View clinical trials related to Endothelial Dysfunction.
Filter by:Several epidemiological and intervention studies suggest that a high dietary intake of tomatoes is associated with lower risk of cardiovascular disease (CVD), while, low intake is associated with an increased incidence of CVD. This beneficial effects have been attributed especially to lycopene, an antioxidant present in high concentration within tomatoes but other substances could be of importance. Endothelial dysfunction is an early marker of atherosclerosis leading to CVD. The aim of the present study is therefore to investigate whether consumption of tomato products ameliorates peripheral endothelial function, triggered by a high fat meal, in human volunteers in a randomised, crossover dietary intervention study. Study design: Investigators are randomising healthy men (N=14-28) to consume a high fat meal either with or without tomato sauce (80 gr) in a cross-over design with a 7 days wash-out period. During the week before the study all the subjects will be maintained in a low fibers diet and only subjects randomized to tomatoes will receive a daily dose of 80 mg of tomato sauce (80 gr for 7 days= total load 560 mg). We hypothesize that tomato sauce can improve the deleterious effects of a high fat meal on vascular function.
The goal of this study is to determine if n-acetylcysteine, given as PharmaNAC, reduces oxidative stress and improves vascular function in HIV-infected older adults already on HIV treatment.
Cardiovascular disease (CVD) is the leading cause of deaths in the Western world. Established risk factors include high LDL cholesterol, high blood pressure and diabetes. Poor blood vessel health is considered a predictor of future CVD risk, but can be reversed. Several different measurements can be used to determine blood vessel health; such as blood pressure (BP), and newer techniques which measure blood flow through the arteries after a blood pressure cuff restricts blood flow for a few minutes in one arm. Flavonoids are compounds found in plant-based foods, and are associated with a reduced risk of CVD. From the previous studies, there is strong evidence that orange juice and citrus foods which have higher amount of specific citrus flavonoids improved cardiovascular risk factors such as BP and blood vessel health. Absorption of citrus flavonoids occurs in the colon after bacteria breakdown the forms found in food. After the flavonoids are absorbed into the blood they are modification by liver enzymes before they are excreted in the urine. A large range of citrus flavonoid have been found excreted in the urinary, ranging anywhere from 0-57% of the dose. Variation in the potential health effect may reflect the level of the citrus flavonoid absorbed, and this is not often considered in human studies. This study is a 4-week double-blinded, randomized, cross-over intervention trial using a commercially-available orange juice supplement and a placebo control. The aims of the study are to determine whether orange juice supplements reduce blood pressure and improve blood vessel health after 4 weeks. Furthermore, to determine if there is a relationship between absorption of flavonoids (as measured by urinary excretion) and changes in blood pressure or blood vessel health. The participants will need to attend 4 sessions on 4 separate study days, every 4 weeks for 12 weeks. On each study day they will have their weight, height, waist circumference, and blood pressure measured. A finger-prick blood sample, using a single-use lancet (Accu-Chek Safe T Pro Plus), will be taken to check the fasting blood glucose level. Blood flow in fingertips will be monitored before and after reducing blood flow in your forearm using a blood pressure cuff (called an EndoPAT). Participants will be asked to collect urine for 24 hr on each of the study days, and to consume the supplements provided daily for two sets of 4 weeks (there will be 4 weeks in the middle without any supplements). An improvement in blood pressure and/or blood flow will provide evidence that blood vessel health has improved through short-term (4 week) use of a citrus flavonoid supplement
Study aims and hypotheses are as follows: Primary Hypotheses: Compared to the neutral condition, the anger recall task will acutely induce endothelial dysfunction by impairing endothelium-dependent arterial vasodilation (Hypothesis 1a); increasing circulating levels of EC-derived microparticles (EMPs), a marker of EC injury (Hypothesis 1b); and reducing circulating levels of bone marrow-derived endothelial progenitor cells (EPCs), a marker of EC reparative capacity (Hypothesis 1c). Secondary Hypotheses: Compared to the neutral condition, the depressed mood and separately the anxiety recall tasks will acutely impair endothelium-dependent arterial vasodilation, increase circulating levels of EMPs, and reduce circulating levels of bone marrow-derived EPCs. There will be a relation of the level of self-reported anger, depressed mood, and anxiety with endothelial dysfunction.
Irisin is a signaling protein that is released into the blood from skeletal muscle after proteolysis of the membrane protein FNDC5 . FNDC5, encoded by the Fndc5 gene. Irisin activity on subcutaneous white adipose tissue, both in culture and in vivo, stimulated UCP1 expression and induction of brown adipocytes in white adipose tissue depots, a process known as white fat ''browning''. Irisin increases total energy expenditure in animal models, and irisin expression in mice fed a high fat diet resulted in a significant improvement in glucose tolerance and a reduction in fasting insulin levels. Collectively, these data suggest that decreased serum irisin levels may be associated with the development of insulin resistance and Type 2 diabetes. Indeed, some studies showed that irisin levels were decreased in newly diagnosed Type 2 diabetes. Endothelial dysfunction is an early physiological event in atherosclerosis. However, to date, no data are available on the relationship between circulating irisin and endothelial dysfunction in diabetes. Therefore, the investigators hypothesized that circulating irisin level is associated with endothelial dysfunction.
The objective is to demonstrate the effect of phenolic acids on endothelial function.
Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in the United States with older age being a primary risk factor. The number of adults greater than age 65 years will almost double to 70 million by 2030, therefore identifying therapeutic strategies for treating or preventing age-related disorders in humans is of major biomedical importance. Cardiovascular aging, defined as a reduction in vascular and cardiac functions with normal aging, occurs even in the absence of CVD risk factors and overt CVD. A key feature of cardiovascular aging is stiffening of the large elastic central arteries such as the aorta. This is important because aortic stiffness directly contributes to clinical problems such as increased blood pressure, reduced blood flow to the heart muscle, and thickening of the heart muscle. Therefore, these clinical consequences are hypothesized to mediate a substantial proportion of the increase in CVD risk in older adults. However, effective drug treatments for aortic stiffness are not currently available and the biological reasons (mechanisms) involved in causing aortic stiffening remain undefined. In addition, the inability of smaller blood vessels to relax, impairment of the heart to relax during the filling phase of the heart cycle (i.e., diastole), and increased blood pressure variability, have all been linked to aortic stiffness. Furthermore, chronic low-grade inflammation with advancing age has been proposed to be a common mechanistic link (i.e., biological reason) between these reductions in cardiovascular function in older adults. Therefore, the investigators propose that inflammation could be a novel therapeutic target to treat cardiovascular aging in older adults. Our central hypothesis is that inflammation mediates the age-related deterioration in cardiovascular functions observed with advancing age through the development of oxidative stress (i.e., imbalance between damaging oxygen free radicals vs. protective antioxidants). Our hypothesis predicts that chronic inhibition of inflammation with Salsalate, an FDA-approved anti-inflammatory drug similar to aspirin that is used to treat rheumatoid arthritis pain and known to inhibit the 'master' regulator of inflammation in the cell (i.e., nuclear factor kappa B), will improve cardiovascular function in older adults. In addition, the investigators hypothesize that the mechanism for the improvement in cardiovascular function during inhibition of inflammation will be by suppressing oxidative stress. To test our hypothesis, the investigators will randomize older healthy adults (age 50-79 years) to 3 g/day of salsalate or placebo (i.e., pill with inactive substance) pills for 4 weeks and have cardiovascular function measured at baseline and again after 4 weeks.
Vitamin D deficiency has been linked to endothelial dysfunction in adults. Obese adolescents have a high prevalence of Vitamin D deficiency as well as evidence of endothelial dysfunction. Our hypothesis is that supplementation of Vitamin D deficient adolescents with Vitamin D would lead to improvement in endothelial dysfunction.
Purpose of the study is to characterize the chronic effect of dietary nitrate on vascular function in healthy volunteers with particular emphasis on age-related alterations.
Introduction: Cycling is currently promoted at the municipal, provincial and national level as a form of active transportation that increases physical activity while at the same time reducing traffic congestion, traffic-related air pollution and greenhouse gas emissions. While at a population level the health benefits of exercise via cycling are estimated to substantially exceed any health impacts related to air pollution exposure and injuries from traffic accidents , cyclists are known to experience elevated exposures to traffic-related air pollutants. Combined with exposure to elevated concentrations of air pollutants, cyclists also are subject to substantially increased inhaled doses due to their level of exertion and consequently increased inhalation rate. Therefore, given that cyclists experience exposures to relatively high concentrations of traffic-related air pollutants and that their inhalation of these pollutants is increased, it is important to evaluate the potential health impacts of this scenario. Research on the potential health impacts related to exercise (cycling) and urban air pollution exposure can help inform public communication strategies related to air quality and its health impacts. In addition, as our previous work suggests substantial variability in air pollution exposures to cyclists that is related to the route type and the levels of traffic along cycling routes, there is potential for transportation planners to promote increased cycling by enhancing infrastructure while at the same time developing routes that also minimize exposure to air pollution. The cyclist population is also interested in information regarding the air pollution exposures and potential health impacts related to cycling. The objective of this study is to investigate the relationship between traffic-related air pollution exposure, and respiratory and cardiovascular health impacts in commuting cyclists. Specifically, the investigators propose to: 1. determine commuting cyclists' exposure to traffic-related air pollutants (PM 2.5, PM10, ultrafine particulate, black carbon) while cycling along two different bicycle routes in the city of Vancouver; 2. estimate the pollutant dose received by each cyclist, and relate this to the health effects observed; and 3. determine if there is a change in lung function, endothelial function, and C-reactive protein level related to the level of air pollution exposure and dose