399 Clinical Trials for Various Conditions
The goal of this study is to learn whether insufficient sleep affects glucose metabolism differently in healthy men and women.
Fasting hyperglycemia contributes disproportionately to nonenzymatic glycosylation and the microvascular complications of type 2 diabetes. However, little is known about the regulation of glucose concentrations in the fasting state relative to what is known about the postprandial state. The proposed experiment is part of a series of experiments designed to establish how glucagon and insulin interact with their receptors to control fasting glucose in health and in prediabetes.
Background: As people age, the cells in the pancreas that produce insulin begin to release less of this hormone, and levels of blood glucose (sugar) rise. This can lead to illnesses such as diabetes. Urolithin A (UA) is a natural nutritional supplement that may improve how the body controls blood glucose. Objective: To learn if UA improves levels of insulin and other hormones that help control blood glucose. Eligibility: People aged 55 years and older with a body mass index of 27 or higher. Design: Participants will have 6 clinic visits over 8 weeks. Participants will be screened. They will have a physical exam with blood and urine tests and a test of their heart function. UA gelcaps are taken by mouth every morning at home. Half of participants will take UA. The other half will take a placebo. The placebo looks like the study drug but does not contain any medicine. Participants will not know which they are taking. Participants will have tests during the study including: Oral glucose tolerance: Participants will drink a sweet liquid. Blood will be drawn at intervals over the next 3 hours. Continuous glucose monitor: A sensor with a needle that goes just under the skin will be placed on the upper arm. Participants will wear this sensor throughout the study. Exercise. Participants will walk on a treadmill while their heart rate, hearth rhythm, and blood pressure are monitored. They will walk in a hallway at normal and fast paces. Imaging scans of the thigh; scans of the brain are optional....
The purpose of our study is to understand the impact of different meal timing alterations on blood sugars, metabolism, microbiome and sleep physiology in people with prediabetes and diabetes; and to study the temperature/heart rate response to different meals in different people.
This is a prospective randomized placebo-controlled double-blind crossover pilot study determining the effect of dichloroacetate on brain function under clamped hypoglycemia in T1DM.
The goal of this study is to learn more about how a nutritional supplement "ketone ester" (deltaG ®) has an effect on brain and heart function and on alcohol consumption in individuals with and without alcohol use disorder. The study will use Fluorodeoxyglucose (FDG) Positron Emission Tomography/Computed Tomography (PET/CT) scans after a single dose of ketone ester or Placebo in 10 people with alcohol use disorder and 10 healthy control volunteers.
The study team will examine the effect of a ketogenic diet alone and ketogenic diet supplemented with oral ketones on how the body of individuals with type 2 diabetes respond to insulin, regulates insulin secretion, food intake and energetic pathways and influences body fat distribution.
The study will test: 1. whether estrogen treatment in transwomen is associated with improved insulin sensitivity and beta cell function 2. whether testosterone treatment in transmen is associated with worsening insulin sensitivity and beta cell function 3. whether estrogen therapy leads to enhanced immune response in older transwormen
Glucagon is a 30 amino acid peptide hormone that is produced exclusively in alpha-cells of the pancreatic islets. Glucagon binds to a G-protein coupled receptor and activates intracellular signaling by increasing the synthesis of cyclic AMP by adenylate cyclase. The glucagon receptor is most prominently expressed by hepatocytes and the cardinal action of glucagon is to stimulate hepatic glucose output by increasing glycogenolysis and gluconeogenesis. A deep body of literature supports physiologic actions of glucagon to maintain fasting blood glucose and counter-regulate hypoglycemia, and the current view of glucose metabolism is that insulin and glucagon have opposing and mutually balancing effects on glycemia. However, it has long been appreciated that glucagon actually stimulates insulin secretion and islet β-cells express the glucagon receptor and respond to its activation by increasing cAMP. The most potent stimulus for glucagon release is hypoglycemia and both low glucose per sé, as well as sympathetic nervous system activity are potent activators of the alpha-cell. However, glucagon is also stimulated by elevations of circulating amino acids, including after protein containing meals; this setting is one in which the release of glucagon during a period of elevated glycemia could contribute to postprandial insulin secretion. In fact, we have demonstrated that normal mice injected with glucagon while fasting (BG 75 mg/dl) have a prompt rise in blood glucose, whereas mice given glucagon while feeding (BG 150 mg/dl) increase insulin output 3 fold and have a decrease in glycemia. Moreover, in studies with isolated mouse and human islets we have demonstrated that glucagon stimulates insulin release by activating both the glucagon and GLP-1 receptors. This counter-intuitive observation has been reported by several other groups as well as ours. In the studies proposed herein we wish to extend our novel observations to humans. The possibility that glucagon acts in the fed state to promote insulin secretion and glucose disposal would change current views of physiology in both healthy and diabetic persons. Moreover, since one of the more promising area of drug development is the creation of peptides that activate multiple receptors (GLP-1 + glucagon, GLP-1 + GIP + glucagon) the results of our studies have potential implications for therapeutics as well.
The goal of this proposal is to determine the effect of a high protein diet in which the increase in protein intake is derived from different sources (animal vs plant and protein-rich whole foods vs protein isolates) on: i) liver and muscle insulin sensitivity; ii) the metabolic response to a meal, and iii) 24-h plasma concentration profiles of glucose, glucoregulatory hormones, and protein-derived metabolites purported to cause metabolic dysfunction.
The aim of the study is to investigate the effects of capsaicin rich foods on resting energy expenditure and substrate oxidation. We plan to recruit 30 healthy lean and overweight individuals age 18-45 (women) and age 18-50 (men) who will undergo two test days in random order. During one day they will receive a breakfast of toast, orange juice and an omelette with 4tsp of cayenne pepper while on the other day they will receive the same breakfast without the cayenne pepper. Metabolic rate and Respiratory quotients is measured for 30 minutes before the meal and for 2 hours after the meal. Capillary glucose levels and heart rate and blood pressure are measured before the meal and every 30 minutes thereafter for 2 hours.
It is believed that important brain centers send signals through the vagus nerve to the liver to suppress the amount of glucose (sugar) that gets produced. People who have received liver transplants have had their vagus nerve cut during transplantation, and many of these individuals have diabetes at one year post-transplant. The goals of this study are: to see whether metabolic control centers in the brain can still be activated normally with the medication diazoxide in patients who have had a liver transplant, and to understand whether disrupting the vagus nerve would result in excess glucose being produced by the liver (ie. a potential mechanism for why these patients develop diabetes).
Many adults who are overweight have obstructive sleep apnea (OSA) which disrupts sleep and makes it difficult to breath during the night. OSA increases the risk for a person to become insulin resistant and diabetic. It is not known why OSA causes this problem, i.e., whether it is disrupted sleep or lack of oxygen., which can change how the body handles glucose in adipose tissue, muscle tissue and liver. The purpose of this research study is to determine the key issues and mechanisms responsible for dysregulated glucose metabolism in people with OSA. The investigators will do this by comparing glucose metabolism in people who have OSA, and those who do not, and by evaluating the effect of treating OSA by providing continuous positive airway pressure (CPAP) or simply oxygen during the night. The proposed study will evaluate the primary causes(s) (hypoxia, sleep fragmentation, or both) and pathophysiological mechanisms responsible for the OSA-associated metabolic abnormalities. Knowing the primary cause of Obstructive Sleep Apnea and pathophysiological mechanisms responsible for the OSA-associated metabolic abnormalities could help develop potentially novel therapeutic strategies to provide treatment for adults in improving OSA and associated comorbidities.
The molecular nature of insulin resistance in human muscle is still incompletely defined. Our data indicate that acetylation of mitochondrial proteins in humans is regulated by muscle contraction and is dysregulated in insulin resistance. Poor function of mitochondria in skeletal muscle is a hallmark of insulin resistance in skeletal muscle. We propose to use a combination of clinical research and mass spectrometry techniques to determine how the cytosolic and mitochondrial protein acetylation is regulated by muscle contraction in insulin sensitive and resistant human volunteers. We will test the hypothesis that mitochondrial protein acetylation is decreased to a greater degree following a bout of exercise in insulin sensitive than in insulin resistant human muscle. Using these techniques we also propose to determine how acetylation of mitochondrial adenine nucleotide translocase (ANT1) at lysines 10, 23, and 92 regulates ANT1 structure and function. Finally, we propose 4) to use a combination of molecular modeling and in vitro assays together with the approach developed in Aim 3 to characterize the role of acetylation in other mitochondrial proteins. Protein targets for this aim will be prioritized based on the potential role of the protein in insulin resistance or mitochondrial function as well as dysregulation of its acetylation state in insulin resistant muscle.
The transition from normal glucose tolerance to overt type 2 diabetes mellitus (T2D) encompasses a variety of glycemic abnormalities that are commonly referred to as 'prediabetes'. While intensive lifestyle interventions are the cornerstone of T2D prevention, developing safe, cost-effective adjunct therapeutic strategies is a clinically relevant goal. Cinnamon supplementation has been shown to improve fasting plasma glucose in patients with T2D. This placebo-controlled, randomized study will determine if cinnamon improves glucose homeostasis in patients with prediabetes over a 12-week period.
the aim of this study is to examine the role of autonomic nervous system in the increase in hepatic glucose production in response to glucosuria caused by inhibition of renal glucose uptake
The primary purpose of this pilot study is to test a novel head worn light device (Re-Timer®) as an intervention to improve glucose metabolism in people with prediabetes. The hypothesis is that morning light treatment will improve glucose metabolism. This is a pilot study and the data from this project will be used to develop a larger clinical trial.
The Investigators will measure if hepatic metabolism is upregulated in obese girls with PCOS and hepatic steatosis (HS), compared to PCOS without HS and obese controls without HS.
Researchers hope to determine the organ (liver and/or kidney) responsible for the increase in endogenous glucose production (EGP) following the induction of glucosuria (when glucose is excreted in detectable amounts in the urine) with an SGLT2 inhibitor, dapagliflozin.
The purpose of this study is to determine if the altered nutrient exposure to the GI tract after bariatric surgery reveals a negative incretin effect of ghrelin.
This proposed study; Investigation of mechanisms for transmission of impaired glucose metabolism in infants exposed to diabetes in utero, will test the overarching hypothesis that impaired maternal substrate oxidation (metabolic inflexibility) and placental lipotoxicity are characteristics of diabetic pregnancies and in utero development within these conditions programs a metabolically inflexible phenotype in the offspring.
The purpose of the study is to better understand how the body handles sugars glucose and fats, such as cholesterol and triglycerides in sickle cell disease, and what puts certain persons at risk to develop diabetes. This understanding may help us to find new treatments to control blood sugar and prevent diabetes in people with and without sickle cell disease (SCD). In this research, DNA and RNA will be isolated from blood cells. DNA will be used to find genes that cause or protect from diabetes, high cholesterol and high triglyceride, and RNA will be used for studies designed to find out how genes are doing their job of eventually producing proteins.
You are invited to participate in a study designed to investigate the effects of diabetes mellitus, high and low glucose, and high blood insulin on the brain. You were selected as a possible participant because you fit into one of the following categories. a) you are either healthy and competent, are not pregnant and you have no known medical disease and therefore your glucose metabolism will be typical of a normal person, or b) you have diabetes.
The purpose of this study is learn the effect of gastric bypass surgery and sleeve gastrectomy on glucose metabolism mediated by neural and hormonal factors initiated after eating.
This study will determine the influence of two non-caloric sweeteners on glucose metabolism via the gut microbiome in adult men and women.
This project investigated how glucose metabolism differs due to sleep deprivation for three consecutive nights as compared to sufficient sleep for three nights by examining concentrations of glucose, insulin, and other factors involved in glucose metabolism.
To asses the modulating properties of the cleaved pentapeptide product of GLP-1 amide.
Given that glutamate carboxylation or decarboxylation is key to the metabolic role of osteocalcin (at least in mouse models) and that carboxylation is vitamin K dependent, it is critical to isolate the effect of vitamin K manipulation on carboxylation of osteocalcin and its subsequent effect on glucose metabolism in clinical trials. The purpose of this randomized, double-blind, placebo-controlled clinical trial in adults is to determine whether eight weeks of daily supplementation with vitamin K2 (menaquinone-7) can improve markers in blood associated with diabetes risk.
This observational study tests the hypothesis that endogenous aldosterone impairs insulin secretion and insulin sensitivity in subjects with primary aldosteronism.
African Americans suffer a disproportionately high risk of diabetes compared to other Americans. Reasons for race disparities in diabetes incidence are not completely understood. Although a difference in prevalence of obesity does explain a significant portion of the racial disparity in diabetes risk, it does not explain all of this disparity. Strategies to control the diabetes epidemic and reduce its racial disparity often overlook preventive measures. Currently, the most powerful known strategy for preventing diabetes is weight loss in the overweight/obese. However, because weight loss is often difficult to achieve and maintain, other opportunities to prevent diabetes should be identified, particularly in African Americans. Among potential novel opportunities is correction of low or low-normal potassium levels (hypokalemia). In secondary analyses, we have found low-normal potassium (K) to be a novel risk factor for diabetes; and we have found that this association between low-K and diabetes risk may be stronger in African Americans compared to whites. Therefore, a previously unrecognized alternative or adjunct strategy for preventing diabetes, particularly in African Americans, may involve correction of low or low-normal K levels (hypokalemia). Large-scale, adequately-powered, randomized controlled trials are needed to establish the effectiveness of this approach. However, prior to those trials, the pathophysiology of the association between low K and poor glucose metabolism must be understood. This pilot clinical trial will begin to determine the effect of K supplementation on measures of glucose metabolism in African Americans. In this pilot clinical trial, 30 African Americans with prediabetes and a low-normal serum K \[\<4.0 milliequivalent/Liter (Eq/L)\] will be randomized to K-supplements, 20mEq (2-10mEq tablets) twice daily or a matching placebo capsules twice daily. Prior to randomization, baseline measures will be taken including measures of glucose metabolism with a 3-hour oral glucose tolerance test (OGTT), baseline chemistries and a baseline 24-hour urinary potassium measurement. Patients will take the intervention daily and will undergo repeat testing of all of these measures at the end of a 3 month period. The primary endpoint will be change in glucose tolerance, as measured by change in glucose area-under-the-curve (AUC) of a 3-hour oral glucose tolerance test (OGTT). Secondary endpoints will include changes in fasting, 1-hour, and 2-hour post-challenge glucose levels, as well as measurements of insulin secretion and insulin sensitivity as measures by the oral glucose minimal model method.(1) The baseline data from this trial will allow us to quantify abnormalities in glucose metabolism in African Americans with prediabetes/early diabetes and low-normal serum K. The post-intervention data will provide estimates of the impact of K-supplements compared to no supplements on these abnormalities. Data derived from the pilot study will be used in the design of a larger scale, adequately powered clinical trial. This trial will also help to assess the feasibility of recruiting this target population. With this pilot trial, we will begin to determine whether or not K-supplements, an inexpensive, well-tolerated, and simple intervention, could help to reduce diabetes risk among African Americans.