343 Clinical Trials for Various Conditions
The goal of this clinical trial is to characterize blood vessel function and oxidative stress (a harmful condition that damages cells and tissues) in emergency medical technicians (EMTs). The main questions it aims to answer are: 1. Does an overnight shift work in emergency medical technicians reduce blood vessel function and increase oxidative stress? 2. Can supplementing with antioxidants help reduce the negative effects of night shift work in emergency medical technicians? Researchers will compare antioxidants to a placebo (a look-alike substance that contains no drug) to see if antioxidants work in reducing the negative effects of night shift work in emergency medical technicians. Participants will: 1. Report to the lab two separate times following an overnight shift to assess blood vessel functioning and oxidative stress 3. Take an antioxidant supplement or placebo during each night of shift work.
High-resistance, short-duration inspiratory muscle strength training (IMST) is a novel lifestyle intervention involving 30 inhalations against a resistive load which requires only \~5 min/day and is thus ideal for youth with T2D (Y-T2D). We seek to 1: assess changes in casual and 24-hr SBP, endothelial function, and arterial stiffness after 3 months of IMST vs. sham training in Y-T2D, 2: Define changes in eGFR andalbuminuria after 3 months of IMST vs. sham in Y-T2D, 3: Interrogate mechanisms of IMST by translational assessments of NO bioavailability, endothelial NO synthase (eNOS) activation, and ROS/oxidative stress, and determine the role of circulating factors.
The objective of this proposal is to determine whether heightened negative affective responsivity (NA-R) to daily stressors is related to blunted nitric oxide (NO)-mediated endothelium-dependent dilation (EDD) in working age adults and the extent to which this association is impacted by major depressive disorder (MDD).
The goal of this clinical trial is to investigate the autonomic and vascular function in men and women with Type 1 diabetes. The main questions it aims to answer are: 1. Patients with type 1 diabetes exhibit attenuated vascular function during steady-state exercise 2. Patients with type 1 diabetes have altered autonomic function at rest and during exercise pressor reflex 3. Patients with type 1 diabetes have attenuated muscle sympathetic activity
People who experience repeated bouts of circadian misalignment, such as shift workers, are at higher risk of cardiovascular disease (CVD) and Type 2 diabetes (T2D) compared to daytime workers. However, the mechanism(s) by which shift work and associated circadian misalignment increase CVD and T2D risk are unknown. This project will examine whether elevated plasma lipids are a mechanism by which circadian misalignment impairs vascular function, insulin sensitivity, glucose homeostasis and muscle lipid accumulation, which could be targeted to prevent and treat cardiometabolic disease in people who chronically experience circadian misalignment, which includes more than 20% of the US workforce.
The goal of this clinical trial is to investigate whether metformin improves vascular function in individuals with prediabetes. The main questions it aims to answer are: 1. Does metformin improve large conduit artery endothelial function in individuals with prediabetes? 2. Does metformin improve microvascular endothelial function in individuals with prediabetes? Researchers will compare metformin to a placebo to see if metformin improves vascular function in prediabetes. The trial duration is 12 weeks. Participants will take metformin or a placebo once a day for 2 weeks. After 2 weeks, participants will take metformin or a placebo twice a day for the remaining 10 weeks. There will be a screening visit, two baseline visits, a 4-week safety visit, and two 12-week end-of-study visits. Adherence will be calculated from pill count and adverse events will be quantified via a questionnaire.
This is a longitudinal study to determine the influence of the menopause transition on autonomic and vascular function. PI Keller-Ross has published data demonstrating that postmenopausal females have greater sympathetic neural reactivity during a stressor compared with age-matched males and younger females and males. A paucity of literature exists, however, on the role of the menopause transition in autonomic function because the majority of experimental studies on menopause physiology are cross-sectional and/or focused on older, postmenopausal females . The influence of age on HTN is robust, whereas the effects of menopause are still unclear. Preliminary data demonstrate a clear association between age and sympathetic activity in females; how the transition through menopause influences these relations, however, remains unknown. The study will enroll 80 midlife (45-55 years of age) females to measure longitudinally the trajectory of autonomic and vascular function during the transition through menopause. The study hypothesizes that through the menopause transition, an increase in sympathetic activity and an impaired baroreflex sensitivity and endothelial function will emerge.
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.
This project will evaluate the impact of L-Citrulline, tetrahydrobiopterin (BH4), and atorvastatin administration on physical capacity and vascular function in Veterans with heart failure with preserved ejection fraction (HFpEF).
The long-term goal of our work is to evaluate the effect of intensive postpartum blood pressure control on maternal cardiovascular health, risk of chronic hypertension, and reversal of vascular dysfunction generated by hypertensive disorders of pregnancy, thus attenuating the lifelong trajectory of cardiovascular disease risk.
Otherwise healthy women who develop preeclampsia during pregnancy are more likely to develop and die of cardiovascular disease later in life. The reason why this occurs is unclear but may be related to impaired endothelial function and dysregulation of the angiotensin system that occurs during preeclampsia and persists postpartum, despite the remission of clinical symptoms. The purpose of this investigation is to determine the mechanisms contributing to this lasting blood vessel damage caused by reduced endothelial function in women who have had preeclampsia compared to women who had a healthy pregnancy. Identification of these mechanisms and treatment strategies may lead to better clinical management of cardiovascular disease risk in these women. The purpose of this study is to examine differences in the microvascular balance of angiotensin II receptors women who have had preeclampsia. This will help the investigators better understand the mechanisms of dysregulated angiotensin II receptors in formerly preeclamptic women, and how activation or inhibition of these receptors may restore microvascular function. In this study, the investigators use the blood vessels in the skin as a representative vascular bed for examining mechanisms of microvascular dysfunction in humans. Using a minimally invasive technique (intradermal microdialysis for the local delivery of pharmaceutical agents) the investigators examine the blood vessels in a dime-sized area of the skin.
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.
The risk of cardiovascular disease (CVD) is significantly elevated in patients with chronic kidney disease (CKD). Notably, women with CKD commonly experience menstrual disturbances induced by CKD, which may contribute to impaired vascular function and elevated CVD risk. However, most of the literature in nephrology focuses on male patients, and studies on women's vascular health are limited. Establishing effective therapies for improving vascular function and reducing CVD risk in women with CKD is a high research priority of the NIH. Equol contributes to improvement in vascular function, mediated in part by its anti-oxidative and anti-inflammatory properties. However, there is no information on the effect of equol on vascular function in women with CKD. The proposed project aims to determine the acute effect (1-hour, 2-hours, and 3-hours post ingestion) of oral equol supplementation on vascular function in postmenopausal women with and without CKD.
The glycocalyx serves as the interface between flowing blood and endothelial cells, the single cell layer that lines blood vessels, and is crucial for normal blood vessel function. Specifically, the glycocalyx protects endothelial cells from oxidative stress and inflammation and enables blood vessel dilation, which is largely dependent on the bioavailability of the vasodilatory molecule nitric oxide. Importantly, glycocalyx thickness decreases with age and is predictive of major adverse cardiovascular events in older adults free of cardiovascular disease. Therefore, interventions aimed at restoring glycocalyx thickness in older adults are desperately needed. Endocalyx Pro is a commercially available glycocalyx precursor supplement, manufactured by Microvascular Health Solutions, designed to 1) repair a damaged glycocalyx, 2) protect against damage to the glycocalyx, and 3) synthesize new glycocalyx components, and has been used to increase glycocalyx thickness in humans. However, no study has tested if glycocalyx thickness restores glycocalyx thickness in older adults and improves blood vessel function. Thus, the purpose of this investigation is to determine if 12-weeks of Endocalyx Pro supplementation alters glycocalyx thickness and blood vessel function in older adults. The investigators will use a camera placed under the tongue to determine glycocalyx thickness. The investigators will measure blood vessel function by measuring brachial artery dilation with ultrasound and arterial stiffness using pressure probes placed on the carotid and femoral artery.
This observational study will examine the association of chronic traumatic cerebrovascular injury and cardiovascular risk factors with TBI-related cognitive impairment and vascular dementia. Cerebrovascular, inflammatory, and neurodegenerative blood biomarkers as well as clinical and neuroimaging data
The objective of this project is to provide evidence that L-Citrulline (CIT) supplementation can improve vascular function in the fasted and acute hyperglycemia conditions in middle-aged and older women with metabolic syndrome.
Type 2 diabetes (T2D) confers a high risk of cardiovascular disease (CVD), particularly among older adults who tend to be physically inactive. Prolonged sedentary behavior (SB) has been shown to negatively influence markers of cardiovascular risk (e.g., blood glucose, blood pressure), even among individuals who are physically active. Most studies that have examined the effects of breaking up SB have focused on young healthy males and prioritized glycemic outcomes. Additionally, sex differences in these outcomes have not been adequately examined. The present study will address these gaps. This 3-arm crossover randomized controlled trial will compare the effects of 3 SB conditions on markers of vascular function. The 3 conditions are: 1) 4 hours of prolonged SB, 2) 4 hours of SB broken up by 5 minutes of self-paced walking every hour, and 3) 4 hours of SB with one 20-minute bout of self-paced walking. In addition to examining the overall effects of each condition, sex differences in physiological responses will be evaluated.
This study aims to identify the influence of social determinants of health domains on vascular function in a low income, racial, and ethnic minority population at risk for disparities. We hypothesize that individuals of a lower social economic position and those struggling with depression are at greater risk of cardiovascular disease.
Preeclampsia is a pregnancy disorder affecting \~5-10% of pregnancies in the United States. Women who develop preeclampsia during pregnancy are more likely to develop and die of cardiovascular disease later in life, even if they are otherwise healthy. The reason why this occurs is unclear but may be related to blood vessel damage and increased inflammation that occurs during the preeclamptic pregnancy and persists postpartum. Low dose aspirin (LDA; 75-150mg/daily) is currently the most effective and clinically accepted therapy for reducing preeclampsia prevalence in women at high risk for developing the syndrome. The purpose of this study is to interrogate the mechanisms by which LDA therapy mitigates persistent vascular dysfunction in postpartum women who have had preeclampsia. In this study, the investigators use the blood vessels in the skin as a representative vascular bed for examining mechanisms of microvascular dysfunction in humans. Using a minimally invasive technique (intradermal microdialysis for the local delivery of pharmaceutical agents) they examine the blood vessels in a dime-sized area of the skin in women who have had a history of preeclampsia. As a compliment to these measurements, they also draw blood from the subjects and isolate the inflammatory cells.
The primary aim of the proposed investigation is to examine the hypothesis that a relatively short period of rhamnan sulfate supplementation would improve key markers of vascular dysfunction in middle-aged and older adults with at least one risk factors for cardiovascular disease.
The treatment of high blood pressure, or hypertension, is multifaceted and can include pharmacological therapies (i.e., medications) and lifestyle modifications such as physical activity. Chronotherapy, which describes timing of a treatment with the body's daily rhythms, has recently been used with hypertension medications and has been shown to be effective at lowering blood pressure and reducing the risk of cardiovascular disease events. Specifically, taking medications in the evening was shown to be more effective than morning medication routines. Little information is available about the effectiveness of chronotherapy combined with exercise (i.e., planned physical activity) interventions in older adults with hypertension. The purpose of this study is to examine how exercise performed in the morning and early evening affects blood pressure and other measures of blood vessel health in postmenopausal females with hypertension.
Kidney disease is a common problem among people with type 1 diabetes and can lead to disability, dialysis, and early death. Inflammation plays a key role in the development of kidney disease in type 1 diabetes and targeting leukotrienes, inflammatory chemicals the body releases in response to allergic reactions, may represent a promising therapy to slow the progression of diabetic kidney disease. The current proposal will investigate whether montelukast, a leukotriene blocker, lowers increased levels of protein in the urine (an early marker of diabetic kidney disease), and improves kidney and cardiovascular function in people with type 1 diabetes and kidney disease.
The risk of cardiovascular disease (CVD) is significantly elevated in patients with chronic kidney disease (CKD). Notably, women with CKD commonly experience menstrual disturbances induced by CKD, which may contribute to impaired vascular function and elevated CVD risk. However, most of the literature in the field of nephrology focuses on male patients, and studies on women's vascular health are limited. Moreover, endogenous sex hormones, particularly estradiol, are well-documented to be cardioprotective in women without CKD; however, the role of sex hormones on vascular function in women with CKD remains unclear. The goals of the proposed project are: 1) to evaluate vasuclar function in pre- and post-menopausal women with CKD vs. age-matched healthy women; 2) to evaluate sex hormone concentrations and determine whether they associate with vascular function in the proposed cohort; and 3) to gain mechanistic insight on the association between sex hormones and vascular dysfunction in the proposed cohort.
The investigators will assess the vascular effects of riding in a car in heavily trafficked roadways, and whether filtering the car's air reduces those effects.
The purpose of this study is to investigate the effect of blood flow restriction (BFR) resistance training on vascular function. The investigators aim to compare the effects of different BFR devices (wide-rigid cuffs and narrow elastic bands) on vascular function. The investigators hypothesize that BFR resistance training with wide-rigid cuffs might have a minor negative effect (short-term and reversible) on vascular function, while BFR resistance training with narrow-elastic bands may improve vascular function. Both training methods are equally effective in increasing muscle strength.
The concept that direct stimulation of soluble guanylate cyclase (sGC) could be a particularly effective approach to increase cyclic guanosine monophosphate (cGMP) in conditions of increased inflammation/oxidative stress, endothelial dysfunction, and reduced nitric oxide (NO) bioavailability. Thus, the aim of the proposed study is to examine the effect of Vericiguat on peripheral vascular function, inflammatory status, and patient health status. The study also aims to identify patients who are particularly likely to benefit from Vericiguat treatment and predict that these patients will be defined by baseline peripheral vascular dysfunction and high inflammatory state.
This study aims to determine the effects of \~12 weeks of repeated hot water immersion ("heat therapy") vs. thermoneutral water immersion on blood pressure and vascular function in late middle-life to older (≥40 years) adults. The study also aims to determine the effects of \~12 weeks of heat therapy on fluid cognitive and cerebrovascular function.
The overall objective of this project is to bring forth evidence that L-Citrulline (L-CIT) supplementation and low intensity resistance exercise training (LIRET) alone and combined will improve vascular function and muscle fitness (mass, strength, and exercise performance) in postmenopausal women with hypertension. The investigators' central hypothesis is that adjuvant L-CIT supplementation may synergistically enhance vascular (arterial stiffness, BP, muscle oxygenation, blood flow) and muscular (strength, exercise performance) responses to LIRET in postmenopausal women with hypertension by improving endothelial vasodilatory function.
Emerging data show that SARS-CoV-2 infection causes gut microbiome changes strongly associated with Post-Acute Sequelae of SARS-CoV-2 (PASC). The investigators and others have established that an orally ingested probiotic (Lactobacillus plantarum 299v, Lp299v) reduces circulating levels of cell-free mitochondrial DNA (cf-mtDNA), decreases toll-like receptor 9 (TLR9) activation \[and downstream interleukin (IL-6)\], and improves micro- and macrovascular (brachial artery) endothelial dysfunction \[as measured by flow-mediated dilation (FMD%)\] in humans. Recently published data also report impaired brachial FMD% and increased vascular stiffness post-SARS-CoV-2 infection. Based on these data, the investigators hypothesize that supplementation with Lp299v will attenuate SARS-CoV-2 associated endothelial dysfunction by reducing cf-mtDNA, TLR9 activation, and inflammation.
The prevalence of type 2 diabetes (T2D) continues to increase in the US, with 26.8 million adults carrying a diagnosis. Importantly, T2D is widespread in the Veteran population. This epidemic of T2D also contributes to the staggering rates of cardiovascular disease and cardiovascular mortality. Lifestyle modifications, including increased physical activity, are recommended as first-line therapy for the management of T2D. Unfortunately, patients with T2D exhibit diminished vascular adaptations to exercise. The proposed project will test the overall hypothesis that degradation of the endothelial glycocalyx, a characteristic feature of T2D, precludes shear stress mechanotransduction and consequent exercise-induced vascular adaptations. As such, the investigators pose that restoration of the endothelial glycocalyx via dietary supplementation of glycocalyx precursors will potentiate vascular adaptations to exercise in Veterans with T2D.