1,721,060 research outputs found
Statin Intolerance : Diagnosis and Remedies
Despite the efficacy of statins in reducing cardiovascular events in both primary and secondary prevention, the adherence to statin therapy is not optimal, mainly due to the occurrence of muscular adverse effects. Several risk factors may concur to the development of statin-induced myotoxicity, including patient-related factors (age, sex, and race), statin properties (dose, lipophilicity, and type of metabolism), and the concomitant administration of other drugs. Thus, the management of patients intolerant to statins, particularly those at high or very high cardiovascular risk, involves alternative therapies, including the switch to another statin or the use of intermittent dosage statin regimens, as well as nonstatin lipid lowering drugs (ezetimibe and fibrates) or new hypolipidemic drugs such as PCSK9 monoclonal antibodies, the antisense oligonucleotide against the coding region of human apolipoprotein B mRNA (mipomersen), and microsomal triglyceride transfer protein inhibitor lomitapide. Ongoing clinical trials will reveal whether the lipid-lowering effects of alternative therapies to statins can also translate into a cardiovascular benefit
Berberine, a plant alkaloid with lipid- and glucose-lowering properties : from in vitro evidence to clinical studies
Berberine (BBR) is an isoquinoline plant alkaloid endowed with several pharmacological activities, including anti-microbial, glucose- and cholesterol-lowering, anti-tumoral and immunomodulatory properties. The main mechanism by which BBR exerts a protective role in atherosclerosis relates to its cholesterol-lowering activity. BBR significantly increases hepatic low density lipoprotein receptor (LDLR) expression and reduces the expression and secretion of the LDLR modulator proprotein convertase subtilisin/kexin type 9 (PCSK9). In addition to this, several other atheroprotective effects have been ascribed to BBR, including anti-inflammatory and anti-oxidant properties, inhibition of vascular smooth muscle cell proliferation and improvement of endothelial dysfunction. BBR also increases glucose utilization in adipocytes and myocytes, while decreases glucose absorption in intestinal cells, resulting in a net hypoglycemic effect. In hypercholesterolemic animals, BBR significantly decreases LDL-C and total cholesterol (TC) levels and reduces aortic lesions, an effect similar to that of statins. In diabetic animals, BBR significantly reduces glucose levels, improves glucose tolerance, reduces body weight gain and adipose tissue mass. Several clinical studies have also tested the efficacy of BBR in humans. In hypercholesterolemic subjects, BBR induces a significant reduction of TC, triglycerides and LDL-C levels and a significant increase of HDL-C levels, without major adverse effects. BBR also reduces glycemia and plasma cholesterol in diabetic patients, improves lipid and glucose profile and decreases body mass index and waist circumference in subjects with metabolic syndrome. These findings, together with the good tolerability, suggest that BBR administration might be considered a potential therapeutic approach for the treatment of hypercholesterolemia or diabetes. Given the level of evidence available to date well-designed randomized controlled trials to test safety and efficacy of BBR are warranted
Omega-3 polyunsaturated fatty acids in the treatment of atherogenic dyslipidemia
Abstract:
Epidemiological studies have established an association between high triglycerides (TG) plasma levels and increased cardiovascular risk. Increased TG levels, commonly coupled with low HDL-C levels, are common in high cardiovascular risk subjects including those with dyslipidemia, metabolic syndrome and type 2 diabetes. Management of hypertriglyceridemia (HTG) includes lifestyle modification for mild-to-moderate HTG and pharmacological therapies for the treatment of high and very high TG levels. Among drugs, fibrates, nicotinic acid and omega-3 polyunsaturated fatty acids may be considered. Omega-3 fatty acids reduce plasma TG levels by several mechanisms; beside the effects on TG, omega-3 can also influence the levels of other lipids and lipoproteins including HDL-C and LDL-C. Clinical trials have also shown that omega-3 fatty acid supplementation is effective also when added in combination with other lipid-lowering drugs. These findings suggest that omega-3 fatty acids may be usefully considered for the management of high TG levels
Update on the management of severe hypertriglyceridemia : focus on free fatty acid forms of omega-3
High levels of plasma triglycerides (TG) are a risk factor for cardiovascular diseases, often associated with anomalies in other lipids or lipoproteins. Hypertriglyceridemia (HTG), particularly at very high levels, significantly increases also the risk of acute pancreatitis. Thus, interventions to lower TG levels are required to reduce the risk of pancreatitis and cardiovascular disease. Several strategies may be adopted for TG reduction, including lifestyle changes and pharmacological interventions. Among the available drugs, the most commonly used for HTG are fibrates, nicotinic acid, and omega-3 polyunsaturated fatty acids (usually a mixture of eicosapentaenoic acid, or EPA, and docosahexaenoic acid, or DHA). These last are available under different concentrated formulations containing high amounts of omega-3 fatty acids, including a mixture of EPA and DHA or pure EPA. The most recent formulation contains a free fatty acid (FFA) form of EPA and DHA, and exhibits a significantly higher bioavailability compared with the ethyl ester forms contained in the other formulations. This is due to the fact that the ethyl ester forms, to be absorbed, need to be hydrolyzed by the pancreatic enzymes that are secreted in response to fat intake, while the FFA do not. This higher bioavailability translates into a higher TG-lowering efficacy compared with the ethyl ester forms at equivalent doses. Omega-3 FFA are effective in reducing TG levels and other lipids in hypertriglyceridemic patients as well as in high cardiovascular risk patients treated with statins and residual HTG. Currently, omega-3 FFA formulation is under evaluation to establish whether, in high cardiovascular risk subjects, the addition of omega-3 to statin therapy may prevent or reduce major cardiovascular events
Soluble Lectin-Like Oxidized Low Density Lipoprotein Receptor-1 as a Biochemical Marker for Atherosclerosis-Related Diseases
Abstract
Lectin-like oxidized low density lipoprotein receptor-1 (LOX-1), the main oxidized low-density lipoprotein (OxLDL) in endothelial cells, is upregulated in atherosclerotic lesions and is involved in several cellular processes that regulate the pathogenesis of atherosclerosis. The LOX-1 expressed on the cell surface can be proteolytically cleaved and released in a soluble form (sLOX-1) in the circulation under pathological conditions. Serum levels of sLOX-1, in fact, are elevated at the early stages of acute coronary syndrome and are associated with coronary plaque vulnerability and with the presence of multiple complex coronary lesions. Moreover, in subjects with stable CAD, levels of serum sLOX-1 are associated with the presence of lesions in the proximal and mid-segments of the left anterior descending artery that are the most prone to rupture; in subjects undergoing percutaneous coronary intervention, baseline preprocedural serum sLOX-1 levels are associated with the incidence of periprocedural myocardial infarction. Altogether, these findings suggest that circulating levels of sLOX-1 might be a diagnostic and prognostic marker for atherosclerotic-related events
Omega-3 polyunsaturated fatty acids in the treatment of hypertriglyceridaemia
Hypertriglyceridaemia (HTG) is an independent risk factor for cardiovascular disease; high-risk patients with HTG, such as those with metabolic syndrome or diabetes, may benefit from hypolipidaemic therapies. Several lipid-lowering drugs act by reducing triglyceride (TG) levels, including fibrates, nicotinic acid and omega-3 fatty acids. The omega-3 polyunsaturated fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) dose-dependently reduce plasma TG levels; the effect tends to be greater in patients with higher TG levels at baseline. Evidence from clinical trials suggests that EPA+DHA doses of ≥ 2 g/day are required to achieve significant effects. The optimal TG-lowering doses of EPA+DHA are 3-4 g/day, with little evidence to support lipid-altering efficacy of doses of EPA and DHA <1g/day. Predicted changes in fasting serum TG levels at the recommended dietary intakes of EPA and/or DHA of 200-500 mg/day are -3.1% to -7.2%. Reductions of plasma TG levels at the optimal doses are from 25-35% up to 45% in the presence of severely elevated TG levels (≥ 500 mg/dl; ≥ 5.65 mmol/l), along with a reduction in non-high-density lipoprotein-cholesterol (non-HDL-C) and an increase in HDL-C. This observation has also been confirmed in statin-treated patients
Modified HDL: biological and physiopathological consequences
Epidemiological and clinical studies have demonstrated the inverse association between HDL cholesterol levels (HDL-C) and the risk of coronary heart disease (CHD). This correlation is believed to relate to the ability of HDL to promote reverse cholesterol transport. Remodeling of HDL due to chemical/physical modifications can dramatically affect its functions, leading to dysfunctional HDL that could promote atherogenesis. HDL modification can be achieved by different means: (i) non-enzymatic modifications, owing to the presence of free metal ions in the atherosclerotic plaques; (ii) cell-associated enzymes, which can degrade the apoproteins without significant changes in the lipid moiety, or can alternatively induce apoprotein cross-linking and lipid oxidation; (iii) association with acute phase proteins, whose circulating levels are significantly increased during inflammation which may modify HDL structure and functions; and (iv) metabolic modifications, such as glycation that occurs under hyperglycaemic conditions. Available data suggest that HDL can easily be modified losing their anti-atherogenic activities. These observation results mainly from in vitro studies, while few in vivo data, are available. Furthermore the in vivo mechanisms involved in HDL modification are ill understood. A better knowledge of these pathways may provide possible therapeutic target aimed at reducing HDL modificatio
Statins and oxidative stress during atherogenesis
Oxidised low-density lipoprotein (LDL) is believed to be the most atherogenic form of LDL. However, while a number of experimental data support this concept, the protective role of antioxidants that may prevent LDL oxidation in atherosclerosis is only partially confirmed by studies in man. Observational and epidemiological data as well as randomised trials failed to provide clear-cut indications, because of mixed results on the protective role of antioxidants against cardiovascular diseases. In spite of the lack of a general consensus, recent data reinforce the concept that a regular intake of antioxidants present in food blocks the progression of atherosclerosis and that the reduced ability of LDL to oxidise may represent a good marker to follow the action of antioxidants. Among their properties statins also possess antioxidant activities and the aim of this paper is to review the scientific evidence for such an effect and its possible clinical relevance
Proprotein Convertase Subtilisin Kexin 9 Inhibitors
High levels of low-density lipoprotein cholesterol (LDL-C) are directly associated with an increased risk of cardiovascular disease. Reducing LDL-C levels reduces the incidence of cardiovascular events. Several lipid-lowering approaches are available to achieve the LDL-C levels recommended by current guidelines, statins being the first-line therapy. However, many patients cannot achieve the recommended LDL-C levels with current therapies. The discovery of the role of proprotein convertase subtilisin kexin 9 (PCSK9) in the regulation of plasma LDL-C levels suggested it as a potential pharmacologic target and led to the development of PCSK9 inhibitors for the management of LDL-C levels
Dual effect of hypochlorite in the modification of high density lipoproteins
HDL-cholesterol levels are inversely correlated to the risk of cardiovascular disease. In recent years the concept that not only the quantity, but also the quality of HDL is related to their atheroprotective function has gained momentum. In fact several studies have showed that HDL can shift their properties from anti-atherogenic to pro-atherogenic upon chemical or enzymatic "modification". However, not all kind of modifications affect the antiatherogenic properties of HDL. For example, tyrosylation of HDL improves its ability to remove cholesterol from cultured cells and inhibits mice atherosclerotic lesion formation; oxidation of HDL(3) with 15-lipoxygenase or with copper ions for short time induce the formation of pre-β-migrating particles that are highly effective as cholesterol acceptors from lipid laden cells. Myeloperoxidase modifies HDL and apoA-I and reduces their ability to promote ABCA1-mediated cholesterol efflux. In the present study we show that modification with low concentration HOCl (a myeloperoxidase product) induces the formation of pre-β-migrating particles, thus improving the function of HDL in the reverse cholesterol transport, without affecting the anti-inflammatory activity. At higher HOCl concentration, pre-β-migrating particles were not detectable and the anti-inflammatory properties of HDL were lost. These findings suggest that during early phases of inflammation, when a low HOCl concentration is generated, changes in HDL occur that increase their ability to remove cholesterol and sparing anti-inflammatory properties; later during acute inflammation, when higher HOCl concentration are present changes in HDL occur that severely decrease their ability to remove cholesterol from macrophages and to protect endothelial cells from pro-inflammatory stimuli
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