ascorbic-acid and Peripheral-Vascular-Diseases

Peripheral vascular disease (PVD) is a manifestation of systemic atherosclerosis in the lower limbs, and PVD patients have a 3- to 5-fold increased risk of cardiovascular mortality compared with age-matched controls. Nevertheless, recent reports show how PVD patients are undertreated with regard to CVD risk-factor reduction and the use of lipid-lowering or antiplatelet drugs. There is appreciable evidence that demonstrates the beneficial effects of certain nutrients and dietary habits in the prevention of CVD, but there has been little attention paid to the role of nutrients in PVD. The purpose of the present review is to provide an overview of our understanding of how foods could possibly benefit PVD. In the last few decades, several nutrients have arisen as potentially health-promoting in PVD. While nutritional interventions in PVD show positive clinical effects for fish oil, carnitine or vitamin E, others such as olive oil or vitamin C seem to interact only at a biochemical level by decreasing risk factors. Moreover, only epidemiological associations exist for the potential role of fibre, folates or vitamin B6 in this disease. In all cases, the limited data available provide no clear-cut evidence in favour of the clinical benefit of nutritional interventions aimed at reducing risk factors and ameliorating symptoms in PVD patients. No practical recommendations can be given at this stage, and further studies are clearly needed.

Topics: Antioxidants; Ascorbic Acid; Atherosclerosis; Carnitine; Dietary Fats, Unsaturated; Dietary Fiber; Fish Oils; Humans; Nutritional Physiological Phenomena; Olive Oil; Peripheral Vascular Diseases; Plant Oils; Vitamin B Complex; Vitamin E

Ischemia-reperfusion (IR) injury causes tissue injury and endothelial dysfunction. There is evidence that oxidative stress plays an important role.. We tested if IR-induced endothelial dysfunction could be prevented by administration of the antioxidant vitamin C. Twenty-six healthy male subjects and eight male patients with peripheral arterial disease (PAD) were enrolled in this randomised placebo-controlled study. Forearm blood flow (FBF) measurements in response to the vasodilators acetylcholine (ACh; endothelium-dependent agonist) or nitroglycerin (NTG; endothelium-independent) were performed before and after forearm ischemia for 20 min. FBF responses were reassessed during reperfusion with intra-arterial co-administration of 24 mg/min vitamin C or placebo. In six volunteers responses to the NO-synthase inhibitor N-monomethyl-L-arginine (L-NMMA) were also assessed before and after ischemia with and without vitamin C.. ACh-induced vasodilation was blunted in subjects receiving placebo after reperfusion (p<0.05 versus baseline). Administration of vitamin C completely prevented impaired responsiveness. NTG-induced vasodilation was not affected by reperfusion or vitamin C. This finding was consistent in patients with PAD and impaired endothelial function, where local vitamin C infusion restored FBF reactivity to ACh before and after IR injury (p<0.05 versus baseline). Again, NTG-induced vasodilation was not affected. Blunted L-NMMA responses seen during reperfusion could be completely reversed by vitamin C.. Our data indicate that IR-induced vascular injury can be prevented by administration of antioxidants.

Topics: Adult; Antioxidants; Ascorbic Acid; Endothelium, Vascular; Enzyme Inhibitors; Forearm; Humans; Injections, Intra-Arterial; Male; Middle Aged; omega-N-Methylarginine; Oxidative Stress; Peripheral Vascular Diseases; Plethysmography; Regional Blood Flow; Reperfusion Injury; Vasodilation

Excess reactive oxygen species are implicated in the impaired peripheral vascular function evident during exercise in older individuals. We tested the hypothesis that an acute infusion of the antioxidant ascorbic acid (AA) in old rats would improve antioxidant capacity and reduce oxidative stress and, therefore, elevate hindlimb muscle blood flow at rest and during treadmill exercise in muscles containing principally type I and IIa muscle fibers. Total and individual hindlimb skeletal muscle blood flow was measured (radiolabeled microspheres) in old rats (26-28 months) at rest (n = 8) and during treadmill exercise (n = 8; 20 m·min⁻¹, 5% grade) before and after AA treatment (76 mg·(kg body mass)⁻¹ intra-arterial (i.a.) injection). AA elevated total antioxidant capacity (rest, ~37%; and exercise, 31%) and reduced oxidative stress (~26%, exercise only). AA reduced resting total hindlimb muscle blood flow (control, 25 ± 3; AA, 16 ± 2 mL·min⁻¹·(100 g)⁻¹; p < 0.05) and blood flow to 8 of 28 individual muscles with no fiber-type correlation (p > 0.05). During exercise there was no effect of AA on total hindlimb muscle blood flow (control, 154 ± 14; AA, 162 ± 13 mL·min⁻¹·(100 g)⁻¹; p > 0.05) or blood flow to any individual muscle. This disconnect between whole-body antioxidant status and skeletal muscle blood flow in old rats mandates consideration when pursuing antioxidant treatments experimentally or clinically in older populations.

Topics: Aging; Animals; Animals, Outbred Strains; Antioxidants; Ascorbic Acid; Biomarkers; Combined Modality Therapy; Hindlimb; Infusions, Intravenous; Motor Activity; Muscle Fibers, Fast-Twitch; Muscle Fibers, Slow-Twitch; Muscle, Skeletal; Oxidative Stress; Peripheral Vascular Diseases; Rats; Rats, Inbred F344; Regional Blood Flow

Peripheral arterial disease (PAD) is a major health problem especially when associated to concomitant diabetes and hypercholesterolemia. Hyperglycemia with an overwhelming generation of oxygen radicals and formation of glycation end-products exacerbates oxidation-sensitive mechanisms activated by tissue ischemia. Administration of autologous bone marrow cells (BMC) is an increasing notable intervention to induce therapeutic angiogenesis, ameliorated by metabolic intervention (MT). Recently, hemangioblasts (HS) with functional properties were isolated.. The effects of integrate regimen with intravenous BMC, HS, and MT (1.0% vitamin E, 0.05% vitamin C, and 6% l-arginine) were examined in the ischemic hindlimb of ApoE(-/-) diabetic and non-diabetic. Blood flow ratio was monitored by use of a laser Doppler blood flowmeter. Capillary density was determined in sections of the adductor and semimembranous muscles with antibody against CD31.. BMC or HS alone, and BMC plus HS increased blood flow and capillary densities and decreased interstitial fibrosis. These effects were amplified by additional MT, at least in part, through the nitric oxide pathway, reduction of systemic oxidative stress and macrophage infiltration. Investigation of molecular mechanisms in bone marrow (BM)-derived progenitor cells from mice revealed that BMC therapy and, more consistently, in combination with MT ameliorated functional activity via decreased cellular senescence and increased telomerase and chemokine CXCR4 activities. Telomerase activity was also increased by HS alone or HS+MT and, more consistently, by BMC+HS alone or in combination with MT.. Intravenous autologous BMC and HS intervention together with MT increased therapeutic angiogenesis in the ApoE(-/-) diabetic mouse hindlimb.

Topics: Animals; Apolipoproteins E; Arginine; Ascorbic Acid; Bone Marrow Transplantation; Diabetes Mellitus, Experimental; Hemangioblasts; Hindlimb; Ischemia; Mice; Neovascularization, Physiologic; Peripheral Vascular Diseases; Regional Blood Flow; Vitamin E

Dysfunctional endothelium caused by oxidative stress is thought to play a role in pathogenesis of a variety of conditions including atherosclerosis. We investigated whether a microcirculatory disturbance in hemodialysis (HD) patients was associated with increased oxidative stress and endothelial injury.. Transcutaneous oxygen tension (TcPO2) on the dorsum of the foot at rest was measured as a marker of microcirculation in 33 patients undergoing HD without clinical manifestations of peripheral arterial disease and 20 healthy controls. Furthermore, in order to examine whether TcPO2 was affected by antioxidants, oral supplementation with a combination of vitamin C (200 mg daily) and vitamin E (600 mg daily) was administered for 6 months to 8 patients with microcirculatory disturbance (TcPO2 values of 50 mmHg or less). Serum biochemical parameters including vitamins were also measured.. Mean TcPO2 value was significantly lower in HD patients than in control subjects (47.9 +/- 13.5 mmHg versus 62.4 +/- 11.9 mmHg, p < 0.001). After vitamin supplementation, TcPO2 values remarkably increased (40.6 +/- 10.0 mmHg versus 57.4 +/- 6.5 mmHg, p < 0.005). Serum vitamin C and vitamin E levels increased significantly as well, while serum levels of thrombomodulin, a marker of endothelial injury, and thiobarbituric acid reactants, a marker of lipid peroxidation, were significantly decreased in comparison with those before supplementation.. Our results suggest that the microcirculatory disturbance in HD patients seems to be associated with endothelial damage caused by oxidative stress. Combined supplementation with vitamin C and vitamin E may be of clinical benefit in improving the cutaneous microcirculation by reducing oxidative stress.

Topics: Antioxidants; Ascorbic Acid; Blood Gas Monitoring, Transcutaneous; Endothelium, Vascular; Female; Foot; Humans; Kidney Failure, Chronic; Lipid Peroxidation; Male; Microcirculation; Middle Aged; Oxidative Stress; Peripheral Vascular Diseases; Renal Dialysis; Skin; Thiobarbituric Acid Reactive Substances; Thrombomodulin; Vitamin E

Peripheral arterial disease (PAD) is a severe atherosclerotic condition frequently accompanied by inflammation and oxidative stress. We hypothesized that vitamin C antioxidant levels might be low in PAD and are related to inflammation and disease severity.. We investigated vitamin C (L-ascorbic acid) levels in 85 PAD patients, 106 hypertensives without PAD, and 113 healthy subjects. Serum L-ascorbic acid concentrations were low among PAD patients (median, 27.8 micromol/L) despite comparable smoking status and dietary intake with the other groups (P<0.0001). Subclinical vitamin C deficiency (<11.4 micromol/L), confirmed by low serum alkaline phosphatase activity, was found in 14% of the PAD patients but not in the other groups. Serum C-reactive protein (CRP) concentrations were significantly higher in PAD patients (P<0.0001) and negatively correlated with L-ascorbic acid levels (r=-0.742, P<0.0001). In stepwise multivariate analysis, low L-ascorbic acid concentration in PAD patients was associated with high CRP level (P=0.0001), smoking (P=0.0009), and shorter absolute claudication distance on a standardized graded treadmill test (P=0.029).. Vitamin C concentrations are lower in intermittent claudicant patients in association with higher CRP levels and severity of PAD. Future studies attempting to relate vitamin C levels to disease occurrence should include in their analysis an inflammatory marker such as CRP.

Topics: Aged; Arteriosclerosis; Ascorbic Acid; Aspirin; C-Reactive Protein; Female; Fibrinogen; Humans; Hypertension; Inflammation; Lipids; Male; Middle Aged; Multivariate Analysis; Peripheral Vascular Diseases; Severity of Illness Index; Smoking

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: Ascorbic Acid; Humans; Peripheral Vascular Diseases

The aim of this study was to determine the levels of plasma fatty acids in patients with peripheral arterial disease and in control subjects and to identify whether any risks of disease related to these differences were influenced by smoking and antioxidant intake. A random sample of 1592 men and women aged 55 to 74 years was selected from the general population (the Edinburgh Artery Study), from which 153 cases of peripheral arterial disease were identified by the presence of intermittent claudication and low ankle systolic pressures at rest and during reactive hyperemia; these were matched by age and sex to 153 control subjects with no evidence of cardiovascular disease. In 113 case and 122 control subjects, fatty acid levels were measured in three plasma fractions (triglyceride, cholesteryl ester, and phospholipid), and smoking habits and dietary antioxidant intake were determined by questionnaire. Arachidonic acid, eicosapentaenoic acid, docosahexaenoic acid, and docosapentaenoic acid (DPA/n-3) were significantly lower in the cases than controls (P < .01). More case than control subjects were current or exsmokers (86% versus 50%; P < .001), and the case subjects had lower vitamin C intake (64.8 mg versus 71.1 mg; P < .05). By logistic regression adjustment for smoking and vitamin C intake, only DPA/n-3 (odds ratio, 0.19; P < .01) and arachidonic acid (odds ratio, 0.44; P < .05) remained significantly related to disease; only DPA/n-3 reduced the risk associated with smoking. We conclude that in subjects with peripheral arterial disease compared with healthy control subjects, the largest differences occurred in fatty acids of the n-3 series, particularly DPA/n-3.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Aged; Antioxidants; Ascorbic Acid; Case-Control Studies; Diet; Eicosapentaenoic Acid; Fatty Acids, Essential; Female; Humans; Male; Middle Aged; Peripheral Vascular Diseases; Smoking

Topics: Ascorbic Acid; Central Nervous System Stimulants; Folic Acid; Humans; Peripheral Vascular Diseases; Pyrrolidines; Surgical Procedures, Operative; Vascular Diseases; Vitamin B Complex

Topics: Ascorbic Acid; Humans; Peripheral Arterial Disease; Peripheral Vascular Diseases; Vascular Diseases; Vitamins

Topics: Ascorbic Acid; Central Nervous System Stimulants; Folic Acid; Humans; Peripheral Vascular Diseases; Vascular Diseases; Vitamin B Complex; Vitamins

Topics: Ascorbic Acid; Cardiovascular Diseases; Cardiovascular System; Cerebrovascular Disorders; Humans; Peripheral Vascular Diseases; Vascular Diseases; Vitamin D; Vitamins