Vascular Diseases Clinical Trials

Risk of cardiovascular diseases (CVD) is significantly elevated in patients with chronic kidney disease (CKD); however, this increased risk is only partially explained by traditional CV risk factors. Arterial dysfunction is an important nontraditional CV risk factor gaining increased recognition in the field of nephrology. This process is best represented, both physiologically and pathophysiologically, by increases in the gold standard measure of arterial stiffening, carotid to femoral artery pulse wave velocity (CFPWV), which reflects, in particular, increases in aortic stiffness. Aortic stiffening with CKD is mediated by structural and functional (increased vascular smooth muscle tone) changes in the arterial wall stimulated by oxidative stress and chronic low-grade inflammation. Caloric restriction (CR) is a promising strategy for prevention of CKD-associated arterial dysfunction and CVD. However, long-term adherence to chronic CR regimens with optimal nutrition is very difficult to achieve. Research has shown that boosting NAD+ bioavailability to stimulate SIRT-1, a "CR mimetic" approach, reduces CFPW and oxidative stress in old mice, and this lab recently took the first step in translating these findings in a study of adults with normal kidney function and elevated systolic blood pressure (SBP). The data found that supplementation with nicotinamide riboside, a natural, commercially available precursor of NAD+ and novel CR mimetic, increased NAD+ bioavailability and reduced CFPWV and SBP. A randomized, placebo-controlled, double-blind, single-site phase IIa clinical trial to assess the safety and efficacy of oral nicotinamide riboside (500 mg capsules 2x/day; NIAGEN®; ChromaDex Inc.) for 3 months vs. placebo for decreasing aortic stiffness and SBP in patients (35-80 years) with stage III and IV CKD is being proposed. It is hypothesized that treatment will reduce CFPWV and SBP, as related to increases in systemic NAD+ bioavailability and reductions in oxidative stress, and inflammation. Aim 1: To measure CFPWV (primary outcome) before/after nicotinamide riboside vs. placebo treatment; Aim 2: To measure casual and 24h-ambulatory SBP (secondary outcome) before and after treatment; Aim 3: To determine the safety and tolerability of treatment with nicotinamide riboside vs. placebo; Aim 4: To measure systemic NAD+ and NAD+-related metabolite concentrations, as well as circulating markers of oxidative stress, inflammation, and vasoconstriction factors before and after treatment. Read Less

Long-term allograft function in kidney transplant recipients (KTRs) remain suboptimal, and graft failure causes significant morbidity and mortality, with cardiovascular disease being the leading cause of death in KTRs and the most common cause of death with a functioning graft. Sodium-glucose cotransporter 2 (SGLT2) inhibitors safely lower cardiovascular and kidney disease risk in the non-transplant population, yet data in KTRs are lacking. This clinical trial seeks to establish the efficacy and safety of dapagliflozin, a SGLT2 inhibitor, for improving cardiovascular and kidney graft function in adult KTRs with type 2 diabetes and post-transplant diabetes, and to leverage innovate translational methods to define the underlying mechanisms of action. Read Less

Cardiovascular diseases (CVDs) are the number one cause of death in America and most of the post-industrial world. Hypertension is a leading risk factor for CVDs including stroke, myocardial infarction, and heart failure. Black Americans suffer from the highest rates of hypertension of any racial/ethnic group in America, among the highest in the world. There are also well-documented racial disparities in vascular dysfunction (e.g., endothelial dysfunction, arterial stiffening). Thus, racial disparities in hypertension and vascular dysfunction exacerbate the burden of CVDs, with Black Americans being 30% more likely to die from CVD than any other race in the US. It is established that mitochondrial dysfunction contributes to vascular dysfunction. However, there is a knowledge gap regarding whether targeting mitochondrial dysfunction attenuates oxidative stress, vascular dysfunction, and CVD risk among Black adults at heightened CVD risk. Thus, the investigators will conduct an 8-week trial with the mitochondrial antioxidant MitoQ in middle-aged and older Black and non-Black adults. Our overarching hypothesis is that mitochondrial dysfunction contributes to heightened oxidative stress, vascular dysfunction, and higher BP in Black adults; and that MitoQ will attenuate these racial differences. Importantly, the investigators will also assess social determinants of health (e.g., income, neighborhood disadvantage, discrimination) and health behaviors (e.g., diet, physical activity) and uncover their role in oxidative stress, vascular function, and BP Regarding methodology, the investigators will perform blood draws, vascular testing, preceding and following an 8-week, 20mg daily consumption of MitoQ and placebo. The investigators will also measure urine biomarkers of kidney function and blood pressure in adults (45-75 years old). Read Less

After the participant meets all inclusion and exclusion criteria, they will be randomized equally to either the Resistance Training group (RT) or Aerobic Training group (AT). Both groups will participate in an 8 week initial control period, followed by 8 weeks of supervised exercise training, followed by 8 weeks of deconditioning. All participants will undergo the same assessments and procedures one time prior to the initial 8 week control period, and at each of the three periods. Assessments include: blood draws; arterial stiffness testing; ultrasounds of the brachial artery to measure flow-mediated dilation (FMD); gluteal adipose tissue biopsies; exercise testing to determine VO2 max; body composition analysis via DEXA scans; ambulatory blood pressure measurement; diet analysis via food journals; medical history questionnaires; urine analysis for pregnancy; and activity monitoring via accelerometer. Total participation will be 24-26 weeks. Read Less