30 Clinical Trials for Various Conditions
This study investigated if elevated BP and aortic stiffness characterized in obese individuals are attenuated following acute grape seed extract supplementation. It is hypothesized that acute dietary supplementation with grape seed extract attenuates aortic stiffness, systolic blood pressure, diastolic blood pressure, mean arterial pressure, and total peripheral resistance and these effects are partially due to reductions in peripheral vasoconstriction
Nitric oxide gas is important in regulating blood vessel dilation, and consequently, blood flow. This gas is continuously produced by endothelial cells, which line the blood vessels. This study will examine whether nitrite, a molecule that normally circulates in the blood stream, can also dilate blood vessels. The results of this study may be valuable in developing treatments for people with conditions associated with impaired endothelial production of nitric oxide, including high blood pressure, high blood cholesterol, diabetes, estrogen deficiency, and others. Healthy, non-smoking normal volunteers 21 years of age or older may be eligible for this study. People who lack the enzyme G6PD or cytochrome B5 in their red blood cells may not participate. Absence of these enzymes can lead to episodes of sudden shortness of breath and cyanosis (blueness of the skin due to lack of sufficient oxygen). Participants will undergo the procedures described in study Parts A and B, as follows: * Part A - After numbing the skin, small tubes are placed in the artery and vein at the inside of the elbow of the dominant arm (right- or left-handed) and a small tube is placed in a vein of the other arm. The tubes are used for infusing saline (salt water) and for drawing blood samples. A pressure cuff is placed around the upper part of the dominant arm, and a rubber band device called a strain gauge is also placed around the arm to measure blood flow. When the cuff is inflated, blood flows into the arm, stretching the strain gauge at a rate proportional to the flow. Grip-strength of the dominant arm is measured with a dynamometer to determine maximum grip-strength. Then, several measurements of blood flow, nitrite, hemoglobin, and handgrip are made before and after administration of L-NMMA, a drug that blocks endothelial production of nitric oxide. * Part B - Part A testing is repeated, except that sodium nitrite dissolved in a saline solution is infused into the artery of the forearm for a few minutes before and during the hand-grip exercises. In addition, blood samples are drawn before and after each handgrip exercise to measure methemoglobin, a substance that, at excessive levels, can cause adverse side effects.
Post-menopausal females experience elevated cardiovascular disease risk (CVD), compared to premenopausal females and age-matched males. Current exercise guidelines appear inadequate to ameliorate this increased risk and higher intensity exercise may be necessary. Oral inorganic nitrate supplementation enhances both exercise performance and CVD risk profile in several clinical conditions. However, the effects of this intervention in post-menopausal females is unexplored.
The overall objective of this proposed trial is to examine the vascular protective effects provided by the daily consumption of 39g of freeze dried strawberry powder (FDSP) for four weeks. The study population will be older men (60-80 years of age).
This study aims to obtain data on the potential influence of Vine to Bar product(s) containing Chardonnay marc on cardiometabolic health. These initial studies will inform the design and timing of data collection for future dietary intervention trials that will examine the influence of Chardonnay marc intake on outcomes/biomarkers of both cardiometabolic health and the gut microbiome. This includes collecting data on the potential differences in response to the products based on the unique food matrix for each of the products that will be tested. Moreover, as there is a paucity of data on the influence of cocoa flavanol intake on vascular function beyond 4 hours post intake, the response of the selected outcomes will be assessed after 6 hours of flavanol intake. This is a time point that captures the increased circulating presence of microbial derived flavanol metabolites.
Cardiovascular diseases are the leading cause of morbidity and mortality and contribute most to healthcare costs in the U.S. Age is the strongest cardiovascular disease risk factor, with \>90% of all deaths from cardiovascular disease occurring in adults \>50 years old. The age-associated increased risk of cardiovascular disease is due, in large part, to the development of arterial dysfunction, including endothelial dysfunction and stiffening of the large elastic arteries. Therefore, novel, effective interventions that improve arterial function will have a large public health impact by decreasing the risk of cardiovascular diseases. The short-chain fatty acid acetate is endogenously produced by the gut microbiome from fermentation of dietary soluble fiber. High-fiber diets reduce risk of cardiovascular diseases, but unfortunately, a low percentage of Americans meet guidelines for adequate dietary fiber intake and, despite nationwide efforts to improve this, trends in fiber intake have not improved over the last 20+ years. Thus, directly supplementing acetate may be a more practical and feasible intervention for effectively improving arterial function in older adults and reducing the risk of cardiovascular diseases. The investigators will conduct a study to determine the efficacy of 12 weeks of oral supplementation with acetate for improving arterial function in late middle-aged and older (50+ years) adults. They will also assess the safety and tolerability of acetate supplementation in these adults and perform innovative mechanistic analyses to determine how acetate supplementation improves arterial function. The investigators hypothesize that oral acetate supplementation will improve arterial function by decreasing oxidative stress and increasing nitric oxide bioavailability, and also hypothesize that acetate supplementation will be safe and promote high rates of adherence.
The research is designed as a randomized, 2-arm, parallel, controlled, human clinical trial to investigate the effects of avocado and mango consumption for 8 weeks on indices of macro- and micro- vascular function in individuals with prediabetes. FMD of the brachial artery, pulse wave velocity (PWV), central blood pressure (cBP), and Optical Coherence Tomography Angiography (OCTA) of the eye will be used for vascular assessments. The research plan will also explore cognitive and kidney function benefits of regular avocado and mango intake using specified cognitive tasks and kidney function biomarkers
This study evaluates whether addition of the thromboxane receptor antagonist to chronic aspirin therapy improves endothelial function and reduces non-platelet thromboxane generation in patients with established cardiovascular disease. Half of participants will receive ifetroban and the other half will receive matching placebo for the 4 week study period.
The goal of this clinical trial is to better understand how day-to-day stress affects cardiovascular health and brain function in middle-aged adults. The main question is aims to answer is whether the link between daily stress and vascular dysfunction is a potential mechanism of increased risk for future cognitive decline. Participants will complete two 15-day "testing cycles" separated by \~6 months. During each cycle, participants will complete two daily assessments of stress and brain health using an online survey tool for 14-consecutive days. On the last day of each cycle, vascular function will be assessed during a laboratory visit.
To determine the effects of 4 weeks of creatine monohydrate supplementation on markers of macrovascular and microvascular function, cognitive performance, and physical performance.
Specific Aim 1: To test the hypothesis that prolonged (3-month) treatment with galantamine inhibits NADPH IsoLG-protein adducts formation and improves markers of endothelial cell (EC) dysfunction in AAs. Aim 1a: The investigators will determine if galantamine inhibits NADPH IsoLG-protein adducts formation, superoxide production, and immune cell activation compared to placebo. For this purpose, the investigators will study peripheral blood mononuclear cell (PBMC), a critical source of systemic oxidative stress, collected from study participants. Aim 1b: The investigators will determine if galantamine reduces intracellular Iso-LGs, ICAM-1, and 3-nitrotyrosine, a marker of vascular oxidative stress, in ECs harvested from study participants. Specific Aim 2: To determine if prolonged (3-month) treatment with galantamine improves endothelial dysfunction as measured by vascular reactivity in AAs. The investigators will measure vascular reactivity in response to ischemia in two vascular beds: (a) in conduit arteries (brachial artery) using brachial artery diameter flow-mediated dilation (FMD), and (b) in the microvasculature (MBV) using contrast-enhanced ultrasonography in skeletal muscle. Sub-study (optional) Will study the effect of trans-auricular vagus nerve stimulation (TaVNS) during a period of enhanced vascular oxidative stress This proposal will study a novel mechanism that could alter the oxidative and immunogenic responses that contributes to endothelial dysfunction in AAs and will offer a potential pathway for the development of more effective therapies aimed at decreasing the progression of endothelial dysfunction to cardiovascular disease in this population.
This project is an attempt to understand how Orkambi treatment affects exercise capacity and the function of the arteries in CF patients who are homozygous F508del. Our goal is to perform the exercise and vascular measurements every 3 months after a patient starts taking Orkambi.
Chronic obstructive pulmonary disease (COPD) affects up to 14 million people and is among the top five leading causes of death worldwide. Although COPD is a disease of the lungs, recent evidence indicates that COPD is associated with multiple systemic consequences including vascular endothelial dysfunction. Recently, it has been suggested that more patients with COPD die from cardiovascular disease and coronary heart disease than of direct pulmonary complications. Examination of the mechanisms that contribute to a reduction nitric oxide (NO) bioavailability resulting in vascular endothelial dysfunction in patients with COPD are important as endothelial dysfunction has been indicated to be an independent predictor of future atherosclerotic cardiovascular disease and events.
Cystic fibrosis has many health consequences. A reduction in the ability to perform exercise in patients with CF is related to greater death rates, steeper decline in lung function, and more frequent lung infections. However, the physiological mechanisms for this reduced exercise capacity are unknown. The investigators recently published the first evidence of systemic vascular dysfunction in patients with CF. Therefore, it is reasonable to suspect that the blood vessels are involved with exercise intolerance in CF. This study will look at how and if oxidative stress contributes to both artery dysfunction and exercise intolerance in CF.
Patients with stage IV and V chronic kidney disease and end stage renal disease requiring hemodialysis at University of Alabama at Birmingham (UAB) Dialysis Clinics will be recruited from the UAB Vascular Access Clinic, which has been the site for recruitment of patients requiring new vascular access for the last 10 years.
Cystic fibrosis (CF) has many health consequences. A reduction in the ability to perform exercise in patients with CF is related to greater death rates, steeper decline in lung function, and more frequent lung infections. However, the physiological mechanisms for this reduced exercise capacity are unknown. The investigators laboratory recently published the first evidence of systemic vascular dysfunction in patients with CF. Therefore, it is reasonable to suspect that the blood vessels are involved with exercise intolerance in CF. This study will look at how 1) blood flow and 2) artery function contribute to exercise capacity in CF.
The investigators will test the hypothesis that markers of vascular endothelial dysfunction will be exaggerated acutely with an extreme high sodium diet compared to an extreme low-sodium diet. The investigators will compare patients with postural orthostatic tachycardia (POTS) to healthy control subjects.
Background: - The endothelium is the inner lining of blood vessels. The cells in this lining help regulate blood flow and immune system function. Problems with endothelial cells can contribute to heart disease, high blood pressure, and diabetes. Certain genes or parts of genes may be related to problems with endothelial function. Researchers want to study healthy adults who have genes that may affect their endothelial function. More information on these genes may provide more information on genetic risk for certain diseases. Objectives: - To study healthy adults who have genetic markers related to endothelial cell problems. Eligibility: * Healthy volunteers between 18 and 65 years of age. * Current participants of the Environmental Polymorphisms Registry and have certain genes related to endothelial cell problems. Design: * Participants will have a single study visit to collect information and samples. * Participants will be screened with a physical exam and medical history. Blood and urine samples will be collected. * Participants will have an ultrasound of the artery in the arm and will be given a short-acting medication called nitroglycerin to study blood flow and blood pressure.
Primary Specific Aim: To test the hypothesis that amiloride will improve vascular health of young adults with prehypertension.
The overall objectives of this study are to examine the relationships between circulating vitamin D, insulin sensitivity, and multiple indices of vascular function and to examine whether vitamin D deficiency in African Americans (AA) and White Hispanics (WH) is responsible for ethnic differences in insulin sensitivity and hypertension in AA, WH and European Americans (EA), as well as mechanisms underlying the association between insulin resistance and blood pressure. We hypothesize that 1) serum 25(OH)D is associated with insulin sensitivity and vascular functioning, independent of adiposity, 2) lower insulin sensitivity and vascular functioning in AA and WH relative to EA is due to lower circulating 25(OH)D in AA, and 3) the relationship between insulin resistance and vascular dysfunction is mediated by 25(OH)D. Acronyms: African American (AA), European American (EA), White Hispanics (WH), Serum 25-hydroxy vitamin D (25()H)D, Body mass index (BMI), Alabama (AL).
The overall objectives of this study are to examine the relationships between circulating vitamin D, insulin sensitivity, and multiple indices of vascular function and to examine whether vitamin D deficiency in AA is responsible for ethnic differences in insulin sensitivity and hypertension in AA and EA, as well as mechanisms underlying the association between insulin resistance and blood pressure. We hypothesize that 1) serum 25(OH)D is associated with insulin sensitivity and vascular functioning, independent of adiposity, 2) lower insulin sensitivity and vascular functioning in AA relative to EA is due to lower circulating 25(OH)D in AA, and 3) the relationship between insulin resistance and vascular dysfunction is mediated by 25(OH)D. Acronyms: African American (AA), European American (EA), Serum 25-hydroxy vitamin D (25()H)D, Body mass index (BMI), Alabama (AL).
The purpose of this study is to evaluate the cardiovascular and lipid effects of two doses of an omega-3 fatty acid concentrate in a group of people who normally are not treated for high lipids.
The main goals of the study are to evaluate the effect of Exenatide on endothelial-dependent vasodilation, as measured by flow mediated dilation (FMD), to evaluate the effect on endothelial-independent vasodilation, as measured by nitroglycerin (TNG) response, and to evaluate the effect on arterial stiffness, as measured by pulse wave analysis (PWA). We will also measure the effects on various markers of endothelial function, subclinical inflammation, fibrinolysis, and oxidative stress. The control group for the study will receive Lantus insulin, with a goal of similar glycemic control between the treatment and control groups. Specific Aims We will test the following hypotheses: 1. Treatment of patients with type 2 diabetes who are inadequately controlled by monotherapy with a Sulfonylurea (SU) or Metformin, or on combination therapy of a SU and Metformin with Exenatide (GLP-1 mimetic) will result in improved endothelial dependent vasodilation, as measured by FMD, as compared to the control group, who will be treated with Lantus insulin to achieve comparable HbA1c levels. 2. Treatment with Exenatide (GLP-1 mimetic) will result in improved arterial stiffness, as measured by AI by PWA, as compared to the control group, who will be treated with Lantus insulin to achieve comparable HbA1c levels. 3. Endothelial dependent vasodilation, as measured by FMD, and arterial stiffness, as measured by AI, measured in the postprandial state (following a standard test meal) will be improved following treatment with Exenatide as compared to treatment with once daily basal insulin (Lantus). 4. Treatment will result in no improvement in endothelial-independent vasodilation, as measured by a response to TNG, as compared to the control group, who will be treated with Lantus insulin to achieve comparable HbA1c levels. 5. Treatment with Exenatide, compared with treatment with Lantus, will result in a reduction in various plasma markers of inflammation (CRP, TNFA, IL6), endothelial activation (ICAM, VCAM, endothelin 1), fibrinolysis (PAI-1 protein, PAI-1 activity), and oxidative stress (FOX2).
The proposed research will determine the effectiveness of nitrite, a naturally occurring compound in the body, for improving the health and function of arteries in middle-aged and older adults. The study also will provide insight into how sodium nitrite therapy improves artery health by determining the physiological mechanisms (biological reasons) involved. Overall, the proposed research will provide important new scientific evidence on the effectiveness of sodium nitrite for decreasing the risk of developing cardiovascular diseases with aging.
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.
The goal of this clinical trial is to learn about the effect of urolithin A, a dietary supplement, on blood flow in middle-aged adults with obesity. The main question it aims to answer is: - Does urolithin A supplementation improve blood flow in large and small blood vessels in middle-aged adults with obesity? Participants will be asked to: * Take the dietary supplement daily for 4 weeks * Attend two study visits to have their blood vessels checked, answer questionnaires, and give a sample of blood Researchers will compare people who took the dietary supplement with others who took a placebo to see if the blood flow in the blood vessels improved.
Patients with high aldosterone hormone have higher blood glucose than normal people. This study is being done to understand how aldosterone hormone affects the nerve activity that controls blood flow in the muscles and blood glucose. The information may be helpful in selecting blood pressure medications which can improve not only blood pressure but also improve blood sugar.
The purpose of this study is to determine if Nebivolol improves microvascular perfusion in skeletal muscle during exercise in hypertensive patients and whether this improvement is accompanied by reduction in vascular oxidative stress or increased endothelial nitric oxide synthase (eNOS) expression in humans.
Diabetes is the most common metabolic disease of childhood. Vascular disease is a leading complication of diabetes, and attempts to maintain close glycemic control do not prevent the sequelae that claim the lives and quality of life of millions of diabetics each year. Up to forty percent of patients with diabetes mellitus ultimately develop diabetic nephropathy, the most common cause of end-stage renal disease requiring dialysis in the US. Flavonoid-rich diets are a promising intervention to prevent the endothelial dysfunction that apparently leads to this deadly complication. The mechanisms are still unclear but probably involve nitric oxide synthesis. The investigators hypothesize that early maintenance of the integrity of renal vasculature will significantly improve the lifelong prognosis for patients with diabetes. Flavonoids with anti-inflammatory and antioxidant activities could be used to protect endothelial function, and together with good glycemic control, prevent the development and progression of nephropathy. The investigators aims are to: 1. compare endothelial function by studying reactive hyperemia, nitric oxide, and proinflammatory factors in adolescents (12-21 years old) with diabetes versus healthy sex- and age-matched control subjects. 2. identify early markers in urine for vascular endothelial injury. 3. examine the effects of flavonoids on vascular function, urine nitric oxide, and proinflammatory factors in patients with diabetes mellitus.
Biomarkers for Cardiovascular Disease Summary: This study will examine the function of the lining cells of blood vessels and measure substances in the blood to see how they relate to various blood tests, including new tests under development to determine cardiovascular disease risk. Nitric oxide is a molecule produced by healthy blood vessels that helps keep them relaxed. Nitrate is a substance formed from nitric oxide in the blood. The release of nitric oxide by blood vessels is reduced in patients with coronary artery disease, compared with healthy people. Also, blood nitrite levels rise in some of these patients. Other substances in the blood and urine also change with risk for heart disease. This study will measure nitrite levels and other inflammatory substances in the blood and urine. Healthy volunteers, people with various risk factors for heart disease, and people with blockage of one or more major heart arteries or a history of heart attack may be eligible for this study. Candidates must be 21 years of age or older. People who have an irregular heart rhythm or who cannot take oral nitrates are excluded. Participants undergo the following tests and procedures: * Blood tests: Samples are drawn three times for routine tests and to look for certain proteins that may affect the heart. Samples are collected once before any other tests, once before starting the exercise stress test (see below) and again after the stress test. * Urine test: A sample may be tested for proteins in the urine and for other research studies. * Brachial artery reactivity study: This ultrasound study tests how well a person's arteries widen. The subject rests on a bed. An ultrasound measuring device is placed over the artery just above the elbow. The size of the artery and blood flow through it are measured before and after inflating a pressure cuff around the forearm. The pressure cuff stops the flow of blood to the arm for 5 minutes and then is released while more ultrasound pictures are taken. After the subject rests, a nitroglycerin tablet (medicine that causes blood vessels to relax) is placed under the tongue. After the nitroglycerin is given, the size of the artery and blood flow through it are measured again. After a rest period, the study will be repeated in the healthy volunteers and first 20 patients with heart disease. * Echocardiography (heart ultrasound): This test involves holding a small probe against the chest to use sound waves for obtaining pictures of the heart. A small catheter (plastic tube) may be placed in a vein to inject a contrast agent that enhances the pictures. * Metabolic stress testing: Subjects will be asked to breathe in and out of a mask while baseline measurements are taken. Then they exercise on a treadmill while wearing a breathing mask. This test shows how much oxygen the body uses at rest and with exercise. * Genetic testing (optional): A blood sample is collected to examine DNA - genetic material that determines inherited traits and contains information about body proteins. Some parts of DNA may be used as markers of the level of damage produced by oxygen by-products that may reflect the extent of heart disease in patients. Also, gene variations may make an individual more likely to develop a heart problem. Such markers may guide doctors in predicting how fast the disease will progress or may help find a new type of drug to prevent disease. * Time requirements: This study is expected to take approximately 5-6 hours for completion within one or two days. * Follow-up: Patients are contacted by phone every 6 months for information on chest pain, surgical procedures related to the heart, and hospitalizations.