Cardiovascular Safety of Plant Sterol and Stanol Consumption.

Plant sterols and stanols as components of functional foods are widely used for cholesterol lowering. The regular intake of these functional foods is associated with a decrease in low density lipoprotein cholesterol of about 10 % and an increase in plasma plant sterol or stanol concentrations by about a factor of 2. There is no doubt that a decrease in low density lipoprotein cholesterol is beneficial to cardiovascular health. However, due to the concomitant increase in circulating plant sterols safety issues associated with the intake of plant sterol containing functional foods have been raised. Herein, we will review and evaluate those arguments raised against the use of plant sterols and stanols.

Expected impact of applying new 2013 AHA/ACC cholesterol guidelines criteria on the recommended lipid target achievement after acute coronary syndromes.

BACKGROUND 2013 AHA/ACC guidelines on the treatment of cholesterol advised to tailor high-intensity statin after ACS, while previous ATP-III recommended titration of statin to reach low-density lipoprotein cholesterol (LDL-C) targets. We simulated the impact of this change of paradigm on the achievement of recommended targets. METHODS Among a prospective cohort study of consecutive patients hospitalized for ACS from 2009 to 2012 at four Swiss university hospitals, we analyzed 1602 patients who survived one year after recruitment. Targets based on the previous guidelines approach was defined as (1) achievement of LDL-C target < 1.8 mmol/l, (2) reduction of LDL-C ≥ 50% or (3) intensification of statin in patients who did not reach LDL-C targets. Targets based on the 2013 AHA/ACC guidelines approach was defined as the maximization of statin therapy at high-intensity in patients aged ≤75 years and moderate- or high-intensity statin in patients >75 years. RESULTS 1578 (99%) patients were prescribed statin at discharge, with 1120 (70%) at high-intensity. 1507 patients (94%) reported taking statin at one year, with 909 (57%) at high-intensity. Among 482 patients discharged with sub-maximal statin, intensification of statin was only observed in 109 patients (23%). 773 (47%) patients reached the previous LDL-C targets, while 1014 (63%) reached the 2013 AHA/ACC guidelines targetsone year after ACS (p value < 0.001). CONCLUSION The application of the new 2013 AHA/ACC guidelines criteria would substantially increase the proportion of patients achieving recommended lipid targets one year after ACS. Clinical trial number, NCT01075868.

Effects of dietary restriction combined with different exercise programs or physical activity recommendations on blood lipids in overweight adults

Background and aim: Many exercise studies, although generally showing the beneficial effects of supervised aerobic, resistance or combined exercise on blood lipids, have sometimes reached equivocal conclusions. The aim of this study is to evaluate the impact of different programs that combined exercise and dietary restriction on blood lipids versus a clinical practice intervention for weight loss, in overweight adults. Methods: For this study 66 subjects participated in a supervised 22 weeks training program, composed of three sessions per week and they were randomized in three groups: strength training (S; n = 19), endurance training (E; n = 25), a combination of E and S (SE; n = 22). Eighteen subjects served as physical activity group (PA) that followed a clinical intervention consisted of physical activity recommendations. All groups followed the same dietary treatment, and blood samples were obtained for lipids measurements, at the beginning and end of the study. Results: Lipid profile improved in all groups. No significant differences for baseline and post-training values were observed between groups. In general, SE and PA decreased low-density lipoprotein cholesterol (LDL-C) values (p menor que 0.01). S decreased triglyceride levels (p menor que 0.01) and E, SE, and PA decreased total cholesterol levels (p menor que 0.05, p menor que 0.01 and p menor que 0.01, respectively). Conclusions: These results suggest that an intervention program of supervised exercise combined with diet restriction did not achieved further improvements in blood lipid profile than diet restriction and physical activity recommendations, in overweight adults. (Clinical Trials gov number: NCT01116856).

Análisis de los efectos de un programa nutricional y de ejercicio físico sobre el perfil lipídico en personas con sobrepeso y obesidad

Introducción. Las enfermedades cardiovasculares (ECV) son la principal causa de muerte en nuestro país. Entre los factores independientes más importantes para el desarrollo de ECV se encuentran en primer lugar las alteraciones del perfil lipídico como el aumento del colesterol total (TC), las lipoproteínas de baja densidad (LDL) y los triglicéridos (TG) y/o la disminución de las lipoproteínas de alta densidad (HDL). Entre las diferentes formas de abordar el problema para prevenir y tratar estas patologías se encuentra la modificación de los hábitos de vida a través de un programa combinado de dieta y ejercicio. La evidencia confirma la efectividad de la primera variable, sin embargo, en el empleo del ejercicio se encuentran discrepancias acerca de cuál es el modo más eficaz para mejorar el perfil lipídico. Objetivo. Estudiar los cambios en las variables del perfil lipídico y los índices lipoproteicos comparando cuatro tipos de intervención que combinan dieta y diferentes modos de ejercicio, así como, analizar otras variables independientes (género, edad y genotipo ApoE) que pueden tener influencia sobre estos cambios. Diseño de la investigación. Los datos analizados en esta tesis forman parte del estudio “PROgramas de Nutrición y Actividad Física para el tratamiento de la obesidad” (PRONAF). Se trata de un estudio clínico desarrollado en España entre el 2008 y el 2011. La metodología del estudio nos permite comparar cuatro tipos de intervención para la pérdida de peso y evaluar su impacto sobre el perfil lipídico. El diseño fue experimental aleatorizado donde a todos los participantes se les sometió a un programa de dieta equilibrada hipocalórica junto a uno de los tres modos de ejercicio (grupo de entrenamiento de fuerza, grupo de entrenamiento de resistencia y grupo de entrenamiento combinado de los modos anteriores; los cuales fueron igualados en volumen e intensidad) o grupo de recomendaciones de actividad física. Las principales variables analizadas en los estudios que comprende esta tesis doctoral fueron: HDL, LDL, TG y TC, los índices derivados de estas y variables de la composición corporal y del entrenamiento. Conclusiones. Los cuatro tipos de intervención mostraron ser favorables para mejorar las variables del perfil lipídico y los índices lipoproteicos, sin diferencias significativas entre ellos. Tras la intervención, los varones mostraron una respuesta más favorable en los cambios del perfil lipídico. El genotipo ApoE2 obtuvo una reducción mayor en la concentración de TG y TC que el genotipo ApoE3 y ApoE4. Por último, los índices lipoproteicos mejoraron tras un programa de pérdida de peso, obteniéndose mayores cambios en el grupo de dieta más entrenamiento aeróbico para los índices ApoB/ApoA-1, TG/HDL y LDL/ApoB. ABSTRACT Introduction. The main cause of death in our country is cardiovascular disease (CVD). The most important independent factors for the development of CVD are the lipid profile alterations: increased total cholesterol (TC), low density lipoprotein (LDL) and triglycerides (TG) and/or decreased high-density lipoprotein (HDL). Among the different approaches to prevent and treat these diseases is modifying the lifestyle combining a diet and exercise program. The evidence confirms the effectiveness of the first variable, however, there is still controversy about the most effective mode of exercise combined with diet to achieve improvements. Objective. To study changes in lipoprotein profile comparing four types of intervention combining diet with different modes of exercise, and to analyze the independent variables (gender, age, and ApoE genotype) that can influence these changes. Research design. The data analized in this thesis are part of the study Nutrition and Physical Activity Programs for Obesity Treatments (the PRONAF study according to its Spanish initials). This is a clinical research carried out in Spain between 2008 and 2011. The aim of this study was to compare four types of intervention to weight loss with diet combining exercise. The design was experimental randomized where all participants were subjected to follow a hypocaloric balanced diet along one of the three modes of exercise (strength training group, resistance training group and combined training group of the above modes, which were matched by volume and intensity) or physical activity recommendations group. The main variables under investigation in this thesis were: HDL, LDL, TG and TC, the lipoprotein ratios, body composition and training variables. Main outcomes. The four types of interventions shown to be favorable to improve the lipid profile and lipoprotein level, with no significant differences between intervention groups. After the intervention, the men showed a more favorable respond in lipid profile changes. The genotype ApoE2 obtained more positive changes in the concentration of TG and TC than ApoE3 and ApoE4 genotype. Last, the lipoprotein ratios improve after weight loss treatment with diet combined different modes exercise. Our results reflected greater changes for E group in apoB/ApoA1, TG/HDL and LDL/ApoB compared within different intervention groups.

The epitopes for some antiphospholipid antibodies are adducts of oxidized phospholipid and β2 glycoprotein 1 (and other proteins)

Circulating autoantibodies to phospholipids (aPLs), such as cardiolipin (CL), are found in patients with antiphospholipid antibody syndrome (APS). We recently demonstrated that many aPLs bound to CL only after it had been oxidized (OxCL), but not to a reduced CL analogue that could not undergo oxidation. We now show that the neoepitopes recognized by some aPLs consist of adducts formed between breakdown products of oxidized phospholipid and associated proteins, such as β2 glycoprotein 1 (β2GP1). Addition of human β2GP1, polylysine, native low-density lipoprotein, or apolipoprotein AI to OxCL-coated wells increased the anticardiolipin antibody (aCL) binding from APS sera that first had been diluted so that no aCL binding to OxCL could be detected. No increase in aCL binding was observed when these proteins were added to wells coated with reduced CL. The ability of β2GP1, polylysine, or low-density lipoprotein to be a “cofactor” for aCL binding to OxCL was greatly reduced when the proteins were methylated. Incubation of β2GP1 with oxidized 1-palmitoyl-2-linoleyl-[1-14C]-phosphatidylcholine (PC), but not with dipalmitoyl-[1-14C]-PC, led to formation of covalent adducts with β2GP1 recognized by APS sera. These data suggest that the reactive groups of OxCL, such as aldehydes generated during the decomposition of oxidized polyunsaturated fatty acids, form covalent adducts with β2GP1 (and other proteins) and that these are epitopes for aCLs. Knowledge that the epitopes recognized by many aPLs are adducts of oxidized phospholipid and associated proteins, including β2GP1, may give new insights into the pathogenic events underlying the clinical manifestations of APS.

Substantial narrowing of the Niemann–Pick C candidate interval by yeast artificial chromosome complementation

Niemann–Pick disease type C (NP-C) is an autosomal recessive lipidosis linked to chromosome 18q11–12, characterized by lysosomal accumulation of unesterified cholesterol and delayed induction of cholesterol-mediated homeostatic responses. This cellular phenotype is identifiable cytologically by filipin staining and biochemically by measurement of low-density lipoprotein-derived cholesterol esterification. The mutant Chinese hamster ovary cell line (CT60), which displays the NP-C cellular phenotype, was used as the recipient for a complementation assay after somatic cell fusions with normal and NP-C murine cells suggested that this Chinese hamster ovary cell line carries an alteration(s) in the hamster homolog(s) of NP-C. To narrow rapidly the candidate interval for NP-C, three overlapping yeast artificial chromosomes (YACs) spanning the 1 centimorgan human NP-C interval were introduced stably into CT60 cells and analyzed for correction of the cellular phenotype. Only YAC 911D5 complemented the NP-C phenotype, as evidenced by cytological and biochemical analyses, whereas no complementation was obtained from the other two YACs within the interval or from a YAC derived from chromosome 7. Fluorescent in situ hybridization indicated that YAC 911D5 was integrated at a single site per CT60 genome. These data substantially narrow the NP-C critical interval and should greatly simplify the identification of the gene responsible in mouse and man. This is the first demonstration of YAC complementation as a valuable adjunct strategy for positional cloning of a human gene.

Estrogen reduces atherosclerotic lesion development in apolipoprotein E-deficient mice.

We have studied the effects of endogenous and exogenous estrogen on atherosclerotic lesions in apolipoprotein E-deficient mice. Female mice ovariectomized (OVX) at weaning displayed increases (P < 0.01) in fatty streak lesions in the proximal aorta and aortic sinus compared with female mice with intact ovarian function. These differences between the OVX and sham controls were apparent in both chow- and "Western-type" diet-fed mice. Moreover, increases in lesion size following OVX occurred without changes in plasma cholesterol. Hormone replacement with subdermal 17-beta-estradiol pellets releasing either 6, 14, or 28 micrograms/day significantly decreased (P < 0.001) atherosclerotic lesion area in both male and OVX female mice. In contrast, neither 17-alpha-estradiol (28 micrograms/day) or tamoxifen (85 micrograms/day) affected lesion progression in OVX female mice. In the Western diet-fed group, exogenous estradiol markedly reduced plasma cholesterol and triglycerides, whereas, in animals fed the chow diet, exogenous estrogen and tamoxifen treatment only decreased plasma and very low density lipoprotein triglycerides. However, lesion area was only weakly correlated with plasma cholesterol and triglycerides, 0.35 and 0.44 tau values, respectively (P < 0.01). In summary, in the apolipoprotein E-deficient mouse 17-beta-estradiol protects against atherosclerotic lesion formation, and this can only be partially explained through effects on plasma lipoprotein levels.

Involvement of specific macrophage-lineage cells surrounding arterioles in barrier and scavenger function in brain cortex.

The transport of solutes between blood and brain is regulated by a specific barrier. Capillary endothelial cells of brain are known to mediate barrier function and facilitate transport. Here we report that specific cells surrounding arterioles, known as Mato's fluorescent granular perithelial (FGP) cells or perivascular microglial cells, contribute to the barrier function. Immunohistochemical and in situ hybridization studies indicate that, in normal brain cortex, type I and type II macrophage scavenger receptors are expressed only in FGP/perivascular microglial cells, and surface markers of macrophage lineage are also detected on them. These cells mediate the uptake of macromolecules, including modified low density lipoprotein, horseradish peroxidase, and ferritin injected either into the blood or into the cerebral ventricles. Accumulation of scavenged materials with aging or after the administration of a high-fat diet results in the formation of honeycomb-like foam cells and the narrowing of the lumen of arterioles in the brain cortex. These results indicate involvement of FGP/perivascular microglial cells in the barrier and scavenger functions in the central nervous system.

Mutagenesis of the human apolipoprotein B gene in a yeast artificial chromosome reveals the site of attachment for apolipoprotein(a).

Lipoprotein(a) [Lp(a)] is a lipoprotein formed by the disulfide linkage of apolipoprotein (apo) B100 of a low density lipoprotein particle to apolipoprotein(a). Prior studies have suggested that one of the C-terminal Cys residues of apo-B100 is involved in the disulfide linkage of apo-B100 to apo(a). To identify the apo-B100 Cys residue involved in the formation of Lp(a), we constructed a yeast artificial chromosome (YAC) spanning the human apo-B gene and used gene-targeting techniques to change Cys-4326 to Gly. The mutated YAC DNA was used to generate transgenic mice expressing the mutant human apo-B100 (Cys4326Gly). Unlike the wild-type human apo-B100, the mutant human apo-B100 completely lacked the ability to bind to apo(a) and form Lp(a). This study demonstrates that apo-B100 Cys-4326 is required for the assembly of Lp(a) and shows that gene targeting in YACs, followed by the generation of transgenic mice, is a useful approach for analyzing the structure of large proteins coded for by large genes.

Network Analyis Approach to Find New Candidate Genes and Pathways Involved in the Pathophysiology of Familial Hypercholesterolemia

Introduction: Familial hypercholesterolaemia (FH) is a common genetic cause of premature coronary heart disease (CHD) due to lifelong elevated plasma low-density lipoprotein (LDL) levels. Worldwide only 40 % of patients (FH+) with a clinical diagnosis of FH carry a mutation in any of the three genes (namely: LDLR, APOB, PCSK 9) that are currently known to be associated to the disease. We guess that the remaining 60 % of the patients (FH-) probably includes a high percentage of individuals with a polygenic form of dyslipidemia or an environmental form of hypercholesterolemia and a small percentage of individuals with mutations in some novel genes, never associated before with dyslipidemias. Here we present the preliminary results of an integrative approach intended to identify new candidate genes and to dissect pathways that can be dysregulated in the disease.

Using percentiles to diagnose familial hypercholesterolemia in Portugal

Aims: Familial hypercholesterolemia (FH) is a genetic disorder of lipid metabolism, clinically characterised by high levels of low-density lipoprotein cholesterol (LDL-C) that leads to cholesterol accumulation in tendons and arteries, premature atherosclerosis and increased risk of premature coronary heart disease. In 1999, the Portuguese FH Study was established at the National Institute of Health to identify the genetic cause of hypercholesterolemia in individuals with a clinical diagnosis of FH and to perform an epidemiologic study to determine the prevalence and distribution of FH in Portugal. In the last 16 years, a genetic defect was identified in 749 patients, representing 3. 7 % of the cases estimated to exist in Portugal. Index patients were included in this study using the Simon Broome (SB) criteria. However, there are different FH clinical criteria to diagnose index cases. Since there are no clinical criteria to identify relatives with FH, the aim of this work was to investigate if a diagnostic tool based on population specific 95 th percentile improves the clinical identification of Portuguese FH patients comparing with SB criteria.

Rapid Communication: Cholesterol deficiency-associated APOB mutation impacts lipid metabolism in Holstein calves and breeding bulls.

During the last months, the number of reports on Holstein calves suffering from incurable idiopathic diarrhea dramatically increased. Affected calves showed severe hypocholesterolemia and mostly died within days up to a few months after birth. This new autosomal monogenic recessive inherited fat metabolism disorder, termed cholesterol deficiency (CD), is caused by a loss of function mutation of the bovine gene. The objective of the present study was to investigate specific components of lipid metabolism in 6 homozygous for the mutation (CDS) and 6 normal Holstein calves with different genotypes. Independent of sex, CDS had significantly lower plasma concentrations of total cholesterol (TC), free cholesterol (FC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), very-low-density lipoprotein cholesterol (VLDL-C), triacylglycerides (TAG), and phospholipids (PL) compared with homozygous wild-type calves ( < 0.05). Furthermore, we studied the effect of the genotype on cholesterol metabolism in adult Holstein breeding bulls of Swissgenetics. Among a total of 254 adult males, the homozygous mutant genotype was absent, 36 bulls were heterozygous carriers (CDC), and 218 bulls were homozygous wild-type (CDF). In CDC bulls, plasma concentrations of TC, FC, HDL-C, LDL-C, VLDL-C, TAG, and PL were lower compared with CDF bulls ( < 0.05). The ratios of FC:cholesteryl esters (CE) and FC:TC were higher in CDC bulls compared with CDF bulls, whereas the ratio of CE:TC was lower in CDC bulls compared with CDF bulls ( < 0.01). In conclusion, the CD-associated mutation was shown to affect lipid metabolism in affected Holstein calves and adult breeding bulls. Besides cholesterol, the concentrations of PL, TAG, and lipoproteins also were distinctly reduced in homozygous and heterozygous carriers of the mutation. Beyond malabsorption of dietary lipids, deleterious effects of apolipoprotein B deficiency on hepatic lipid metabolism, steroid biosynthesis, and cell membrane function can be expected, which may result in unspecific symptoms of reduced fertility, growth, and health.

Homocysteine and cardiovascular disease in renal disease

Elevated homocysteine (hyperhomocysteinaemia) in renal patients is a major concern for physicians. Although cause and effect between homocysteine and cardiovascular disease (CVD) has not been established in either the general population or renal patients, there is much evidence that this relationship does exist. Purported mechanisms that may explain this effect include increases in endothelial injury, smooth muscle cell proliferation, low-density lipoprotein oxidation and changes in haemostatic balance. Renal patients have a much greater incidence of hyperhomocysteinaemia and this may be explained by decreases in either the renal or extrarenal metabolism of the compound. We conclude that data from long-term placebo-controlled trials are urgently required to determine whether hyperhomocysteinaemia in renal patients is a cause of CVD events and requires therapeutic targeting.

The relationship between antioxidant supplements and oxidative stress in renal transplant recipients: A review

Renal transplant recipients (RTRs) have elevated oxidative stress and a high incidence of cardiovascular morbidity and mortality. Although recent studies do not support the use of antioxidant supplements as a cardioprotectant in the general population, evidence suggests that RTRs may represent individuals that would benefit from this therapy. RTRs have elevated oxidative stress probably caused by the immunosuppressive therapy, and although only a small number of studies have examined the effects of antioxidant supplementation in these patients, most have reported beneficial findings. This review discusses these studies along with the rationale for the use of antioxidant supplements in RTRs and a call for more research to investigate this important topic.

Effect of atorvastatin on cyclosporine pharmacokinetics in liver transplant recipients

BACKGROUND: The development of hyperlipidemia after liver transplant is frequently treated with hydroxymethylglutaryl coenzyme A reductase inhibitors (statins) such as atorvastatin. As atorvastatin and the primary immunosuppressant drug, cyclosporine, are metabolized by the same pathway, there is the potential for an interaction. OBJECTIVE: To determine the effect of atorvastatin on cyclosporine pharmacokinetics in liver transplant recipients. METHODS: Six stable, long-term adult liver transplant recipients from a single center who developed posttransplant dyslipidemia were recruited to participate in a 14-day, open-label study of atorvastatin 10 mg/d coadministered with standard posttransplant immunosuppression using constant oral doses-of cyclosporine and corticosteroids. A 10-point pharmacokinetic profile was performed prior to and on day 14 after commencement of atorvastatin therapy. Cyclosporine concentrations were measured by HPLC-electrospray-tandem mass spectrometry. The AUC was calculated by the linear trapezoidal rule, with other parameters determined by visual inspection. RESULTS: Atorvastatin coadministration increased the cyclosporine AUC by 9% (range 0-20.6%; 3018 vs 3290 ng(.)h/mL; p = 0.04). No significant change was evident for other cyclosporine pharmacokinetic parameters. Total cholesterol and low-density lipoprotein cholesterol levels were significantly lower on day 14 than at baseline (p < 0.02). One patient developed a twofold increase in transaminases after 2 weeks of atorvastatin therapy, but no other clinical or biochemical adverse events were recorded. CONCLUSIONS: Atorvastatin coadministration increases the cyclosporine AUC by approximately 10% in stable liver transplant recipients. This change in systemic exposure to cyclosporine is of questionable clinical significance. Atorvastatin is effective in reducing cholesterol levels in liver transplant recipients.