beta-carotene and Coronary-Artery-Disease

Laboratory and observational studies suggest that antioxidant and B vitamin supplementation may prevent atherosclerosis. Although trials have not shown a benefit of these supplements on clinical cardiovascular events, it is unknown whether they affect the progression of atherosclerosis as measured by imaging techniques.. The objective was to perform a meta-analysis of randomized controlled trials of the effect of vitamin-mineral supplementation on atherosclerosis progression.. We searched the MEDLINE, EMBASE, and CENTRAL databases for relevant studies. No language restrictions were applied. We separately analyzed trials using antioxidants (vitamins E and C, beta-carotene, or selenium) and trials using B vitamins (folate, vitamin B-6, or vitamin B-12). The progression of atherosclerosis was evaluated by B-mode ultrasound, intravascular ultrasound, or angiography. Effect sizes were calculated for the difference in slope of atherosclerosis progression between participants assigned to supplements and those assigned to the control group.. In trials not involving percutaneous transluminal coronary angioplasty, the pooled effect size was -0.06 (95% CI: -0.20, 0.09; 7 trials) for antioxidants and -0.93 (95% CI: -2.11, 0.26; 4 trials) for B vitamins. In trials involving percutaneous transluminal coronary angioplasty, the pooled relative risk of restenosis was 0.82 (95% CI: 0.54, 1.26; 3 trials) for antioxidants and 0.84 (95% CI: 0.34, 2.07; 2 trials) for B vitamins.. Our meta-analysis showed no evidence of a protective effect of antioxidant or B vitamin supplements on the progression of atherosclerosis, thus providing a mechanistic explanation for their lack of effect on clinical cardiovascular events.

Topics: Adult; Aged; Angiography; Angioplasty, Balloon, Coronary; Antioxidants; Ascorbic Acid; Atherosclerosis; beta Carotene; Coronary Artery Disease; Dietary Supplements; Disease Progression; Female; Folic Acid; Humans; Male; Middle Aged; Randomized Controlled Trials as Topic; Selenium; Trace Elements; Ultrasonography, Interventional; Vitamin B 12; Vitamin B 6; Vitamin E; Vitamins

The current evidence does not support the indiscriminate use of vitamins A, C, or E or beta carotene to prevent or reduce cardiovascular disease. Despite a plausible theory that antioxidants can prevent diseases caused by oxidative damage, trials thus far have not proven this. In fact, some studies found antioxidants may be harmful in some people. We review important studies of the effects of four antioxidants (vitamins A, C, and E, and beta carotene) and analyze whether the current evidence supports or confirms or rejects the presumed protective role.

Topics: Antioxidants; Ascorbic Acid; beta Carotene; Clinical Trials as Topic; Coronary Artery Disease; Dietary Supplements; Female; Humans; Lipid Peroxidation; Male; Oxidation-Reduction; Oxidative Stress; Patient Education as Topic; Prognosis; Risk Assessment; Treatment Outcome; Vitamin A; Vitamin E

Research into the oxidation of lipoproteins has yielded many new insights into the pathogenesis of atherosclerosis. However, despite lipoprotein oxidation's biologically plausible role in atherogenesis, several studies have reported inconsistent effects of antioxidants on clinical coronary end points, in sharp contrast with the studies of lipid modification with the 3-hydroxy-3-methylglutaryl coenzyme A inhibitors, or statins. There appears to be little support for the use of antioxidants in coronary prevention. However, the picture remains incomplete. What are the limitations of available antioxidant studies and the agents used? Until the picture can be clarified, lipid modification with strategies proved to reduce the risk for coronary events, such as statins or dietary changes in the style of the Mediterranean diet, should be better implemented in clinical practice.

Topics: Animals; Antioxidants; Ascorbic Acid; beta Carotene; Clinical Trials as Topic; Coronary Artery Disease; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hyperlipidemias; Probucol; Rabbits; Vitamin E

Oxidative stress occurs when there is an imbalance between free radical production and antioxidant capacity. This may be due to increased free radical formation in the body and/or loss of normal antioxidant defenses. Oxidative stress has been associated with the development of cardiovascular disease. The role of antioxidants in the primary and secondary prevention of coronary heart disease is currently under study. Although epidemiologic evidence indicates that antioxidants may decrease cardiovascular risk, clinical trial data are not conclusive. Information regarding the use and benefits of antioxidants in persons with diabetes is limited. Persons with diabetes may be more prone to oxidative stress because hyperglycemia depletes natural antioxidants and facilitates the production of free radicals. In addition, other factors such as homocysteine, insulin resistance, and aging may be contributory. This article highlights landmark clinical trials that have examined the cardioprotective effect of antioxidants. Because these trials have not been designed to study persons with diabetes, and clinical trial data for this group are not available, correlational studies are also presented. Finally, the concept of oxidative stress, the antioxidant and pro-oxidant factors that may contribute to oxidative stress, and the consequences of oxidative stress in persons with type 2 diabetes are presented. Key words: antioxidants, clinical trials,

Topics: Antioxidants; Ascorbic Acid; beta Carotene; Blood Glucose; Clinical Trials as Topic; Coronary Artery Disease; Diabetes Mellitus, Type 2; Ferritins; Homocysteine; Humans; Oxidative Stress; Reactive Oxygen Species; Vitamin E

This presentation reviews data from epidemiologic and clinical trials on antioxidant vitamins, angiotensin-converting enzyme inhibitors, and homocysteine and their effect on atherosclerotic cardiovascular disease. Each of these areas seems promising, but the results of large, on-going studies must be determined before definitive conclusions can be made as to the effectiveness of these therapies.

Topics: Adult; Aged; Angiotensin-Converting Enzyme Inhibitors; Ascorbic Acid; beta Carotene; Cohort Studies; Coronary Artery Disease; Female; Homocysteine; Humans; Male; Middle Aged; Oxidative Stress; Randomized Controlled Trials as Topic; Vitamin E

The oxidative modification of low density lipoprotein (LDL) may be an early step in atherogenesis. Furthermore, evidence of oxidized LDL has been found in vivo. The most persuasive evidence shows that supplementation of some animal models with antioxidants slows atherosclerosis. The purpose of this review is to examine the roles that vitamin E, vitamin C and beta-carotene may play in reducing LDL oxidation.. English language articles published since 1980, particularly from groups active in this field of research.. In vitro, animal, and human studies on antioxidants, LDL oxidation, and atherosclerosis were selected.. Vitamin E has shown the most consistent effects with regard to LDL oxidation. Beta-carotene appears to have only a mild or no effect on oxidizability. Ascorbate, although it is not lipophilic, can also reduce LDL oxidative susceptibility.. LDL oxidizability can be reduced by antioxidant nutrients. However, more research is needed to establish their utility in the prevention of coronary artery disease.

Topics: Animals; Antioxidants; Ascorbic Acid; beta Carotene; Carotenoids; Coronary Artery Disease; Humans; Lipoproteins, LDL; Oxidation-Reduction; Vitamin E

Topics: Antioxidants; Arteriosclerosis; Autoantigens; beta Carotene; Cardiovascular Diseases; Carotenoids; Coronary Artery Disease; Humans; Lipid Peroxidation; Lipoproteins, LDL; Male; Middle Aged; Vitamin E

Oxidative theory of atherosclerosis implies that plasma levels of lipophilic antioxidants might serve as indicators of lipoprotein oxidation in the arterial wall and as markers of the development of atherosclerosis. However, it is unknown whether the measurement of plasma antioxidants is able to reflect atherogenesis or its risk. In order to assess whether the levels of lipophilic antioxidants in human plasma can discriminate between subjects with and without atherosclerosis, we measured the lipophilic antioxidants alpha-tocopherol, gamma-tocopherol, alpha-carotene, beta-carotene and ubiquinol-10 in plasma of 34 patients with coronary heart disease (CHD) and in 40 control subjects. We found that alpha-carotene and gamma-tocopherol were significantly lower in plasma of CHD patients compared to controls. This decrease was significantly independent of whether the antioxidants were expressed as its absolute amounts in plasma (P < 0.001 for alpha-carotene, and P = 0.001 for gamma-tocopherol) or normalized to plasma lipids (P < 0.001 for both). In contrast, beta-carotene was only lower in plasma of CHD patients in comparison to controls, when normalized to the lipids (P = 0.02). Independent contributions of different parameters to the variation in these plasma antioxidants were estimated using multiple regression approach. The analysis showed that both the decrease in alpha-carotene and the decrease in gamma-tocopherol were significantly associated only with the presence of CHD (P < 0.001 for each regression), while the decrease in beta-carotene was significantly related to the presence of hyperlipidaemia (P < 0.001). In striking contrast, no decrease in plasma alpha-tocopherol and ubiquinol-10 was detected in the patient group independently of how these antioxidants were expressed. These data suggest that plasma levels of alpha-carotene and gamma-tocopherol may represent markers of atherosclerosis in humans. Measuring these antioxidants may be of clinical importance as a practical approach to assess atherogenesis and/or its risk.

Topics: Adult; Antioxidants; beta Carotene; Biomarkers; Coronary Artery Disease; Female; Humans; Lipid Peroxidation; Male; Middle Aged; Multivariate Analysis; Reference Values; Regression Analysis; Sensitivity and Specificity; Severity of Illness Index; Vitamin E

Dietary nutrients have significant effects on the risk of cardiovascular diseases. However, the results were not uniform across different countries. The study aims to determine the relative importance of dietary nutrients associated with coronary artery disease (CAD) among the Nepalese population. A hospital-based matched case-control study was carried out at Shahid Gangalal National Heart Center in Nepal. In the present study, patients with more than seventy percent stenosis in any main coronary artery branch in angiography were defined as cases, while those presenting normal coronary angiography or negative for stressed exercise test were considered controls. Dietary intakes of 612 respondents over the past 12 months were evaluated using a semi-quantitative customized food frequency questionnaire. In conditional regression model, the daily average dietary intake of β-carotene (OR: 0.54; 95%CI: 0.34, 0.87), and vitamin C (OR: 0.96; 95%CI: 0.93, 0.99) were inversely, whereas dietary carbohydrate (OR: 1.16; 95%CI: 1.1, 1.24), total fat/oil (OR: 1.47; 95%CI: 1.27, 1.69), saturated fatty acid (SFA) (OR: 1.2; 95%CI: 1.11, 1.3), cholesterol (OR: 1.01; 95%CI: 1.001, 1.014), and iron intakes (OR: 1.11; 95%CI: 1.03, 1.19) were positively linked with CAD. Moreover, in random forest analysis, the daily average dietary intakes of SFA, vitamin A, total fat/oil, β-carotene, and cholesterol were among the top five nutrients (out of 12 nutrients variables) of relative importance associated with CAD. The nutrients of relative importance imply a reasonable preventive measure in public health nutrients specific intervention to prevent CAD in a resource-poor country like Nepal. The findings are at best suggestive of a possible relationship between these nutrients and the development of CAD, but prospective cohort studies and randomized control trials will need to be performed in the Nepalese population.

Topics: Aged; Ascorbic Acid; beta Carotene; Case-Control Studies; Coronary Angiography; Coronary Artery Disease; Dietary Carbohydrates; Dietary Fats; Fatty Acids; Female; Humans; Iron; Male; Middle Aged; Models, Theoretical; Nepal; Nutrients; Nutrition Surveys; Prospective Studies; Public Health

This study was carried out to detect vulnerable coronary plaques by color fluorescent angioscopy.. Collagen fibers (CFs) mainly provide mechanical support to coronary plaques. Oxidized low-density lipoprotein (Ox-LDL) induces macrophage proliferation, which in turn destroy CFs while accumulating lipids. As such, demonstration of the absence of CFs, deposition of lipids, and the Ox-LDL may suggest plaque instability.. Fluorescence of the major components of the atherosclerotic plaques was examined by fluorescent microscopy using a 345-nm band-pass filter and 420-nm band-absorption filter (A-imaging). Fluorescence of Ox-LDL was examined using a 470-nm band-pass filter and 515-nm band-absorption filter (B-imaging) and Evans blue dye as an indicator. Fluorescence in 57 excised human coronary plaques was examined by A-imaging color fluorescent angioscopy. Oxidized LDL in 31 excised coronary plaques and in 12 plaques of 7 patients was investigated by B-imaging color fluorescent angioscopy.. Collagen I, collagen IV, and calcium exhibited blue, light blue, and white autofluorescence, respectively. In the presence of beta-carotene which coexists with lipids in the vascular wall, collagen I and IV exhibited green, collagen III and V white, cholesterol yellow, cholesteryl esters orange fluorescence. Oxidized LDL exhibited reddish brown fluorescence in the presence of Evans blue dye. Therefore, coronary plaques exhibited blue, green, white-to-light blue, or yellow-to-orange fluorescence based on plaque composition. Histological examination revealed abundant CFs without lipids in blue plaques; CFs and lipids in green plaques; meager CFs and abundant lipids in white-to-light blue plaques; and the absence of CFs and deposition of lipids, calcium, and macrophage foam cells in the thin fibrous cap in yellow-to-orange plaques, indicating that the yellow-to-orange plaques were most vulnerable. Reddish brown fluorescence characteristic of Ox-LDL was observed in excised coronary plaques, as also in patients.. Color fluorescent angioscopy provides objective information related to coronary plaque composition and may help identify unstable plaques.

Topics: Aged; Angioscopy; Autopsy; beta Carotene; Biomarkers; Calcium; Cholesterol; Collagen; Coronary Artery Disease; Coronary Vessels; Disease Progression; Female; Fluorescent Dyes; Humans; Lipoproteins, LDL; Male; Microscopy, Fluorescence; Middle Aged; Predictive Value of Tests

Cholesterol (C) and cholesteryl esters (CE) within coronary plaques are minimally visualized directly by any of the available imaging modalities in vivo. If they are rendered visible in vivo, the progression of coronary plaques and the effects of respective therapies on these plaques can be objectively evaluated.. The C and CE within human coronary plaques can be visualized by near-infrared fluorescence angioscopy (NIRFA).. By exciting at 710 ± 25 nm and emitting at 780 nm, near-infrared fluorescence (NIRF) of lipid components was examined by microscopy in vitro. Lipid components in 49 plaques of 32 excised human coronary arteries were examined by NIRFA in vitro. Coronary plaques were examined by NIRFA in 25 patients with coronary artery disease.. C, CE, and calcium (Ca) individually did not exhibit NIRF but did in the presence of β-carotene, which is known to coexist with lipids in the vascular wall. Other substances that are contained in atherosclerotic plaques did not.² The excised human coronary plaques were classified as those with NIRF and those without. The former plaques were classified into homogenous, doughnut-shaped, and spotty types. Histological examinations revealed that these image patterns were determined by the differences in the locations of C, CE, and Ca, and that those deposited within 700 μm in depth from the plaque surface were imaged by NIRFA. Homogenous, doughnut-shaped, or spotty NIRFA images were also observed in patients.. NIRFA is feasible for 2-dimensional imaging of C and CE deposited in human coronary plaques.

Topics: beta Carotene; Biomarkers; Cadaver; Calcium; Cholesterol; Cholesterol Esters; Coronary Artery Disease; Feasibility Studies; Female; Fluorescein Angiography; Humans; Japan; Male; Middle Aged; Predictive Value of Tests

The interrelationships between plasma beta-carotene, alpha-tocopherol, and the level of systemic inflammation and oxidative stress were investigated in patients with advanced coronary artery disease (CAD). Plasma beta-carotene, alpha-tocopherol, malondialdehyde, free radicals, interleukin-6, high sensitive C-reactive protein levels, and other risk factors of CAD were determined in a group of patients with advanced CAD [significant stenosis according to coronarographic examination (n=91) and a control group of examined patients with coronary arteries with no stenosis (n=49)]. Between-group differences in continuous variables were analyzed with the Hotelling T2-test (software NCSS2000), analyses of correlation matrix with the software STATISTICA. Advanced CAD coincided with significantly lower plasma concentrations of high-density lipoprotein (HDL)-cholesterol and beta-carotene as well as with elevated levels of all inflammatory markers, but only with mild increase of oxidative stress. Beta-carotene significantly inversely correlated with interleukin-6. This inverse correlation could suggest potential protective effect of beta-carotene on atherosclerosis due to the inhibition of inflammatory processes.

Topics: Aged; alpha-Tocopherol; beta Carotene; C-Reactive Protein; Cholesterol; Coronary Artery Disease; Female; Humans; Interleukin-6; Male; Malondialdehyde; Middle Aged; Oxidative Stress; Surveys and Questionnaires

Neopterin is released from human monocyte-derived macrophages upon stimulation with interferon-gamma and is a sensitive indicator for cellular immune activation. Furthermore, reactive oxygen species (ROS) are produced in case of immune activation and inflammation. In a cross-sectional approach, plasma concentrations of neopterin and of antioxidant compounds and vitamins were compared in 1463 patients investigated by coronary angiography, which were recruited within the LUdwigshafen RIsk and Cardiovascular Health (LURIC) study. Serum neopterin concentrations were higher in patients with coronary artery disease (CAD; mean+/-S.D.: 8.7+/-7.3 nmol/L) compared to controls (7.4+/-5.0 nmol/L; Welch's t-test: p<0.001). Mean concentrations of ascorbic acid (p<0.0001), gamma-tocopherol (p<0.05), lycopene (p<0.001), lutein+zeaxanthin (p<0.05), alpha-carotene (p<0.05) and beta-carotene (p<0.05) were lower in CAD than in controls. Neopterin concentrations correlated with CAD-score (r(s)=0.156; p<0.0001) and inversely with antioxidants lycopene (r(s)=-0.277; p<0.0001) and lutein+zeaxanthin (r(s)=-0.175; p<0.0001) levels and with vitamins ascorbic acid (r(s)=-0.207; p<0.0001) and alpha-tocopherol (r(s)=-0.105; p<0.0001). The study demonstrates that higher neopterin production is associated with lower concentrations of antioxidant compounds in patients at risk for atherosclerosis. Results suggest that lower concentrations of antioxidant compounds may relate to higher grade of chronic immune activation in patients.

Topics: Adult; Aged; Aged, 80 and over; Antioxidants; Ascorbic Acid; beta Carotene; Carotenoids; Coronary Angiography; Coronary Artery Disease; Female; Humans; Lutein; Lycopene; Male; Middle Aged; Neopterin; Oxidative Stress; Risk Factors; Vitamin E; Xanthophylls; Young Adult; Zeaxanthins

Low circulating levels of carotenoids have been associated with cardiovascular disease. The distribution of different carotenoids in blood may have an impact on the cardioprotective capacity. The aim of the present study was to determine the plasma levels of 6 major carotenoids in patients with coronary artery disease (CAD) and relate the findings to clinical, metabolic and immune parameters.. Plasma levels of oxygenated carotenoids (lutein, zeaxanthin, beta-cryptoxanthin) and hydrocarbon carotenoids (alpha-carotene, beta-carotene, lycopene) were determined in 39 patients with acute coronary syndrome, 50 patients with stable CAD and 50 controls. Serological assays for inflammatory activity and flow cytometrical analysis of lymphocyte subsets were performed. Both patient groups had significantly lower plasma levels of oxygenated carotenoids, in particular lutein+zeaxanthin, compared to controls. Low levels of oxygenated carotenoids were associated with smoking, high body mass index (BMI), low high density lipoprotein (HDL) cholesterol and, to a minor degree, inflammatory activity. Plasma levels of lutein+zeaxanthin were independently associated with the proportions of natural killer (NK) cells, but not with other lymphocytes, in blood.. Among carotenoids, lutein+zeaxanthin and beta-cryptoxanthin were significantly reduced in CAD patients independent of clinical setting. The levels were correlated to a number of established cardiovascular risk factors. In addition, the relationship between NK cells and lutein+zeaxanthin may indicate a particular role for certain carotenoids in the immunological scenario of CAD.

Topics: Acute Disease; Aged; Angina Pectoris; beta Carotene; Biomarkers; C-Reactive Protein; Carotenoids; Chronic Disease; Coronary Artery Disease; Cryptoxanthins; Female; Humans; Interleukin-6; Killer Cells, Natural; Lutein; Lycopene; Lymphocyte Count; Male; Middle Aged; Myocardial Ischemia; Xanthophylls; Zeaxanthins

Clinical triallists are often reluctant to alter the protocol or the design of an ongoing study in part because of concern that changes may affect the integrity of the study. This paper encourages considering changes in long-term clinical trials when the medical environment changes or when the accruing data from the trial lead to questioning the assumptions underlying the original design. One must make such changes in a way that will not cast doubt on the integrity of the trial. An important aspect of the design is choice of sample size. Methodology for sample size recalculation has matured over the decade. Several techniques are now available for the usual types of endpoints - continuous, discrete and time-to-failure - as well as for longitudinal analysis. Published papers describe the choices of variance at the time of recalculation, approaches to estimation and testing at the end of the study, and the time of recalculation. In a study with a sponsor, a Data Safety Monitoring Board (DSMB) and an Executive Committee, one or more of these three groups is responsible for recommending increases in sample size when the accruing data indicate that the assumed variance underestimated the true variance. Sometimes a statistician independent of all three bodies performs the relevant calculations and sends the recommendation to the sponsor. This paper argues that the DSMB should not generally be the responsible body because knowledge of treatment effect can place it in an uncomfortable position.

Topics: Aspirin; beta Carotene; Clinical Trials Data Monitoring Committees; Coronary Artery Disease; Data Interpretation, Statistical; Game Theory; Humans; Hypolipidemic Agents; Longitudinal Studies; Neoplasms; Randomized Controlled Trials as Topic; Research Design; Sample Size; Treatment Outcome

In this study, we tested whether 1,200 IU/day of alpha-tocopherol was more potent than 400 and 800 IU of alpha-tocopherol in decreasing low-density lipoprotein (LDL) oxidative susceptibility in a 2-month study. The decrease in LDL oxidation was significantly greater with 1,200 IU/day than 400 IU/day.

Topics: Antioxidants; Ascorbate Oxidase; beta Carotene; Clinical Trials as Topic; Coronary Artery Disease; Dose-Response Relationship, Drug; Follow-Up Studies; Humans; Lipoproteins, LDL; Male; Oxidation-Reduction; Vitamin E

The goal of this investigation was to determine whether participation in an atherosclerosis treatment program would reduce the oxidative susceptibility of LDL from patients with coronary artery disease. The treatment program included intensive exercise therapy, stress management, and consumption of a diet containing 10% fat. The size and antioxidant and lipid contents of LDL particles from 25 patients were analyzed at baseline and after 3 mo of therapy. The susceptibility of LDL to copper-mediated oxidation was measured by a conjugated diene assay and headspace gas chromatography (HSGC). Atherosclerosis treatment significantly reduced plasma total cholesterol and apolipoprotein B concentrations and the molar ratio of LDL cholesterol ester to apolipoprotein B (P < 0.01). The LDL content of alpha-tocopherol and beta-carotene was increased (27% and 17%, respectively, P < 0.04) and the molar ratio of LDL cholesterol ester the sum of LDL alpha-tocopherol and LDL beta-carotene decreased from 159 at baseline to 122 at 3 mo (P < 0.01). The lag phase of LDL conjugated diene formation increased 24%, whereas the maximum rate of oxidation slowed 29% (P < 0.01). As assessed by HSGC, copper-catalyzed formation of volatile lipid oxidation products was reduced 15% (P < 0.007); the reduction in volatiles was correlated with an increase in the alpha-tocopherol content of LDL (r=-0.48, P < 0.01). The principal determinants of reduced LDL oxidative susceptibility were the particle contents of alpha-tocopherol and beta-carotene. To our knowledge, this is the first report to document a reduction in LDL oxidation in coronary artery disease patients undergoing atherosclerosis-reversal therapy.

Topics: Aged; Apolipoproteins B; beta Carotene; Cholesterol; Copper; Coronary Artery Disease; Diet, Fat-Restricted; Exercise; Female; Humans; Lipid Peroxidation; Lipoproteins, LDL; Male; Middle Aged; Particle Size; Vitamin E

Familial hypercholesterolemia (FH) is an autosomal dominant genetic disorder characterized by a lifelong elevation in the concentration of low-density lipoprotein (LDL) bound cholesterol in blood by cholesterol deposits and by early coronary artery disease. The LDL apheresis technique has been introduced with the goal of reducing LDL cholesterol levels, thereby preventing the development of atherosclerosis. The literature on LDL apheresis reports 2 different facets, the therapeutic aspect associated with the lessening of LDL concentration and the initiation of a peroxidation process associated with the biocompatibility of the artificial membrane. Lipid and protein peroxidation gives rise to toxic and atherogenic hydroperoxide, mostly lipid hydroperoxides, and derivative compounds, which may offset the benefit of the procedure. In this paper, plasma hydroperoxide levels are determined along with the elevation of the serum and LDL antioxidant status in hypercholesterolemic patients before and following repeated LDL apheresis sessions. Hydroperoxide concentration has been expressed both in terms of plasma volume and LDL concentration. A highly significant increase in LDL lipid hydroperoxides is demonstrated when expressed in terms of LDL concentration and is associated with the LDL apheresis procedure. The usefulness of antioxidant supplementation in LDL apheresis is discussed.

Topics: Adult; Antioxidants; beta Carotene; Biocompatible Materials; Blood Component Removal; Case-Control Studies; Cholesterol; Cholesterol, LDL; Coronary Artery Disease; Female; Follow-Up Studies; Humans; Hyperlipoproteinemia Type II; Lipid Peroxidation; Lipid Peroxides; Lipoproteins, LDL; Male; Membranes, Artificial; Middle Aged; Peroxides; Triglycerides; Vitamin A; Vitamin E

Topics: Antioxidants; beta Carotene; Coronary Artery Disease; Humans; Lipid Peroxidation; Myocardial Infarction; Myocardial Ischemia; Smoking; Vitamin E

Topics: Animals; Antioxidants; Arteriosclerosis; beta Carotene; Carotenoids; Coronary Artery Disease; Glutathione Peroxidase; Humans; Lipid Peroxidation; Lipoproteins, LDL; Male; Muscle, Smooth, Vascular; Reactive Oxygen Species; Risk Factors; Selenium; Tunica Intima; Vitamin E

The oxidative modification of LDL in vivo may have an important role in atherogenesis. To determine whether LDL fatty acid, anti-oxidant composition and sensitivity to oxidation in vitro is different in subjects with established atherosclerosis we compared 20 men with angiogram proven coronary disease with 25 controls without clinical evidence of arterial disease. LDL-cholesterol, total triglycerides and LDL fatty acid composition did not differ significantly between the groups. LDL oxidation lag time and oxidation rate in coronary patients (132 min, 0.02 absorbance units/min) and controls (140, 0.017) were not significantly different. However coronary disease subjects taking beta-blockers had evidence for reduced LDL oxidizability (lag time 148 +/- 7 min; oxidation rate 0.017 +/- 0.002 abs units/min) compared with those not on beta-blockers (lag time 114 +/- 7 min, rate 0.025 +/- 0.003, P < 0.005). LDL beta-carotene was significantly lower in coronary patients (0.92 mumol/mmol LDL cholesterol; controls 1.58; P = 0.001). LDL alpha-tocopherol appeared lower in coronary patients (2.8 mumol/mmol LDL cholesterol; controls 3.3; P = 0.056) and was significantly lower in smokers (2.56; non-smokers 3.24; P = 0.04). LDL oxidation rate was negatively correlated with LDL alpha-tocopherol (r = -0.51, P = 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adrenergic beta-Antagonists; beta Carotene; Carotenoids; Coronary Artery Disease; Fatty Acids; Humans; Lipids; Lipoproteins, LDL; Male; Middle Aged; Oxidation-Reduction; Vitamin E