Exploiting the vascular protective effects of high-density lipoprotein and its apolipoproteins: an idea whose time for testing is coming, part I

Regulation of adipocyte autophagy--the potential anti-obesity mechanism of high density lipoprotein and ApolipoproteinA-I

Obesity is reaching epidemic worldwide and is risk factor for cardiovascular disease and type 2 diabetes. Although plasma high density lipoprotein (HDL) and apolipoprotein A-I (apoA-I) are inversely correlated to obesity, whether HDLs have anti-obesity effect remains unclear until a recent study reporting the direct anti-obesity effect of apoA-I and its mimetic peptide. However, the mechanism is not fully understood. Increasing adipose energy expenditure through attainment of brown adipocyte phenotype in white adipose tissue is considered a potential strategy to combat obesity. Specific inhibition of autophagy in adipose tissue is associated with reduced adiposity which is attributed to the attainment of brown adipocyte phenotype in white adipose tissue and the increased energy expenditure. HDL and apoA-I could activate PI3K-Akt-mTORC1 signaling which negatively regulates autophagy. The links between HDL/apoA-I and autophagy brings a new understanding on the anti-obesity effect of HDL and apoA-I.

Consistency of extended-release niacin/laropiprant effects on Lp(a), ApoB, non-HDL-C, Apo A1, and ApoB/ApoA1 ratio across patient subgroups

BACKGROUND

According to prior analyses, extended-release niacin/laropiprant (ERN/LRPT) consistently reduces low-density lipoprotein cholesterol (LDL-C) and triglycerides (TG) and increases high-density lipoprotein cholesterol (HDL-C) levels across a wide range of dyslipidemic patient subgroups.

OBJECTIVES

This analysis examined ERN/LRPT's consistency across four phase III, randomized, double-blind trials in improving other lipid/lipoprotein parameters associated with cardiovascular risk, across several key dyslipidemic patient subgroups.

METHODS

In three of the studies, the randomized population included patients with primary hypercholesterolemia or mixed hyperlipidemia; in the remaining study, the population included patients with type 2 diabetes mellitus. The lipid-altering consistency of ERN/LRPT's efficacy was evaluated versus the pre-defined comparator (placebo or active control) among key subgroups of sex, race (White, non-White), region (US, ex-US), baseline age (<65 years, ≥65 years), use of statin therapy (yes, no), coronary heart disease (yes, no), risk status (low, multiple, high), and type of hyperlipidemia (primary hypercholesterolemia, mixed dyslipidemia), as well as across baseline LDL-C, HDL-C, and TG levels. The consistency of the treatment effects on lipoprotein(a).[Lp(a)], apolipoprotein B (ApoB), non-HDL-C, ApoA1, and ApoB/ApoA1 ratio was evaluated by examining treatment difference estimates of the percentage change from baseline with 95% confidence intervals.

RESULTS

Treatment with ERN/LRPT produced significantly greater improvements in Lp(a), ApoB, non-HDL-C, ApoA1, and ApoB/ApoA1 ratio compared with placebo/active comparator in each study. These effects were generally consistent across key subgroups within each study.

CONCLUSION

ERN/LRPT produced lipid-altering efficacy on the parameters evaluated in four controlled studies; these effects were generally consistent across all examined subgroups. ERN/LRPT represents an effective and reliable therapeutic option for the treatment of dyslipidemia in a wide range of patient types.

CLINICAL TRIAL REGISTRATION

Registered as Clinicaltrials.gov NCT00269204, NCT00269217, NCT00479388, and NCT00485758.

Persistent dyslipidemia in statin-treated patients: Russian real-world clinical practice data (Russian part of the DYSIS Study)

The high prevalence of persistent dyslipidemia in primary and specialized care patients treated with statins justifies the need to identify its reasons and develop the recommendations on the treatment optimization. At present, Russian studies focusing on the achievement of target lipid levels remain scarce, which emphasizes the importance of the problem and its further investigation.Aim.Cross-sectional epidemiological study which assessed the prevalence of persistent dyslipidemia in statin-treated patients and analysed the predictors of the achievement of target lipid levels.Material and methods.The lipid profile parameters were analysed in 1586 statin-treated out-patients with varied levels of cardiovascular risk, taking into account the type of lipid-lowering therapy and its doses. The assessment of the cardiovascular event (CVE) risk and the definition of target levels of low-density lipoprotein cholesterol (LDL–CH), as well as normal levels of triglycerides (TG) and high-density lipoprotein cholesterol (HDL–CH), was based on the clinical recommendations by the European Society of Cardiology (ESC 2007) and by the European Society of Cardiology and the European Atherosclerosis Society (ESC/EAS 2011).Results.The analysis based on the ESC 2007 recommendations has demonstrated that the target levels of LDL–CH (<2,5 mmol/l for high-risk patients) were not achieved in 53,5% of the participants. The elevation of LDL–CH levels could be isolated or combined with the HDL–CH decrease and/or the TG increase. Low levels of HDL–CH were observed in 32,3% of the patients, while high TG levels were registered in 55,6% of the participants. The achievement of target LDL–CH levels was predicted by the higher-dose statin therapy (odds ratio 0,44). The analysis based on the ESC/EAS 2011 recommendations has shown that the prevalence of target LDL–CH levels was 12,2% in very high-risk patients (<1,8 mmol/l), 30,3% in high-risk patients (<2,5 mmol/l), and 53,4% in moderate-risk patients (<3,0 mol/l).Conclusion.Over a half of the statin-treated patients failed to achieve target levels of LDL–CH. The lowest prevalence of target LDL–CH levels was observed in very high-risk and high-risk patients. The predictors of target LDL–CH level achievement included moderate cardiovascular risk and higher-dose statin therapy. The obtained results suggest that the correction of persistent dyslipidemia in statin-treated patients could be achieved via increasing the satin dose and combining lipid-lowering medications.

Preparation and activity analysis of recombinant human high-density lipoprotein

Population studies have consistently shown a highly inverse correlation between plasma concentration of high-density lipoprotein and the risk of atherosclerotic cardiovascular disease in humans. High-density lipoprotein (HDL) as a therapeutic target is an intense area of ongoing investigation. Aiming to solve the shortcomings of native HDL application, we prepared recombinant human HDL (rhHDL) that contains a similar composition and has similar functions with native HDL. Six kinds of recombinant human apolipoproteins (rhapo)-rhapoA-I, rhapoA-II, rhapoA-IV, rhapoC-I, rhapoC-II, and rhapoE-were expressed in Pichia pastoris and purified with chromatography. By the facilitation of cholate, six kinds of rhapo penetrated among the phosphatidylcholine acyl chains. After purification by density-gradient centrifugation, rhHDL was acquired. Based on morphological observation, we confirmed that the micellar complexes of rhapo with phosphatidylcholine and cholesterol were prepared. We carried on comparative studies in vitro and in vivo between native HDL and rhHDL. Cellular cholesterol efflux assays showed that rhHDL could promote the efflux of excess cholesterol from macrophages. Furthermore, rhHDL has similar effects with native HDL on the blood lipid metabolism in hyperlipidemic mice. In conclusion, rhHDL has similar effects on antiatherosclerosis with native HDL through reverse cholesterol transport, antioxidative, and antithrombotic properties. It could be used as a therapeutic HDL-replacement agent.

Progress in HDL-based therapies for atherosclerosis

Atherosclerosis is a chronic inflammatory disease affecting medium and large arteries resulting from a complex interaction between genetic and environmental risk factors that include dyslipidemia, hypertension, diabetes mellitus, and smoking. The most serious manifestations of atherosclerotic vascular disease, such as unstable angina, myocardial infarction, ischemic stroke, and sudden death, largely result from thrombosis superimposed on a disrupted (ruptured or eroded) atherosclerotic plaque. Adoption and maintenance of a healthy lifestyle coupled with management of modifiable risk factors significantly reduce the adverse clinical consequences of athero-thrombosis. Reducing low-density lipoprotein cholesterol levels using statins and other agents serves as the primary pharmacologic approach to stabilize atherosclerotic vascular disease. However, a large residual risk remains, prompting the search for additional therapies for atherosclerosis management, such as raising atheroprotective high-density lipoprotein (HDL) and/or improving HDL function. This review focuses on new and emerging HDL-based therapeutic strategies targeting atherosclerosis.

High-density lipoprotein of patients with type 2 diabetes mellitus elevates the capability of promoting migration and invasion of breast cancer cells

Epidemiological studies suggested complicated associations between type 2 diabetes mellitus and breast cancer. There is a significant inverse association between high-density lipoprotein (HDL) and the risk and mortality of breast cancer. However, HDL could be modified in various ways in diabetes patients, and this may lead to the altered effects on many different types of cells. In our study, we found that glycation and oxidation levels are significantly higher in HDL from type 2 diabetes mellitus patients compared to that from healthy subjects. Diabetic HDL dramatically had a stronger capability to promote cell proliferation, migration and invasion of breast cancer (as examined both on hormone-independent cells and on hormone-dependent cells). In addition, glycated and oxidized HDL, which were produced in vitro, acted in similar way as diabetic HDL. Diabetic HDL, glycated HDL and oxidized HDL also induced higher synthesis and secretion of VEGF-C, MMP-2 and MMP-9 from malondialdehyde (MDA)-MB-231 cells. It was indicated that diabetic, glycated and oxidized HDL promote MDA-MB-231 cell migration and invasion through ERK and p38 MAPK pathways, and Akt pathway plays an important role as well in MDA-MB-231 cell invasion. The Akt, ERK and p38 MAPK pathways are also involved in VEGF-C and MMP-9 secretion induced by diabetic, glycated and oxidized HDL. Our study demonstrated that glycation and oxidation of HDL in diabetic patients could lead to abnormal actions on MDA-MB-231 cell proliferation, migration and invasion, thereby promoting the progression of breast cancer. This will largely draw the attention of HDL-based treatments in diabetic patients especially those with breast cancer.

Disturbed one-carbon metabolism causing adverse reproductive outcomes in mice is associated with altered expression of apolipoprotein AI and inflammatory mediators PPARα, interferon-γ, and interleukin-10

Low dietary choline or deficiency of methylenetetrahydrofolate reductase (Mthfr) leads to hyperhomocysteinemia (Hhcy) and adverse reproductive outcomes. Homocysteine reduces synthesis of ApoAI, the major lipoprotein in HDL-cholesterol; ApoAI is regulated by PPARα and has antiinflammatory properties. Our aim was to determine whether pregnancy complications due to genetic or nutritional deficiencies in 1-carbon metabolism could relate to dysregulation of ApoAI and inflammatory mediators. We fed pregnant mice, with or without a deficiency of Mthfr, control or choline-deficient (ChDD) diets for 10-12 wk and examined levels of ApoAI, PPARα, IFNγ, and IL-10. ApoAI mRNA was reduced in livers of Mthfr(+/-) mice and ApoAI protein was reduced due to Mthfr deficiency or choline deficiency in liver and plasma. Placental ApoAI protein was also reduced due to Mthfr genotype or choline-deficient diet and in developmentally delayed embryos. Reduced liver PPARα expression (mRNA and protein) was observed in ChDD-fed mice and was associated with increased methylation of a CpG dinucleotide in its promoter. Hepatic IFNγ increased due to genotype, and placental IFNγ was higher in Mthfr(+/-) ChDD-fed dams compared to Mthfr(+/+) mice fed ChDD or Mthfr(+/-) mice fed CD. IL-10 was reduced in livers of ChDD-fed mice. We propose that a deficiency of dietary choline or Mthfr leads to Hhcy and reduced expression of maternal ApoAI, with reduced ApoAI transfer to embryo. Disturbances in 1-carbon metabolism also reduce maternal PPARα expression, possibly through promoter hypermethylation, and increase IFNγ and decrease IL-10 levels. This disturbance of the T helper (Th1) (IFNγ):Th2 (IL-10) ratio and the increase in inflammatory mediators may contribute to pregnancy complications.

Changes in the Serum Level of High Density Lipoprotein-cholesterol after Smoking Cessation among Adult Men

Background

Smoking and obesity are known risk factors for cardiovascular diseases, while low serum levels of high density lipoprotein-cholesterol is an independent risk factor for mortality from ischemic heart diseases. This study examines changes in the serum level of high density lipoprotein-cholesterol depending on changes in the state of smoking and body mass index.

Methods

A survey and blood check-up were conducted on medical examination, along with acts of smoking among male adults of 25 years or older who visited the health promotion center of Daegu Medical Center from 2007 to 2010, and the results were analyzed. The subjects were divided into two different groups, current smokers and abstainers, and body mass index, total cholesterol, high density lipoprotein-cholesterol, low density lipoprotein-cholesterol, and triglycerides for three years were compared in both groups. Changes between the first and second visits in body mass index and lipid profiles of the two groups were compared to analyze changes after abstaining.

Results

The subject group which showed a significant increase in high density lipoprotein-cholesterol level was only abstainers whose body mass index had decreased by more than 0.5 kg/m².

Conclusion

Smoking cessation increases serum levels of high density lipoprotein-cholesterol. If reduction of body mass index and smoking cessation are combined, the risk of cardiovascular disease will be lower in proportion to the increase in serum high density lipoprotein.

HDL Mimetic Peptide Administration Improves Left Ventricular Filling and Cardiac output in Lipopolysaccharide-Treated Rats

AIMS: Cardiac dysfunction is a complication of sepsis and contributes to morbidity and mortality. Since raising plasma apolipoprotein (apo) A-I and high density lipoprotein (HDL) concentration reduces sepsis complications, we tested the hypothesis that the apoA-I mimetic peptide 4F confers similar protective effects in rats treated with lipopolysaccharide (LPS). METHODS AND RESULTS: Male Sprague-Dawley (SD) rats were randomized to receive saline vehicle (n=13), LPS (10 mg/kg: n=16) or LPS plus 4F (10 mg/kg each: n=13) by intraperitoneal injection. Plasma cytokine and chemokine levels were significantly elevated 24 hrs after LPS administration. Echocardiographic studies revealed changes in cardiac dimensions that resulted in a reduction in left ventricular end-diastolic volume (LVEDV), stroke volume (SV) and cardiac output (CO) 24 hrs after LPS administration. 4F treatment reduced plasma levels of inflammatory mediators and increased LV filling, resulting in improved cardiac performance. Chromatographic separation of lipoproteins from plasma of vehicle, LPS and LPS+4F rats revealed similar profiles. Further analyses showed that LPS treatment reduced the agarose electrophoretic mobility of isolated HDL fractions. HDL-associated proteins were characterized by SDSPAGE and mass spectrometry. ApoA-I and apoA-IV were reduced while apoE content was increased in LPStreated rats. 4F treatment in vivo attenuated changes in HDL-associated apolipoproteins and increased the electrophoretic mobility of the particle. CONCLUSIONS: The ability of 4F to reduce inflammation and improve cardiac performance in LPS-treated rats may be due to its capacity to neutralize endotoxin and prevent adverse changes in HDL composition and function.

New insights into the mechanism of low high-density lipoprotein cholesterol in obesity

Obesity, a significant risk factor for various chronic diseases, is universally related to dyslipidemia mainly represented by decreasing high-density lipoprotein cholesterol (HDL-C), which plays an indispensible role in development of cardiovascular disease (CVD). However, the mechanisms underlying obesity and low HDL-C have not been fully elucidated. Previous studies have focused on the alteration of HDL catabolism in circulation following elevated triglyceride (TG). But recent findings suggested that liver and fat tissue played pivotal role in obesity related low HDL-C. Some new molecular pathways like microRNA have also been proposed in the regulation of HDL metabolism in obesity. This article will review recent advances in understanding of the potential mechanism of low HDL-C in obesity.

Persistent dyslipidemia in Austrian patients treated with statins for primary and secondary prevention of atherosclerotic events - Results of the DYSlipidemia International Study (DYSIS)

BACKGROUND

Statins reduce cardiovascular events by about one third; thus two out of three events occurring without any lipid lowering treatment still might happen under statin treatment. One reason may be that lipid targets are not met. The DYSlipidemia International Study (DYSIS) was performed to determine the prevalence of persistent dyslipidemia despite statin treatment in Austria.

PATIENTS AND METHODS

Between April 2008 and February 2009, 910 outpatients on current statin treatment and aged ≥ 45 years were recruited by general practitioners, cardiologists, endocrinologists, and internists. A clinical examination was performed and lipid values were obtained under stable statin therapy. The ESC guidelines version 2007 served as criteria to judge the attainment of treatment targets for LDL cholesterol and to reach normal HDL cholesterol and triglyceride levels. In 765 patients a full lipid profile including fasting cholesterol, fasting triglycerides, HDL-cholesterol, and LDL-cholesterol could be obtained.

RESULTS

Of our patients, 74.5% had at least one lipid parameter not at target. Specifically, 52.3% did not reach the LDL-cholesterol target as according to the ESC guidelines 2007 - and 56.4% as according to the Austrian lipid consensus 2010 -, 59.1% had above-target total cholesterol levels and 42.5% had elevated triglyceride levels. In 23% of the patients the HDL cholesterol was below levels associated with increased cardiovascular risk. In patients with only one single value beyond normal or targeted level, LDL cholesterol had a prevalence of 24.3%, HDL of 11.9% and triglycerides of 24.5%. In 8.4% of patients, all 3 parameters, LDL-cholesterol, HDL-cholesterol and triglycerides, were out of range.

CONCLUSIONS

About three quarters of the Austrian patients under chronic statin therapy in routine clinical practice failed to meet lipid values as set by international and Austrian guidelines. There is an urgent need for more effective strategies to better control dyslipidemia in statin treated patients with the aim of further reducing cardiovascular events.

Lipid and low-density-lipoprotein apheresis. Effects on plasma inflammatory profile and on cytokine pattern in patients with severe dyslipidemia

Available evidence on the effects of therapeutic plasmapheresis (TP) techniques and in particular lipid- and LDL-apheresis (LDL-a) on plasmatic inflammatory mediators including cytokines were reviewed. Studies on this issue are not numerous. However, the review of existing evidence clearly suggests an active role of apheresis on the profile of inflammatory molecules and on cytokine pattern in plasma. These non-lipid-lowering effects can be defined to some extent pleiotropic or pleiotropic-equivalent. Although further studies are desirable, the data reported in this review confirm that lipid- and LDL-a not only show acute lipid-lowering and cholesterol-lowering effects, but also efficacy in reducing several proinflammatory peptides, including cytokines. This effect was not related apparently to lipids and lipoproteins reduction. Thus, TP (lipid- and LDL-a), commonly utilized in the treatment of severe genetically determined lipid disorders, unresponsive to hypolipidemic drugs, offers new possibilities of interpretation of its role in the mechanisms leading to the blockade of atherosclerotic lesion development and progression. The ability of TP on short-term to induce such a profound change in the plasmatic metabolic and inflammatory profiles must be kept in mind in the treatment of acute coronary syndromes, before and after interventions of coronary revascularization, and in the acute phase of cerebrovascular ischemia, at least in patients with severe dyslipidemia. Further studies are needed, in particular aimed at assessing if circulating cytokines may be downregulated by TP not only by direct removal, but through indirect effects on both gene translation and transcription perhaps via the cytokine receptor function.

The antiatherogenic, renal protective and immunomodulatory effects of purslane, pumpkin and flax seeds on hypercholesterolemic rats

BACKGROUND

Atherosclerosis remains one of the leading causes of death all over the world. Flax, pumpkin and purslane seeds are rich sources of unsaturated fatty acids, antioxidants and fibers, known to have antiatherogenic activities.

AIMS

This study was to examine the efficiency of using either flax/pumpkin or purslane/pumpkin seed mixture (components of ω-3 and ω-6) on hyperlipidemia, kidney function and as immunomodulators in rats fed high cholesterol diets.

MATERIALS AND METHODS

40 male albino rats were divided into four groups: control group, hypercholesterolemic rats, fed the balanced diet supplemented with cholesterol at a dose level of 2 g/100 g diet; the other two groups of animals fed the same previous hypercholesterolemic diet supplemented with either flax/pumpkin seed mixture or pumpkin/purslane seed mixture at ratio of (5/1) (ω-3 and ω-6).

RESULTS

The present study showed that 2% cholesterol administration caused a significant increase in total cholesterol, total lipids, and triacylglycerol in both serum and liver. Serum phospholipids, LDL-C, and atherogenic index AI also significantly increased compared to control group. Cholesterol-enriched diet significantly increased serum urea, creatinine, sodium and potassium levels as well as significantly increased serum IgG and IgM compared to healthy control. Consumption of flax/pumpkin or purslane/pumpkin seed mixtures by hypercholesterolemic rats resulted in a significantly decrement in lipid parameters and significant improvement in IgG and IgM levels as compared with hypercholesterolemic rats.

CONCLUSION

Our results suggests that both flax/pumpkin and purslane/pumpkin seed mixtures had anti-atherogenic hypolipidemic and immunmodulator effects which were probably mediated by unsaturated fatty acids (including alpha linolenic acid) present in seed mixture.

Antidiabetic effect of flax and pumpkin seed mixture powder: effect on hyperlipidemia and antioxidant status in alloxan diabetic rats

Reactive oxygen species play a crucial role in the pathogenesis of diabetes and its complications. This study aims to examine the effects of flax and pumpkin powder seed mixture on alloxan induced diabetes in Wistar rats. Animals were allocated into three groups of six rats each: a control group (CD), diabetic group (DD) and diabetic rats fed with flax and pumpkin seed mixture (DMS) group. The diabetic rats (DD) presented a significant increase in glycemia, plasma and liver lipid parameters such as total lipid, total cholesterol and triglycerides compared to the control group (CD). In addition, plasma and liver malonaldialdehyde levels (MDA, an index of lipid peroxidation) significantly increased compared to (CD). Antioxidant enzymes activities such as catalase, superoxide dismutase, and reduced glutathione (GSH) levels significantly decreased in the plasma and liver of diabetic rats compared to controls. Diet supplemented with flax and pumpkin seed mixture in the DMS group ameliorated antioxidant enzymes activities and level of GSH in diabetic rats and significantly decreased MDA levels. The present study revealed a significant increase in the activities of aspartate aminotransferase and alanine aminotransferase on diabetic status, indicating considerable hepatocellular injury. The administration of flax and pumpkin seed mixture attenuated the increased levels of the plasma enzymes produced by the induction of diabetes and caused a subsequent recovery towards normalization comparable to the control group animals. Our results thus suggest that flax and pumpkin seed mixture supplemented to diet may be helpful in preventing diabetic complications in adult rats.

Lipid-lowering therapy with statins for the primary and secondary prevention of cardiovascular disease

Cardiovascular disease (CVD) still ranks as the top cause of mortality worldwide. Lipid-modifying therapy has revolutionized the treatment of the disease and is partly responsible for the recent decline in deaths due to CVD. Treatment strategies have evolved since the introduction of the earlier lipid-lowering agents (fibrates, niacin, bile acid resins) to the advent of statins, which have become the standard drugs in cholesterol therapy. The strategy of using high-intensity statin therapy as the initial treatment approach in high-risk individuals, rather than focusing on specific cholesterol levels alone, remains a subject of debate.

Extended-release niacin/laropiprant lipid-altering consistency across patient subgroups

BACKGROUND

In patients with primary hypercholesterolemia or mixed dyslipidemia, extended-release niacin/laropiprant (ERN/LRPT) improves key lipid parameters associated with increased atherosclerotic coronary heart disease (CHD) risk.

AIM

This analysis examined data from four Phase III, randomised, double-blind trials to determine the consistency of ERN/LRPT's lipid-altering efficacy among subgroups of patients.

METHODS

Data from four Phase III, randomised, double-blind trials of ERN/LRPT were analysed to determine the consistency of ERN/LRPT's lipid-altering efficacy among subgroups of gender, race (white, non-white), region (US, ex-US), baseline age (<65, ≥65 years), use of statin therapy, CHD risk status (low, multiple, high) and type of hyperlipidemia (primary hypercholesterolemia, mixed dyslipidemia), as well as across baseline low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglyceride (TG) levels. End-points included the per cent change from baseline in LDL-C, HDL-C and TG levels. Consistency of the treatment effects on LDL-C, HDL-C and TG across subgroups was evaluated by examining treatment difference estimates with 95% confidence intervals.

RESULTS

  Treatment with ERN/LRPT significantly improved LDL-C, HDL-C and TG levels compared with placebo/active comparator in each study cohort. These effects were generally consistent across all examined subgroups.

CONCLUSION

Extended-release niacin/laropiprant represents an effective therapeutic option for the treatment of dyslipidemia across a range of patient types.

Development of a model for prediction of coronary atherosclerotic regression: evaluation of high-density lipoprotein cholesterol level and peripheral blood monocyte count

Monocytes and high-density lipoprotein cholesterol (HDL-C) play important roles in the process of coronary atherosclerosis. We hypothesized that a reasonable predictive model of coronary plaque regression might be constructed using the change in the peripheral monocyte count and the serum HDL-C level. The plaque volume, as assessed by volumetric intravascular ultrasound, was measured at the baseline and after 6 months of pravastatin therapy in 114 patients with coronary artery disease. After 6 months of pravastatin therapy, a significant decrease of the plaque volume by 9.9% (p < 0.0001, vs. baseline) was observed; furthermore, a corresponding increase of the serum HDL-C level and decrease of the peripheral blood monocyte count were also seen (12.5%, p < 0.01 and -7.3%, p < 0.0001). In a multivariate regression analysis using the serum lipids and traditional risk factors as the covariates, the increase in the serum HDL-C (β -0.56, p < 0.0001) and the decrease in monocyte count (β 0.23, p = 0.03) were identified as independent predictors of the plaque regression. A model for the prediction of plaque regression according to whether the achieved the change in (Δ) monocyte count and ΔHDL-C were above or below the median values was prepared. Among the four groups, the group with ΔHDL-C ≥8.8% and Δmonocyte count ≤-8.6% showed the largest plaque regression (-20.4%), and the group with ΔHDL-C <8.8% and Δmonocyte count >-8.6% showed the increase of the plaque volume (2.6%). In view of the inflammatory nature of atherosclerosis, the model constructed using the two predictors may be a useful model for the prediction of plaque regression.

Lower levels of high-density lipoprotein cholesterol on admission and a recurrence of ischemic stroke: a 12-month follow-up of the Fukuoka Stroke Registry

BACKGROUND

Despite recent progress in treatments for secondary prevention, ischemic stroke recurs in 8% to 12% of stroke survivors. We investigated the predisposing factors associated with recurrence within the first 12 months after an ischemic event to explore more effective preventive strategies.

METHODS

Between June 2007 and April 2008, acute (within 7 days of onset) ischemic stroke patients were registered in the Fukuoka Stroke Registry (FSR), a multicenter, prospective, observational database. The clinical characteristics on admission were analyzed, and the patients were followed for 12 months.

RESULTS

Two hundred sixty patients (151 males and 109 females, 71 ± 11 years of age) were registered; 25 (9.6%) had recurrence of ischemic stroke during the follow-up period. Kaplan-Meier curve analysis revealed a significant difference in recurrence-free survival between patients with high-density lipoprotein (HDL) cholesterol <40 mg/dL on admission and those with HDL cholesterol ≥ 40 mg/dL (P = .042). Adjusted multivariate logistic regression analysis showed that age (odds ratio 1.06; 95% CI, 1.00-1.11; P = .035) and HDL cholesterol <40 mg/dL (odds ratio 2.73; 95% CI, 1.01-7.38; P = .048) on admission were independently associated with a recurrence of ischemic stroke within 12 months of the initial onset.

CONCLUSIONS

Aging and low HDL cholesterol levels are considered independent risk factors for a recurrence of ischemic stroke.

Expression and recovery of biologically active recombinant Apolipoprotein AI(Milano) from transgenic safflower (Carthamus tinctorius) seeds

Apolipoprotein AI Milano (ApoAI(Milano) ) was expressed as a fusion protein in transgenic safflower seeds. High levels of expression corresponding to 7 g of ApoAI(Milano) per kilogram of seed have been identified in a line selected for commercialization. The ApoAI(Milano) fusion protein was extracted from seed using an oilbody-based process and matured in vitro prior to final purification. This yielded a Des-1,2-ApoAI(Milano) product which was confirmed by biochemical characterization including immunoreactivity against ApoAI antibodies, isoelectric point, N-terminal sequencing and electrospray mass spectrometry. Purified Des-1,2-ApoAI(Milano) readily associated with dimyristoylphosphatidylcholine in clearance assays comparable to Human ApoAI. Its biological activity was assessed by cholesterol efflux assays using Des-1,2-ApoAI(Milano) :1-palmitoyl-2-oleoyl phosphatidylcholine complexes in vitro and in vivo. This study has established that high levels of biologically functional ApoAI(Milano) can be produced using a plant-based expression system.

Hypolipidemic effect of n-butanol Extract from Asparagus officinalis L. in mice fed a high-fat diet

During industrial processing of Asparagus (Asparagus officinalis L.), around half of each spear is discarded. However, these discarded asparagus (by-products) might be used as food supplements for their potential therapeutic effects. This study evaluated the hypolipidemic effect of n-butanol extract (BEA) from asparagus by-products in mice fed a high-fat diet (HFD). Continuous HFD feeding caused hyperlipidemia, oxidative stress and liver damage in mice. Interestingly, while BEA significantly decreased the levels of body weight gain, serum total cholesterol and low density lipoprotein cholesterol, it dramatically increased the high density lipoprotein level when administered at three different doses (40, 80 or 160 mg/kg body weight) for 8 weeks in hyperlipidemic mice. In addition, BEA decreased the levels of alanine transaminase, aspartate transaminase and alkaline phosphatase in serum. Finally, superoxide dismutase activity and the total antioxidation capacity were evidently increased, while the malondialdehyde level and the distribution of lipid droplets were reduced in liver cells of BEA-treated mice. Taken together, the findings of this study suggested that BEA had a strong hypolipidemic function and could be used as a supplement in healthcare foods and drugs or in combination with other hypolipidemic drugs.

The role of high-density lipoproteins in reducing the risk of vascular diseases, neurogenerative disorders, and cancer

High-density lipoprotein (HDL) is one of the major carriers of cholesterol in the blood. It attracts particular attention because, in contrast with other lipoproteins, as many physiological functions of HDL influence the cardiovascular system in favourable ways unless HDL is modified pathologically. The functions of HDL that have recently attracted attention include anti-inflammatory and anti-oxidant activities. High anti-oxidant and anti-inflammatory activities of HDL are associated with protection from cardiovascular disease. Atheroprotective activities, as well as a functional deficiency of HDL, ultimately depend on the protein and lipid composition of HDL. Further, numerous epidemiological studies have shown a protective association between HDL-cholesterol and cognitive impairment. Oxidative stress, including lipid peroxidation, has been shown to be the mediator of the pathologic effects of numerous risk factors of Alzheimer's disease. Lifestyle interventions proven to increase HDL- cholesterol levels including "healthy" diet, regular exercise, weight control, and smoking cessation have also been shown to provide neuro-protective effects. This review will focus on current knowledge of the beneficial effects of HDL-cholesterol as it relates to cardiovascular diseases, breast and lung cancers, non-Hodgkin's lymphoma, as well as its neuroprotective potential in reducing the risk of Alzheimer's disease and dementia.

Emerging therapies for atherosclerosis prevention and management

Atherosclerosis is a chronic immunoinflammatory disease involving medium and large arteries, resulting from a complex interaction between genetic and environmental risk factors. Acute atherosclerotic vascular disease largely results from thrombosis that supervenes on a disrupted atherosclerotic plaque. A healthy lifestyle coupled with management of modifiable risk factors reduces the adverse clinical consequences of atherothrombosis. Reducing low-density lipoprotein cholesterol levels using statins and other agents is the primary pharmacologic approach to stabilize atherosclerosis, but a large residual risk burden remains, stimulating the search for additional therapies for atherosclerosis management. This review focuses on new and emerging therapeutic strategies targeting atherosclerosis.

Emerging drugs for hyperlipidemia

IMPORTANCE OF THE FIELD

Elevated concentrations of low-density lipoprotein (LDL) cholesterol are associated with increased risk of coronary atherosclerosis, and morbidity and mortality from coronary heart disease (CHD). Lowering of LDL cholesterol leads to a reduction in cardiovascular morbidity and all-cause mortality in individuals at risk for cardiovascular events and patients with established CHD. The mainstays of lipid lowering therapy today are the HMG-CoA reductase inhibitors (statins); however, the residual risk of cardiovascular events amongst individuals treated with statins remains a major healthcare concern.

AREAS COVERED IN THIS REVIEW

Emerging targets for lipid lowering therapy target pathways that regulate lipoprotein assembly, lipoprotein clearance and pro-atherogenic lipoprotein modification. These emerging drugs have novel mechanisms that include inhibition of lipoprotein assembly (antisense mRNA inhibitors of apolipoprotein B and microsomal transfer protein inhibitors), enhanced lipoprotein clearance (proprotein convertase subtilisin kexin type 9, thyroid hormone analogues), inhibition of pro-atherogenic lipoprotein remodeling (cholesterol ester transfer protein inhibitors (dalcetrapib, anacetrapib) and peroxisome proliferator activator agents (GFT-505, aleglitazar)) and inhibition of lipoprotein modification (heme oxygenase-1 inhibitor (succinobucol), phospholipase A(2) inhibitors (varespladib, darapladib)).

WHAT THE READER WILL GAIN

A review of the most recent data on emerging drugs in the treatment of hyperlipidemia.

TAKE HOME MESSAGE

With these medications, we will achieve more effective reductions in cardiovascular morbidity and mortality than achieved with current lipid lowering therapies.

Conformation of dimeric apolipoprotein A-I milano on recombinant lipoprotein particles

Apolipoprotein A-I Milano (apoA-I(Milano)) is a naturally occurring human mutation of wild-type apolipoprotein A-I (apoA-I(WT)) having cystine substituted for arginine(173). Two molecules of apo-I(WT) form disks with phospholipid having a defined relationship between the apoA-I(WT) molecules. ApoA-I(Milano) forms cystine homodimers that would not allow the protein to adopt the conformation reported for apoA-I(WT). The conformational constraints for dimeric apoA-I(Milano) recombinant high-density lipoprotein (rHDL) disks made with phospholipid were deduced from a combination of chemical cross-linking and mass spectrometry. Lysine-selective homobifunctional cross-linkers were reacted with homogeneous rHDL having diameters of 78 and 125 A. After reduction, cross-linked apoA-I(Milano) was separated from monomeric apoprotein by gel electrophoresis and then subjected to in-gel trypsin digest. Cross-linked peptides were confirmed by MS/MS sequencing. The cross-links provided distance constraints that were used to refine models of lipid-bound dimeric apoA-I(Milano). These studies suggest that a single dimeric apoA-I(Milano) on 78 A diameter rHDL girdles the edge of a phospholipid disk assuming a "belt" conformation similar to the "belt" region of apoA-I(WT) on rHDL. However, the C-terminal end of dimeric apoA-I(Milano) wraps around the periphery of the particle to shield the fatty acid chains from water rather than folding back onto the "belt" as does apoA-I(WT). The two apoA-I(Milano) dimers on a 125 A diameter rHDL do not encircle the periphery of a phospholipid disk but appear to reside on the surface of a laminar micelle.

Baseline and on-treatment high-density lipoprotein cholesterol and the risk of cancer in randomized controlled trials of lipid-altering therapy

OBJECTIVES

We sought to examine the relationship between high-density lipoprotein cholesterol (HDL-C) levels and the risk of the development of cancer in large randomized controlled trials (RCTs) of lipid-altering interventions.

BACKGROUND

Epidemiologic data demonstrate an inverse relationship between serum total cholesterol levels and incident cancer. We recently reported that lower levels of low-density lipoprotein cholesterol are associated with a significantly higher risk of incident cancer in a meta-analysis of large RCTs of statin therapy. However, little is known about the relationship between HDL-C levels and cancer risk.

METHODS

A systematic MEDLINE search identified lipid intervention RCTs with >or=1,000 person-years of follow-up, providing baseline HDL-C levels and rates of incident cancer. Using random-effects meta-regressions, we evaluated the relationship between baseline HDL-C and incident cancer in each RCT arm.

RESULTS

A total of 24 eligible RCTs were identified (28 pharmacologic intervention arms and 23 control arms), with 625,477 person-years of follow-up and 8,185 incident cancers. There was a significant inverse association between baseline HDL-C levels and the rate of incident cancer (p = 0.018). The inverse association persisted after adjusting for baseline low-density lipoprotein cholesterol, age, body mass index (BMI), diabetes, sex, and smoking status, such that for every 10-mg/dl increment in HDL-C, there was a 36% (95% confidence interval: 24% to 47%) relatively lower rate of the development of cancer (p < 0.001).

CONCLUSIONS

There is a significant inverse association between HDL-C and the risk of incident cancer that is independent of LDL-C, age, BMI, diabetes, sex, and smoking.

Helicobacter Pylori infection is a significant risk for modified lipid profile in Japanese male subjects

AIM

Helicobacter Pylori infection was associated with the risk of cardiovascular disease; however, the relation between Helicobacter Pylori infection and the lipid profile has not been fully established.

METHODS

We measured anti-Helicobacter Pylori antibody concentration and lipid profiles in 6,289 Japanese subjects aged 21-64 years (5,077 male and 1,212 female).

RESULTS

The prevalence of Helicobacter Pylori-seropositive subjects was 46.8% and 39.6% in men and women, respectively. Adjusted mean values of low-density lipoprotein (LDL) cholesterol and high-density lipoprotein (HDL) cholesterol in men were significantly higher and lower in Helicobacter Pylori-seropositive than-negative subjects, respectively, (LDL-cholesterol: 129.0±0.8 vs. 125.3±0.7 mg/dL, p< 0.001, HDL-cholesterol: 54.6±0.3 vs. 56.6±0.3 mg/dL, p< 0.01), whereas these associations were not significant in female subjects. Moreover, the odds ratio of Helicobacter Pylori infection for high LDL-cholesteremia and low HDL-cholesteremia in male subjects was 1.23 (95% CI (confidence interval): 1.08-1.40, p< 0.05) and 1.29 (95% CI: 1.03-1.59, p< 0.05), respectively. Female subjects did not have such associations.

CONCLUSIONS

The present study demonstrates that Helicobacter Pylori infection is significantly associated with high LDL-cholesteremia and low HDL-cholesteremia in Japanese male subjects.

Hypolipidaemic and hepatoprotective effects of ethanolic and aqueous extracts from Asparagus officinalis L. by-products in mice fed a high-fat diet

BACKGROUND

Asparagus (Asparagus officinalis L.) by-products, i.e. the parts of the spears discarded during industrial processing, might have potential use as food supplements for their therapeutic effects. In this study the hypolipidaemic and hepatoprotective effects of ethanolic (EEA) and aqueous (AEA) extracts from asparagus by-products were evaluated in mice fed a high-fat diet (HFD).

RESULTS

Continuous HFD feeding caused obvious hyperlipidaemia and liver damage in mice. However, both EEA and AEA significantly decreased the levels of body weight gain, serum total cholesterol and serum low-density lipoprotein cholesterol in hyperlipidaemic mice when administered at a daily dose of 200 mg kg(-1) for 8 weeks. Also, serum high-density lipoprotein cholesterol levels were evidently increased in the AEA-treated group. Moreover, both EEA and AEA dramatically decreased the activities of alanine and aspartate transaminases in serum. Finally, superoxide dismutase activity and total antioxidant capacity were increased and malondialdehyde level and the distribution of lipid droplets decreased in liver cells of both EEA- and AEA-treated mice.

CONCLUSION

The findings of this study suggest that both EEA and AEA have strong hypolipidaemic and hepatoprotective properties and could be used as supplements in healthcare foods and drugs or in combination with other hypolipidaemic drugs.

Safety of extended-release niacin/laropiprant in patients with dyslipidemia

OBJECTIVE

To evaluate the safety profile of extended-release niacin/laropiprant (ERN/LRPT), pooling data from studies in the clinical development program.

METHODS

Data were pooled from three active- or placebo-controlled phase 3 studies and three 1-year extensions of phase 2 studies that ranged from 12 to 52 weeks (N = 4747): ERN/LRPT = 2548; ERN or Niaspan® (ERN-NSP = 1268); or simvastatin or placebo (SIMVA-PBO = 931).

RESULTS

The safety and tolerability profile for ERN/LRPT was similar to that of ERN-NSP, except for fewer flushing-related adverse experiences and discontinuations with ERN/LRPT than ERN-NSP. The incidence of consecutive ≥3× the upper limit of normal increases in alanine aminotransferase and/or aspartate aminotransferase was numerically (but not statistically) greater with ERN/LRPT (1.0%) than ERN-NSP (0.5%) and similar to SIMVA-PBO (0.9%). Elevations were reversible with therapy discontinuation and not associated with clinical hepatotoxicity. There was no evidence that ERN/LRPT administered alone or concurrently with a statin had adverse effects on muscle. ERN/LRPT and ERN-NSP produced small median increases in fasting blood glucose levels (∼4 mg/dL) after 24 weeks of treatment, consistent with known effects of niacin.

CONCLUSION

The favorable safety and tolerability profile of ERN/LRPT for up to 1 year supports the use of LRPT to achieve improved therapeutic dosing of niacin, an agent with comprehensive lipid-modifying efficacy and shown to reduce cardiovascular risk.

Relations of lipid concentrations to heart failure incidence: the Framingham Heart Study

BACKGROUND

The relations of lipid concentrations to heart failure (HF) risk have not been elucidated comprehensively.

METHODS AND RESULTS

In 6860 Framingham Heart Study participants (mean age, 44 years; 54% women) free of baseline coronary heart disease, we related high-density lipoprotein cholesterol (HDL-C) and non-HDL-C to HF incidence during long-term follow-up, adjusting for clinical covariates and myocardial infarction at baseline and updating these at follow-up examinations. We evaluated dyslipidemia-specific population burden of HF by calculating population attributable risks. During follow-up (mean of 26 years), 680 participants (49% women) developed HF. Unadjusted HF incidence in the low (<160 mg/dL) versus high (> or =190 mg/dL) non-HDL-C groups was 7.9% and 13.8%, respectively, whereas incidence in the high (> or =55 [men], > or =65 [women] mg/dL) versus low (<40 [men], <50 [women] mg/dL) HDL-C groups was 6.1% and 12.8%, respectively. In multivariable models, baseline non-HDL-C and HDL-C, modeled as continuous measures, carried HF hazards (confidence intervals) of 1.19 (1.11 to 1.27) and 0.82 (0.75 to 0.90), respectively, per SD increment. In models updating lipid concentrations every 8 years, the corresponding hazards (confidence intervals) were 1.23 (1.16 to 1.31) and 0.77 (0.70 to 0.85). Participants with high baseline non-HDL-C and those with low HDL-C experienced a 29% and 40% higher HF risk, respectively, compared with those in the desirable categories; the population attributable risks for high non-HDL-C and low HDL-C were 7.5% and 15%, respectively. Hazards associated with non-HDL-C and HDL-C remained statistically significant after additional adjustment for interim myocardial infarction.

CONCLUSIONS

Dyslipidemia carries HF risk independent of its association with myocardial infarction, suggesting that lipid modification may be a means for reducing HF risk.

Novel targets that affect high-density lipoprotein metabolism: the next frontier

As the significance of treating coronary artery disease (CAD) remains a high priority in reducing morbidity and mortality worldwide, newer treatment strategies continue to evolve. The efficacy of statin therapy in reducing low-density lipoprotein cholesterol and reducing cardiovascular events is well established. Yet, addressing residual macrovascular risk becomes a compelling rationale for proposing that pharmacologic therapy targeted at low concentrations of high-density lipoprotein (HDL) cholesterol is a rationale target for enhanced management of CAD. This article reviews current options for the therapeutic management of HDL cholesterol, including discussion of novel agents aimed at reducing cardiovascular disease risk in patients with low levels of HDL cholesterol.

Design of the DEFINE trial: determining the EFficacy and tolerability of CETP INhibition with AnacEtrapib

BACKGROUND

Residual cardiovascular (CV) risk often remains high despite statin therapy to lower low-density lipoprotein cholesterol (LDL-C). New therapies to raise high-density lipoprotein cholesterol (HDL-C) are currently being investigated. Anacetrapib is a cholesteryl ester transfer protein (CETP) inhibitor that raises HDL-C and reduces LDL-C when administered alone or with a statin. Adverse effects on blood pressure, electrolytes, and aldosterone levels, seen with another drug in this class, have not been noted in studies of anacetrapib to date.

METHODS

Determining the EFficacy and Tolerability of CETP INhibition with AnacEtrapib (DEFINE) is a randomized, double-blind, placebo-controlled trial to assess the efficacy and safety profile of anacetrapib in patients with coronary heart disease (CHD) or CHD risk equivalents (clinical trials.gov NCT00685776). Eligible patients at National Cholesterol Education Program-Adult Treatment Panel III LDL-C treatment goal on a statin, with or without other lipid-modifying medications, are treated with anacetrapib, 100 mg, or placebo for 18 months, followed by a 3-month, poststudy follow-up. The primary end points are percent change from baseline in LDL-C and the safety and tolerability of anacetrapib. Comprehensive preplanned interim safety analyses will be performed at the 6- and 12-month time points to examine treatment effects on key safety end points, including blood pressure and electrolytes. A preplanned Bayesian analysis will be performed to interpret the CV event distribution, given the limited number of events expected in this study.

RESULTS

A total of 2,757 patients were screened at 153 centers in 20 countries, and 1,623 patients were randomized into the trial. Lipid results, clinical CV events, and safety outcomes from this trial are anticipated in 2010.

Association between dyslipidemia and vascular events in patients treated with statins: report from the UK General Practice Research Database

OBJECTIVE

A retrospective cohort study was conducted to evaluate the association between low high-density lipoprotein cholesterol (HDL-C) and/or elevated triglycerides (TG) and cardiovascular (CV) and/or cerebrovascular (CB) events among patients with elevated low-density lipoprotein cholesterol (LDL-C) despite statin treatment.

METHODS

Patient demographics, clinical characteristics, laboratory data, and CV/CB events, were collected from the UK General Practice Research Database. Abnormal lipid levels were defined using US and European clinical guidelines. The association between the frequency of CV/CB events among patients with HDL-C/TG abnormalities versus patients with isolated low LDL-C was estimated using multivariate Cox proportional hazards regression.

RESULTS

Of 19,843 statin-treated patients, 6823 had elevated LDL-C despite therapy for a mean follow-up of 1.99+/-1.06 years. Among these patients, 3115 (45.7%) also had HDL-C/TG abnormalities. A total of 715 patients (10.5%) experienced CV/CB events. In statin-treated patients not at LDL-C goal, the relative risk of a vascular event was 24% higher in patients with HDL-C/TG abnormalities (HR=1.24, 95% CI: 1.06-1.46, p=0.006) than in patients without HDL-C/TG abnormalities. Additional variables that were associated with a significantly increased risk of CV/CB events included age (p<0.0001), gender (p=0.027), and medication possession ratio (p<0.0001), while diabetes mellitus (p<0.0001), hypertension (p<0.0001), 10-year Framingham risk score>30% (p=0.005), statin dose (p<0.0001), and LDL-C level at baseline (p<0.0001) were associated with a significantly decreased risk of CV/CB events.

CONCLUSION

Among statin-treated patients with elevated LDL-C from UK clinical practices, reduced HDL-C and/or elevated TGs were associated with a significantly increased relative risk of CV/CB events.

Association of leukocyte subtype counts with coronary atherosclerotic regression following pravastatin treatment

The purpose of this study was to clarify the relation between differential leukocyte counts and inhibition of the development of coronary atherosclerosis in patients with coronary artery disease. A 6-month prospective study was conducted in 84 patients treated with pravastatin. Plaque volume, as assessed by volumetric analysis using intravascular ultrasound, decreased significantly by 12.6% (p <0.0001 vs baseline) after treatment; furthermore, a corresponding decrease of total leukocyte count (8.9%, p <0.01 vs baseline) was seen. Change in plaque volume was correlated with changes in monocyte (r = 0.35, p = 0.002) and lymphocyte (r = 0.25, p = 0.03) counts but not with changes in neutrophil, eosinophil, or basophil counts. In a multivariate regression analysis with changes in serum lipids, traditional risk factors, and medications as covariates, the decrease in monocyte count was identified as an independent predictor of coronary plaque regression (beta coefficient 0.313, 95% confidence interval 0.089 to 0.353, p = 0.0014). No correlation was found between change in monocyte count and changes in any other lipid levels. This study demonstrated that monocyte count was the only leukocyte type significantly and independently associated with coronary atherosclerotic regression, even after adjustment for changes in any lipid levels. In conclusion, the decrease in monocyte count as a nonlipid-lowering effect of statins may be used as a novel marker of coronary atherosclerotic regression.

The common apolipoprotein A-1 polymorphism -75A>G is associated with ethnic differences in recurrent coronary events after recovery from an acute myocardial infarction

Since data regarding the relationship between a common polymorphism (SNP) of the apoA1 gene with apoA1 levels and risk of coronary artery disease are inconsistent, we hypothesized that its association with recurrent coronary events differs for White and Black individuals with diagnosed coronary heart disease. The apoA1 -75G>A SNP was genotyped in a cohort of 834 Black (n=129) and White (n=705) post-myocardial infarction patients. Recurrent coronary events (coronary-related death, non-fatal myocardial infarction, or unstable angina) were documented during an average follow-up of 28 months. Thirty percent of White and 21% of Black patients carried the SNP. Cox proportional-hazards regression analysis, adjusting for clinical and laboratory covariates, demonstrated that the SNP was not associated with recurrent events in the total cohort (HR=1.37, 95% CI 0.95-1.97; p= 0.09) but was the only variable associated with an increased risk of recurrent cardiac events in Blacks (HR=2.40, 95% CI 1.07-5.40; p= 0.034). Conversely in Whites, the SNP was not associated with recurrent events (HR=1.12, 95% CI 0.75-1.67; p= 0.59) whereas apoB (HR=1.78, 95% CI 1.20 -2.65; p= 0.0042) and calcium channel blocker use (HR=2.53, 95% CI 1.72-3.72; p<0.001) were associated; p= 0.0024 for interaction between ethnicity and the SNP. A common apoA1 SNP is associated with a significantly increased risk of recurrent cardiac events among Black, but not White, postmyocardial infarction patients. Relationships with lipoproteins may help explain this finding.

Atherogenesis and atherothrombosis--focus on diabetes mellitus

Diabetes mellitus represents a major cause of cardiovascular morbidity and mortality in developed countries, and atherothrombosis accounts for most deaths among patients with diabetes mellitus. Atherothrombosis is defined as atherosclerotic lesion disruption with superimposed thrombus formation. As a long-term, progressive disease process, atherosclerosis often results in an acute atherothrombotic event through plaque rupture and formation of a platelet-rich thrombus. The principal clinical manifestations of atherothrombosis are sudden cardiac death, myocardial infarction, ischaemic stroke, and peripheral arterial ischaemia comprising both intermittent claudication and critical limb ischaemia. Atherosclerosis is the leading cause of morbidity and mortality in the industrialized world, and diabetes mellitus magnifies the risk of cardiovascular events. In addition to the well-known microvascular complications of diabetes mellitus - such as nephropathy, retinopathy and neuropathy - the risk of macrovascular complications affecting the large conduit arteries markedly increases in patients with diabetes mellitus.

Cardiovascular risk reduction: what do recent trials with rosuvastatin tell us?

Abundant evidence from large-scale clinical trials supports the importance of lowering low-density lipoprotein cholesterol (LDL-C) to decrease the risk of cardiovascular disease (CVD) events. The LDL-C targets in various guidelines remain important treatment goals but, even in trials where statin therapy achieves substantial reduction of LDL-C, a significant number of CVD events still occur and the residual risk remains high. These findings suggest that lipid parameters other than LDL-C, such as high-density lipoprotein cholesterol (HDL-C), triglycerides, and LDL particle size, can influence the risk of CVD. On this basis, other strategies that can alter the lipid profile, in particular raising HDL.C, may provide additional benefits. Other factors such as HDL-C functionality and susceptibility to oxidation and inflammatory factors can also influence cardiovascular risk. In addition to the modifications of the lipid profile, statins have cholesterol-independent beneficial pleiotropic effects. The contribution of these effects to event reduction is not yet fully understood. Recently, the body of evidence has expanded to support the use of intensive statin therapy in broader patient populations. The JUPITER trial has shown the benefit of intensive statin treatment in low-risk subjects with high levels of high-sensitivity C-reactive protein and average levels of LDL-C. Unlike the setting of primary and secondary prevention, the results of statin trials in patients with heart failure have shown no clear benefit in terms of survival. The recently published AURORA trial was carried out to investigate the effect of rosuvastatin in patients with end-stage renal disease undergoing chronic hemodialysis. In this trial no benefit on cardiovascular events was shown with statin therapy. In conclusion, large outcomes trials have clearly shown that statin treatments have a favorable benefit/risk profile in a large range of patients at different levels of risk, with the exception of patients with heart failure and those with renal disease undergoing dialysis. Further evidence is needed on the role of therapeutic strategies on the so-called residual risk.

High-density Lipoprotein Cholesterol: Current Perspective for Clinicians

High-density lipoproteins are regarded as “good guys” but not always. Situations involving high-density lipoproteins are discussed and medication results are considered. Clinicians usually consider high-density lipoprotein cholesterol. Nicotinic acid is the best available medication to elevate high-density lipoprotein cholesterol and this appears beneficial for cardiovascular risk. The major problem with nicotinic acid is that many patients do not tolerate the associated flushing. Laropiprant decreases this flushing and has an approval in Europe but not in the United States. The most potent medications for increasing high-density lipoprotein cholesterol are cholesteryl ester transfer protein inhibitors. The initial drug in this class, torcetrapib, was eliminated by excess cardiovascular problems. Two newer cholesteryl ester transfer protein inhibitors, R1658 and anacetrapib, initially appear promising. High-density lipoprotein cholesterol may play an important role in improving cardiovascular risk in the 60% of patients who do not receive cardiovascular mortality/morbidity benefit from low-density lipoproteins reduction by statins.