Endothelial Dysfunction Clinical Trials

Patients with Type 2 Diabetes Mellitus (T2DM) have changes in blood vessel health that can lead to a higher chance of developing heart attacks or strokes. New medications for T2DM including dapagliflozin, which is a Sodium-Glucose Cotransporter-2 inhibitor (SGLT2) inhibitor, may help protect the heart and blood vessels. The overarching objective of this mechanistic study is to learn how a Sodium-Glucose Cotransporter-2 (SGT2) inhibitor, dapagliflozin, impacts vascular health in patients with Type 2 Diabetes Mellitus (T2DM). The investigators will compare the changes in vascular health to changes in endothelial cell (EC) phenotype including non-coding RNA (ncRNA) to develop evidence supporting the mechanism of cardiovascular benefit of SGLT2 inhibitors. This study will provide novel information regarding the mechanism of effects of novel treatments for endothelial function and vascular health in patients with T2DM to reduce cardiovascular (CV) risk. The research aims to assess the: * effects of dapagliflozin on EC phenotype. * impact of dapagliflozin on vasodilator function and additional measures of vascular health including arterial stiffness and circulating markers of vascular health. Read Less

The use of electronic nicotine delivery systems, or e-cigarettes - colloquially referred to as "vaping" - in the United States has increased exponentially since their introduction to the US market in 2007. Prevalence of ever and current e-cigarette use is highest among teenagers and young adults with 16-28% of this population having reported vaping. While the majority of e-cigarette users are current tobacco smokers, 32.5% of current e-cigarette users are never- or former-smokers, representing a growing population of young adults who exclusively vape. While e-cigarettes have been marketed as a safer alternative to tobacco cigarettes, clinical studies examining these claims are limited. Cardiovascular disease (CVD) is the primary cause of premature death among tobacco cigarette smokers and reductions in vascular endothelial function, a significant predictor of future CVD, are detectible in otherwise healthy young adults who smoke. Despite the explosion in e-cigarette use among young adults, the health effects - especially the effects on mechanisms of vascular function - of these devices remain relatively unexplored. The purpose of this study is to directly asses the mechanistic role of inflammation in this dysfunction. Read Less

Women with a history of gestational diabetes mellitus (GDM) are at a 2-fold greater risk for the development of overt cardiovascular disease (CVD) following the effected pregnancy. While subsequent development of type II diabetes elevates this risk, prior GDM is an independent risk factor for CVD morbidity, particularly, within the first decade postpartum. GDM is associated with impaired endothelial function during pregnancy and decrements in macro- and microvascular function persist postpartum, despite the remission of insulin resistance following delivery. Collectively, while the association between GDM and elevated lifetime CVD risk is clear, and available evidence demonstrates a link between GDM and vascular dysfunction in the decade following pregnancy, the mechanisms mediating this persistent dysfunction remain unexamined. The purpose of this investigation is to examine the role of endothelin-1, a potent vasoconstrictor, in aberrant microvascular function in otherwise healthy women with a history of GDM and to identify whether this mechanism is influenced by physical activity and sedentary behavior. Read Less

The proposed mechanistic trial will test the effect of dietary sodium reduction on cardiac and vascular structure and function in those with elevated blood pressure or hypertension. Findings from this study will fill the knowledge gap on the underlying mechanisms of dietary sodium intake on cardiovascular disease risk in addition to blood pressure and could provide further evidence on sodium reduction for the prevention of cardiovascular disease. Read Less

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

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