Pharmacological Management of Dyslipidemia in Atherosclerosis: Limitations, Challenges, and New Therapeutic Opportunities.

Clinical and epidemiological studies during the last 7 decades indicated that elevated low-density lipoprotein cholesterol (LDL-C) levels and reduced high-density lipoprotein cholesterol (HDL-C) levels correlate with the pathogenesis and progression of atherosclerotic lesions in the arterial wall. This observation led to the development of LDL-C-lowering drugs for the prevention and treatment of atherosclerosis, some with greater success than others. However, a body of recent clinical evidence shows that a substantial residual cardiovascular risk exists even at very low levels of LDL-C, suggesting that new therapeutic modalities are still needed for reduction of atherosclerosis morbidity and mortality. Unfortunately, HDL-C-raising drugs developed toward this goal had disappointing results thus far. Here, we critically review the literature presenting available evidence and challenges that need to be met and discuss possible new avenues for the development of novel lipid pharmacotherapeutics to reduce the burden of atherosclerosis.

Molecular genetics of familial hypercholesterolemia in Israel-revisited.

BACKGROUND AND AIMS: Familial hypercholesterolemia (FH) is an autosomal dominant disease caused by mutations in the genes for LDL receptor (LDLR), apolipoprotein B (APOB) and proprotein convertase subtilisin/kexin type9 (PCSK9). The purpose of the current investigation was to define the current spectrum of mutations causing FH in Israel. METHODS: New families were collected through the MEDPED (Make Early Diagnosis Prevent Early Death) FH program. Molecular analysis of the LDLR, PCSK9 and APOB genes was done using High Resolution Melt and direct sequencing in 67 index cases. A 6-SNP LDL-C gene score calculation for polygenic hypercholesterolaemia was done using TaqMan genotyping. RESULTS: Mean serum cholesterol was 7.48 ± 1.89 mmol/L and the mean serum LDL-C was 5.99 ± 1.89 mmol/L. Mutations in the LDLR and APOB gene were found in 24 cases (35.8%), with 16 in LDLR, none in PCSK9 and one, p.(R3527Q), in the APOB gene, which is the first APOB mutation carrier identified in the Israeli population. Of the LDLR mutations, two were novel; p.(E140A) and a promoter variant, c.-191C > A. The c.2479G > A p.(V827I) in exon 17 of the LDLR gene was found in 8 patients (33.3% of the mutations) with modestly elevated LDL-C, but also in a compound heterozygous patient with a clinical homozygous FH phenotype, consistent with this being a "mild" FH-causing variant. A significantly higher 6-SNP LDL-C score was found in mutation-negative cases compared with a normal Caucasian cohort (p = 0.03), confirming that polygenic inheritance of common LDL-C raising SNPs can produce an FH phenocopy. CONCLUSIONS: The results indicate a different spectrum of genetic causes of FH from that found previously, in concordance with the heterogeneous and changing origins of the Israeli population, and confirm that a polygenic cause is also contributing to the FH phenotype in Israel.

Metabolic syndrome, obesity, and the risk of cancer development.

BACKGROUND: Metabolic syndrome and its components are severe global health issues that are increasing in frequency as the prevalence of obesity increases. Various studies have established a correlation between metabolic syndrome and diseases including, diabetes mellitus, non-alcoholic fatty liver disease, cirrhosis, and cardiovascular disease. In recent years, correlations have also been detected between obesity and metabolic syndrome and the prevalence of certain types of cancer. The current study examines whether obesity and metabolic syndrome components are risk factors for cancer among the adult population in Israel. METHODS: A cohort study analysis was performed of 24,987 initially healthy men and women who underwent yearly medical assessments at the Institute for Medical Screening in the Sheba Medical Center. Data from the Institute for Medical Screening database was correlated with that from the Israel Cancer Center in the Ministry of Health updated to December 2013. The correlation between metabolic syndrome, obesity, and the overall risk of cancer as well as the risks of specific types of cancer were examined. RESULTS: Of 20,444 subjects for whom complete data were available, 1535 were diagnosed with cancer during the mean follow-up time of 104.3months. In a multi-variant analysis, no significant correlation was found between metabolic syndrome or obesity and the incidence of cancer. When the data were stratified by gender and cancer type, however, a significant association between metabolic syndrome and breast cancer in women was observed (P=0.03, HR=1.67, 95% CI=1.05-2.67). CONCLUSION: Metabolic syndrome correlates with higher than expected breast cancer incidence in women.

Remembering Statins: Do Statins Have Adverse Cognitive Effects?

The issue of statin-associated cognitive impairment has been a hot topic among both patients and health care providers, especially since the U.S. Food and Drug Administration (FDA) issued a statement regarding rare postmarketing reports of ill-defined cognitive impairment associated with statin use. This statement was based on case reports, and no objective measures of cognitive function were used. Nevertheless, many patients at high risk of cardiovascular disease have expressed concerns about possible cognitive decline and may have opted to forgo statin therapy. In this overview, the evidence leading to the statement by the FDA is reviewed. Potential mechanisms of the effect of LDL cholesterol reduction and statin therapy on cognition are discussed. Evidence from observational and prospective randomized trials is summarized, leading to the conclusion that as for now, there is no good evidence that statins cause cognitive impairment to a significant degree. Reported cases seem to be rare, and a causal relationship has not been established.

[ISRAELI GUIDELINES FOR THE TREATMENT OF HYPERLIPIDEMIA - 2014 UPDATE].

Atherosclerosis is one of the leading causes of morbidity and mortality in the world, including in Israel. This document updates the clinical recommendations of the Israeli medical societies (The Society for Research, Prevention and Treatment of Atherosclerosis, The Israel Heart Society, The Israel Association of Family Physicians, The Israel Society of Internal Medicine) from 2012. The need for an update stems from new studies and from the 2013 ACC/AHA Guideline on the Treatment of Blood Cholesterol to Reduce Atherosclerotic Cardiovascular Risk in Adults. These recommendations take into account the guidelines of leading medical organizations in the world, as well as the specific circumstances and needs of the medical system in Israel.

Vitamin A-deficient diet accelerated atherogenesis in apolipoprotein E(-/-) mice and dietary ß-carotene prevents this consequence.

Vitamin A is involved in regulation of glucose concentrations, lipid metabolism, and inflammation, which are major risk factors for atherogenesis. However, the effect of vitamin A deficiency on atherogenesis has not been investigated. Therefore, the objective of the current study was to examine whether vitamin A deficiency accelerates atherogenesis in apolipoprotein E-deficient mice (apoE(-/-)). ApoE(-/-) mice were allocated into the following groups: control, fed vitamin A-containing chow diet; BC, fed chow diet fortified with Dunaliella powder containing ßc isomers; VAD, fed vitamin A-deficient diet; and VAD-BC group, fed vitamin A-deficient diet fortified with a Dunaliella powder. Following 15 weeks of treatment, liver retinol concentration had decreased significantly in the VAD group to about 30% that of control group. Vitamin A-deficient diet significantly increased both plasma cholesterol concentrations and the atherosclerotic lesion area at the aortic sinus (+61%) compared to the control group. Dietary ßc fortification inhibited the elevation in plasma cholesterol and retarded atherogenesis in mice fed the vitamin A-deficient diet. The results imply that dietary vitamin A deficiency should be examined as a risk factor for atherosclerosis and that dietary ßc, as a sole source of retinoids, can compensate for vitamin A deficiency.

[Phytosterols: another way to reduce LDL cholesterol levels].

Phytosterols are sterols found naturally in various oils from plants. Phytosterols compete with cholesterol for a place in the mixed micelles, needed for cholesterol absorption by the small intestine. As a result, cholesterol absorption, either from food or from bile salts is lowered by about 50%, leading to a towering of about 10% of blood cholesterol level, despite an increase in hepatic cholesterol synthesis. This reduction is achieved when phytosterols are given both as monotherapy, and in addition to statin therapy. The average Western diet contains about 400-800 mg of phytosterols per day, while the dose needed for lowering the blood cholesterol level is about 2-3 grams per day. Therefore, for the purpose of reducing blood cholesterol, they should be given either as phytosterol-enriched food or as supplements. The reduction in the level of LDL-choLesterol achieved with phytosterols may reduce the risk of coronary disease by about 25%. Hence, the American Heart Association recommended the consumption of phytosterols, as part of a balanced diet, for towering blood cholesterol levels.

[Prevention and treatment of atherosclerosis and cardiovascular diseases].

Atherosclerosis is one of the main causes of morbidity and mortality world-wide and specifically in Israel. These guidelines update the previous guidelines of the Israeli Society for Research, Prevention and Treatment of Atherosclerosis, published in 2005. The need for an update is based on new scientific data published in recent years necessitating changes in the recommendations for preventing and treating atherosclerosis. These guidelines were written in collaboration between all the societies outlined here and the content of this statement was approved by the delegates of these societies. The recommendations were written taking into consideration guidelines published by other international medical societies and also the specific needs of the Israeli medical system. Due to limitations of space, in the current paper we present: assessment of cardiovascular risk, smoking cessation and the treatment of dyslipidemia. Other sections including: recommendations to the general population, nutritional and physical activity recommendations, treatment of hypertension, prevention of ischemic stroke and the metabolic syndrome are available at http://www.ima.org.il/harefuah.

The metabolic effects of omega-3 plant sterol esters in mixed hyperlipidemic subjects.

PURPOSE: The aim of the current study was to evaluate the therapeutic effects of omega-3 plant sterol esters (n-3-PSE) on lipid profile and other coronary heart disease risk factors in subjects with mixed hyperlipidemia. METHODS: Ninety-one patients with mixed hyperlipidemia were randomized in a double blind fashion to receive either placebo (corn oil) or n-3-PSE. Twenty four patients dropped out or were excluded from the efficacy analysis due to protocol violation. The primary efficacy endpoint was mean change in plasma low-density lipoprotein cholesterol (LDL-C) levels after 12 weeks of treatment. Other efficacy measures included plasma lipids, lipoproteins, and high-sensitivity C-reactive protein (hsCRP) levels. Participants who completed the double-blind study were given the option to continue into an open-label, 12-weeks follow up phase. RESULTS: n-3-PSE treatment did not result in a significant change in LDL-C levels. Triglyceride levels were reduced significantly by 19% (51 mg/dL, p < 0.0001) in the n-3-PSE group in comparison with the placebo group (p = 0.025). Diastolic blood pressure and hsCRP were reduced by 7% (5.9 mmHg) and 7.8% (0.6 mg/L), respectively, and were significantly different from the placebo group (p = 0.036 and p = 0.018, respectively). CONCLUSIONS: In patients with mixed hyperlipidemia, n-3-PSE treatment may offer a safe and effective therapy for triglyceride level reduction while avoiding the typical increase in LDL-C levels associated with n-3 fatty acid treatment. The observed reduction in blood pressure and inflammation markers warrants further evaluation. The positive effect of n-3-PSE treatment was preserved at the end of the follow up phase.

Changes in triglyceride levels over time and risk of type 2 diabetes in young men.

OBJECTIVE: The association between changes in triglyceride concentrations over time and diabetes is unknown. We assessed whether two triglyceride determinations obtained 5 years apart can predict incident type 2 diabetes. RESEARCH DESIGN AND METHODS: Triglyceride levels at baseline (time 1) and 5 years later (time 2), followed by subsequent follow-up of 5.5 years, were measured in 13,953 apparently healthy men (age 26-45 years) with triglycerides <300 mg/dl (<3.39 mmol/l). RESULTS: During 76,742 person-years, 322 cases of diabetes occurred. A multivariate model adjusted for age, BMI, total cholesterol-to-HDL cholesterol ratio, family history of diabetes, fasting glucose, blood pressure, physical activity, and smoking status revealed a continuous independent rise in incident diabetes with increasing time 1 triglyceride levels (P(trend) < 0.001). Men in the lowest tertile of time 1 triglyceride levels who progressed to the highest tertile over follow-up (low-high) exhibited a hazard ratio (HR) of 12.62 (95% CI 3.52-31.34) compared with those remaining in the lowest tertile at both time points (reference group: low-low). Whereas men who were at the top triglyceride level tertile throughout follow-up (high-high) had a HR for diabetes of 7.08 (2.52-14.45), those whose triglyceride level decreased to the lowest tertile (high-low) exhibited a HR of 1.97 (0.67-6.13). Alterations in triglyceride levels during follow-up were associated with changes in BMI, physical activity, and eating breakfast habit (P < 0.05), but remained an independent modifier of diabetes risk even after adjustment for such changes. CONCLUSIONS: Two measurements of fasting triglyceride levels obtained 5 years apart can assist in identifying apparently healthy young men at increased risk for diabetes, independent of traditional risk factors and of associated changes in BMI and lifestyle parameters.

Characterisation of atherosclerotic lesions with scanning electron microscopy (SEM) of wet tissue.

Atherosclerotic cardiovascular disease (CVD) is the universal leading cause of mortality and a major cause of morbidity. Additionally, the global epidemic of diabetes is associated with considerable cardiovascular mortality risk due to accelerated premature atherosclerosis. Development of effective therapies for atherosclerosis is dependent upon improved tools to assess atherosclerotic lesion progression in animal models. We present a novel technique that utilises scanning electron microscopy (SEM) for imaging wet biological specimens, thus enabling rapid and high-resolution imaging of atherosclerotic lesions. This wet SEM technique was used in an apoE-deficient mice model for morphological characterisation of early and advanced atherosclerotic lesions. Further demonstration of lipid-rich atherosclerotic lesions was carried out with osmium tetroxide staining for cholesterol. Gold immunolabelling of specific epitopes was applied in identification of the cellular and molecular components within the atherosclerotic lesions, namely foam cells, smooth muscle cells and collagen. The wet SEM technique demonstrates an accurate and detailed structural evaluation of the pathological process of atherosclerosis. Understanding the mechanisms that precipitate the atherosclerotic process, utilising this novel technique, may assist in the development of innovative therapeutic interventions for CVD management and prevention in the general population and in those with diabetes.

[Cholesterol absorption as a target for the treatment of hypercholesterolemia].

Hypercholesterolemia is a major risk factor for atherosclerosis. HMG-CoA Reductase inhibitors (statins), which block hepatic synthesis of cholesterol, are the mainstay of therapy of hypercholesterolemia. Recent trials have demonstrated the importance of maintaining very low LDL-cholesterol levels in high-risk patients. Such low levels are sometimes hard to reach with statin monotherapy. Another source of cholesterol is intestinal absorption of dietary cholesterol and bile salts. Recent studies have elucidated the mechanism of intestinal cholesterol absorption. Ezetimibe, a specific inhibitor of cholesterol absorption can be used as an add-on therapy to statins in order to achieve treatment goals.

9-cis beta-carotene-rich powder of the alga Dunaliella bardawil increases plasma HDL-cholesterol in fibrate-treated patients.

The effect of fibrates on high density lipoprotein (HDL)-cholesterol levels is suggested to be mediated by its binding to peroxisome proliferator-activated receptor-alpha (PPARalpha). Upon ligand binding, PPARalpha heterodimerizes with the 9-cis retinoic acid receptor (RXR) and it is this heterodimer which regulates gene expression. We assessed the hypothesis that a combined treatment with fibrate plus 9-cis beta-carotene-rich powder of the alga Dunaliella bardawil, as a source of 9-cis retinoic acid, would improve the drug's effect on HDL-cholesterol levels. In an open-labeled first trial, 20 fibrate-treated men with plasma HDL-cholesterol levels below 40 mg/dl were given Dunaliella capsules, providing 60 mg beta-carotene/day, containing all-trans and 9-cis beta-carotene (1:1 ratio, w/w). Twenty-two fibrate-treated patients participated in a double-blind placebo-controlled second trial. Eleven patients were treated with Dunaliella capsules, and 11 patients were treated with beta-carotene-deficient Dunaliella capsules. Following 6 weeks of the dual treatment plasma HDL-cholesterol increased by 24.5 and 12.7% in the first and second trials, respectively (P=0.002 and 0.012). The dual treatment also increased HDL-cholesterol levels in human apolipoprotein A-I transgenic mice by 87.5% (P=0.021). The results show that a combination treatment of fibrate plus 9-cis beta-carotene-rich Dunaliella powder amplifies the effect of the drug on HDL-cholesterol levels.

[Guidelines for the prevention and treatment of atherosclerosis and cardiovasculer diseases: treatment of diabetes mellitus, dyslipidemia and the prevention of stroke].

Atherosclerosis is one of the principal causes of morbidity and mortality worldwide. The recent decades have witnessed great advances both in the identification of risk factors for the development of atherosclerosis and the treatment of its complications. This effort was rewarded with the reduction of mortality rates from cardiovascular diseases. The need for an update of the recommendations for the prevention of atherosclerosis and cardiovascular diseases stems from a large body of recently published trials, leading to fundamental changes in the way we treat patients with various levels of risk. The second part of the guidelines deals with the treatment of diabetes mellitus, dyslipidemia and the prevention of stroke.