beta-carotene and Arterial-Occlusive-Diseases

Patients with peripheral arterial disease (PAD) have high rates of cardiovascular morbidity and mortality, including that caused by associated coronary heart disease and cerebrovascular disease. Previous studies have shown that coagulation parameters are altered in PAD and that altered coagulation may play a critical role in the susceptibility to cardiovascular complications in PAD. It is therefore important to assess the effect of secondary prevention measures on coagulation in patients with PAD. The Arterial Disease Multiple Intervention Trial (ADMIT), a multicenter, randomized, placebo-controlled trial, was conducted to determine the feasibility of a combined lipid-modifying, antioxidant, and antithrombotic treatment regimen in patients with PAD. The objective of this study was to assess the effect of the ADMIT interventions on coagulation.. ADMIT participants were randomly assigned to low-dose warfarin, niacin, and antioxidant vitamin cocktail or corresponding placebos in a 2 x 2 x 2 factorial design. Specialized coagulation studies were performed in a subset of 80 ADMIT participants at baseline and after 12 months of treatment.. Low-dose warfarin (1 to 4 mg/d) resulted in a significant decrease in factor VIIc (P <.001) and in plasma F1.2 (P =.001). Unexpectedly, niacin treatment also resulted in significant decrease in both fibrinogen (48 mg/dL; P <.001) and F1.2 (P =.04). von Willebrand factor increased after antioxidant vitamin treatment (P =.04).. A regimen of low-dose warfarin effectively modifies coagulation in patients with PAD. Niacin also favorably modifies fibrinogen and plasma F1.2. Niacin, in addition to its lipid effects, modifies abnormal coagulation factors that accompany PAD.

Topics: Aged; Anticoagulants; Antioxidants; Arterial Occlusive Diseases; Ascorbic Acid; beta Carotene; Blood Coagulation; Disease Progression; Drug Therapy, Combination; Feasibility Studies; Female; Fibrinogen; Humans; Male; Niacin; Vitamin E; von Willebrand Factor; Warfarin

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

The success of percutaneous transluminal coronary angioplasty is limited by restenosis in 30-50% of cases. Cellular production of reactive oxygen species at the site of injury has been implicated as a contributing factor in the process of restenosis. beta-Carotene is a lipid-soluble antioxidant whose effects on this process have not been previously investigated. We attempted to elucidate whether beta-carotene treatment was capable of reducing restenosis. Femoral artery stenoses were produced by nitrogen-desiccation in rabbits fed a high-cholesterol diet. The animals were randomized to receive either a parenteral bolus of beta-carotene immediately prior to angioplasty, followed by 5 days of subcutaneous treatment (Acute Treatment); 5 days of subcutaneous pretreatment with beta-carotene followed by a parenteral bolus immediately prior to angioplasty and then another 5 days of subcutaneous treatment (Pretreatment); or vehicle only (Control). Angiography was performed immediately before and after angioplasty, and 28 days after angioplasty. The animals were then sacrificed, and the femoral arteries were harvested for histopathology. By quantitative angiography, the late loss of luminal diameter between angioplasty and final angiography was not significantly different between the acute treatment group, the pretreatment group and the control group. By histopathology, the area of intimal hyperplasia and the percent cross-sectional area stenosis were also not significantly different. The late loss in luminal diameter after angioplasty correlated significantly with the acute gain in luminal diameter produced by angioplasty. The amount of intimal hyperplasia correlated significantly with the arterial injury score assessed by histopathology. In summary, in this animal model of restenosis, parenteral beta-carotene failed to significantly reduce the amount of either intimal hyperplasia or late loss in luminal diameter after angioplasty.

Topics: Angioplasty, Balloon, Coronary; Animals; Antioxidants; Arterial Occlusive Diseases; beta Carotene; Cholesterol; Cholesterol, Dietary; Diet, Atherogenic; Endothelium, Vascular; Femoral Artery; Hyperplasia; Injections, Subcutaneous; Premedication; Rabbits; Radiography; Recurrence