in all the groups of patients during rehabilitation. The decreases were less pronounced among the APOE E2 carriers. However, the observed variation among the groups with respect to reduction of lipid levels was accounted for mainly by the initial lipid levels (30-47%) and only marginally on the APOE genotype (1%) . We therefore found no evidence that APOE genotyping will be useful in guiding dietary or pharmacological lipid-lowering treatment decisions.     

Hormone replacement therapy in postmenopausal women and its effects on plasma lipid levels.

Postmenopausal women run the same risks of coronary heart disease as men. The lipid alterations observed at this time reflect increased blood levels of total cholesterol, low-density lipoprotein cholesterol (LDL-C) and lipoprotein (a), and reduced high-density lipoprotein cholesterol (HDL-C) levels. These changes lead to a higher risk of coronary artery disease, and hormonal therapy has a favorable effect on lipid metabolism. In this paper we review the literature on hormone replacement therapy (HRT) in postmenopausal women with the emphasis on the role of lipids in the pathogenesis of coronary heart disease, and on the action of estrogens and their correlation with progestogens, as well as routes of HRT administration. We conclude that the HRT changes the lipid profile in a potentially anti-atherogenic direction, usually reducing LDL-C and increasing HDL-C and triglycerides. Otherwise, for postmenopausal women with established coronary disease HRT is not recommended.     

Five polymorphisms in gene candidates for cardiovascular disease in Afro-Brazilian individuals

Associations of polymorphisms in the angiotensin I-converting enzyme (ACE), apolipoprotein B (APOB) and apolipoprotein E (APOE) genes with hypertension and variations in lipid serum levels were evaluated in 184 Afro-Brazilians with a familial history of coronary artery disease (CAD). ACE (Ins/Del) and APOB (Ins/Del, XbaI, and EcoRI) and APOE (HhaI) polymorphisms were determined by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analyses on agarose, and polyacrylamide gel electrophoresis. Serum lipids were measured by means of routine enzymatic assays. The results showed a high frequency of hypertension (44%) in Afro-Brazilians that was increased in subjects >40 years old and those with a blood mass index (BMI) higher than 25 kg/m(2) (P<0.001). The ACE Del allele was associated with hypertension in men >40 years old (P<0.05). APOE (HhaI) and APOB (XbaI and Ins/Del) polymorphisms were not associated with hypertension or variations in serum concentrations of lipids, while subjects with the APOB E- allele had higher low-density lipoprotein cholesterol (LDL-C) levels than E+ carriers (P<0.05). These results suggest that ACE Ins/Del polymorphism is associated with hypertension, and APOB EcoRI polymorphism is associated with LDL-C variation in Afro-Brazilians.     

Preventing, stopping, or reversing coronary artery disease--triglyceride-rich lipoproteins and associated lipoprotein and metabolic abnormalities: the need for recognition and treatment

A substantial number of treated patients with or at high risk for coronary artery disease continue to have fatal and nonfatal coronary artery events in spite of significant reduction of elevated levels of low-density lipoprotein cholesterol. Other lipoprotein abnormalities besides an elevated level of low-density lipoprotein cholesterol contribute to risk of coronary artery disease and coronary artery events, and the predominant abnormalities that appear to explain much of this continued risk are an elevated serum triglyceride level and a low level of high-density lipoprotein cholesterol. Most patients with coronary artery disease have a mixed dyslipidemia with hypertriglyceridemia, which is associated and metabolically intertwined with other atherogenic risk factors, including the presence of triglyceride-rich lipoprotein remnants, low levels of high-density lipoprotein cholesterol, small, dense, low-density lipoprotein particles, postprandial hyperlipidemia, and a prothrombotic state. Aggressive treatment of these patients needs to focus on these other lipoprotein abnormalities as much as on low-density lipoprotein cholesterol. Combination drug therapy will usually be required. Reliable assessment of risk of coronary artery disease from lipoprotein measurements and response to therapy requires inclusion of all atherogenic lipoproteins in laboratory measurements and treatment protocols. At present this may be best accomplished by use of non-high-density lipoprotein cholesterol (total cholesterol minus high-density lipoprotein cholesterol) calculated from standard laboratory lipoprotein values. Ultimately, a more comprehensive assessment of coronary artery disease risk and appropriate therapy may include measurement of lipoprotein subclass distribution including determination of low-density lipoprotein particle concentration and sizes of the various lipoprotein particles.     

Apolipoprotein E phenotypes, serum lipoproteins and apolipoproteins in angiographically assessed coronary heart disease

To determine the influence of the apolipoprotein E polymorphism on the occurrence of coronary artery disease (CAD) and on serum lipids, lipoproteins and apolipoproteins we studied 145 patients with angiographically defined CAD and compared them with 153 control subjects without history or complaints of vascular disease and with 35 subjects without significant stenosis on coronary arteriography. Subjects with hypertension, diabetes mellitus and endocrine or metabolic disorders were excluded. Covariance analysis and logistic regression analysis were performed with adjustment for age, sex, smoking habits and relative body weight. There were no significant differences for the apoE phenotypes on risk of cardiovascular disease. The CAD group had significantly higher mean values of serum cholesterol and triglycerides, very-low-density lipoprotein (VLDL)-cholesterol and VLDL-triglycerides, low-density lipoprotein (LDL)-cholesterol and apoprotein B; they had lower high-density lipoprotein (HDL)-cholesterol and apo A-I. The combination of LDL-cholesterol, apoA-I and VLDL-cholesterol was the best model in predicting cardiovascular disease. ApoE phenotype group E3/E2 had significantly lower values for serum cholesterol, LDL-cholesterol, and apoB and higher levels of apoE in comparison with the phenotype groups E3/E3 and E4/E3. The combination of LDL-cholesterol, cholesterol, apoE and VLDL-triglycerides was the best model in predicting the apoE phenotype. Thus, taking other risk factors into account, the apoE phenotype is not an independent risk factor for CAD; the apoE polymorphism influences lipoprotein levels and possibly, in that way, indirectly also the risk for CAD.     

Abnormalities in apolipoprotein and lipid levels in an HIV-infected Brazilian population under different treatment profiles: the relevance of apolipoprotein E genotypes and immunological status.

HIV infection is associated with disturbances in lipid metabolism due to a host's response mechanism and the current antiretroviral therapy. The pathological appearance and progression of atherosclerosis is dependent on the presence of injurious agents in the vascular endothelium and variations in different subsets of candidate genes. Therefore, the Hha I polymorphism in the apolipoprotein E gene was evaluated in addition to triglycerides, total cholesterol, very low-density lipoprotein (VLDL), LDL, high-density lipoprotein (HDL), and apolipoprotein (apo) Al, B and E levels in 86 Brazilian HIV-infected patients and 29 healthy controls. The allele frequency for apoE in the HIV-infected group and controls was in agreement with data on the Brazilian population. Dyslipidemia was observed in the HIV group and verified by increased levels of triglycerides, VLDL and apoE, and decreased levels of HDL and apoAl. The greatest abnormalities in these biochemical variables were shown in the HIV-infected individuals whose immune function was more compromised. The effect of the genetic variation at the APOE gene on biochemical variables was more pronounced in the HIV-infected individuals who carried the apoE2/3 genotype. The highly active anti-retroviral therapy (HAART)-receiving group presented increased levels of total cholesterol and apoE. Dyslipidemia was a predictable consequence of HIV infection and the protease inhibitors intensified the increase in apoE values.     

Dyslipidemia in type 2 diabetes

Type 2 diabetes mellitus is associated with a cluster of lipid abnormalities:elevated plasma triglycerides, reduced high-density lipoprotein cholesterol, and smaller and denser low-density lipoproteins,which have been associated with an increased risk of cardiovascular disease. Insulin resistance may contribute to dyslipidemia associated with type 2 diabetes by increasing hepatic secretion of large,triglyceride-rich very low-density lipoprotein particles and by impairing the clearance of lipoprotein particles from plasma. Lifestyle interventions may be effective in improving the diabetic dyslipidemia syndrome. For patients who do not respond to lifestyle changes, pharmacologic therapies (lipid-lowering medications and anti-diabetic agents) are available. Clinical trials demonstrate that the use of such pharmaceutics to treat diabetic dyslipidemia concomitantly reduces the risk of coronary artery disease.     

Resolving hyperlipidemia after liver transplantation in a patient with primary sclerosing cholangitis

A 64-year-old man with primary sclerosing cholangitis (PSC) and resultant liver failure presented to our hospital with severe dyslipidemia (total cholesterol, 525 mg/dL; low-density lipoprotein (LDL) cholesterol, 489 mg/dL; high-density lipoprotein (HDL) cholesterol, 13 mg/dL; triglycerides, 114 mg/d) and coronary artery disease. The abnormal lipid profile of patients with cholestatic liver disease, such as PSC, includes an abnormal atherogenic LDL called lipoproteinX. The patient's dyslipidemia persisted despite treatment with a statin. Lipids normalized only after liver transplantation (total cholesterol, 135 mg/dL; LDL cholesterol, 60 mg/dL; high-density lipoprotein cholesterol, 48 mg/dL; triglycerides, 130 mg/dL). To the best of our knowledge, the dramatic improvement in the lipid profile after liver transplantation represents the first such published report for PSC. The recognition of dyslipidemia and atherosclerosis in those with cholestatic liver disease and the normalization of lipid profile after liver transplantation warrant further study. We present a review of dyslipidemia in cholestatic liver disease, its relationship to atherosclerosis, and its treatment.     

PCSK9基因I474V多态性与冠心病相关性的研究

目的探讨人蛋白原转化酶枯草杆菌蛋白酶9(PCSK9)基因I474V位点在冠心病(CAD)患者和健康人群中的分布特点以及与血脂水平、CAD发生、病变程度的相关性,为阐明CAD的遗传发病机理、患者危险性分级评估等提供实验依据。方法采集经冠状动脉造影确诊的CAD患者血液标本288例,健康对照者血液标本300例,提取基因组DNA模板,应用双向等位基因特异性引物聚合酶链反应(Bi-PASA PCR)技术检测PCSK9基因I474V多态性位点,并用基因测序法验证结果。血清总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)水平用酶法测定。结果 PCSK9基因I474V多态性位点主要以II和IV基因型存在。CAD组和对照组在I474V位点的等位基因频率、基因型频率分布差异无统计学意义(P>0.05)。CAD组和对照组之间TC、LDL-C、HDL-C水平差异具有统计学意义(P<0.05),TG水平差异无统计学意义(P>0.05)。CAD组中II和IV基因型之间TC、TG水平的差异具有统计学意义(P<0.01),HDL-C、LDL-C水平差异无统计学意义(P>0.05)。与非I474V携带者比较,I474V携带者血TC、TG水平增高。IV基因型的冠状动脉病变支数明显高于II基因型(P<0.05)。结论 PCSK9基因I474V多态性位点主要以II和IV基因型存在,CAD患者PCSK9基因I474V位点的基因型与TC、TG水平升高相关联,同时与CAD病变严重程度存在一定关联。     

Apolipoproteins and coronary artery disease

In this study, we compared the relative utility of plasma levels of cholesterol, triglycerides, high-density lipoprotein (HDL) cholesterol, and apolipoproteins in identifying men with angiographically significant coronary artery disease in a combined sample of consecutive male patients undergoing coronary angiography (N = 304) and healthy, normal male control subjects (N = 135). The plasma apolipoprotein levels were measured by using specific radioimmunoassays. We found that plasma levels of apolipoprotein A-I, followed by those of apolipoproteins A-II and B, were better discriminators than plasma cholesterol, triglycerides, or HDL cholesterol levels for identifying those with coronary artery disease. In confirmation of previous findings, the presence of coronary artery disease resulted in lower levels of apolipoproteins A-I and A-II and HDL cholesterol and higher levels of apolipoprotein B, cholesterol, and triglycerides. Linear and quadratic discriminant function analysis demonstrated that by using the age of the patients and apolipoprotein A-I, A-II, and B levels, one could correctly classify patients either as being normal or as having angiographically significant coronary artery disease in more than 75% of the cases. Thus, plasma apolipoprotein levels (especially A-I and A-II) may be considerably better markers for coronary artery disease than traditional lipid determinations.     

原发性高血压伴高尿酸血症与冠心病发生的相关性研究

目的:探讨在原发性高血压病患者中,高尿酸血症与冠心病的关系。方法:观察121例原发性高血压病及原发性高血压病伴冠心病患者血尿酸浓度及总胆固醇、低密度脂蛋白胆固醇、高密度脂蛋白胆固醇等冠心病危险因素,用冠状动脉造影方法确诊冠心病。结果:高血压伴冠心病组患者血尿酸浓度及高尿酸血症发生率高于单纯高血压组;血尿酸浓度越高,冠状动脉病变支数越多。结论:高尿酸血症是冠心病的一个危险因素,有必要监测及及时干预高血压患者的血尿酸浓度。     

The effect of the APOE polymorphism on HDL-C concentrations depends on the cholesterol ester transfer protein gene variation in a Southern European population

BACKGROUND: Apolipoprotein E (ApoE) locus has consistently shown a significant association with low-density lipoprotein cholesterol (LDL-C). However, its impact on high-density lipoprotein cholesterol (HDL-C) has been highly controversial suggesting that it may be context-dependent. We examined the gene-gene interaction between the common ApoE and the CETP polymorphisms in determining HDL-C concentrations in men and women from the general population. METHODS: 550 unrelated Caucasian subjects were randomly selected from a Mediterranean Region in Spain. Plasma lipids, anthropometric, clinical and lifestyle variables were measured. Common ApoE and CETP-TaqIB polymorphisms were determined. RESULTS: We have found a gene-gene interaction between and ApoE and the CETP loci in determining HDL-C concentrations. Thus, after adjustment for gender, age, body mass index, tobacco smoking, alcohol consumption, physical exercise and medication, carriers of the E4 allele had lower HDL-C concentrations [mean and (standard error): 40.1 (2.6) mg/dL] than E2 subjects [47.7 (3.2) mg/dL; p=0.019], and even lower than those of the E3 subjects [44.7 (1.4) mg/dL; p=0.042], only if they had the B1B1 genotype. However, mean HDL-C concentrations were higher among those with E4 allele carrying the B2 allele at the CETP gene locus [50.5 (2.3) mg/dL], and lower among E2 subjects carrying the B2 allele [45.5 (2.6) mg/dL]. This interaction was observed in both men and women. This gene-gene interaction remained statistically significant even after additional adjustment for triglycerides. CONCLUSIONS: The effect of the ApoE polymorphism on HDL-C concentrations depends on the CETP polymorphism, explaining some of the controversial results previously reported for this polymorphism.     

Influence of apolipoprotein E polymorphism on plasma vitamin A and vitamin E levels

BACKGROUND: Plasma concentrations of vitamins A and E are positively correlated with those of concurrent lipids and, on the other hand, lipid levels are influenced by apolipoprotein E polymorphism. Therefore, the effect of this polymorphism on both vitamins was analysed in an adult population. MATERIALS AND METHODS: Subjects were recruited from a working population. Their anthropometric, lifestyle and dietary intake variables and menopausal status were recorded. Their apolipoprotein E phenotype and their plasma vitamins A and E (by high-performance liquid chromatography) and lipid (enzymatically) concentrations were determined after an overnight fast. The associations of the phenotype with vitamins and lipids were studied in men and women separately and controlling for significant covariates. RESULTS: The apolipoprotein E phenotype was associated with the concentrations of total, low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol in women, whereas no associations with lipids were found in men. Vitamin A and vitamin E levels were higher in men than in women, but only the difference in the former persisted after lipid adjustment. Apolipoprotein E2 slightly increased vitamin A levels in women, an effect which was still evident with lipid adjustment. Actually, both the apolipoprotein E phenotype and triglyceride were selected as significant predictors of this vitamin by multiple regression. This phenotype did not affect vitamin E levels in either sex. CONCLUSIONS: Lipids do not mediate the effect of gender on vitamin A levels. Apolipoprotein E polymorphism is an independent determinant of vitamin A levels in women. Pending confirmation by others, we propose that enhancement of this vitamin may contribute to the beneficial impact of the epsilon2 allele on human ageing and health.     

Serum lipoprotein profile in patients with cancer. A comparison with non-cancer subjects

The association of cancer with low serum total cholesterol is well established. Less clear is the relationship of cancer with the cholesterol distribution among the different lipoprotein classes. Conflicting results have been reported on low-density lipoprotein cholesterol, high-density lipoprotein cholesterol and serum triglyceride levels in different types of tumor. Total serum cholesterol, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol, and serum triglycerides were analyzed in 530 patients with newly diagnosed cancer (97 with hematological malignancies, 92 with tumor of the lung, 108 of the upper digestive system, 103 of colon, 32 of breast, and 98 of the genitourinary system) and in 415 non-cancer subjects. Anthropometric (body mass index) and biochemical (serum albumin) indices of nutritional status were also determined in all subjects. Total cholesterol, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol, serum albumin, and body mass index were significantly lower in cancer than in non cancer-subjects. The lowest values of total cholesterol, low-density lipoprotein-cholesterol and high-density lipoprotein-cholesterol were recorded in patients with hematological malignancies and the highest in patients with breast tumor. All the cancer groups, with the exception of women with breast cancer, showed significantly lower total cholesterol, low-density lipoprotein-cholesterol and high-density lipoprotein-cholesterol than age- and sex-matched non-cancer subjects. Multiple regression analysis with low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol, and triglycerides as dependent variables and sex, age, body mass index, albumin, and cancer (dummy variable) as independent variables, showed that cancer was independently associated with low levels of low-density lipoprotein-cholesterol and high-density lipoprotein-cholesterol and with high values of serum triglycerides. Total cholesterol, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol, serum triglycerides, body mass index and serum albumin were significantly lower in patients with metastatic than in patients with non-metastatic solid tumor. The significant difference in low-density lipoprotein-cholesterol and serum triglycerides between patients with metastatic and non-metastatic cancer was lost when lipoprotein cholesterol and serum triglyceride levels were adjusted for nutritional variables. The lipid profile in cancer patients is characterized by low low-density lipoprotein-cholesterol, low high-density lipoprotein-cholesterol and relatively high serum triglycerides. The abnormality is a common feature of both hematological and solid tumors and is not entirely explained by poor nutrition.     

Apolipoprotein E genotype and plasma levels in coronary artery disease. A case-control study in the Italian population.

OBJECTIVES: To investigate the role of the apolipoprotein B and apolipoprotein E polymorphisms in coronary artery disease (CAD) susceptibility in the Italian population and their relation to plasma lipid and apolipoprotein levels. METHODS: APOB (APOB Xbal, EcoRI, Ins/Del), and APOE (APOE Cfol) polymorphisms were analyzed in 150 male CAD patients and 110 matched controls. In the same subjects plasma lipid, apoB, and apoE levels were measured. RESULTS: No differences in the distribution of the APOB polymorphisms were observed between patients and controls. Among patients the number of e*4-carriers was significantly higher than in controls. e*4-carriers were more frequent among the hypertensive patients and had a higher systolic blood pressure (p = 0.007) than the non-e*4 carriers. The APOB Xbal polymorphism was found to influence the distribution of HDL-cholesterol. Patients showed significantly lower levels of apoE (39.29 mg/L) than controls (54.32 mg/dL) and the lowest concentrations were associated to the E4/E3 and E4/E4 genotypes. CONCLUSION: Quantitative data are consistent with the hypothesis that apoE has an anti-atherosclerotic role and suggest that the apoE quantitation could be a useful parameter for defining cardiovascular risk. e*4 allele appears to be a risk factor for CAD in the Italian population and could act by its association with low apoE levels.     

Hyperlipidemia. What to do when life-style changes aren't enough

Most lipid abnormalities seen in a primary care practice can be grouped into three categories: hypercholesterolemia, combined hyperlipidemia, and hypertriglyceridemia. Three to 6 months of dietary and life-style alterations should be tried before drug treatment is initiated. Drugs for each category should be chosen on the basis of clinical efficacy, established long-term safety, and effects on low-density and high-density lipoprotein cholesterol and triglyceride levels. To maximize compliance, physicians should advise patients on dosing schedules, side effects, and required monitoring. Combination drug therapy is often necessary to reach treatment goals, especially in patients with genetic hyperlipidemia and/or symptomatic coronary artery disease.     

Risk factors for coronary artery disease: a study comparing hypercholesterolaemia and hypertriglyceridaemia in angiographically characterized patients

Fifty-two male patients undergoing coronary angiography were allocated to four groups each consisting of 13 subjects: group I had normal coronary arteries and patients in groups II-IV exhibited coronary artery disease. In group II, plasma cholesterol was below 250 mg dl-1 and triglycerides below 160 mg dl-1; in group III, cholesterol was above 270 mg dl-1 and triglycerides under 160 mg dl-1; and in group IV, cholesterol was under 270 mg dl-1 and triglycerides above 180 mg dl-1. The hypertriglyceridaemic group IV had the highest coronary score. In addition, it had lowest lipoprotein lipase activity, lowest HDL-cholesterol and lowest high-density lipoproteins-2 (HDL-2) levels, suggesting that this type of hypertriglyceridaemia is caused--at least in part--by lipoprotein lipase deficiency with impaired removal of the triglyceride-rich lipoproteins and increased catabolism of HDL-2. Our findings point towards a type of hypertriglyceridaemia strongly associated with coronary artery disease which should therefore be treated accordingly.     

Niacin as a component of combination therapy for dyslipidemia

Dyslipidemia is one of the most important modifiable risk factors for coronary disease. Despite the availability of highly effective lipid-modifying agents, many patients still do not reach lipid targets established by national guidelines. Niacin has been known to be an effective treatment of dyslipidemia for almost half a century. Niacin substantially increases high-density lipoprotein cholesterol (HDL-C) levels while lowering levels of low-density lipoprotein cholesterol (LDL-C), triglycerides, and lipoprotein(a). In addition, niacin converts small LDL particles into more buoyant, less atherogenic LDL particles. Combined with other agents, niacin offers an important treatment option for patients with dyslipidemia. In particular, niacin complements LDL-C-lowering drugs; it is the most effective agent available for increasing HDL-C levels while lowering levels of LDL-C and triglycerides and improving other lipid risk factors such as lipoprotein(a). Combining niacin with statins or bile acid sequestrant therapy is safe and effective for improving lipid levels and decreasing coronary risk. Differences in niacin formulations dictate tolerability profiles and should be considered when selecting niacin as part of lipid therapy. Furthermore, adverse effects on glucose and insulin sensitivity should be considered when selecting candidates for niacin therapy. Adding niacin to lipid-lowering regimens is a valuable option for physicians treating patients with dyslipidemia and should be considered in appropriate patients.