Update on CETP inhibition

The association between consumption of red and processed meats with metabolic syndrome and its components in obese and overweight women: a cross-sectional study

OBJECTIVES

Previous studies have shown a relation between the consumption of different types of meats and chronic disorders. This study aims to investigate the association between red and processed meat intake with metabolic syndrome (MetS) and its components in healthy obese and overweight women.

METHODS

This cross-sectional study was conducted on Iranian women. The dietary assessment and body composition were measured by a validated food frequency questionnaire (FFQ) and bioelectrical impedance analysis, respectively. Blood samples were collected by standard protocols.

RESULTS

A total of 231 women (mean age 36.47 ± 8.44 years) were included in the current study. After controlling for potential confounders, there was a marginally significant associations between higher intake of processed meat with the MetS (OR:1.01, 95% CI: 0.94,2.94, P:0.06) and high serum triglycerides (TG) (OR:1.27, 95% CI: 0.94,2.98, P:0.07). There was a significant associations between high intake of red meats with lower odds of higher waist circumference (WC) (OR:0.31, 95% CI: 0.10,0.97, P:0.04). Also, there was a significant associations were found between high intake of processed meats with greater odds of having lower high-density lipoprotein cholesterol (HDL-c) (OR:0.64, 95% CI: 0.30,0.95, P:0.03).

CONCLUSIONS

The current study suggests that higher intakes of processed meat may be associated with the MetS in Iranian women with excess body weight, while this was not the case for red meat. More studies however are necessary in different communities to draw definitive conclusions.

Beneficial Effect of Cuban Policosanol on Blood Pressure and Serum Lipoproteins Accompanied with Lowered Glycated Hemoglobin and Enhanced High-Density Lipoprotein Functionalities in a Randomized, Placebo-Controlled, and Double-Blinded Trial with Healthy Japanese

This study evaluated the efficacy and safety of 20 mg of Cuban policosanol in blood pressure (BP) and lipid/lipoprotein parameters of healthy Japanese subjects via a placebo-controlled, randomized, and double-blinded human trial. After 12 weeks of consumption, the policosanol group showed significantly lower BP, glycated hemoglobin (HbA1c), and blood urea nitrogen (BUN) levels. The policosanol group also showed lower aspartate aminotransferase (AST), alanine aminotransferase (ALT), and γ-glutamyl transferase (γ-GTP) levels at week 12 than those at week 0: A decrease of up to 9% (p < 0.05), 17% (p < 0.05), and 15% (p < 0.05) was observed, respectively. The policosanol group showed significantly higher HDL-C level and HDL-C/TC (%), approximately 9.5% (p < 0.001) and 7.2% (p = 0.003), respectively, than the placebo group and a difference in the point of time and group interaction (p < 0.001). In lipoprotein analysis, the policosanol group showed a decrease in oxidation and glycation extent in VLDL and LDL with an improvement of particle shape and morphology after 12 weeks. HDL from the policosanol group showed in vitro stronger antioxidant and in vivo anti-inflammatory abilities. In conclusion, 12 weeks of Cuban policosanolconsumption in Japanese subjects showed significant improvement in blood pressure, lipid profiles, hepatic functions, and HbA1c with enhancement of HDL functionalities.

The APOEε3/ε4 Genotype Drives Distinct Gene Signatures in the Cortex of Young Mice

Introduction

Restrictions on existing APOE mouse models have impacted research toward understanding the strongest genetic risk factor contributing to Alzheimer’s disease (AD) and dementia, APOEε4, by hindering observation of a key, common genotype in humans – APOEε3/ε4. Human studies are typically underpowered to address APOEε4 allele risk as the APOEε4/ε4 genotype is rare, which leaves human and mouse research unsupported to evaluate the APOEε3/ε4 genotype on molecular and pathological risk for AD and dementia.

Methods

As a part of MODEL-AD, we created and validated new versions of humanized APOEε3/ε3 and APOEε4/ε4 mouse strains that, due to unrestricted breeding, allow for the evaluation of the APOEε3/ε4 genotype. As biometric measures are often translatable between mouse and human, we profiled circulating lipid concentrations. We also performed transcriptional profiling of the cerebral cortex at 2 and 4 months (mos), comparing APOEε3/ε4 and APOEε4/ε4 to the reference APOEε3/ε3 using linear modeling and WGCNA. Further, APOE mice were exercised and compared to litter-matched sedentary controls, to evaluate the interaction between APOEε4 and exercise at a young age.

Results

Expression of human APOE isoforms were confirmed in APOEε3/ε3, APOEε3/ε4 and APOEε4/ε4 mouse brains. At two mos, cholesterol composition was influenced by sex, but not APOE genotype. Results show that the APOEε3/ε4 and APOEε4/ε4 genotype exert differential effects on cortical gene expression. APOEε3/ε4 uniquely impacts ‘hormone regulation’ and ‘insulin signaling,’ terms absent in APOEε4/ε4 data. At four mos, cholesterol and triglyceride levels were affected by sex and activity, with only triglyceride levels influenced by APOE genotype. Linear modeling revealed APOEε3/ε4, but not APOEε4/ε4, affected ‘extracellular matrix’ and ‘blood coagulation’ related terms. We confirmed these results using WGCNA, indicating robust, yet subtle, transcriptional patterns. While there was little evidence of APOE genotype by exercise interaction on the cortical transcriptome at this young age, running was predicted to affect myelination and gliogenesis, independent of APOE genotype with few APOE genotype-specific affects identified.

Discussion

APOEε4 allele dosage-specific effects were observed in circulating lipid levels and cortical transcriptional profiles. Future studies are needed to establish how these data may contribute to therapeutic development in APOEε3/ε4 and APOEε4/ε4 dementia patients.

Therapeutic approaches targeting Apolipoprotein E function in Alzheimer's disease

One of the primary genetic risk factors for Alzheimer’s disease (AD) is the presence of the Ɛ4 allele of apolipoprotein E (APOE). APOE is a polymorphic lipoprotein that is a major cholesterol carrier in the brain. It is also involved in various cellular functions such as neuronal signaling, neuroinflammation and glucose metabolism. Humans predominantly possess three different allelic variants of APOE, termed E2, E3, and E4, with the E3 allele being the most common. The presence of the E4 allele is associated with increased risk of AD whereas E2 reduces the risk. To understand the molecular mechanisms that underlie APOE-related genetic risk, considerable effort has been devoted towards developing cellular and animal models. Data from these models indicate that APOE4 exacerbates amyloid β plaque burden in a dose-dependent manner. and may also enhance tau pathogenesis in an isoform-dependent manner. Other studies have suggested APOE4 increases the risk of AD by mechanisms that are distinct from modulation of Aβ or tau pathology. Further, whether plasma APOE, by influencing systemic metabolic pathways, can also possibly alter CNS function indirectly is not complete;y understood. Collectively, the available studies suggest that APOE may impact multiple signaling pathways and thus investigators have sought therapeutics that would disrupt pathological functions of APOE while preserving or enhancing beneficial functions. This review will highlight some of the therapeutic strategies that are currently being pursued to target APOE4 towards preventing or treating AD and we will discuss additional strategies that holds promise for the future.

Blood Pressure Lowering Effect of Cuban Policosanol is Accompanied by Improvement of Hepatic Inflammation, Lipoprotein Profile, and HDL Quality in Spontaneously Hypertensive Rats

We investigated the antihypertensive effect of policosanol on spontaneously hypertensive rats (SHR). For this, we analyzed blood pressure, blood lipid, and lipoprotein properties in male SHR after consumption of Cuban policosanol (PCO). The experimental groups were as follows: normotensive Wistar Kyoto (WKY) control, SHR group fed normal diet (ND), SHR group fed 20 mg of PCO, SHR group fed 100 mg of PCO, and SHR group fed 200 mg of PCO per kg of body weight. After eight weeks, the SHR control group showed gradual increases up to 21% in systolic blood pressure (SBP) and diastolic blood pressure (DBP) compared with values at week 0. However, policosanol consumption had a dose-dependent reduction effect on SBP and also reduced DBP up to 17% in a dose-dependent manner. Heart rate (HR) bpm increased by six percent in the SHR control, whereas the 20 mg, 100 mg, and 200 mg of policosanol groups showed a reduction of 36%, 28%, and 34% respectively. Although serum total cholesterol (TC) level of SHR was not affected by policosanol consumption (70⁻80 mg/dL), serum triglyceride (TG) level significantly decreased in the SHR + 200 mg of PCO group. Serum high-density lipoprotein cholesterol (HDL-C) level was also significantly elevated by policosanol consumption. The % HDL-C/TC ratio was elevated in the policosanol group up to 67⁻70%, whereas the SHR control group showed a ratio of 58%. Serum cholesteryl ester transfer protein (CETP) activity was reduced by policosanol in a dose-dependent manner. Although the serum glutamate oxaloacetate transaminase (GOT)/ glutamate pyruvate transaminase (GPT) were similar across all groups, policosanol consumption caused reduction of reactive oxygen species (ROS) levels in hepatic tissue. The SHR control group showed a 2.1-fold higher serum C-reactive protein (CRP) level than the WKY group, whereas the CRP level decreased in the SHR + 200 mg of PCO group (up to 45%) than SHR control group. Aldosterone level was reduced in the policosanol group (up to 34%) in a dose-dependent manner compared to the control. In conclusion, eight weeks of policosanol consumption in SHR resulted in remarkable reduction of blood pressure, serum aldosterone, and serum TG levels along with the elevation of HDL-C and improvement of hepatic inflammation.

Anti-atherosclerosis effect of different doses of CETP vaccine in rabbit model of atherosclerosis

AIM

To evaluate atheroprotective effects of different doses of cholesteryl ester transfer protein (CETP) vaccine, three doses of Tetanus toxoid-CETP (TT-CETP) peptide including 10, 50 and 100/rabbit, termed FA10, FA50, FA100, respectively, were administered in rabbit model of atherosclerosis.

METHODS

Animals were vaccinated subcutaneously (S.C.) with 100μl of vaccine in presence of complete Freund's adjuvant (CFA) for the first administration. Rabbits were boosted 4 times at 3 weeks intervals with the same peptide dose formulated in incomplete Freund's adjuvant (IFA). Animals were fed with diet supplemented with 2% cholesterol from week 11 to week 19. Anti-TT-CETP specific antibody and CETP activity in sera were determined. Therapeutic response was examined by tracking plasma lipoprotein levels (HDL-C, LDL-C and total cholesterol), and pathologic observation of intima/media thickness at the site of aortic lesions.

RESULTS

All TT-CETP vaccine doses generated strong anti TT-CETP antibody response. CETP activity reduced in rabbits vaccinated with FA100 (P=0.031). FA100 showed significant increase in level of HDL-C rather than control group (P=0.006). However, no significant reduction were found in atherosclerotic lesion when compared to control.

CONCLUSION

Inhibition of CETP activity and increased HDL-C were found with FA100, but the vaccine failed to prevent aortic lesion development in immunized rabbits when compared to control. Our result supports the hypothesis stated that CETP may not be an attractive therapeutic target for the prevention of cardiovascular disease.

Therapeutic ultrasound: Increased HDL-Cholesterol following infusions of acoustic microspheres and apolipoprotein A-I plasmids

BACKGROUND

Low levels of HDL-C are an independent cardiovascular risk factor associated with increased premature cardiovascular death. However, HDL-C therapies historically have been limited by issues relating to immunogenicity, hepatotoxicity and scalability, and have been ineffective in clinical trials.

OBJECTIVE

We examined the feasibility of using injectable acoustic microspheres to locally deliver human ApoA-I DNA plasmids in a pre-clinical model and quantify increased production of HDL-C in vivo.

METHODS

Our novel site-specific gene delivery system was examined in naïve rat model and comprised the following steps: (1) intravenous co-administration of a solution containing acoustically active microspheres (Optison™, GE Healthcare, Princeton, New Jersey) and human ApoA-I plasmids; (2) ultrasound verification of the presence of the microspheres within the liver vasculature; (3) External application of locally-directed acoustic energy, (4) induction of microsphere disruption and in situ sonoporation; (4) ApoA-I plasmid hepatic uptake; (5) transcription and expression of human ApoA-I protein; and (6) elevation of serum HDL-C.

RESULTS

Co-administration of ApoA-I plasmids and acoustic microspheres, activated by external ultrasound energy, resulted in transcription and production of human ApoA-I protein and elevated serum HDL-C in rats (up to 61%; p-value < 0.05).

CONCLUSIONS

HDL-C was increased in rats following ultrasound directed delivery of human ApoA-I plasmids by microsphere sonoporation. The present method provides a novel approach to promote ApoA-I synthesis and nascent HDL-C elevation, potentially permitting the use of a minimally-invasive ultrasound-based, gene delivery system for treating individuals with low HDL-C.

A novel gene regulator, pyrrole-imidazole polyamide targeting ABCA1 gene increases cholesterol efflux from macrophages and plasma HDL concentration

Pyrrole-imidazole (PI) polyamides are nuclease-resistant novel compounds that inhibit transcription factors by binding to the minor groove of DNA. A PI polyamide that targets mouse ABCA1 and increases ABCA1 gene expression was designed and evaluated as an agent to increase plasma HDL concentration. A PI polyamide was designed to bind the activator protein-2 binding site of the mouse ABCA1 promoter. The effect of this PI polyamide on ABCA1 expression was evaluated by real-time RT-PCR and Western blotting using RAW264 cells. In vivo effects of this polyamide on ABCA1 gene expression and plasma HDL level were examined in C57B6 mice. One milligram per kilogram of body weight of PI polyamide was injected via the tail veins every 2 days for 1 week, and plasma lipid profiles were evaluated. PI polyamide showed a specific binding to the target DNA in gel mobility shift assay. Treatment of RAW264 cells with 1.0 μM PI polyamide significantly increased ABCA1 mRNA expression. PI polyamide also significantly increased apolipoprotein AI-mediated HDL biogenesis in RAW264 cells. Cellular cholesterol efflux mediated by apolipoprotein AI was significantly increased by the PI polyamide treatment. PI polyamide significantly increased expression of ABCA1 mRNA in the liver of C57B6 mice. Plasma HDL concentration was increased by PI polyamide administration. All of the HDL sub-fractions showed a tendency to increase after PI polyamide administration. The designed PI polyamide that targeted ABCA1 successfully increased ABCA1 expression and HDL biogenesis. This novel gene-regulating agent is promising as a useful compound to increase plasma HDL concentration.

KEY MESSAGES

A novel pyrrole-imidazole (PI) polyamide binds to ABCA1. PI polyamide interfered with binding of AP-2ɑ protein to the ABCA1 gene promoter. PI polyamide inhibited the AP-2ɑ-mediated reduction of ABCA1 gene and protein expression. PI polyamide increased ABCA1 protein and apolipoprotein AI mediated HDL biogenesis. PI polyamide is a new gene regulator for the prevention of atherosclerotic diseases.

A reappraisal of the risks and benefits of treating to target with cholesterol lowering drugs

Atherosclerotic cardiovascular disease (CVD) is the number one cause of death globally, and lipid modification, particularly lowering of low density lipoprotein cholesterol (LDLc), is one of the cornerstones of prevention and treatment. However, even after lowering of LDLc to conventional goals, a sizeable number of patients continue to suffer cardiovascular events. More aggressive lowering of LDLc and optimization of other lipid parameters like triglycerides (TG) and high density lipoprotein cholesterol (HDLc) have been proposed as two potential strategies to address this residual risk. These strategies entail use of maximal doses of highly potent HMG CoA reductase inhibitors (statins) and combination therapy with other lipid modifying agents. Though statins in general are fairly well tolerated, adverse events like myopathy are dose related. There are further risks with combination therapy. In this article, we review the adverse effects of lipid modifying agents used alone and in combination and weigh these effects against the evidence demonstrating their efficacy in reducing cardiovascular events, cardiovascular mortality, and all cause mortality. For patients with established CVD, statins are the only group of drugs that have shown consistent reductions in hard outcomes. Though more aggressive lipid lowering with high dose potent statins can reduce rates of non fatal events and need for interventions, the incremental mortality benefits remain unclear, and their use is associated with a higher rate of drug related adverse effects. Myopathy and renal events have been a significant concern with the use of high potency statin drugs, in particular simvastatin and rosuvastatin. For patients who have not reached target LDL levels or have residual lipid abnormalities on maximal doses of statins, the addition of other agents has not been shown to improve clinical outcomes and carries an increased risk of adverse events. The clinical benefits of drugs to raise HDLc remain unproven. In patients without known cardiovascular disease, there is conflicting evidence as to the benefits of aggressive pursuit of numerical lipid targets, particularly with respect to all cause mortality. Certainly, in statin intolerant patients, alternative agents with a low side effect profile are desirable. Bile acid sequestrants are an effective and safe choice for decreasing LDLc, and omega-3 fatty acids are safe agents to decrease TG. There remains an obvious need to design and carry out large scale studies to help determine which agents, when combined with statins, have the greatest benefit on cardiovascular disease with the least added risk. These studies should be designed to assess the impact on clinical outcomes rather than surrogate endpoints, and require a comprehensive assessment and reporting of safety outcomes.

Ultrasound-directed, site-specific gene delivery

With the implementation of gene therapy looming in the near term, an effective delivery system using noninvasive, nonviral-mediated methods appears as an attractive option. This novel platform technology uses gas-filled, ultrasound-directed acoustic microspheres for both diagnostic imaging and therapy and yet may provide a key component for future success in the pursuit of single-gene replacement therapy.

Physical activity and cardiometabolic risk in male children and adolescents: the Balcarce study

AIMS

This study aims to evaluate the relationship between the amount of physical activity and different traditional and novel cardiometabolic risk factors, as well as atheroprotective agents, in male children and adolescents.

MAIN METHODS

Cross-sectional study. A total of 337 male children and adolescents aged 7-14 years old from the rural city of Balcarce, Buenos Aires, Argentina were studied.

KEY FINDINGS

The main finding of the present study was that, in male children and adolescents, physical activity was inversely associated with lipoprotein-associated phospholipase A2 (Lp-PLA2) activity (r=-0.39, p<0.001) and with cholesteryl ester transfer protein activity (r=-0.23, p<0.05) apart from other proatherogenic agents after adjusting for age and BMI. Strikingly, among the parameters evaluated, overweight, hyperglycemia and Lp-PLA2 activity resulted to be independently related to physical activity as shown by stepwise regression analysis.

SIGNIFICANCE

The strong negative association between exercise and Lp-PLA2 activity and the fact that the latter resulted to be the unique continuous variable that persisted associated with physical activity would add an additional benefit of exercise in early prevention of vascular inflammation and atherogenesis.

Modulation of lipid metabolism with the overexpression of NPC1L1 in mouse liver

Niemann-Pick C1-like 1 protein (NPC1L1), a transporter crucial in intestinal cholesterol absorption, is expressed in human liver but not in murine liver. To elucidate the role of hepatic NPC1L1 on lipid metabolism, we overexpressed NPC1L1 in murine liver utilizing adenovirus-mediated gene transfer. C57BL/6 mice, fed on normal chow with or without ezetimibe, were injected with NPC1L1 adenovirus (L1-mice) or control virus (Null-mice), and lipid analyses were performed five days after the injection. The plasma cholesterol levels increased in L1-mice, and FPLC analyses revealed increased cholesterol contents in large HDL lipoprotein fractions. These fractions, which showed α-mobility on agarose electrophoresis, were rich in apoE and free cholesterol. These lipoprotein changes were partially inhibited by ezetimibe treatment and were not observed in apoE-deficient mice. In addition, plasma and VLDL triglyceride (TG) levels decreased in L1-mice. The expression of microsomal triglyceride transfer protein (MTP) was markedly decreased in L1-mice, accompanied by the reduced protein levels of forkhead box protein O1 (FoxO1). These changes were not observed in mice with increased hepatic de novo cholesterol synthesis. These data demonstrate that cholesterol absorbed through NPC1L1 plays a distinct role in cellular and plasma lipid metabolism, such as the appearance of apoE-rich lipoproteins and the diminished VLDL-TG secretion.

Treatment of familial hypercholesterolemia: is there a need beyond statin therapy?

Familial hypercholesterolemia (FH) is a genetic lipid disorder that is characterized by severely elevated cholesterol levels and premature cardiovascular disease. Both the heterozygous and homozygous forms of FH require aggressive cholesterol-lowering therapy. Statins alone frequently do not lower these patients' cholesterol to therapeutic levels, and some patients are intolerant to statins. Combination or monotherapy with other current pharmacotherapies are options, but even with these some FH patients do not meet their low-density lipoprotein (LDL) cholesterol goals. In the cases of statin intolerance, LDL apheresis may be another treatment option. There are currently several novel therapies in development for LDL lowering that target either production or catabolism of LDL, plaque regression, and potentially gene transfer. We conclude that there is a need beyond statins for patients with FH, especially in cases of statin intolerance, and when even the highest doses of statin do not get patients to goal cholesterol levels.

Cholesteryl ester transfer-protein modulator and inhibitors and their potential for the treatment of cardiovascular diseases

Elevated low-density lipoprotein (LDL) cholesterol and lowered high-density lipoprotein (HDL) cholesterol are important risk factors for cardiovascular disease. Accordingly, raising HDL cholesterol induced by cholesteryl ester transfer protein (CETP) inhibition is an attractive approach for reducing the residual risk of cardiovascular events that persist in many patients receiving low-density LDL cholesterol-lowering therapy with statins. The development of torcetrapib, a CETP inhibitor, was terminated due to its adverse cardiovascular effects. These adverse effects did not influence the mechanism of CETP inhibition, but affected the molecule itself. Therefore a CETP modulator, dalcetrapib, and a CETP inhibitor, anacetrapib, are in Phase III of clinical trials to evaluate their effects on cardiovascular outcomes. In the dal-VESSEL (dalcetrapib Phase IIb endothelial function study) and the dal-PLAQUE (safety and efficacy of dalcetrapib on atherosclerotic disease using novel non-invasive multimodality imaging) clinical studies, dalcetrapib reduced CETP activity by 50% and increased HDL cholesterol levels by 31% without changing LDL cholesterol levels. Moreover, dalcetrapib was associated with a reduction in carotid vessel-wall inflammation at 6 months, as well as a reduced vessel-wall area at 24 months compared with the placebo. In the DEFINE (determining the efficacy and tolerability of CETP inhibition with anacetrapib) clinical study, anacetrapib increased HDL cholesterol levels by 138% and decreased LDL cholesterol levels by 36%. In contrast with torcetrapib, anacetrapib had no adverse cardiovascular effects. The potential of dalcetrapib and anacetrapib in the treatment of cardiovascular diseases will be revealed by two large-scale clinical trials, the dal-OUTCOMES (efficacy and safety of dalcetrapib in patients with recent acute coronary syndrome) study and the REVEAL (randomized evaluation of the effects of anacetrapib through lipid modification, a large-scale, randomized placebo-controlled trial of the clinical effects of anacetrapib among people with established vascular disease) study. The dal-OUTCOMES study is testing whether dalcetrapib can reduce cardiovascular events and the REVEAL study is testing whether anacetrapib can reduce cardiovascular events. These reports are expected to be released by 2013 and 2017, respectively.

Animal models of atherosclerosis

Atherosclerosis is a chronic inflammatory disorder that is the underlying cause of most cardiovascular disease. Both cells of the vessel wall and cells of the immune system participate in atherogenesis. This process is heavily influenced by plasma lipoproteins, genetics, and the hemodynamics of the blood flow in the artery. A variety of small and large animal models have been used to study the atherogenic process. No model is ideal as each has its own advantages and limitations with respect to manipulation of the atherogenic process and modeling human atherosclerosis or lipoprotein profile. Useful large animal models include pigs, rabbits, and nonhuman primates. Due in large part to the relative ease of genetic manipulation and the relatively short time frame for the development of atherosclerosis, murine models are currently the most extensively used. Although not all aspects of murine atherosclerosis are identical to humans, studies using murine models have suggested potential biological processes and interactions that underlie this process. As it becomes clear that different factors may influence different stages of lesion development, the use of mouse models with the ability to turn on or delete proteins or cells in tissue specific and temporal manner will be very valuable.

HOMA-IR and non-HDL-C as predictors of high cholesteryl ester transfer protein activity in patients at risk for type 2 diabetes

BACKGROUND AND AIMS

Metabolic syndrome (MS) and type 2 diabetes are highly associated with an abnormal lipoprotein profile, which may be generated and accentuated by high cholesteryl ester transfer protein (CETP) activity. Given the difficulty in measuring CETP activity, the aim was to identify simple biochemical predictors of high CETP activity.

DESIGN AND METHODS

Eighty five subjects at risk for type 2 diabetes were classified according to the presence of MS. Lipoprotein profile, HOMA-IR and endogenous CETP activity were evaluated.

RESULTS

As expected, MS patients presented higher concentration of glucose, insulin, triglycerides and non-HDL-C and lower HDL-C levels. Moreover, MS patients exhibited increased HOMA-IR and CETP activity. Employing a ROC curve for MS, high CETP activity was defined as >250%ml⁻¹ h⁻¹. The predictive variables of high CETP were non-HDL-C≥160mg/dl (OR=11.1;95%IC=3.3-38.2;p<0.001) and HOMA-IR>2.1 (OR=4.4;95%IC=1.3-14.8;p<0.05).

CONCLUSIONS

High non-HDL-C and insulin resistance were predictors for increased CETP activity which measurement is not accessible for clinical laboratories.

HCV and the hepatic lipid pathway as a potential treatment target

Atherosclerosis has been described as a liver disease of the heart [1]. The liver is the central regulatory organ of lipid pathways but since dyslipidaemias are major contributors to cardiovascular disease and type 2 diabetes rather than liver disease, research in this area has not been a major focus for hepatologists. Virus-host interaction is a continuous co-evolutionary process [2] involving the host immune system and viral escape mechanisms [3]. One of the strategies HCV has adopted to escape immune clearance and establish persistent infection is to make use of hepatic lipid pathways. This review aims to: • update the hepatologist on lipid metabolism • review the evidence that HCV exploits hepatic lipid pathways to its advantage • discuss approaches to targeting host lipid pathways as adjunctive therapy.

Lipid transfers to HDL are predictors of precocious clinical coronary heart disease

BACKGROUND

High-density-lipoprotein (HDL) has several antiatherogenic properties and, although the concentration of HDL-cholesterol negatively correlates with incidence of coronary artery disease (CAD), this is not sufficient to evaluate the overall HDL protective role. The aim was to investigate whether precocious CAD patients show abnormalities in lipid transfers to HDL, a fundamental step in HDL metabolism and function.

METHODS

Thirty normocholesterolemic CAD patients aged <50 y and 30 controls paired for sex, age and B.M.I. were studied. Fasting blood samples were collected for the in vitro lipid transfer assay and plasma lipid determination. A donor nanoemulsion labeled with radioactive free-cholesterol, cholesteryl esters, phospholipids and triglycerides was incubated with whole plasma and after chemical precipitation of non-HDL fractions, supernatant was counted for radioactivity in HDL.

RESULTS

LDL and HDL-cholesterol and triglycerides were equal in both groups. Transfers of free-cholesterol (3.8±1.2%vs 7.0±3.3%,p<0.0001) and triglycerides (3.7±1.7%vs 4.9±1.9%, p=0.0125) were diminished in CAD patients whereas cholesteryl ester transfer increased (6.5±1.9%vs 4.8±1.8%, p=0.0008); phospholipid transfer was equal (17.8±3.5% vs 19.5±3.9%).

CONCLUSION

Alterations in the transfer of lipids to HDL may constitute a new marker for precocious CAD and relation of this metabolic alteration with HDL antiatherogenic function should be investigated in future studies.

Cardiovascular complications of diabetes: recent insights in pathophysiology and therapeutics

Cardiovascular complications represent the principal cause of death in patients with Type 2 diabetes. It is therefore of great importance to dissect the genetic determinants and molecular mechanisms responsible for diabetic cardiovascular complications. New research is of particular importance since, somewhat unexpectedly, large-scale clinical trials have indicated that glycemic control does not appear to have the anticipated major influence as a factor dictating cardiovascular outcome in diabetics. Hence, additional pathophysiological factors such as dyslipidemia, as well as proinflammatory and proatherosclerotic mechanisms, need to be more carefully examined. In this article, we will focus on recent studies in both animal models and humans as well as cellular mechanistic studies that advance our knowledge on the role of dyslipidemia, inflammation and atherosclerotic events in the cardiovascular complications of diabetes. We also translate our focus on research insights to related therapeutic opportunities.

Aspartame-fed zebrafish exhibit acute deaths with swimming defects and saccharin-fed zebrafish have elevation of cholesteryl ester transfer protein activity in hypercholesterolemia

Although many artificial sweeteners (AS) have safety issues, the AS have been widely used in industry. To determine the physiologic effect of AS in the presence of hyperlipidemia, zebrafish were fed aspartame or saccharin with a high-cholesterol diet (HCD). After 12 days, 30% of zebrafish, which consumed aspartame and HCD, died with exhibiting swimming defects. The aspartame group had 65% survivability, while the control and saccharin groups had 100% survivability. Under HCD, the saccharin-fed groups had the highest increase in the serum cholesterol level (599 mg/dL). Aspartame-fed group showed a remarkable increase in serum glucose (up to 125 mg/dL), which was 58% greater than the increase in the HCD alone group. The saccharin and HCD groups had the highest cholesteryl ester transfer protein (CETP) activity (52% CE-transfer), while the HCD alone group had 42% CE-transfer. Histologic analysis revealed that the aspartame and HCD groups showed more infiltration of inflammatory cells in the brain and liver sections. Conclusively, under presence of hyperlipidemia, aspartame-fed zebrafish exhibited acute swimming defects with an increase in brain inflammation. Saccharin-fed zebrafish had an increased atherogenic serum lipid profile with elevation of CETP activity.