Combined effects of ezetimibe and phytosterols on cholesterol metabolism: a randomized, controlled feeding study in humans

BACKGROUND

Both ezetimibe and phytosterols inhibit cholesterol absorption. We tested the hypothesis that the combination of ezetimibe and phytosterols is more effective than ezetimibe alone in altering cholesterol metabolism.

METHODS AND RESULTS

Twenty-one mildly hypercholesterolemic subjects completed a randomized, double-blind, placebo-controlled, triple-crossover study. Each subject received a phytosterol-controlled diet plus (1) ezetimibe placebo+phytosterol placebo, (2) 10 mg/d ezetimibe+phytosterol placebo, and (3) 10 mg/d ezetimibe+2.5 g phytosterols for 3 weeks each. All meals were prepared in a metabolic kitchen. Primary outcomes were intestinal cholesterol absorption, fecal cholesterol excretion, and low-density lipoprotein cholesterol levels. The combined treatment resulted in significantly lower intestinal cholesterol absorption (598 mg/d; 95% confidence interval [CI], 368 to 828) relative to control (2161 mg/d; 95% CI, 1112 to 3209) and ezetimibe alone (1054 mg/d; 95% CI, 546 to 1561; both P<0.0001). Fecal cholesterol excretion was significantly greater (P<0.0001) with combined treatment (962 mg/d; 95% CI, 757 to 1168) relative to control (505 mg/d; 95% CI, 386 to 625) and ezetimibe alone (794 mg/d; 95% CI, 615 to 973). Plasma low-density lipoprotein cholesterol values during treatment with control, ezetimibe alone, and ezetimibe+phytosterols averaged 129 mg/dL (95% CI, 116 to 142), 108 mg/dL (95% CI, 97 to 119), and 101 mg/dL (95% CI, 90 to 112; (P<0.0001 relative to control).

CONCLUSION

The addition of phytosterols to ezetimibe significantly enhanced the effects of ezetimibe on whole-body cholesterol metabolism and plasma low-density lipoprotein cholesterol. The large cumulative action of combined dietary and pharmacological treatment on cholesterol metabolism emphasizes the potential importance of dietary phytosterols as adjunctive therapy for the treatment of hypercholesterolemia.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00863265.

Differential effects on inhibition of cholesterol absorption by plant stanol and plant sterol esters in apoE-/- mice

AIMS

'Functional foods' supplemented with plant sterol esters (PSE) and plant stanol esters (PSA) are therapeutic options for the management of hypercholesterolaemia. However, their effects on blood monocytes, endothelial function, atherogenesis, and sterol tissue concentrations are poorly understood.

METHODS AND RESULTS

Male apoE-/- mice (n= 30) were randomized to three different diets for 6 weeks (n= 10 per group): high-cholesterol (1.25%) western-type diet (WTD), WTD + 2% PSE, and WTD + 2% PSA. Both supplements reduced serum cholesterol. WTD + PSE resulted in increased plant sterol serum concentrations and increased inflammatory Ly-6C(high) monocyte numbers. WTD + PSA increased plant stanol serum concentrations and Ly-6C-monocyte numbers, but decreased vascular superoxide release, lipid hydroperoxides, and inflammatory cytokines in aortic tissue, in plasma, and in circulating monocytes. Despite reduced serum cholesterol concentrations, both supplements impaired endothelial vasodilation compared with WTD. WTD + PSA reduced the development of atherosclerotic lesions compared with WTD alone (12.7 ± 3.7 vs. 28.3 ± 3.5%), and WTD + PSE was less effective (17.5 ± 3.7%). WTD + PSE and WTD + PSA reduced the cholesterol content in the liver, but not in the brain. However, WTD + PSE and WTD + PSA increased plant sterol and plant stanol concentrations in the liver as well as in the brain.

CONCLUSION

PSE and PSA supplementation reduced serum cholesterol, but increased plant sterol and plant stanol concentrations. Elevated levels of PSE and PSA were associated with endothelial dysfunction and increased central nervous system depositions. Atherosclerotic lesion retardation was more pronounced in WTD + PSA, coinciding with higher regenerative monocyte numbers, decreased oxidative stress, and decreased inflammatory cytokines compared with WTD + PSE.

Primary hyperlipidemias in children: effect of plant sterol supplementation on plasma lipids and markers of cholesterol synthesis and absorption

Plant sterols lower serum cholesterol concentration. Available data have confirmed the lipid-lowering efficacy in adults, while there is a relative dearth of data in children and almost exclusively restricted to subjects with familial hypercholesterolemia (FH). Aim of the present study was to evaluate the efficacy, tolerability and safety of plant sterol supplementation in children with different forms of primary hyperlipidemias. The effect of plant sterol consumption on plasma lipids was evaluated in 32 children with heterozygous FH, 13 children with Familial Combined Hyperlipidemia (FCH) and 13 children with Undefined Hypercholesterolemia (UH) in a 12-week open-label intervention study using plant sterol-enriched yoghurt. Plasma lipids and apolipoproteins were measured by routine methods. Markers of cholesterol synthesis (lathosterol) and absorption (campesterol and sitosterol) were measured by GC-MS. Tolerability and adherence to recommended regimen was very high. A significant reduction was observed in LDL-cholesterol in the three groups (10.7, 14.2 and 16.0% in FH, FCH and UH, respectively). Lathosterol concentrations were unchanged, reflecting a lack of increased synthesis of cholesterol. Of the two absorption markers, only sitosterol showed a slight but significant increase. Daily consumption of plant sterol dairy products favorably changes lipid profile by reducing LDL-cholesterol. To our knowledge, this is the first report of the use of plant sterols-enriched foods in treating children with primary hyperlipidemia such as FCH and UH, likely to be the most frequent form also in the young age in the western populations.

Cholesterol-lowering effects of plant steryl and stanyl laurate by oral administration in mice

The present study was conducted to investigate the efficacy of synthesized plant steryl and stanyl laurate in lowering the cholesterol level and to further examine the cholesterol-lowering potential of the free plant sterols and stanols dissolved in liquid emulsion on serum and liver lipids in mice by oral administration. Experimental results showed that both plant steryl and stanyl laurate could significantly decrease the serum levels of TC, LDL-C, LDL-C/HDL-C, and liver cholesterol contents and markedly increase fecal cholesterol concentrations but have no effect on serum TAG level, indicating that the produced plant steryl and stanyl laurate retained the cholesterol-lowering potential of natural plant sterols and stanols. However, no statistical difference in cholesterol-lowering efficacy was observed between plant steryl laurate and plant stanyl laurate, and free plant sterols and stanols dissolved in liquid emulsion could also significantly decrease serum cholesterol levels and markedly increase fecal cholesterol excretion. These results suggested that the esterified plant sterols/stanols had comparable effects to the free plant sterols/stanols in lowering serum TC levels but that they did gain a solubility advantage from the free plant sterols/stanols. Therefore, plant steryl/stanyl laurate could be considered as a potential nutraceutical or functional ingredient to reduce or prevent atherosclerosis and its related complications.

Role of phytosterols in lipid-lowering: current perspectives

The cholesterol-lowering effect of plant sterols was first discovered in the early 1950s. However, it is only recently that plant sterols have become clinically important, when advances in food-technology have made it possible to combine sterols with a variety of food products including margarines, yogurts, fruit juices and cereal bars. We review the clinical trial evidence of lipid-lowering efficacy of plant sterols and discuss their implications in routine clinical practice. To generate the evidence we searched the Pubmed database for English language literature, using relevant keywords and medical subject heading (MeSH) terms, and extracted the findings from recently published studies and meta-analyses on this topic. Our findings suggest that the short-term use of food supplements rich in plant sterols is a safe and effective strategy; to maximize the benefits of dietary and lifestyle therapy, either with or without statin therapy, among majority of dyslipidemic patients with need for additional lipid-lowering.

In vivo evaluation of a Poly-2p barrier cream protective effect

AIM

Theoretically, skin barrier creams reduce or even prevent the penetration into the skin by building up a physical barrier, like a thin film between the skin and the irritant. Practically, controversial experiences concerning the effectiveness of barrier creams exist. For this, we propose an in vivo method to evaluate the efficacy of barrier creams trough clinical scoring and instrumental analysis.

METHODS

Nineteen housewives with hand dermatitis in remission phase were enrolled in the study. Every patient was evaluated clinically and an arbitrary score was assigned by the investigator considering erythema, exudation, lichenification and xerosis. A score was also assigned by every patient to itching and burning. As measurement of the functional state of the skin and of the effectiveness of the barrier cream, transepidermal water loss (TEWL), corneometry, colorimetry and visco-elasticity determination were performed. To investigate the protection properties against irritant products, the 24-h irritancy patch test with sodium lauryl sulphate 1% in water was used.

RESULTS

Through the patch test technique the efficacy of the barrier cream was tested compared to other topical products containing corticosteroids, lipids, humectants or urea, with already known anti-inflammatory, lenitive or protective properties. The results showed this methods easy and fast in handling, non-invasive, standardized, and in vivo applicable for evaluation and ranking of barrier creams.

CONCLUSION

The study preparation demonstrated high tolerability and indubitable efficacy in improving the skin barrier function even towards a very well known irritant.

Effects of microcrystalline plant sterol suspension and a powdered plant sterol supplement on hypercholesterolemia in genetically obese Zucker rats

Because dietary fat appears to be an effective vehicle for dispensing plant sterols into the diet, a special plant-sterol-containing ingredient has recently been developed. This ingredient is a plant sterol suspension in oil in which the sterols are in microcrystalline form. The objective of the present study was to analyse the cholesterol-lowering effects and safety of two different plant sterol preparations, an orally administered microcrystalline plant sterol suspension (MPS) in rapeseed oil and a powdered plant sterol supplement, in obese Zucker rats. Dietary plant sterol supplements (0.5%, w/w) were given concurrently with a high cholesterol diet (HCD, 1% cholesterol and 18% fat, w/w). No significant changes in serum triglyceride, blood glucose, serum glutamate oxaloacetic transaminase and glutamic pyruvic transaminase values or body and liver weights were observed. The powdered plant sterol supplement lowered the serum cholesterol by 25% (P&lt; 0.05) and the MPS diet by 35% (P&lt; 0.001) compared with HCD by the end of the 12-week experiment. Interestingly, the plant sterol supplements also produced a marked reduction in serum ubiquinone levels, suggesting a possible effect on isoprene synthesis. Unlike the powdered plant sterol, both MPS and plain rape-seed oil decreased the serum baseline diene conjugation values, suggesting that they protect against oxidative stress-induced lipid peroxidation in rats. This lipid peroxidation diminishing effect is probably due to some antioxidative components in rapeseed oil. These findings indicate that an unesterified plant sterol, such as the microcrystalline suspension in oil, effectively prevents cholesterol absorption in obese Zucker rats.

Dietary treatment for familial hypercholesterolaemia

BACKGROUND

A cholesterol-lowering diet and several other dietary interventions have been suggested as a management approach either independently or as an adjuvant to drug therapy in children and adults with familial hypercholesterolemia. However, a consensus has yet to be reached on the most appropriate dietary treatment.

OBJECTIVES

To examine whether a cholesterol-lowering diet is more effective in reducing ischaemic heart disease and lowering cholesterol than no dietary intervention in children and adults with familial hypercholesterolaemia. Further, to compare the efficacy of supplementing a cholesterol-lowering diet with either omega-3 fatty acids, soya proteins, plant sterols or plant stanols.

SEARCH STRATEGY

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Inborn Errors of Metabolism Trials Register.Most recent search of the Group's Inborn Errors of Metabolism Trials Register: 09 October 2009.We also searched PubMed till 01 June 2008.

SELECTION CRITERIA

Randomised controlled trials, both published and unpublished, where a cholesterol-lowering diet in children and adults with familial hypercholesterolaemia has been compared to other forms of dietary treatment or to no dietary intervention were included.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the trial eligibility and methodological quality and one extracted the data, with independent verification of data extraction by a colleague.

MAIN RESULTS

In the present update, four new trials have been added making eleven trials with a total of 331 participants eligible for inclusion. Only short-term outcomes could be assessed due to the short duration of follow up in the included studies. None of the primary outcomes, (incidence of ischaemic heart disease, number of deaths and age at death) were evaluated in any of the included studies. No significant difference was noted for the majority of secondary outcomes for any of the planned comparisons. However, a significant difference was found only for the following comparison and outcome: total cholesterol levels for the comparison between plant sterols and cholesterol-lowering diet, mean difference 0.70 (95% confidence interval 0.19 to 1.21).

AUTHORS' CONCLUSIONS

No conclusions can be made about the effectiveness of a cholesterol-lowering diet, or any of the other dietary interventions suggested for familial hypercholesterolaemia, due to the lack of adequate data. Large, parallel, randomised controlled trials are needed to investigate the effectiveness of a cholesterol-lowering diet and the addition of omega-3 fatty acids, plant sterols or stanols, soya protein to a cholesterol-lowering diet.

Dose effects of dietary phytosterols on cholesterol metabolism: a controlled feeding study

BACKGROUND

Phytosterol supplementation of 2 g/d is recommended by the National Cholesterol Education Program to reduce LDL cholesterol. However, the effects of different intakes of phytosterol on cholesterol metabolism are uncertain.

OBJECTIVE

We evaluated the effects of 3 phytosterol intakes on whole-body cholesterol metabolism.

DESIGN

In this placebo-controlled, crossover feeding trial, 18 adults received a phytosterol-deficient diet (50 mg phytosterols/2000 kcal) plus beverages supplemented with 0, 400, or 2000 mg phytosterols/d for 4 wk each, in random order. All meals were prepared in a metabolic kitchen; breakfast and dinner on weekdays were eaten on site. Primary outcomes were fecal cholesterol excretion and intestinal cholesterol absorption measured with stable-isotope tracers and serum lipoprotein concentrations.

RESULTS

Phytosterol intakes (diet plus supplements) averaged 59, 459, and 2059 mg/d during the 3 diet periods. Relative to the 59-mg diet, the 459- and 2059-mg phytosterol intakes significantly (P < 0.01) increased total fecal cholesterol excretion (36 +/- 6% and 74 +/- 10%, respectively) and biliary cholesterol excretion (38 +/- 7% and 77 +/- 12%, respectively) and reduced percentage intestinal cholesterol absorption (-10 +/- 1% and -25 +/- 3%, respectively). Serum LDL cholesterol declined significantly only with the highest phytosterol dose (-8.9 +/- 2.3%); a trend was observed with the 459-mg/d dose (-5.0 +/- 2.1%; P = 0.077).

CONCLUSIONS

Dietary phytosterols in moderate and high doses favorably alter whole-body cholesterol metabolism in a dose-dependent manner. A moderate phytosterol intake (459 mg/d) can be obtained in a healthy diet without supplementation. This trial was registered at clinicaltrials.gov as NCT00860054.

Phytosterol-deficient and high-phytosterol diets developed for controlled feeding studies

Phytosterols reduce cholesterol absorption and low-density lipoprotein cholesterol concentrations, but the quantity and physiological significance of phytosterols in common diets are generally unknown because nutrient databases do not contain comprehensive phytosterol data. The primary aim of this study was to design prototype phytosterol-deficient and high-phytosterol diets for use in controlled feeding studies of the influence of phytosterols on health. A second aim was to quantify the phytosterol content of these prototype diets and three other diets consumed in the United States. This study was conducted from June 2001 to September 2008 and involved designing, preparing, and then analyzing five different diets: an experimental phytosterol-deficient control diet, a relatively high-phytosterol diet based on the Dietary Approaches to Stop Hypertension diet, American Heart Association diet, Atkins lifetime maintenance plan, and a vegan diet. A single day of meals for each diet was homogenized and the resulting composites were analyzed for free, esterified, and glycosylated phytosterols by gas chromatography. Independent samples t tests were used to compare the diets' total phytosterol content. The total phytosterol content of the experimental phytosterol-deficient diet was 64 mg/2,000 kcal, with progressively larger quantities in Atkins, American Heart Association, vegan, and the high-phytosterol Dietary Approaches to Stop Hypertension diet (163, 340, 445, and 500 mg/2,000 kcal, respectively). Glycosylated phytosterols, which are often excluded from phytosterol analyses, comprised 15.9%+/-5.9% of total phytosterols. In summary, phytosterol-deficient and high-phytosterol diets that conform to recommended macronutrient guidelines and are palatable can now be used in controlled feeding studies.

Excretion of endogenous boldione in human urine: influence of phytosterol consumption

Boldenone (17-hydroxy-androsta-1,4-diene-3-one, Bol) and boldione (androst-1,4-diene-3,17-dione, ADD), are currently listed as exogenous anabolic steroids by the World Anti-Doping Agency. However, it has been reported that these analytes can be produced endogenously. Interestingly, only for Bol a comment is included in the list on its potential endogenous origin. In this study, the endogenous origin of ADD in human urine was investigated, and the potential influence of phytosterol consumption was evaluated. We carried out a 5-week in vivo trial with both men (n=6) and women (n=6) and measured alpha-boldenone, beta-boldenone, boldione, androstenedione, beta-testosterone and alpha-testosterone in their urine using gas chromatography coupled to multiple mass spectrometry (GC-MS-MS). The results demonstrate that endogenous ADD is sporadically produced at concentrations ranging from 0.751 ng mL(-1) to 1.73 ng mL(-1), whereas endogenous Bol could not be proven. We also tested the effect of the daily consumption of a commercially available phytosterol-enriched yogurt drink on the presence of these analytes in human urine. Results from this study could not indicate a relation of ADD-excretion with the consumption of phytosterols at the recommended dose. The correlations between ADD and other steroids were consistently stronger for volunteers consuming phytosterols (test) than for those refraining from phytosterol consumption (control). Excretion of AED, bT and aT did not appear to be dependent on the consumption of phytosterols. This preliminary in vivo trial indicates the endogenous origin of boldione or ADD in human urine, independent on the presence of any structural related analytes such as phytosterols.

Plasma membrane sterols are involved in yeast's ability to adsorb polyphenolic compounds resulting from wine model solution browning

The aim of this work was to demonstrate the direct interaction between membrane sterols of yeast lees and some polymerized phenolic compounds resulting from wine model solution browning. For this purpose, we first demonstrated by measurement of steady-state fluorescence anisotropy of the cationic fluorescent TMA-DPH probe the effect of polymerized compounds from the model reactions of (+)-catechin/acetaldehyde and (+)-catechin/glyoxylic acid on the plasma membrane order of Saccharomyces cerevisiae yeast lees enriched with different sterols. In a second set of experiments, we used S. cerevisiae plasma membrane vesicles spiked with different sources of sterol (ergosterol, cholesterol or a mix of grape phytosterols) to assess the effect of the same polymerized compounds on both vesicle integrity and membrane leakiness to protons by ACMA fluorescence. All the obtained results prove that yeast membrane sterols are able to strongly interact with some polymerized compounds resulting from the browning of model solutions, likely explaining the yeast ability to adsorb polyphenolic compounds and mainly the colorless intermediate compounds of the browning reactions.

The effects of phytosterols/stanols on blood lipid profiles: a systematic review with meta-analysis

The objective of this work is to conduct a systematic review that investigates the efficacy of phytosterols/stanols in lowering lipid concentration in individuals with non-familial hypercholesterolemia. Randomized controlled intervention trials were identified through selected international journal databases and reference lists of relevant publications. Two researchers extracted data from each identified trial and only trials of sufficient quality were included in the review. Main outcomes of interest were differences between treatment and control groups in terms of low density lipoprotein cholesterol, total cholesterol, high density lipoprotein cholesterol and triacylglycerol. Of the studies reviewed, 20 out of 76 studies were of sufficient quality. The results of the systematic review indicated that phytosterols/stanols could significantly decrease low density lipoprotein cholesterol, total cholesterol and triacylglycerol in treatment groups compared with control groups and that the mean differences were [-0.35 mmol/L, 95%CI(-0.47, -0.22), p<0.00001], [-0.36 mmol/L, 95%CI(-0.46, -0.26), p<0.00001] and [-0.1 mmol/L, 95%CI(-0.16, -0.03), p=0.004] respectively. Foods enriched with 2.0 g of phytosterols/stanols per day had a significant cholesterol lowering effect.

Preferential campesterol incorporation into various tissues in apolipoprotein E*3-Leiden mice consuming plant sterols or stanols

Intestinal absorption of plant sterols and stanols is much lower as compared with that of cholesterol; and therefore, serum concentrations are low. Circulating plant sterols and stanols are incorporated into tissues. However, hardly any data are available about tissue distributions of individual plant sterols and stanols, particularly in relation to their serum concentrations. We therefore fed female apolipoprotein E*3-Leiden mice a control diet, a plant sterol-enriched diet (1g/100 g diet), or a plant stanol-enriched diet (1g/100 g diet) for 8 weeks. In the sterol group, serum cholesterol-standardized campesterol and sitosterol concentrations were, respectively, 8 and 7 times higher as compared with those in the control group. Consequently, the serum campesterol-sitosterol ratio remained essentially unchanged. Cholesterol-standardized plant sterol concentrations increased significantly in all analyzed tissues, except brain. However, the campesterol-sitosterol ratio also increased in all tissues (except in liver and spleen), suggesting that campesterol is preferentially incorporated over sitosterol in those tissues. For the stanol group, serum plant stanol concentrations also increased; but the increase was but less pronounced. We conclude that, in apolipoprotein E*3-Leiden mice, campesterol is preferentially incorporated into most tissues over sitosterol, which cannot be deduced from changes in serum concentrations.

Phytosterols dissolved in diacylglycerol oil reinforce the cholesterol-lowering effect of low-dose pravastatin treatment

BACKGROUND AND AIMS

Dietary therapy using phytosterols can reinforce statin treatment; however the value of a low-dose combination of those agents remains to be investigated. Plant sterols (PS), dissolved in diacylglycerol (DAG) oil, (PS/DAG) can be effective at a relatively low dose. The objective of the present study was to examine the effect of PS/DAG oil on blood cholesterol concentrations in hypercholesterolemic outpatients on low-dose pravastatin (10 mg/day).

METHODS AND RESULTS

The patients (n=61) were randomly assigned to one of three groups, who consumed TAG (control), DAG or PS/DAG oil. The average intake of PS from the PS/DAG oil during the test period was significantly higher than that for TAG and DAG oils (502 vs. 49 and 38 mg/day, P<0.05). Significant cholesterol-lowering effects from the baseline were observed in the case of the PS/DAG oil treatment alone. Changes in low-density lipoprotein (LDL) cholesterol were inversely correlated with baseline serum campesterol concentrations (r=-0.560, P<0.05), but not baseline LDL cholesterol concentrations. In addition, serum apolipoprotein B concentrations were reduced to a greater extent in subjects with high versus low levels of baseline campesterol (-13.2 mg/dL vs. -3.1 mg/dL, P<0.05). Furthermore, there was a mild, but significant reduction in serum lipoprotein (a) concentration from the baseline (-5.9 mg/dL), which was correlated with the reduction in serum apolipoprotein B concentration (r=0.596, P<0.05).

CONCLUSION

A low-dose combination of PS/DAG oil and pravastatin may be a useful strategy for further ameliorating blood cholesterol and lipoprotein (a) concentrations for hypercholesterolemic patients with a low response to pravastatin.

In vivo spectrophotometric evaluation of skin barrier recovery after topical application of soybean phytosterols

The skin's uppermost thin layer, stratum corneum, plays a crucial role in protecting the body against unwanted influences from the environment. Disruption of the stratum corneum, by tape stripping or chemical injury, results in epidermal recovery of the skin barrier. Soy phytosterols are widely used in the cosmetic field as active ingredients in creams and lipsticks. Furthermore, they deserve an important place among nutracosmeceuticals; in fact, after their absorption from the diet they are transferred from the plasma to the skin, playing an important role in the constitution of skin surface lipids. The aim of the present work was to study the effect of the topical application of soybean phytosterols on skin barrier recovery in human volunteers using the extent of methyl nicotinate (MN)-induced erythema in damaged skin as a parameter to evaluate the rate of stratum corneum recovery. MN was chosen as an erythematogenous substance for its capability to cause an erythema whose intensity and duration are proportional to the quantity of the substance that has entered the living epidermis over time. MN-induced erythema was monitored using reflectance spectrophotometry as a noninvasive instrumental technique. The results show clearly that soy phytosterols exert positive results on skin repair; in fact, three days after tape stripping, the sites treated with a formulation containing phytosterols showed an appreciable recovery of barrier function compared to those treated with a vehicle control without soy phytosterols.

Non-pharmacological control of plasma cholesterol levels

The importance of non-pharmacological control of plasma cholesterol levels in the population is increasing, along with the number of subjects whose plasma lipid levels are non-optimal, or frankly elevated, according to international guidelines. In this context, a panel of experts, organized and coordinated by the Nutrition Foundation of Italy, has evaluated the nutritional and lifestyle interventions to be adopted in the control of plasma cholesterol levels (and specifically of LDL cholesterol levels). This Consensus document summarizes the view of the panel on this topic, with the aim to provide an updated support to clinicians and other health professionals involved in cardiovascular prevention.

[Experience of phytosterols' application in dietetic cardiovascular diseases]

The investigation of influent of antiatherosclerotic diets with phytosterols on clinical and metabolic parameters in patients with cardiovascular diseases. Results of the study show that enrichment of a diets with phytosterols in patients with ischemic heart disease and hypertension improved clinic status, antropometric levels and lipid spectrum of blood. The research has shown, that the use in the treat-preventive purposes phytosterols is rather perspective.

Long-term phytosterol treatment alters gene expression in the liver of apo E-deficient mice

Dietary phytosterols significantly reduce plasma cholesterol concentrations and atherosclerosis in apolipoprotein E-knockout (apo E-KO) mice. We investigated the long-term effects of phytosterol treatment on gene expression in the liver of these mice. Male apo E-KO mice were fed an atherogenic diet supplemented with (n=6) or without (n=6) 2% (wt/wt) phytosterol mixtures for 14 weeks. Liver specimens were collected and stored in RNAlater immediately. mRNA was extracted and subjected to microarray analyses and real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR) assay for confirmation. Oligonuleotide microarray analysis of pooled samples (n=3) revealed that the expression of 132 genes/transcripts was significantly altered in treated animals, considering the false discovery rate (FDR) of 0.23. Real-time RT-PCR techniques confirmed these alterations in the expression of several of these genes, including Hmgcr (2.16-fold; P=.0002), Hmgcs1 (1.79-fold; P=.001), Hsd17b7 (2.11-fold; P=.028), Sqle (2.03-fold; P=.01), Cyp51 (1.8-fold; P=.001), Fads1 (1.55-fold; P=.031), Fads2 (2.17-fold; P=.047), Lpin1 (3.67-fold; P=.001), Ppargc1b (PGC-1beta; a coactivator of sterol-regulatory element-binding proteins; 1.66-fold; P=.007) and Cyp7B1 (1.81-fold; P=.025). In summary, our data suggest that long-term dietary phytosterols can alter the expression of a number of hepatic genes that regulate sterol metabolism in apo E-KO mice. It is possible that these changes are due to inhibition of cholesterol absorption, but are not a direct effect of plant sterols. Further multivariate correlation or association analysis is needed to establish the relations between changes in the expression of these genes and prevention of atherosclerosis by phytosterols.

Comparison of a dietary portfolio diet of cholesterol-lowering foods and a statin on LDL particle size phenotype in hypercholesterolaemic participants

The effect of dietv. statins on LDL particle size as a risk factor for CVD has not been examined. We compared, in the same subjects, the impact of a dietary portfolio of cholesterol-lowering foods and a statin on LDL size electrophoretic characteristics. Thirty-four hyperlipidaemic subjects completed three 1-month treatments as outpatients in random order: a very-low saturated fat diet (control); the same diet with 20 mg lovastatin; a dietary portfolio high in plant sterols (1 g/4200 kJ), soya proteins (21·4 g/4200 kJ), soluble fibres (9·8 g/4200 kJ) and almonds (14 g/4200 kJ). LDL electrophoretic characteristics were measured by non-denaturing polyacrylamide gradient gel electrophoresis of fasting plasma at 0, 2 and 4 weeks of each treatment. The reductions in plasma LDL-cholesterol levels with the dietary portfolio and with statins were comparable and were largely attributable to reductions in the estimated concentration of cholesterol within the smallest subclass of LDL (portfolio − 0·69 (se0·10) mmol/l, statin − 0·99 (se0·10) mmol/l). These were significantly greater (P < 0·01) than changes observed after the control diet ( − 0·17 (se0·08) mmol/l). Finally, baseline C-reactive protein levels were a significant predictor of the LDL size responsiveness to the dietary portfolio but not to the other treatments. The dietary portfolio, like the statin treatment, had only minor effects on several features of the LDL size phenotype, but the pronounced reduction in cholesterol levels within the small LDL fraction may provide additional cardiovascular benefit over the traditional low-fat diet of National Cholesterol Education Program Step II.