Effect of supplementary antioxidant vitamin intake on carotid arterial wall intima-media thickness in a controlled clinical trial of cholesterol lowering

Current Status of Primary, Secondary, and Tertiary Prevention of Coronary Artery Disease

Fifty percent of all death from cardiovascular diseases is due to coronary artery disease (CAD). This is avoidable if early identification is made. Preventive health care has a major role in the fight against CAD. Atherosclerosis and atherosclerotic plaque rupture are involved in the development of CAD. Modifiable risk factors for CAD are dyslipidemia, diabetes, hypertension, cigarette smoking, obesity, chronic renal disease, chronic infection, high C-reactive protein, and hyperhomocysteinemia. CAD can be prevented by modification of risk factors. This paper defines the primary, secondary, and tertiary prevention of CAD. It discusses the mechanism of risk factor-induced atherosclerosis. This paper describes the CAD risk score and its use in the selection of individuals for primary prevention of CAD. Guidelines for primary, secondary, and tertiary prevention of CAD have been described. Modification of risk factors and use of guidelines for prevention of CAD would prevent, regress, and slow down the progression of CAD, improve the quality of life of patient, and reduce the health care cost.

Traditional Risk Factors are Causally Related to Carotid Intima-Media Thickness Progression: Inferences from Observational Cohort Studies and Interventional Trials

In the present review, associations between traditional vascular risk factors (VRFs) and carotid intimamedial thickness progression (C-IMTp) as well as the effects of therapies for VRFs control on C-IMTp were appraised to infer causality between each VRF and C-IMTp. Cohort studies indicate that smoking, binge drinking, fatness, diabetes, hypertension and hypercholesterolemia are associated with accelerated C-IMTp. An exception is physical activity, with mixed data. Interventions for the control of obesity, diabetes, hypertension and hypercholesterolemia decelerate C-IMTp. Conversely, scarce information is available regarding the effect of smoking cessation, stop of excessive alcohol intake and management of the metabolic syndrome. Altogether, these data support a causative role of several traditional VRFs on C-IMTp. Shortcomings in study design and/or ultrasonographic protocols may account for most negative studies, which underlines the importance of careful consideration of methodological aspects in investigations using C-IMTp as the outcome.

AGE-RAGE Axis in the Pathophysiology of Chronic Lower Limb Ischemia and a Novel Strategy for Its Treatment

This review focuses on the role of advanced glycation end products (AGEs) and its cell receptor (RAGE) and soluble receptor (sRAGE) in the pathogenesis of chronic lower limb ischemia (CLLI) and its treatment. CLLI is associated with atherosclerosis in lower limb arteries. AGE-RAGE axis which comprises of AGE, RAGE, and sRAGE has been implicated in atherosclerosis and restenosis. It may be involved in atherosclerosis of lower limb resulting in CLLI. Serum and tissue levels of AGE, and expression of RAGE are elevated, and the serum levels of sRAGE are decreased in CLLI. It is known that AGE, and AGE-RAGE interaction increase the generation of various atherogenic factors including reactive oxygen species, nuclear factor-kappa B, cell adhesion molecules, cytokines, monocyte chemoattractant protein-1, granulocyte macrophage-colony stimulating factor, and growth factors. sRAGE acts as antiatherogenic factor because it reduces the generation of AGE-RAGE-induced atherogenic factors. Treatment of CLLI should be targeted at lowering AGE levels through reduction of dietary intake of AGE, prevention of AGE formation and degradation of AGE, suppression of RAGE expression, blockade of AGE-RAGE binding, elevation of sRAGE by upregulating sRAGE expression, and exogenous administration of sRAGE, and use of antioxidants. In conclusion, AGE-RAGE stress defined as a shift in the balance between stressors (AGE, RAGE) and antistressor (sRAGE) in favor of stressors, initiates the development of atherosclerosis resulting in CLLI. Treatment modalities would include reduction of AGE levels and RAGE expression, RAGE blocker, elevation of sRAGE, and antioxidants for prevention, regression, and slowing of progression of CLLI.

Low serum bilirubin levels associated with subclinical atherosclerosis in patients with obstructive sleep apnea

Background

Obstructive sleep apnea (OSA) is a chronic, progressive disease that can cause cardiovascular complications and atherosclerosis. We evaluated the relationship between serum bilirubin levels and carotid intima-media thickness (cIMT), as a surrogate marker of subclinical atherosclerosis, in patients with OSA.

Methods

We enrolled 84 consecutive patients with OSA. The patients underwent ultrasonography, polysomnography, and echocardiography. Blood samples were obtained from all of the subjects, which were used for biochemical comparisons. The patients were divided into groups according to cIMT values (<0.9 vs. >0.9 mm).

Results

The patient population consisted of 84 OSA patients (mean age: 54.2 + 8.0 years, 62.9% male). The OSA patients with cIMT ≥0.9 had significantly elevated high-sensitive C-reactive protein (hsCRP), Oxygen desaturation index, apnea-hypopnea index (AHI), and significantly lower total and indirect bilirubin levels. Multivariate regression analyses revealed that total bilirubin, hsCRP, and AHI were the independent predictors of subclinical atherosclerosis. There was a negative correlation between total bilirubin and cIMT.

Conclusions

This study showed that high hsCRP and low serum total bilirubin levels could be paving the way for the development of subclinical atherosclerosis. Simple measures such as total bilirubin may provide predictive information regarding the risk of cardiovascular disease in patients with OSA.

The Effects of Omega-3 and Vitamin E Co-supplementation on Carotid Intima-media Thickness and Inflammatory Factors in Patients with Polycystic Ovary Syndrome

Objectives

We sought to evaluate the effects of omega-3 and vitamin E co-supplementation on carotid intima-media thickness (CIMT) and inflammatory factors in patients with polycystic ovary syndrome (PCOS).

Methods

This randomized, double-blind, placebo-controlled trial was done among 60 women with PCOS. Participants were randomly assigned into two groups (n = 30 each group) and assigned to take either 1000 mg omega-3 plus 400 IU vitamin E supplements or a placebo for 12 weeks.

Results

Compared with placebo, omega-3 and vitamin E co-supplementation led to significant decreases in maximum levels of left CIMT (-0.006±0.006 vs. +0.002±0.007 mm, p < 0.001), mean levels of left CIMT (-0.005±0.006 vs. +0.002±0.010 mm, p = 0.010), maximum levels of right CIMT (-0.006±0.010 vs. +0.006±0.010 mm, p = 0.010), and mean levels of right CIMT (-0.005±0.005 vs. +0.001±0.010 mm, p = 0.020). Change in high-sensitivity C-reactive protein (hs-CRP) (-390.6±942.9 vs. +237.0±754.3 ng/mL, p = 0.006) was significantly different between the supplemented patients and placebo group. We did not observe any significant effect in plasma nitric oxide (NO) values following supplementation with omega-3 plus vitamin E compared with the placebo.

Conclusions

Co-supplementation with omega-3 and vitamin E for 12 weeks among patients with PCOS had beneficial effects on CIMT and serum hs-CRP values, but unchanged NO values.

Oxidative Stress-Mediated Atherosclerosis: Mechanisms and Therapies

Atherogenesis, the formation of atherosclerotic plaques, is a complex process that involves several mechanisms, including endothelial dysfunction, neovascularization, vascular proliferation, apoptosis, matrix degradation, inflammation, and thrombosis. The pathogenesis and progression of atherosclerosis are explained differently by different scholars. One of the most common theories is the destruction of well-balanced homeostatic mechanisms, which incurs the oxidative stress. And oxidative stress is widely regarded as the redox status realized when an imbalance exists between antioxidant capability and activity species including reactive oxygen (ROS), nitrogen (RNS) and halogen species, non-radical as well as free radical species. This occurrence results in cell injury due to direct oxidation of cellular protein, lipid, and DNA or via cell death signaling pathways responsible for accelerating atherogenesis. This paper discusses inflammation, mitochondria, autophagy, apoptosis, and epigenetics as they induce oxidative stress in atherosclerosis, as well as various treatments for antioxidative stress that may prevent atherosclerosis.

α-Tocopherol and Atherosclerosis

Cardiovascular disease is the leading cause of morbidity and mortality in the Western world. There is compelling evidence incriminating oxidative stress in the pathogenesis of the atherosclerotic lesion. Several lines of evidence suggest that antioxidants, especially α-tocopherol, have potential beneficial effects with regard to cardiovascular disease. In vitro, α-tocopherol has been shown to inhibit platelet adhesion and aggregation and smooth muscle cell proliferation, exert anti-inflammatory effects on monocytes, and improve endothelial function. Also, supplementation with α-tocopherol has been shown to decrease lipid peroxidation, platelet aggregation, and pro-inflammatory activity of monocytes. However, clinical trials with α-tocopherol supplementation to date have been equivocal. Thus, although mounting in vitro evidence and animal models provide a sound scientific basis for α-tocopherol supplementation, further clinical trials are required before a definitive recommendation can be made with respect to the primary and secondary prevention of heart disease.

Association between Micronutrients Intake/Status and Carotid Intima Media Thickness: A Systematic Review

BACKGROUND

Carotid intima media thickness (IMT) is a noninvasive marker of the extent and severity of subclinical atherosclerosis. Micronutrient intake may affect atherosclerosis and play a major role in the development of cardiovascular diseases (CVDs).

OBJECTIVE

The primary aim of this review was to synthesize the evidence regarding the association between carotid IMT and selected micronutrients.

METHOD

The authors searched PubMed, Cochrane, and EMBASE databases from inception to June 2016 for selected micronutrients, CVD, carotid IMT, and antioxidants. Thirty-five original studies met the inclusion criteria and were reviewed following preferred reporting items for systematic review and meta-analysis guidelines.

RESULTS

Although not all studies found consistent results, the weight of the evidence suggests that high intakes and/or circulatory levels of magnesium, as well as vitamin D and the vitamin B group, may be associated with lower carotid IMT or reduced progression of carotid IMT. The majority of studies did not find any significant association between vitamin E and C and carotid IMT. Less evidence was available for associations of retinol, zinc, and iron with carotid IMT.

CONCLUSIONS

In general, the current evidence concerning micronutrient intake and carotid IMT is largely inconclusive. Pragmatic clinical trials are required to determine whether dietary or supplemental intake of specific micronutrients alters carotid IMT, which is a surrogate measure of cardiovascular risk.

Anti-cytokine therapy for prevention of atherosclerosis

BACKGROUND

Currently a chronic inflammation is considered to be the one of the most important reasons of the atherosclerosis progression. A huge amount of researches over the past few decades are devoted to study the various mechanisms of inflammation in the development of atherosclerotic lesions.

PURPOSE

To review current capabilities of anti-inflammatory therapy for the prevention and treatment of atherosclerosis and its clinical manifestations.

METHODS

Appropriate articles on inflammatory cytokines in atherosclerosis and anti-inflammatory prevention of atherosclerosis were searched in PubMed Database from their respective inceptions until October 2015.

SECTIONS

"The role of inflammatory cytokines in the development of atherosclerotic lesions" describes available data on the possible inflammatory mechanisms of the atherogenesis with a special attention to the role of cytokines. "Modern experience of anti-inflammatory therapy for the treatment of atherosclerosis" describes modern anti-inflammatory preparations with anti-atherosclerotic effect including natural preparations. In "the development of anti-inflammatory herbal preparation for atherosclerosis prevention" an algorithm is demonstrated that includes screening of anti-cytokine activity of different natural products, the development of the most effective combination and estimation of its effect in cell culture model, in animal model of the acute aseptic inflammation and in a pilot clinical trial. A natural preparation "Inflaminat" based on black elder berries (Sambucus nigra L.), violet tricolor herb (Viola tricolor L.) and calendula flowers (Calendula officinalis L.) possessing anti-cytokine activity was developed using the designed algorithm. The results of the following 2-year double blind placebo-controlled clinical study show that "Inflaminat" reduces carotid IMT progression, i.e. has anti-atherosclerotic effect.

CONCLUSION

Anti-cytokine therapy may be a promising direction in moderation of atherogenesis, especially when it begins on the early stages of subclinical atherosclerosis. The use of herbal preparations with anti-cytokine mechanism of action is the most perspective for timely prevention of atherosclerosis, as they have no significant side effects and can be prescribed for long-term administration.

Review: Systemic consequences of COPD

Chronic obstructive pulmonary disease (COPD) is a highly prevalent chronic lung condition, affecting ∼10% of adults over the age of 40 years in the western world. Research over the past 10 years has shown that COPD is more than just a lung disorder; it affects other end-organs including the cardiovascular and the musculoskeletal systems, making it a multi-component, multi-system disease. COPD increases the risk for ischemic heart disease, stroke, osteoporosis, cachexia, and muscle weakness by two to threefold, independent of other factors such as smoking and age. The mechanisms by which COPD affects these end-organs, however, are unclear. In this paper, we review some of the common and serious extra-pulmonary manifestations of COPD and the potential mechanisms by which they can be linked with COPD.

Pathophysiology and Medical Treatment of Carotid Artery Stenosis

Stroke is the third leading cause of mortality. Approximately 80 to 85% strokes are ischemic due to carotid artery stenosis (CAS). The prevalence of significant CAS is 7% in women and 9% in men. Severe asymptomatic CAS varies from 0 to 3.1%. Prevalence of symptomatic CAS is high in patients with peripheral arterial disease. CAS is due to atherosclerosis, the major risk factors for which include dyslipidemia, hypertension, diabetes, obesity, cigarette smoking, advanced glycation end products (AGEs) and its receptors (RAGE, soluble RAGE [sRAGE]), lack of exercise and C-reactive protein (CRP). This article discusses the basic mechanism of atherosclerosis and the mechanisms by which these risk factors induce atherosclerosis. The role of AGEs and its receptors in the development and progression of CAS has been discussed in detail. Lifestyle changes and medical treatment of CAS such as lifestyle changes, lipid-lowering agents, antihypertensive agents, antidiabetic drugs, anti-AGE therapy, measures to elevate soluble receptors of AGE (sRAGE, esRAGE). CRP-lowering agents have been discussed in detail. The drugs especially lipid-lowering agents, and antihypertensive and antidiabetic drugs suppress, regress, and slow the progression of CAS. The possible role of lowering the levels of AGEs and raising the levels of sRAGE in the treatment of CAS has been proposed. Lifestyle changes besides medical treatment have been stressed. Lifestyle changes and medical treatment not only would slow the progression of CAS but would also regress the CAS.

Self-reported menopausal symptoms, coronary artery calcification, and carotid intima-media thickness in recently menopausal women screened for the Kronos early estrogen prevention study (KEEPS)

OBJECTIVE

To determine whether self-reported menopausal symptoms are associated with measures of subclinical atherosclerosis.

DESIGN

Cross-sectional analysis.

SETTING

Multicenter, randomized controlled trial.

PATIENT(S)

Recently menopausal women (n = 868) screened for the Kronos Early Estrogen Prevention Study (KEEPS).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Baseline menopausal symptoms (hot flashes, dyspareunia, vaginal dryness, night sweats, palpitations, mood swings, depression, insomnia, irritability), serum E2 levels, and measures of atherosclerosis were assessed. Atherosclerosis was quantified using coronary artery calcium (CAC) Agatston scores (n = 771) and carotid intima-media thickness (CIMT). Logistic regression model of menopausal symptoms and E2 was used to predict CAC. Linear regression model of menopausal symptoms and E2 was used to predict CIMT. Correlation between length of time in menopause with menopausal symptoms, E2, CAC, and CIMT were assessed.

RESULT(S)

In early menopausal women screened for KEEPS, neither E2 nor climacteric symptoms predicted the extent of subclinical atherosclerosis. Palpitations and depression approached significance as predictors of CAC. Other symptoms of insomnia, irritability, dyspareunia, hot flashes, mood swings, night sweats, and vaginal dryness were not associated with CAC. Women with significantly elevated CAC scores were excluded from further participation in KEEPS; in women meeting inclusion criteria, neither baseline menopausal symptoms nor E2 predicted CIMT. Years since menopause onset correlated with CIMT, dyspareunia, vaginal dryness, and E2.

CONCLUSION(S)

Self-reported symptoms in recently menopausal women are not strong predictors of subclinical atherosclerosis. Continued follow-up of this population will be performed to determine whether baseline or persistent symptoms in the early menopause are associated with progression of cardiovascular disease.

CLINICAL TRIAL REGISTRATION NUMBER

NCT00154180.

EGb 761 promotes osteoblastogenesis, lowers bone marrow adipogenesis and atherosclerotic plaque formation

AIM OF THE STUDY

Our earlier study has demonstrated that EGb 761 (standardized extract of Ginkgo) has the bone sparing effect on the estrogen deficiency induced bone loss model. In the present study, we have addressed the question whether treatment of osteoporosis benefits arterial calcification or vice versa, because both adipocyte and osteoblast originate from the same mesenchymal cell of the bone marrow cell (BMC) population.

MATERIALS AND METHODS

Bone marrow cells were isolated to study the effect of EGb 761 on osteoblast and adipocytes. For in vivo effect hamsters were fed high fat diet and the effect of EGb 761 studied on atherosclerotic plaque formation and endothelial function.

RESULTS

BMC's undergoing induced osteogenic or adipogenic differentiations in the presence of EGb 761 show increase and decrease in mineralization and adipogenesis respectively. Osteogenic and adipogenic mRNAs, reveal lineage dependent expression patterns. Runx-2 (osteoblast transcription factor) showed a progressive increase, whereas PPAR-γ (adipogenic regulator) was attenuated, with same pattern of expression being for late osteogenic and adipogenic genes. EGb 761 led to increase in apoptotic cells and ROS, an important upstream signal. In vivo experiments in hamsters after induction with high cholesterol diet (HCD) show improvement in endothelial function by EGb 761 with lowering in total plasma cholesterol levels. EGb 761 led to vascular preservation of the aortic lumen with impairment of the endothelium dependent relaxation which was corroborated by micro-CT and histological sections of the thoracic region of the aorta.

CONCLUSION

From this data, it can be implied that EGb 761 controls bone loss, adiposity and lowers atherogenic risk factor after HCD induction.

Targeting NADPH oxidases in vascular pharmacology

Oxidative stress is a molecular dysregulation in reactive oxygen species (ROS) metabolism, which plays a key role in the pathogenesis of atherosclerosis, vascular inflammation and endothelial dysfunction. It is characterized by a loss of nitric oxide (NO) bioavailability. Large clinical trials such as HOPE and HPS have not shown a clinical benefit of antioxidant vitamin C or vitamin E treatment, putting into question the role of oxidative stress in cardiovascular disease. A change in the understanding of the molecular nature of oxidative stress has been driven by the results of these trials. Oxidative stress is no longer perceived as a simple imbalance between the production and scavenging of ROS, but as a dysfunction of enzymes involved in ROS production. NADPH oxidases are at the center of these events, underlying the dysfunction of other oxidases including eNOS uncoupling, xanthine oxidase and mitochondrial dysfunction. Thus NADPH oxidases are important therapeutic targets. Indeed, HMG-CoA reductase inhibitors (statins) as well as drugs interfering with the renin-angiotensin-aldosterone system inhibit NADPH oxidase activation and expression. Angiotensin-converting enzyme (ACE) inhibitors, AT1 receptor antagonists (sartans) and aliskiren, as well as spironolactone or eplerenone, have been discussed. Molecular aspects of NADPH oxidase regulation must be considered, while thinking about novel pharmacological targeting of this family of enzymes consisting of several homologs Nox1, Nox2, Nox3, Nox4 and Nox5 in humans. In order to properly design trials of antioxidant therapies, we must develop reliable techniques for the assessment of local and systemic oxidative stress. Classical antioxidants could be combined with novel oxidase inhibitors. In this review, we discuss NADPH oxidase inhibitors such as VAS2870, VAS3947, GK-136901, S17834 or plumbagin. Therefore, our efforts must focus on generating small molecular weight inhibitors of NADPH oxidases, allowing the selective inhibition of dysfunctional NADPH oxidase homologs. This appears to be the most reasonable approach, potentially much more efficient than non-selective scavenging of all ROS by the administration of antioxidants.

N-acetyl cysteine suppresses the foam cell formation that is induced by oxidized low density lipoprotein via regulation of gene expression

Foam cells derived from macrophages have been implicated as markers of early stage atherosclerosis development. In this study, we found that N-acetyl cysteine (NAC), a well-known inhibitor of reactive oxygen species (ROS), decreased the generation of ROS and suppressed foam cell formation in the presence of oxidized low density lipoprotein through down-regulation of cluster of differentiation 36 expression. We investigated gene expression profiles in order to determine the effects of NAC on foam cell formation using a microarray analysis. The level of apolipoprotein E, which is involved in lipid efflux, was increased and the levels of the antioxidant genes glutathione peroxidase 1 and 3 were also increased. The expression levels of the oxidative stress response and the DNA repair genes were decreased. These results were confirmed using quantitative real-time PCR. Our results indicate that oxidative stress plays an important role in foam cell formation, and that regulation of oxidation using antioxidants is a potential therapeutic method for blocking atherosclerosis development.

Association of arterial stiffness with serum bilirubin levels in established coronary artery disease

OBJECTIVE

Elevated serum bilirubin concentrations protect from atherosclerotic diseases, however it is not clear whether or not higher serum bilirubin concentrations have the same effect in coronary artery disease (CAD). The brachial-ankle pulse wave velocity (baPWV) is a reproducible method to assess arterial stiffness. This study was aimed to investigate the relationship between serum total bilirubin (TB) and baPWV in patients with established CAD.

METHODS

We enrolled 638 patients (390 men, 248 women) with established CAD. TB was divided into tertiles. Simple and multiple linear regression analyses were used to assess the correlation between baPWV and TB.

RESULTS

The mean baPWV tended to decrease in men according to TB tertiles: Tertile 1=2,126.0, Tertile 2=1,832.5, and Tertile 3=1,692.5 cm/s. Likewise, the mean baPWV tended to decrease in women according to TB tertiles: Tertile 1=1,920.8, Tertile 2=1,829.0, and Tertile 3=1,701.3 cm/s. Univariate analysis showed that age, BMI, TB, ALT, GGT, Cho, SBP, DBP, UA, and TC were significantly associated with baPWV in men. In women, age, BMI, current smoker, Cho, SBP, DBP, UA, TC, TG, HDL-C, and LDL-C were significantly associated with baPWV. BMI, LnSBP, UA, TB, LnCho, and LnTC were correlated with baPWV in men in the multivariate model. However, only LnSBP, UA, and LnHDL-C were correlated with baPWV in women. TB was found to be a significant determinant for decreased baPWV only in men (β=-0.136; p<0.001).

CONCLUSION

Our findings show that the level of total serum bilirubin is negatively correlated with arterial stiffness in men with established CAD.

Unrefined and refined black raspberry seed oils significantly lower triglycerides and moderately affect cholesterol metabolism in male Syrian hamsters

Unrefined and refined black raspberry seed oils (RSOs) were examined for their lipid-modulating effects in male Syrian hamsters fed high-cholesterol (0.12% g/g), high-fat (9% g/g) diets. Hamsters fed the refined and the unrefined RSO diets had equivalently lower plasma total cholesterol and high-density lipoprotein (HDL) cholesterol in comparison with the atherogenic coconut oil diet. The unrefined RSO treatment group did not differ in liver total and esterified cholesterol from the coconut oil-fed control animals, but the refined RSO resulted in significantly elevated liver total and esterified cholesterol concentrations. The unrefined RSO diets significantly lowered plasma triglycerides (46%; P=.0126) in comparison with the coconut oil diet, whereas the refined RSO only tended to lower plasma triglyceride (29%; P=.1630). Liver triglyceride concentrations were lower in the unrefined (46%; P=.0002) and refined (36%; P=.0005) RSO-fed animals than the coconut oil group, with the unrefined RSO diet eliciting a lower concentration than the soybean oil diet. Both RSOs demonstrated a null or moderate effect on cholesterol metabolism despite enrichment in linoleic acid, significantly lowering HDL cholesterol but not non-HDL cholesterol. Dramatically, both RSOs significantly reduced hypertriglyceridemia, most likely due to enrichment in α-linolenic acid. As a terrestrial source of α-linolenic acid, black RSOs, both refined and unrefined, provide a promising alternative to fish oil supplementation in management of hypertriglyceridemia, as demonstrated in hamsters fed high levels of dietary triglyceride and cholesterol.

Antioxidant vitamins and their use in preventing cardiovascular disease

Atherosclerosis remains one of the leading causes of death in Western populations. Subsequent to the discovery that oxidative stress plays a pivotal role in the development and progression of atherosclerosis, vitamins C and E, along with other antioxidants, were studied as potential therapies for the disease. However, while in vitro and in vivo studies showed promising antiatherogenic effects for vitamins C and E, clinical trials in which patients were given high doses of vitamin E or C showed no benefit and even possible harm. This review will attempt to summarize the known mechanistic data regarding the biochemical effects of vitamins C and E and their relevance to atherosclerosis, and offer an explanation for the failure of clinical trials to show that supplementation with these vitamins provides any benefit when given indiscriminately. We provide one example of how pharmacogenomics may be used to identify a sub-population which may indeed benefit from antioxidant supplementation.

Vitamin E and risk of cardiovascular diseases: a review of epidemiologic and clinical trial studies

Cardiovascular diseases are the leading cause of worldwide mortality. There is strong epidemiologic evidence for a beneficial effect of vitamin E on cardiovascular disease risk. However, conflicting results have been reported by intervention studies. To assess the potential benefit of vitamin E intake on the risk of cardiovascular diseases, fifty-nine published reports from observational studies, retrospective and prospective, randomised clinical trials, meta-analyses as well as pooling analyses were reviewed. The paper provides a detailed discussion about design, quality and limitations of these studies with regard to the evidence of the hypothesized relationship between vitamin E and cardiovascular diseases.

Carotenoid extraction from plants using a novel, environmentally friendly solvent

Few environmentally friendly solvents are available to extract carotenoids for use in foods. The most effective known solvents are products of the petroleum industry and toxic for human consumption. Yet carotenoid extracts are desirable for use in dietary supplements and as additives to enhance the health benefits of processed foods. Ethyl lactate is an excellent solvent to extract both trans- and cis-lycopene isomers from dried tomato powder, the extraction efficiency of which is enhanced by the addition of the antioxidants alpha-tocopherol and alpha-lipoic acid, both of which are known to benefit human health. It is also useful to extract lutein and beta-carotene from dried powders prepared from white corn and carrots. Because of its low flammability and its origin as a byproduct of the corn and soybean industries, it is more advantageous than ethyl acetate, which is a petroleum product.

Relationship between serum bilirubin and carotid atherosclerosis in hypertensive patients

OBJECTIVE

To investigate the relationship between serum bilirubin and carotid atherosclerosis in patients with hypertension.

PATIENTS AND METHODS

Carotid artery ultrasonography was performed in 198 patients (104 males, average age of 65.6+/-7.1 years) with hypertension. Serum levels of bilirubin and C-reactive proteins (CRP) were measured at the same time.

RESULTS

Carotid atherosclerosis was detected in 133 patients, 87 of them had carotid artery plaque. The prevalence of stroke (20.3%) and myocardial infarction (13.5%) in the atherosclerosis group was higher than in the non-atherosclerosis group (9.2% and 6.2%, respectively, p<0.05). The average total serum bilirubin in the atherosclerosis group was lower than in the non-atherosclerosis group (12.8+/-1.3 vs 16.8+/-1.5 micromol/L, p<0.01), whereas the average serum of CRP was higher (4.1+/-1.1 vs 2.3+/-0.7 mg/L, p<0.01). After adjusting other factors such as age, total cholesterol, diabetes and systolic blood pressure, total serum bilirubin was negatively associated with carotid atherosclerosis in women and men, with odds ratios of 0.49 (95% CI, 0.28 to 0.71; p<0.01) and 0.66 (95% CI, 0.46 to 0.80; p<0.01). Serum CRP was positively correlated to carotid atherosclerosis, with odds ratios of 1.76 (95% CI, 1.36 to 2.04; p<0.01) in women and 1.95 (95% CI, 1.46 to 2.82; p<0.01) in men.

CONCLUSION

Carotid atherosclerosis was associated with a high prevalence of stroke or myocardial infarction in hypertensive patients. Serum bilirubin was negatively associated with carotid atherosclerosis.

Is there a role for supplemented antioxidants in the prevention of atherosclerosis?

BACKGROUND

Oxidative stress is thought to play a substantial role in the pathogenesis of atherosclerosis. Supplementation of antioxidants has been studied as a strategy in the prevention of occurrence and progression of atherosclerosis.

METHOD

We searched the MEDLINE and PubMed databases (up to February 2008) for randomized, double-blind, placebo-controlled trials of antioxidant (and in particular vitamins E, C and/or beta-carotene) supplementation, published in English.

RESULTS

We identified 22 trials (N=134,590 subjects) of antioxidant supplementation for the prevention of atherosclerosis (7 primary, 13 secondary and 2 both primary and secondary). Of these studies, 10 examined the effect of a single antioxidant supplementation on primary or secondary prevention of cardiovascular disease, while 12 the effect of a combination of antioxidants.

CONCLUSION

As the majority of studies included in this review does not support a possible role of antioxidant supplementation in reducing the risk of cardiovascular disease, no definite conclusion can be drawn to justify the use of antioxidant vitamin supplements for the prevention of atherosclerotic events.

Fat and fiber consumption are associated with peripheral arterial disease in a cross-sectional study of a Japanese-Brazilian population

BACKGROUND

The Western diet plays a role for the epidemics of obesity and related diseases. This study examined a possible association between peripheral arterial disease (PAD) and the dietary components of Japanese immigrants living in Brazil.

METHODS AND RESULTS

In this cross-sectional study, 1,267 subjects (aged > or =30 years) with complete dietary, clinical and laboratory data were studied according to a standardized protocol. Ankle-to-brachial index was used to identify subjects with PAD. The overall prevalence of PAD was 14.6%. Subjects with PAD were older, had lower education and higher mean values of blood pressure, triglycerides, and fasting and 2-h plasma glucose levels compared with those without the disease. Among the subjects with PAD, the consumption of fiber from whole grains (3.0 vs 3.4 g, p=0.001) and linoleic acids (11.0 vs 11.7 g, p=0.017) were lower and intake of total (72.8 vs 69.1 g, p=0.016) and saturated fatty acids (17.4 vs 16.3 g, p=0.012) were higher than those without PAD. Results of multiple logistic regression analysis showed a significant association between PAD with high total fat intake, low intake of fiber from fruit and oleic acid, independently of other variables.

CONCLUSIONS

Despite limitations in examining the cause - effect relationship, the data support the notion that diet could be important in reducing the occurrence of PAD.

Patients at high risk for ischemic stroke: identification and actions

Atherosclerosis is a disease of chronic inflammation. It is diffuse, multisystemic and affects the vascular, metabolic and immune systems. The traditional evaluation of risk is based on methods of clinical and biological assessments, and conventional imaging. The existence of symptomatic disease and the number of symptomatic sites of atherothrombosis are critical factors in predicting the recurrence of major vascular events. However, these methods are insufficient to predict near-future episodes, above all in the individual standard clinical practice. Active treatment of modifiable risk factors such as hypertension, dyslipidemia and atrial fibrillation can reduce the number of patients who develop a stroke. There is considerable evidence suggesting that a substantial proportion of the population with high blood pressure receives insufficient treatment. More active treatment of this condition is probably the most efficient single measure. Lifestyle factors such as smoking, diet, physical inactivity and obesity contribute to the relatively high incidence of stroke. There is a need to incorporate new systemic markers and new investigation techniques in the future so as to identify the individuals at risk in the population and to administer more individualized intervention therapies.

Alpha-tocopherol supplementation prevents the exercise-induced reduction of serum paraoxonase 1/arylesterase activities in healthy individuals

OBJECTIVE

To investigate PON 1/Aryl activities in basketball players with or without alpha-T supplementation pre- and post-training. Vitamin E (alpha-tocopherol, alpha-T) reduces lipid peroxidation. Paraoxonase 1/arylesterase (PON 1/Aryl) activities are closely related to oxidation and atherogenesis.

SUBJECT/METHODS

Blood was obtained from 10 players pre- (group A), post-exercise (group B) and after 1 month on alpha-T (200 mg per 24 h orally) supplementation pre- (group C) and post-exercise (group D). Lactate, pyruvate, muscle enzyme activities, creatine kinase, lactate dehydrogenase and total antioxidant status (TAS) were measured with commercial kits. Catecholamines and alpha-T were determined with high-performance liquid chromatography methods and PON 1/Aryl activities spectrophotometrically.

RESULTS

Lactate, pyruvate, muscle enzyme activities and catecholamines were increased (P<0.001) in all groups post-training. Alpha-T levels remained unaltered pre- vs post-exercise. TAS was decreased in all the groups post training. PON 1/Aryl activities were significantly decreased post-exercise (group B) (PON1: 65+/-12 U min(-1) ml(-1), Aryl: 58+/-14 KU min(-1) ml(-1)) as compared to those pre-exercise (group A) (PON1: 142+/-16 U min(-1) ml(-1), Aryl: 114+/-12 KU min(-1) ml(-1), P<0.001). In contrast, the studied enzyme activities remained practically unaltered after alpha-T supplementation pre- vs post-training. Both enzyme activities positively correlated to TAS (r=0.60, P<0.001).

CONCLUSIONS

Alpha-T supplementation may result in protection of the enzyme PON 1/Aryl activities from free radical production.

Cellular, molecular and clinical aspects of vitamin E on atherosclerosis prevention

Randomised clinical trials and epidemiologic studies addressing the preventive effects of vitamin E supplementation against cardiovascular disease reported both positive and negative effects, and recent meta-analyses of the clinical studies were rather disappointing. In contrast to that, many animal studies clearly show a preventive action of vitamin E in several experimental settings, which can be explained by the molecular and cellular effects of vitamin E observed in cell cultures. This review is focusing on the molecular effects of vitamin E on the cells playing a role during atherosclerosis, in particular on the endothelial cells, vascular smooth muscle cells, monocytes/macrophages, T cells, and mast cells. Vitamin E may act by normalizing aberrant signal transduction and gene expression in antioxidant and non-antioxidant manners; in particular, over-expression of scavenger receptors and consequent foam cell formation can be prevented by vitamin E. In addition to that, the cellular effects of alpha-tocopheryl phosphate and of EPC-K1, a composite molecule between alpha-tocopheryl phosphate and l-ascorbic acid, are summarized.

Evaluation of oxidative stress in Insulin Dependent Diabetes Mellitus (IDDM) patients

BACKGROUND

Free radical mediated oxidative stress is mainly involved in the pathogenesis of diabetic complications. Proteins and lipids are among the prime targets for oxidative stress. In the present study, we evaluated the oxidative stress in chronic IDDM patients by estimating the lipid peroxidation, protein oxidation, and antioxidants status.

SUBJECTS AND DESIGN

A total of 35 (15 IDDM + 20 normal healthy) children were examined in the study and estimated the lipid peroxidation, protein oxidation, and antioxidants - vitamin A (beta-carotene, retinol), vitamin C, vitamin E and enzymatic antioxidants and nitric oxide.

RESULTS

A statistically significant higher values of protein carbonyl groups and MDA as lipid peroxides were observed in diabetic patients with slight reduction in the synthesis of nitric oxide. It is interesting to note that there was a decrease in the antioxidant levels with corresponding increased protein and lipid oxidation. On PAGE under native conditions, we observed decreased levels of proteins - albumin, transferrin, ceruloplasmin and heptoglobulins and variable GC globulin fractions in IDDM compared to normal healthy controls.

CONCLUSION

Hyperglycemia induces the overproduction of oxygen free radicals and consequently increases the protein oxidation and lipid oxidation. A significance difference in the mean plasma concentration of total antioxidant status was observed in IDDM patients. The findings of the present study suggest that diabetes in an altered metabolic state of oxidation-reduction and that it is convenient to give therapeutic interventions with antioxidants.

Antioxidant Vitamin Intake and Subclinical Coronary Atherosclerosis

Numerous studies have evaluated the association between antioxidants and coronary atherosclerosis but have been limited by its study among individuals with advanced atherosclerosis. The authors studied 865 consecutive patients, 39-45 years of age, without known coronary artery disease and presenting for a periodic physical examination. Antioxidant intake was assessed with the Block Dietary Questionnaire, and coronary atherosclerosis was identified by measuring coronary artery calcification using electron beam computed tomography. The mean age was 42 (+/-2), 83% were male, and the prevalence of coronary artery calcification was 20%. Vitamin supplements were used by 56% of the participants, and the mean (+/-SD) daily intake (dietary plus supplemental) of vitamins A, C, and E were 1683 mg (+/-1245), 371 mg (+/-375), and 97 mg (+/-165), respectively. There was no significant correlation between coronary artery calcification score and individual vitamin or total antioxidant vitamin intake, even after adjusting for traditional cardiac risk factors. The highest quartile of vitamin E was positively associated with calcification (odds ratio=1.77; 95% confidence interval, 1.02-3.06). Antioxidant vitamin intake is not significantly related to coronary artery calcification, implying that there is no effect on the development of early coronary atherosclerosis. High doses of vitamin E may confer an increased risk of calcified atherosclerosis.

Treatment of essential hypertension and non-insulin dependent diabetes mellitus with vitamin C

Inappropriate response of the carotid body region to encroachment of its perfusion results in essential hypertension (EH) and/or non-insulin dependent diabetes mellitus (NIDDM). This encroachment is caused by atherosclerosis. The carotid body perceives the encroachment on the lumen as a reduction in the availability of oxygen and glucose for the brain. Raising the perfusion pressure (thus, resulting in EH) and/ or inducing insulin resistance (causing NIDDM) are seen as compensatory mechanisms in response to the primary pathology, ie the encroachment of the lumen by atherosclerosis. Therefore, the reduction or reversal of the atherosclerosis process will help improve perfusion to the carotid bodies, which will in turn reduce or reverse the pathophysiological compensatory adjustments described above. A supplemental therapy, in addition to the standard treatment, with vitamin C is suggested here. The argument in favour of this suggestion is the basis of this paper. Vitamin C is a very important antioxidant. It is suggested to be used without any interference with the usual therapy prescribed for these two chronic diseases. It is recommended to be administered in small, frequent doses of 100mg every 2h, except during sleep. There is no need for compensation for the occasional missed dose. The safety of larger doses of vitamin C than the current recommendations, represents the beauty and is reassuring in recommending this approach.

Carotid intima-media thickness as a surrogate marker for cardiovascular disease in intervention studies

BACKGROUND

Cardiovascular trials using clinical endpoints to assess efficacy typically require follow-up of large numbers of participants for 3-5 years. This disadvantage has encouraged the search for well-validated surrogate markers for cardiovascular disease (CVD). These markers may provide earlier indications of efficacy in trials involving fewer participants. One approach gaining interest in recent years is the measurement of atherosclerotic progression, a major underlying cause of CVD.

SCOPE

This review article aims to further substantiate the evidence supporting the use of measurement of carotid intima-media thickness (CIMT) as a surrogate marker for atherosclerosis and cardiovascular risk.

FINDINGS

CIMT has consistently been related to future CVD events in population studies. CIMT is significantly related with other markers for CVD risk, such as elevated levels of risk factors and presence of atherosclerosis in the coronary arteries. Furthermore, almost all lipid-lowering trials and a large number of blood pressure lowering trials have consistently shown a reduction in progression of CIMT. In addition, the ultrasound technique for measuring CIMT is safe and highly reproducible.

CONCLUSION

Thus, CIMT may be used as a surrogate endpoint in clinical trials to enable the benefits of new therapies or regimens to be more rapidly translated into clinical practice.

Induction of antioxidant and detoxification response by oxidants in cardiomyocytes: evidence from gene expression profiling and activation of Nrf2 transcription factor

Mild or low doses of oxidants are known to prime cells towards resistance against further damage. In cardiomyocytes, we found that pretreatment with 100 microM H(2)O(2) prevents the cells from apoptosis induced by doxorubicin (Dox). Affymetrix microarray analyses of 28,000 genes reveal that H(2)O(2) treated cells reduced expression of genes encoding cytochrome c, mitochondrial complex I, III, IV and V and several contractile proteins. Elevated expression of antioxidant and detoxification genes appears as a dominant feature of the gene expression profile of H(2)O(2) treated cells. Most of the genes in this category contain an Antioxidant Response Element (ARE) in their promoters. Measurements of ARE promoter-reporter gene activity indicate a dose- and time-dependent activation of the ARE by H(2)O(2). Since the Nrf2 transcription factor regulates ARE-mediated gene expression, we overexpressed Nrf2 to test whether activation of Nrf2 is sufficient to induce cytoprotection. High levels of Nrf2 expression were achieved via adenovirus mediated gene delivery. Transduced Nrf2 was present in the nuclei and caused an increase in the expression of NAD(P)H:quinone oxidoreductase 1 (NQO1), a representative downstream target of Nrf2. Unlike H(2)O(2) pretreated cells, the cells expressing high levels of Nrf2 were not resistant to Dox-induced apoptosis. Therefore, the cytoprotective effect of H(2)O(2) pretreatment is not reliant upon Nrf2 activation alone as measured by resistance against Dox-induced apoptosis.

Evaluating the use of a portable ultrasound machine to quantify intima-media thickness and flow-mediated dilation: agreement between measurements from two ultrasound machines

Flow-mediated dilation (FMD) and common carotid intima-media thickness (CIMT) are intermediate endpoints for cardiovascular disease. The purpose of this study was to determine whether a portable ultrasound machine was capable of valid measurements of FMD and CIMT compared with a clinic-based machine under similar conditions. Vascular images were taken on 23 apparently healthy young adults with the portable type and clinic type instruments. The analyses revealed a high level of agreement between the two machines for measurements of mean [corrected] CIMT (mean difference [MD] = -0.025 mm, limits of agreement [LOA] = -0.080, 0.029 mm), maximum [corrected] CIMT (MD = 0.001 mm, LOA = -0.065, 0.065 mm) and FMD measures of brachial diameter (baseline MD = 0.199 mm, LOA = -0.210, 0.608 mm, maximum MD = 0.218 mm, LOA = -0.162, 0.597 mm). Reasonable agreement was found for %FMD measurements (MD = 0.27%, LOA = -4.91, 5.44%). The within-machine coefficient of variation results for mean [corrected] CIMT (5.0%), maximum [corrected] CIMT (4.3%), baseline (6.3%) and maximum (5.4%) brachial diameter and %FMD (30.1%) were comparable with normal within-subject variation. We conclude that the portable ultrasound machine can provide measurements of FMD and CIMT that are highly comparable with measurements obtained from a clinic-based machine under similar clinical conditions.

High-dose oral vitamin C partially replenishes vitamin C levels in patients with Type 2 diabetes and low vitamin C levels but does not improve endothelial dysfunction or insulin resistance

Endothelial dysfunction is a hallmark of Type 2 diabetes related to hyperglycemia and oxidative stress. Nitric oxide-dependent vasodilator actions of insulin may augment glucose disposal. Thus endothelial dysfunction may worsen insulin resistance. Intra-arterial administration of vitamin C improves endothelial dysfunction in diabetes. In the present study, we investigated effects of high-dose oral vitamin C to alter endothelial dysfunction and insulin resistance in Type 2 diabetes. Plasma vitamin C levels in 109 diabetic subjects were lower than healthy (36 ± 2 μM) levels. Thirty-two diabetic subjects with low plasma vitamin C (<40 μM) were subsequently enrolled in a randomized, double-blind, placebo-controlled study of vitamin C (800 mg/day for 4 wk). Insulin sensitivity (determined by glucose clamp) and forearm blood flow in response to ACh, sodium nitroprusside (SNP), or insulin (determined by plethysmography) were assessed before and after 4 wk of treatment. In the placebo group ( n = 17 subjects), plasma vitamin C (22 ± 3 μM), fasting glucose (159 ± 12 mg/dl), insulin (19 ± 7 μU/ml), and SIClamp [2.06 ± 0.29 × 10−4 dl·kg−1·min−1/(μU/ml)] did not change significantly after placebo treatment. In the vitamin C group ( n = 15 subjects), basal plasma vitamin C (23 ± 2 μM) increased to 48 ± 6 μM ( P < 0.01) after treatment, but this was significantly less than that expected for healthy subjects (>80 μM). No significant changes in fasting glucose (156 ± 11 mg/dl), insulin (14 ± 2 μU/ml), SIClamp [2.71 ± 0.46 × 10−4 dl·kg−1·min−1/(μU/ml)], or forearm blood flow in response to ACh, SNP, or insulin were observed after vitamin C treatment. We conclude that high-dose oral vitamin C therapy, resulting in incomplete replenishment of vitamin C levels, is ineffective at improving endothelial dysfunction and insulin resistance in Type 2 diabetes.

Role of oxidatively modified low density lipoproteins and anti-oxidants in atherothrombosis

Retrospective studies have demonstrated an association between coronary artery disease (CAD) and increased plasma levels of oxidised low density lipoproteins (LDL). A very recent prospective study in heart transplant patients has demonstrated that oxidised LDL is an independent risk factor for transplant CAD, thus further supporting the hypothesis that oxidised LDL is actively involved in the development of CAD. The increase of circulating oxidised LDL is most probably caused by back-diffusion from the atherosclerotic arterial wall in the blood, independent of plaque rupture. Indeed, plasma levels of oxidised LDL were very similar in patients with stable CAD and in patients with acute coronary syndromes. These were, however, associated with increased release of malondialdehyde (MDA)-modified LDL. Oxidised LDL may be generated by radical-mediated or by lipoxygenase or phospholipase catalysed lipid oxidation, and by myeloperoxidase catalysed protein and lipid oxidation. Prostaglandin synthesis by endothelial cells under oxidative stress and platelet activation are associated with the release of aldehydes; these induce the oxidative modification of the apolipoprotein B-100 moiety of LDL in the absence of lipid peroxidation, and thus generate MDA-modified LDL. Efficient prevention of in vivo oxidation may involve efficient cholesterol lowering, improving the anti-oxidative status of LDL by increasing the anti-oxidant content and increasing the oleate content of LDL, and by shifting the LDL away from phenotype B (characterised by small dense LDL particles). Anti-oxidative and anti-inflammatory enzymes associated with HDL may inhibit the oxidation of LDL or reverse the atherothrombotic effects of LDL.

Thematic review series: the immune system and atherogenesis. Recent insights into the biology of macrophage scavenger receptors

Scavenger receptors were originally defined by their ability to bind and internalize modified lipoproteins. Macrophages express at least six structurally different cell surface receptors for modified forms of LDL that contribute to foam cell formation in atherosclerosis. In addition to their role in the pathology of atherosclerosis, macrophage scavenger receptors, especially SR-A, play critical roles in innate immunity, apoptotic cell clearance, and tissue homeostasis. In this review, we highlight recent advances in understanding the biology of macrophage scavenger receptors as pattern recognition receptors for both infectious nonself (pathogens) and modified self (apoptotic cells and modified LDL). We critically evaluate the potential of scavenger receptors and their ligands as targets for therapeutic intervention in human disease.

Complex Multivitamin Supplementation Improves Homocysteine and Resistance to LDL-C Oxidation

OBJECTIVE

We previously reported in an open-label pilot trial that a 24-ingredient multivitamin formula favorably influenced homocysteine concentration and LDL-C oxidation indices following 24 weeks of supplementation. Our current aim was to more thoroughly examine this same formula in a randomized, placebo-controlled, clinical study.

METHODS

We examined 182 participants for selected plasma vitamin concentrations and clinically relevant variables including homocysteine, lipids and LDL-C oxidation indices at baseline and six months.

RESULTS

We found no significant differences between groups for any parameter at baseline. Following six months of vitamin supplementation, we observed elevations in plasma concentrations of vitamin B6 (as pyridoxal 5'-phosphate; PLP), vitamin B12, folate, vitamin C, vitamin E and beta-carotene (p < 0.0001), all of which were significantly greater than respective placebo group changes (p < 0.0001). Homocysteine decreased in the treatment (8.38 +/- 2.9 vs. 6.93 +/- 2.5 micro mol/L; p < 0.0001) and placebo group (8.17 +/- 3.0 vs. 7.42 +/- 2.2 micro mol/L; p < 0.0001) from baseline to six months, respectively, with reductions in the treatment group being greater than placebo (p < 0.008). LDL-C oxidation indices were also improved as LDL-C oxidation rate was decreased (-0.39 micro mol/min/g protein; p < 0.0003) and LDL-C lag time increased (11.3 min; p < 0.003) in supplemented participants. Further analysis also showed that LDL-C oxidation rate was lower (p < 0.0007) and LDL-C lag time longer (p < 0.0001) for the vitamin group than placebo treatment after six months.

CONCLUSION

We conclude that a multi-ingredient vitamin formula with antioxidant properties has measurable effects on homocysteine and LDL-C oxidation indices.

Monocyte chemoattractant protein-1 involvement in the alpha-tocopherol-induced reduction of atherosclerotic lesions in apolipoprotein E knockout mice

We studied the effects of alpha-tocopheryl acetate supplementation on the development of fatty streaks and its ability to modulate the expression of monocyte chemoattractant protein (MCP)-1 in aortic lesions of apolipoprotein E knockout mice. For this purpose, 16-week-old apolipoprotein E knockout mice received alpha-tocopherol supplementation (800 mg)/kg diet) for 6 weeks. After this time, total and lipoprotein cholesterol in the serum, hepatic tocopherol, aortic lesion area and MCP-1 (protein and mRNA) expression were analysed. Our present results showed that the dietary supplementation with alpha-tocopherol did not reduce serum cholesterol nor change lipoprotein profile, but it reduced the area of the aortic lesion by 55 %. The reduction in the lesion size was correlated with the reduced expression of MCP-1 mRNA and protein, as detected by real-time quantitative polymerase chain reaction and immunohistochemistry respectively. In conclusion, the results obtained here are relevant to the study of atherosclerosis, as they correlate the effectiveness of vitamin E supplementation in inhibiting the plaque formation with diminished expression of MCP-1 at the aortic lesion.

Vitamin E in cardiovascular disease: has the die been cast?

Cardiovascular disease, in particular coronary artery disease (CAD), remains the most important cause of morbidity and mortality in developed countries and, in the near future, more so in the developing world. Atherosclerotic plaque formation is the underlying basis for CAD. Growth of the plaque leads to coronary stenosis, causing a progressive decrease in blood flow that results in angina pectoris. Acute myocardial infarction and unstable angina were recently recognised as related to plaque rupture, not progressive coronary stenosis. Acute thrombus formation causes an abrupt coronary occlusion. The characteristics of the fibrin cap, contents of the plaque, rheological factors and active inflammation within the plaque contribute to plaque rupture. Oxidative processes are important in plaque formation. Oxidized low density lipoproteins (LDL) but not unoxidized LDL is engulfed by resident intimal macrophages, transforming them into foam cells which develop into fatty streaks, the precursors of the atherosclerotic plaque. Inflammation is important both in plaque formation and rupture. Animal studies have shown that antioxidants reduce plaque formation and lead to plaque stabilisation. In humans, high intakes of antioxidants are associated with lower incidence of CAD, despite high serum cholesterol levels. This observation suggests a role for inflammation in CAD and that reducing inflammation using antioxidants may ameliorate these processes. Men and women with high intakes of vitamin E were found to have less CAD. Vitamin E supplementation was associated with a significant reduction in myocardial infarction and cardiovascular events in the incidence of recurrent myocardial infarction. In the hierarchy of evidence in evidence-based medicine, data from large placebo-controlled clinical trials is considered necessary. Results from various mega-trials have not shown benefits (nor adverse effects) conferred by vitamin E supplementation, suggesting that vitamin E has no role in the treatment of CAD. These results do not seem to confirm, at the clinical level, the effect of antioxidants against active inflammation during plaque rupture. However, a closer examination of these studies showed a number of limitations, rendering them inconclusive in addressing the role of vitamin E in CAD prevention and treatment. Further studies that specifically address the issue of vitamin E in the pathogenesis of atherosclerosis and in the treatment of CAD need be performed. These studies should use the more potent antioxidant property of alpha-tocotrienol vitamin E.

Lipid standardization of serum fat-soluble antioxidant concentrations: the YALTA study

BACKGROUND

Blood lipids can influence fat-soluble antioxidant concentrations and confound their interpretation as indicators of antioxidant intake status and disease risk.

OBJECTIVES

The objectives were to identify lipoproteins that can confound the interpretation of serum fat-soluble antioxidants, to evaluate the amount of the confounding, and to recommend a method for standardizing blood concentrations of fat-soluble antioxidants.

DESIGN

Several methods of lipid standardization of fat-soluble antioxidants were evaluated in a large cohort of young adults with the use of both cross-sectional and longitudinal data analysis.

RESULTS

Tocopherol and carotenoid concentrations were associated with plasma total cholesterol and its components, LDL, HDL, and VLDL cholesterol (estimated as plasma total triacylglycerols/5), some of which were independent predictors for all of the fat-soluble antioxidants. Among supplement nonusers, the most amphipathic (polar) of the antioxidants (alpha-tocopherol, gamma-tocopherol, and zeaxanthin plus lutein) and lycopene were associated strongly with these lipid fractions (R(2) = 0.09, 0.40). Consistent with a causal association in which blood antioxidant concentrations change as blood lipid concentrations change, similar relations were found for changes in blood antioxidant and lipid concentrations over a 7-y period. Concentrations of the remaining carotenoids (beta-cryptoxanthin, alpha-carotene, and beta-carotene) had a weaker association with plasma lipoproteins (R(2) < 0.06). Similar relations were found for supplement users.

CONCLUSIONS

The simultaneous adjustment of the concentrations of tocopherols, zeaxanthin plus lutein, and lycopene for VLDL, HDL, and LDL cholesterol is recommended. This method is practical and can provide a basis for the standardization of carotenoid and tocopherol concentrations.