beta-carotene and Peripheral-Vascular-Diseases

To determine whether alpha-tocopherol or beta-carotene supplementation affects diabetic macrovascular complications and total mortality.. This study was carried out as part of the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study, a double-blind, randomized trial with a 2x2 factorial design. A total of 29,133 middle-aged male smokers received either vitamin E 50 mg/day or beta-carotene 20 mg/day, or both, or placebo for a median of 6.1 years. At base-line, 1700 men had type 2 diabetes. Of these men, 662 were diagnosed with first-ever macrovascular complication, and 1142 died during the 19-year follow-up.. Neither supplementation affected the risk of macrovascular complication or total mortality during the intervention period. For the alpha-tocopherol-supplemented versus no alpha-tocopherol-supplemented, and beta-carotene-supplemented versus no beta-carotene-supplemented we found relative risk (RR) 0.84 (95% confidence interval (CI) 0.65-1.10) and RR 1.15 (95% CI 0.89-1.50) for macrovascular complication, respectively, and RR 1.00 (95% CI 0.80-1.25) and RR 1.06 (95% CI 0.85-1.33) for total mortality, respectively. No essential changes were found in these effects when the follow-up was extended up to 19 years.. Alpha-tocopherol or beta-carotene supplementation has no protective effect on macrovascular outcomes or total mortality of diabetic male smokers.

Topics: Aged; alpha-Tocopherol; beta Carotene; Coronary Disease; Diabetes Mellitus; Diabetic Angiopathies; Double-Blind Method; Finland; Humans; Male; Middle Aged; Peripheral Vascular Diseases; Smoking; Stroke; Survival Rate; Treatment Outcome; Vitamins

Prospective studies have shown that C-reactive protein (CRP) can be used to predict risk of future cardiovascular events. High-sensitivity methods for CRP (hs-CRP) measurement are needed for this purpose.. We compared the clinical efficacy of an automated and commercially available latex-enhanced assay (Latex) for hs-CRP (Dade Behring) to a validated in-house ELISA, previously shown to predict future peripheral arterial disease (PAD) in asymptomatic populations. Using a prospective, nested, case-control design, we measured baseline hs-CRP concentrations in 144 apparently healthy men who subsequently developed symptomatic PAD and 144 age- and smoking habit-matched controls who remained free of vascular disease over the follow-up period of 60 months.. The two hs-CRP assays correlated highly (r = 0.95; P <0.001), and all but two participants were classified into concordant quartiles or varied by only one quartile. The median hs-CRP of the case group was significantly higher than that of controls when measured by either the ELISA (1.34 vs 0.99 mg/L; P = 0.034) or the Latex method (1.80 vs 1.20 mg/L; P = 0.042). Furthermore, for both ELISA and the Latex method, the calculated relative risks of developing PAD increased significantly with each increasing quartile of hs-CRP. The calculated interquartile increase in relative risk of PAD was 31% (95% confidence interval, 5.2-62.2%; P = 0.01) for ELISA and 34% (95% confidence interval, 8.2-66.1%; P = 0.007) for the Latex method.. Our findings indicate that the Latex method is equally as efficacious as the validated ELISA in classifying patients into cutoff points established by prospective studies for risk stratification for coronary and cerebrovascular disease.

Topics: Aged; Aged, 80 and over; Antioxidants; Aspirin; beta Carotene; C-Reactive Protein; Case-Control Studies; Double-Blind Method; Enzyme-Linked Immunosorbent Assay; Humans; Immunoassay; Latex; Male; Middle Aged; Myocardial Infarction; Peripheral Vascular Diseases; Platelet Aggregation Inhibitors; Prospective Studies; Risk Factors; Sensitivity and Specificity; Stroke

Among apparently healthy men, elevated levels of C-reactive protein (CRP), a marker for systemic inflammation, predict risk of myocardial infarction and thromboembolic stroke. Whether increased levels of CRP are also associated with the development of symptomatic peripheral arterial disease (PAD) is unknown.. Using a prospective, nested, case-control design, we measured baseline levels of CRP in 144 apparently healthy men participating in the Physicians' Health Study who subsequently developed symptomatic PAD (intermittent claudication or need for revascularization) and in an equal number of control subjects matched on the basis of age and smoking habit who remained free of vascular disease during a follow-up period of 60 months. Median CRP levels at baseline were significantly higher among those who subsequently developed PAD (1.34 versus 0.99 mg/L; P=.04). Furthermore, the risks of developing PAD increased significantly with each increasing quartile of baseline CRP concentration such that relative risks of PAD from lowest (referent) to highest quartile of CRP were 1.0, 1.3, 2.0, and 2.1 (Ptrend=.02). Compared with those with no clinical evidence of disease, the subgroup of case patients who required revascularization had the highest baseline CRP levels (median= 1.75 mg/L; P= .04); relative risks from lowest to highest quartile of CRP for this end point were 1.0, 1.8, 3.8, and 4.1 (Ptrend=.02). Risk estimates were similar after additional control for body mass index, hypercholesterolemia, hypertension, diabetes, and a family history of premature atherosclerosis.. These prospective data indicate that among apparently healthy men, baseline levels of CRP predict future risk of developing symptomatic PAD and thus provide further support for the hypothesis that chronic inflammation is important in the pathogenesis of atherothrombosis.

Topics: Adult; Aged; Aged, 80 and over; Antioxidants; Arteriosclerosis; Aspirin; beta Carotene; Body Mass Index; C-Reactive Protein; Cyclooxygenase Inhibitors; Diabetes Mellitus; Double-Blind Method; Heart Diseases; Humans; Hypercholesterolemia; Intermittent Claudication; Male; Middle Aged; Myocardial Revascularization; Peripheral Vascular Diseases; Prospective Studies; Reference Values; Risk Factors

Antioxidants may prevent atherosclerosis by interfering with endothelial activation, which involves the expression of endothelial adhesion molecules. The aim of this study was to explore the relationship between plasma levels of some lipid-soluble antioxidants (gamma-tocopherol, alpha-tocopherol, lycopene, beta-carotene, and ubiquinone), carotid maximum intima-media thickness (IMTmax), an index of atherosclerotic extension/severity, and soluble adhesion molecules (vascular cell adhesion molecule-1 [VCAM-1], intercellular adhesion molecule-1 [ICAM-1], and E-selectin), which are taken as a reflection of vascular cell expression of adhesion molecules.. We studied 11 healthy control subjects, 11 patients with uncomplicated hypertension (UH), and 11 patients with essential hypertension plus peripheral vascular disease (PVD) who were matched for age, sex, smoking habit, and body mass index.. Patients with PVD had elevated IMTmax (2.7 [1.1-3.1] mm, median [range]) compared with both patients with UH(1.2 [0.8-2.4] mm) and control subjects (1.0 [0.6-2] mm). In patients with PVD, soluble (s)VCAM-1 and sICAM-1 were also significantly higher than in the 2 other categories. Plasma levels of lycopene had a trend toward lower values in patients with PVD compared with other groups (P =.13). A statistically significant correlation was found between lycopene and IMTmax (r = 0.42, P =.014) at univariate analysis, which persisted at multivariate analysis (P <.05) and was independent of low-density lipoprotein cholesterol, creatinine clearance, and plasma insulin. Plasma lycopene did not significantly correlate with any of the soluble adhesion molecules tested.. We conclude that the inverse relationship of plasma lycopene with IMTmax is compatible with a protective role of this natural dietary antioxidant in atherosclerosis, although the mechanism of protection does not apparently involve a decrease in endothelial activation measured through soluble adhesion molecules.

Topics: alpha-Tocopherol; Analysis of Variance; Antioxidants; Arteriosclerosis; beta Carotene; Biomarkers; Carotenoids; Carotid Artery Diseases; E-Selectin; Female; gamma-Tocopherol; Humans; Hypertension; Intercellular Adhesion Molecule-1; Lycopene; Male; Middle Aged; Peripheral Vascular Diseases; Ubiquinone; Vascular Cell Adhesion Molecule-1

This study examined cross-sectionally the association of dietary beta-carotene, vitamin C, and vitamin E with peripheral arterial disease in Rotterdam, the Netherlands (1990--1993). The 4,367 subjects from the Rotterdam Study were aged 55--94 years and had no previous cardiovascular disease at baseline. Diet was assessed with a food frequency questionnaire. Peripheral arterial disease was defined as an ankle-arm systolic blood pressure index (AAI) of < or = 0.9 and was present in 204 men and 370 women. In multivariate-adjusted logistic regression analyses, vitamin C intake was significantly inversely associated with peripheral arterial disease in women (highest vs. lowest quartile: relative risk = 0.64, 95% confidence interval (CI): 0.48, 0.89; p(trend) = 0.006), and a 100-mg increase in intake was associated with a 0.013 AAI increase (95% CI: 0.001, 0.025). In men, vitamin E intake was inversely associated with peripheral arterial disease (relative risk = 0.67, 95% CI: 0.44, 1.03; p(trend) = 0.067); a 10-mg increase in intake was associated with a 0.015 AAI increase (95% CI: 0.001, 0.031). Whether these differences in antioxidant intake and the risk of a low AAI and of peripheral arterial disease between sexes are attributable to a different food pattern for men compared with women remains to be elucidated.

Topics: Aged; Aged, 80 and over; Antioxidants; Arterial Occlusive Diseases; Ascorbic Acid; beta Carotene; Cross-Sectional Studies; Diet; Diet Surveys; Energy Metabolism; Female; Humans; Linear Models; Logistic Models; Male; Middle Aged; Multivariate Analysis; Netherlands; Peripheral Vascular Diseases; Population Surveillance; Prospective Studies; Risk Factors; Sex Distribution; Surveys and Questionnaires; Urban Health; Vitamin E

Topics: Angioplasty, Laser; beta Carotene; Carotenoids; Fluorescence; Humans; Peripheral Vascular Diseases