Endothelial Dysfunction Clinical Trials

Cardiopulmonary bypass during cardiac surgery provides blood flow to the body during surgery but has adverse effects on different organs. Blood flow during cardiopulmonary bypass may be pulsatile or non-pulsatile, which may impact normal organ function after surgery. The study will collect data on the type of cardiopulmonary bypass used during surgery and organ function to determine if there is an association between the type of bypass and organ function. Read Less

Impaired endothelial function is observed in disease states related to obesity, such as atherosclerosis, coronary artery disease, and diabetes. Reactive oxygen species (ROS) production and resultant oxidative stress contribute to the development of these obesity-related diseases. The enzyme NADPH-oxidase is a major source of oxidative stress within the vasculature, and has been linked with the Metabolic Syndrome. In the investigator's previously funded studies, the investigators demonstrated for the first time that: 1) in vivo ROS were elevated in skeletal muscle of obese as compared to lean or overweight human subjects, 2) perfusion of the NADPH-oxidase inhibitor apocynin locally into muscle normalized ROS levels and reversed local microvascular endothelial dysfunction in the obese individuals, and 3) aerobic exercise training was effective at attenuating in vivo hydrogen peroxide production and reversing microvascular endothelial dysfunction in the obese individuals. The investigators will investigate in this R15 renewal application the mechanism of exercise training-induced alterations in ROS production and action on endothelial dysfunction in obesity using our newly developed microdialysis methodology of monitoring ROS production, in combination with analysis of muscle biopsy samples obtained before and after our previously tested 8-week intervention of aerobic interval exercise training. The objectives of this study are to determine the impact of in vivo NADPH oxidase activity on endothelial function in obese individuals, and to determine the mechanism of training-induced improvements in endothelial function. The investigator's unique microdialysis methodology will allow monitoring of microvascular/endothelial function and ROS generation, as well as the administration of pharmacological agents directly into muscle. The central hypothesis is that it is upregulation of both mitochondrial ROS and NADPH oxidase-derived ROS that results in endothelial dysfunction in obesity, and that exercise training down-regulates mitochondrial-derived ROS, and NADPH oxidase 4, thereby improving endothelial function. The aims of this proposal are to: 1) determine the contributions of mitochondrial ROS and specific NADPH oxidase isoforms to the NADPH oxidase dependent endothelial dysfunction in skeletal muscle of obese individuals; 2) determine the mechanism of ROS reduction and improved endothelial function resulting from an 8-week aerobic interval training program. Read Less

The investigators will test the hypothesis that, in adults with type 1 diabetes (T1D), glucagon-like peptide-1 receptor agonism (GLP-1RA, i.e. dulaglutide) and exercise training each enhance insulin-mediated skeletal muscle microvascular perfusion via attenuating endothelial oxidative stress and thereby improving endothelial function. Read Less

The goal of this clinical trial is to see how small blood vessels respond to the stress of high intensity exercise, and if a safe and simple intervention called ischemic conditioning can protect blood vessels from the stress of exercise. Participants will come in for 3 study visits and get home-based ischemic conditioning. At Study Visit 1, participants will be assessed for their frailty and physical function. Afterwards, they will perform an exercise test. At Study Visit 2, patients will undergo 2 microvascular assessments, perform a high-intensity exercise, then undergo the same 2 microvascular assessments again. Participants will be given a handheld sphygmomanometer and a blood pressure cuff to take home. Depending on which group the participants get randomized into, participants will place the blood pressure cuff around their non-dominant upper arm and inflate to either a low or high pressure for 2 weeks at home. Participants will repeat the same steps in Study Visit 2 for Study Visit 3. In addition, participants will also be assessed for their frailty and physical function. Read Less

Individuals with spinal cord injury have heart attacks and strokes more frequently, and much earlier in life. People with spinal cord injuries develop plaque in vessels much faster, and the reasons why are unclear. Doctors generally attributed the increased risk with weight gain and developing diabetes, but many studies have shown that even without these common factors, plaque in vessels is developing more often and faster. Endothelial cells are a single layer of cells that line all vessels in the body and plays an important role in vessel health. Damage to endothelial cells is known to lead to heart attacks and strokes. Past studies on endothelial cells of people with spinal cord injury have been unclear. The investigators have new data that these cells are unhealthy after spinal cord injury a measurement. This includes measuring endothelial health by directly altering its function using a catheter in the arm and measuring small particles in blood called endothelial microvesicles. If the project is successful, the investigators will learn important information on the health of endothelial cells after spinal cord injury. The investigators will also be able to use these markers of endothelial cell function to create treatments to improve vessel health and prevent heart attacks and strokes later in life in people with spinal cord injury. Read Less

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality worldwide. Aging is the primary risk factor for CVD, in large part due to adverse modifications to the arteries. These modifications include vascular endothelial dysfunction and arterial stiffness. Vascular endothelial dysfunction is an initiating step in atherosclerosis, and is primarily caused by reduced nitric oxide (NO) bioavailability secondary to excessive superoxide-driven oxidative stress and inflammation. Endothelial dysfunction leads to arterial stiffness and the development of hypertension (HTN) which further increases CVD. Greater than 2/3 of the US population has elevated blood pressure or stage 1-HTN. As such, interventions that improve vascular endothelial dysfunction by increasing NO bioavailability and mitigating excessive oxidative stress and inflammation are needed. Blueberries are rich in bioactive compounds including flavonoids, phenolic acids, and pterostilbene. These compounds and their metabolites have been shown to attenuate oxidative stress and inflammation. The primary goal of this study is to assess the efficacy of blueberries to improve reduce blood pressure and improve vascular endothelial dysfunction and arterial stiffness in middle-aged/older men with elevated blood pressure or stage 1-HTN. Read Less

In a young and healthy person, the production of nitric oxide (NO) by the endothelium, the inner lining of the blood vessel, is responsible for a) the ability of the blood vessel to dilate so it can increase its blood flow and b) act as an anti-clotting product to prevent blood clotting in those vessels. Under physiological stress either due to the development of a disease such as diabetes or simply from aging, the endothelial cells can be impacted and become dysfunctional thereby impairing their ability to make NO and even promote the development of blood clots. When such endothelial dysfunction occurs, it may be a precursor for the future development of cardiovascular (CV) disease like hypertension or even coronary artery disease later on in life in these patients. Therefore, the ability to somehow enhance the local production or availability of NO within such affected blood vessels in patients identified as prone to endothelial dysfunction could play a positive role in either preventing or delaying the onset of endothelial dysfunction and subsequent CV disease in such patients. COMP-4 is a safe, clinically available, well tolerated oral supplement that has been shown in the lab to increase NO production in a number of differing tissues including human vascular endothelial cells. In this proposed human study, the investigators plan on recruiting healthy, young participants willing to take COMP-4 for a 14 day period in whom the investigators will measure in a non-invasive way - by the use of ultrasound - the effect of COMP-4 on its ability to improve blood flow in one of the major blood vessels of the upper arm. In addition, the investigators will also determine whether COMP-4 will be capable of lowering in the blood the levels of two of the most studied inflammatory markers associated with endothelial dysfunction, IL-8 and PAI-1. Read Less

The goal of this mechanistic clinical trial is to learn about the effects of medications called soluble guanylyl cyclase stimulators on vascular function and markers of kidney and brain injury in patients having heart surgery. The main questions it aims to answer are: 1. Does soluble guanylyl cyclase stimulation improve blood vessel function compared to placebo? 2. Does soluble guanylyl cyclase stimulation decrease markers of kidney injury and brain injury compared to placebo? Participants will be randomized to a soluble guanylyl cyclase stimulator called vericiguat or placebo, and researchers will compare vascular function and markers of brain and kidney injury to see if vericiguat improves vascular function and reduces markers of injury. This will provide important information to determine the underlying reasons that patients have some kidney and brain function problems after having heart surgery. Read Less

Elucidate the influence of intense light therapy pretreatment in patients undergoing cardiac surgery. We hypothesize that intense light exposure is associated with the peripheral stabilization of Per2 in human buccal swabs and plasma samples before surgery and with a decrease of Troponin I levels after surgery. In addition, we hypothesize that light therapy leads to Per2 dependent metabolic optimization in the human cardiac tissue. Therefore, a small piece of human heart tissue from the right atrium will be collected during cardiac cannulation, which will be otherwise discarded. Critical illness (being in the intensive care unit) results in circadian malfunction and vessels not working. Vessel function is controlled by the body's circadian clock. Intense light boosts the circadian clock and the vessel function in animal studies. Vessels not working well in critical ill patients results in a myriad of severe diseases (delirium, stroke, heart attack, organ damage etc). Thus we will test if intense light can be used to boost the circadian clock and the associated vessel function in critical ill patients. Read Less

In this project, the investigators propose to test effectiveness of a daily nutraceutical supplement containing bioactive B vitamins to mitigate optic disc edema in astronauts. The proposed countermeasure is intended to maximize functioning of the one-carbon metabolic pathway to provide enough substrate and cofactors to overcome any genetic differences that may impact the efficiency of enzyme function. By optimizing the pathway, this will 1) optimize endothelial function by increasing eNOS coupling and nitric oxide synthesis and 2) optimize collagen firmness and elasticity in the sclera and lamina cribrosa, and 3) minimize changes in total retinal thickness during and after flight. The protocol includes assessments of ocular health and function, along with determinants of vascular endothelial function, advanced glycation end products, and nutritional status and one carbon biochemistry. These additional measures will be critical for the further definition of the causes of optic disc edema in some astronauts after long-duration space flight, and in understanding the effect of the countermeasure. Finally, the supplemented subjects in this study will be compared against total retinal thickness data from previously flown astronauts known to have not taken supplements during their missions. Read Less

This observational study will evaluate the effect of puberty suppression on insulin sensitivity, metabolic rate and vascular health among transgender female youth at baseline and 6 months after initiation of a gondoatropin releasing hormone agonist compared to matched cisgender male controls. Read Less

Above-normal systolic blood pressure (SBP), defined as SBP >/= 120 mmHg, is the major modifiable risk factor for cardiovascular disease, stroke, cognitive decline/dementia, and other chronic health problems. Despite the availability of treatments to lower SBP, over 75 percent of adults with above-normal SBP fail to control BP, which has led to a nearly 50 percent increase in the number of deaths attributable to BP over the past decade. Therefore, above-normal SBP is a major public health burden. Greater than 65 percent of adults 50 years of age and older have above-normal SBP. The number of adults age 50 years and older is rapidly increasing, predicting a continued increase in above-normal SBP driven morbidity and mortality in the absence of effective treatment strategies. This makes developing novel SBP-lowering therapies an urgent biomedical research priority. Increasing SBP is closely linked to vascular dysfunction, observable as impaired endothelial function, increased large-elastic artery stiffness, and impaired cerebrovascular function. Declines in these functions play a large role in the increased risk of chronic disease associated with above-normal SBP. The primary mechanism responsible for SBP-induced vascular dysfunction is thought to be oxidative stress-associated inhibition of nitric oxide bioavailability. Therefore, to have the largest biomedical impact, new SBP-lowering therapies should also improve vascular function by decreasing oxidative stress. Healthy lifestyle practices, such as conventional aerobic exercise, maintaining a healthy diet, or reducing sodium intake, are all first-line strategies to lower SBP. Importantly, these lifestyle practices also improve vascular function, in large part by reducing oxidative stress. However, adherence to healthy lifestyle practices is poor, with adherence to guidelines generally between 20 to 40 percent in adult Americans. The greatest reported barrier to meeting healthy lifestyle guidelines is lack of time. Therefore, time-efficient interventions have great promise for promoting adherence, reducing SBP, and improving other physiological functions. High-resistance inspiratory muscle strength training (IMST) is a time-efficient (5 minutes per session) lifestyle intervention consisting of 30 inspiratory maneuvers performed against a high resistance. Preliminary data suggest 6-weeks of IMST performed 6 days/week reduces SBP by 9 mmHg in adults with above-normal SBP (i.e., greater than 120 mmHg) at baseline. Importantly, this reduction in SBP is equal to or greater than the reduction in blood pressure typically achieved with time- and effort-intensive healthy lifestyle strategies like conventional aerobic exercise. However, these results need to be confirmed in an appropriately powered clinical trial with a longer, guideline-based treatment duration. Furthermore, the influence of IMST on functions impaired by above-normal SBP (endothelial, cerebrovascular, cognitive) needs to be determined, as do the mechanisms through which IMST exerts beneficial effects. Accordingly, we will conduct a randomized, blinded, sham-controlled, parallel group design clinical trial to assess the efficacy of 3-months of IMST (75 percent maximal inspiratory pressure) vs. brisk walking (40-60% heart rate reserve; an established healthy lifestyle strategy) for lowering SBP and improving endothelial, cerebrovascular, and cognitive function in adults age 50 years and older with above-normal SBP. I hypothesize IMST will lower SBP and improve endothelial function by decreasing oxidative stress and increasing nitric oxide bioavailability. I also hypothesize IMST will improve cerebrovascular and cognitive function, and that these improvements will be related to reductions in SBP and improvements in endothelial function. I also expect adherence to the intervention to be excellent (over 80 percent of all training sessions completed at the appropriate intensity). To test my hypothesis, I will recruit 102 adults age 50 years and older who have SBP >/= 120 mmHg. Subjects will undergo baseline testing for casual (resting) SBP, 24-hour ambulatory SBP, endothelial function, arterial stiffness, cognitive function, and cerebrovascular function. Innovative mechanistic probes including pharmaco-dissection with vitamin C, analysis of biopsied endothelial cells, and high-throughput metabolomics, will be performed to assess oxidative stress and nitric oxide bioavailability at baseline. After baseline testing, subjects will be randomized to perform either 3-months of high-resistance IMST or brisk walking. Subjects will train 6 days/week with one training session supervised in the laboratory and the other 5 performed unsupervised at home. Following 3 months of training, subjects will redo all the tests that were done during baseline testing to assess training-induced changes in SBP, physiological functions, and underlying mechanisms. Read Less