Endothelial Dysfunction Clinical Trials

Diabetic kidney disease and cardiovascular disease remain the leading causes of morbidity and mortality in people with type 1 diabetes and are exacerbated with longer duration of diabetes and time outside goal glycemic range. Yet, type 1 diabetes is a complex disease with pathophysiology that extends beyond beta-cell injury and insulin deficiency to include insulin resistance and renal vascular resistance, factors that accelerate cardiovascular disease risk. We have shown that metformin improved peripheral insulin sensitivity and vascular stiffness in youth with type 1 diabetes on multiple daily insulin injections or standard insulin pumps. However, metformin's effect on kidney and endothelial outcomes, and the effects of type 1 diabetes technologies, with or without metformin, on any cardiovascular or kidney outcome, remains unknown. Automated insulin delivery systems combine an insulin pump, continuous glucose monitor, and control algorithm to modulate background insulin delivery and decrease peripheral insulin exposure while improving time in target range and reducing hypoglycemia. We hypothesize that automated insulin delivery systems, particularly when combined with metformin, may modulate renal vascular resistance and insulin sensitivity, thereby impacting cardiometabolic function. MANATEE-T1D is a randomized, double-blind, placebo-controlled trial of 4 months of metformin 2,000 mg daily in 40 youth aged 12-25 years with type 1 diabetes on automated insulin delivery systems vs. 20 control youth with type 1 diabetes on multiple daily injections plus a continuous glucose monitor or an insulin pump in manual mode plus a continuous glucose monitor which will assess for changes in calculated renal vascular resistance and gold standard measures of whole-body and adipose insulin sensitivity, arterial stiffness, and endothelial function. 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

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

1. 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. 2. 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

Background: This study is designed to provide samples to help us study the genes your blood cells are making as well as the proteins, sugars, fats, vitamins and other metabolites found in your blood or urine. Blood samples may also be collected to make special cells. These are called induced pluripotent stem cells or iPSCs. Pluripotent stem cells are cells that can be converted into any type of cell. Researchers want to study in the lab iPSCs that are derived from blood samples. Objective: To collect samples to help study genes, proteins, sugars, fats, vitamins, and other metabolites found in blood or urine. Eligibility: Healthy volunteers and patients ages 18 and older Design: First-time research study participants at NIH will have an initial visit for this study that should last no more than 1 hour. All other visits should last 20 30 minutes. Participants will undergo a limited history and physical exam. Participants may have routine blood and urine tests. If participants are giving a blood sample, they must have a hemoglobin level checked in the past 12 months to make sure it is safe for them to give a blood sample for research. Participants may have a venous blood collection. They may do this at several visits. They will lie on a recliner or couch or sit in a chair. A needle will be placed into a vein in the hand or arm, using sterile techniques. Blood will be withdrawn into multiple syringes or tubes. Participants may be asked to provide urine in an appropriate container... Read Less

This is a pilot clinical trial to test the efficacy of intermittent treatment with the flavonoid compound fisetin for improving vascular endothelial function and reducing aortic stiffness in older adults. This trial will also determine the potential mechanisms by which fisetin may improve vascular function, including by decreasing mitochondrial oxidative stress, cellular senescence and senescence-associated secretory phenotype (SASP) factors in circulation. Lastly, safety, tolerability and adherence of fisetin treatment will be assessed. Read Less

The overall purpose of this study is to understand the role of disrupted sleep in the association of exposure to early life adversity (adverse childhood experiences (ACEs)) with vascular endothelial (dys)function. In Aim 1 (The Iowa ACEs and Sleep Cohort Study), the investigators will utilize a cross-sectional cohort design with a state-of-the-art translational approach. Participants will be recruited to objectively characterize the degree to which lower sleep quality and quantity contribute to ACEs-related endothelial dysfunction, inflammation, and oxidative stress in young adults using: 1. rigorous at home sleep monitoring using 7-nights of wrist actigraphy and 2 nights of home-based polysomnography to objectively measure sleep quality (sleep efficiency, wakefulness after sleep onset and sleep depth), and total sleep duration, 2. in vivo assessment of endothelial function via flow-mediated dilation testing, and 3. in vitro determination of endothelial cell inflammation and oxidative stress from biopsied endothelial cells. This study to achieve this Aim. In Aim 2, approximately 70 eligible participants from Aim 1 (The Iowa ACEs and Sleep Cohort Study) will then be randomized to either a 6-week behavioral sleep intervention (cognitive behavioral therapy for insomnia) or a wait-list control to determine the mechanistic contribution of sleep disruption to vascular dysfunction in young adults with moderate-to-high exposure to adverse childhood experiences (ACEs). Following the intervention, participants will again complete: 1. rigorous at home sleep monitoring using 7-nights of wrist actigraphy and 2 nights of home-based polysomnography to objectively measure sleep quality (sleep efficiency, wakefulness after sleep onset and sleep depth), and total sleep duration, 2. in vivo assessment of endothelial function via flow-mediated dilation testing, and 3. in vitro determination of endothelial cell inflammation and oxidative stress from biopsied endothelial cells. Read Less

The overall objective of this multi-center registry is to identify specific phenotypes of INOCA with both an anatomic evaluation (coronary angiography and intravascular imaging) and physiologic assessment with the Abbott Coroventis Coroflow Cardiovascular System, and to determine long-term outcomes. Read Less

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. Read Less

High blood pressure (BP) is the major modifiable risk factor for cardiovascular diseases (CVD) and related health conditions, particularly among postmenopausal (PM) women. In adults age ≥50 years this risk is primarily driven by above-normal systolic BP (SBP ≥120 mmHg), as diastolic BP plateaus, then decreases in older adulthood. Although SBP is lower in premenopausal women vs. age-matched men, SBP reaches, then surpasses men after age 60. As such, \>75% of PM women in the U.S. have above-normal SBP, which, in turn, is responsible for a 2-fold increase in risk of hypertension and corresponding increases in risk of CVD, chronic kidney disease and many other disorders. A key process linking high SBP to CVD and related conditions is vascular endothelial dysfunction, mediated by excessive reactive oxygen species (ROS)-induced oxidative stress and reductions in nitric oxide (NO) bioavailability. As the number of PM women is rapidly growing, further increases in SBP-related CV disorders are projected without effective intervention. * Aerobic exercise (AE) is a first-line, standard-of-care therapy for lowering BP. In PM women with baseline SBP ≥120 mmHg, AE reduces casual (resting) SBP by \~3 mmHg (back to baseline ≤4 weeks post-training), whereas 24-hour SBP is typically unchanged. However, only 25-30% of PM women meet guidelines for 150 min/week of moderate-intensity AE, citing the extensive time requirement, facility access and travel disruptions as major barriers. Another, far less recognized, limitation is that AE training consistently improves endothelial function in midlife/older men, but not in estrogen-deficient PM (PMe-) women, i.e., in \>95% of the 60+million PM women in the U.S. Thus, establishing new lifestyle therapies that induce and sustain reductions in SBP and increases in endothelial function in PMe- women with above-normal SBP is an important public health goal. * 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. In addition, IMST improved endothelial function in the PMe- women in a small pilot study. * To translate these promising preliminary results towards clinical practice, this randomized clinical trial is being conducted to directly compare the efficacy of a longer, clinically relevant treatment duration of IMST (3 months) against home-based, moderate-intensity (standard-of-care) AE in PMe-women. The primary outcome will be the change in casual SBP (IMST vs. AE). Changes in 24-hour SBP and endothelial function will serve as secondary outcomes. Effects on NO bioavailability, ROS/oxidative stress, and the role of "circulating factors" will provide insight into mechanisms of action. The sustained effects on SBP and endothelial function also will be assessed. * Accordingly, a randomized, blinded, sham-controlled, parallel group design clinical trial will be conducted 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 function in PMe- women age 50 years and older with above-normal SBP. It is hypothesized that IMST will lower SBP and improve endothelial function by decreasing oxidative stress and increasing nitric oxide bioavailability. It is also expect that adherence to the intervention will be excellent (over 80 percent of all training sessions completed at the appropriate intensity). * To test this hypothesis, 90 PMe- women age 50 years and older who have SBP \>/= 120 mmHg will be recruited. Participants will undergo baseline testing for casual (resting) SBP, 24-hour ambulatory SBP and endothelial 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. 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. Subjects will then cease training for 6 weeks before returning to the lab for follow-up testing to determine the persistent effects of IMST. Read Less

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