125 Clinical Trials for Various Conditions
The objective of this protocol is to investigate the effect of consumption of a commercially available energy drink beverage on blood pressure, heart rate, and energy metabolism
This is a randomized, double-blind, placebo-controlled parallel group study of HU6 and placebo in subjects who are overweight or obese with T2D. The study will be conducted in 4 stages.
Protocol Number: 22DK0002 Title: Effects of Ultra-processed versus Unprocessed Diets on Energy Metabolism Background: Many diets worldwide include both processed and unprocessed foods. Researchers want to study the effects these foods have on a person s health. Objective: To study how different diets affect a person s health and metabolism. Eligibility: Adults aged 18 60 without diabetes who have stable weight and can exercise. Design: Participants will be screened with: Medical history Physical exam Heart tests Resting energy expenditure (to determine calorie needs) Blood and urine tests 20-minute stationary bicycle session Food, diet, and mental health questionnaires Participants will stay at NIH for 4 weeks. They will receive 3 meals a day and may eat as little or as much as they want. The diet will change each week. Their weight will be recorded daily. They will ride a stationary bicycle daily. Each week, they will do the following: Spend 1 day in a special room that assesses their metabolism Have 24-hour urine collections Give skin and fecal samples Repeat some screening tests Have scans to measure body fat Complete computerized behavior tasks Wear an activity monitor to track physical activity Wear a glucose monitor. A sensor will be inserted under the skin with a small needle. It will be replaced weekly. Take taste tests. They will swish water and flavored liquids around in their mouth and pick which ones had a non-neutral taste. They will also compare liquids for which ones taste better. Participation will last for 4 weeks. Sponsoring Institution: National Institute of Diabetes and Digestive and Kidney Diseases ...
The proposed research is a feasibility pilot trial designed to optimize the remote collection dried blood spots (DBS) from a finger stick and the analysis of fatty acid from the DBS and to optimize the analysis of mitochondria activity (or energy metabolism) from peripheral blood mononuclear cells (PBMC) or white blood cell samples. Participants in this study will provide a blood sample from venous blood draw and finger sticks. One finger stick collection will be completed remotely using a DBS kit that is sent through the mail while the other finger stick collection will be completed at the research site. These samples will be use to optimize the method for measuring fatty acids and mitochondria function as well as measure other lipids, insulin, glucose and markers of inflammation using established protocols. Demographic, dietary, sleep, and physical activity information will be measured using questionnaires, while height and weight will be measured to calculate body mass index (BMI).
The purpose of this research study is to measure the changes in energy metabolism (how the body burns energy), cardiovascular function (heart function), and lipid metabolism (cholesterol break down and building) before and after thyroidectomy (surgical removal of thyroid gland) in response to two approved therapies for hypothyroidism: levothyroxine (LT4) or Liothyronine/levothyroxine (LT3/LT4) combination therapy.
The three primary goals of this pilot will be followed by a secondary goal to test if dental intervention improves brain health in terms of sleep and cognition. The primary and secondary goals are 1. Explore the ratios of brain energy (ATP/PCr, Pi/PCr) and phospholipids (PME/PDE) metabolites as measured by magnetic resonance spectroscopy at 7 Tesla, and compare the differences in them with the performance of episodic memory, attention, language, and executive functions (abstraction, reasoning, verbal fluency, working memory) in three groups: cognitively normal adults, mild cognitive impairment (MCI) and Alzheimer's disease (AD). 2. Investigate the differences in sleep patterns measured by the ratio sleep quality index (Stable/ Unstable sleep) in cognitively normal adults, MCI and AD and its relation to the performance of episodic memory, attention, language, and executive functions (abstraction, reasoning, verbal fluency, working memory) in three groups. 3. Investigate the differences in the variations of two genes, APOE-E4 and ABCA7, in relationship to the changes in the brain energy metabolites and its relation to the performance of episodic memory, attention, language, and executive functions (abstraction, reasoning, verbal fluency, working memory) in those with cognitively normal adults, MCI and AD. 4. Investigate if dental intervention improves sleep patterns and overall cognitive behavior in the three cohorts.
Background: Researchers want to learn how different diets affect hormone levels, body weight, energy expenditure, liver fat, and more. To do this, they will use specialized techniques and food plans. This is not a weight loss study. Objective: To better understand how low-fat and low-carbohydrate foods affect health. Eligibility: Men and women ages 18-50 who have a stable body weight and can exercise daily Design: Participants will have a screening visit that lasts 4-6 hours. It will include: Medical history Physical exam Fasting blood and urine tests Questionnaires Trying foods from the study Participants will be admitted to the Clinical Center and will stay for 4 weeks without leaving. They can have visitors. Participants will wear activity and glucose monitors throughout the study. They will be weighed daily and will complete daily exercise. They will eat 3 meals daily, plus snacks. They will give urine, saliva, and blood samples. They will fill out questionnaires and rate their hunger, appetite, and sense of taste. They will have body scans. For the scans, they will lie in a machine that takes X-ray pictures of the body. Participants will complete activities to measure how many calories they burn and how the diets affect them: Participants will drink special liquids to measure calories burned, sugar, and sense of taste. Participants will wear a plastic hood while resting. Participants will stay alone in a special room for 24 hours. Participants will eat a low-carb, high-fat diet for 2 weeks and a high-carb, low-fat diet for 2 weeks. Participants may be dismissed if they purposefully use the study to try to change their body weight. Sponsoring Institution: National Institute of Diabetes and Digestive and Kidney Diseases ...
The investigators propose to deliver a 4-week sleep extension intervention to adolescents to evaluate feasibility of the protocol and obtain preliminary data on intra-individual changes in metabolic parameters induced by sleep extension.
This study will explore differences in energy metabolism and metabolic flexibility under various conditions in older men and women.
The purpose of this study is to determine if when one eats protein can change how the body uses food for energy. Researchers will also test if eating a high protein breakfast can change one's craving for snack foods.
The purpose of this study is to measure energy expenditure during the first 3 months of life in infants.
The investigators seek to examine the metabolic changes that occur amongst obese and lean pregnant women with normal glycemic control as well as pregnant women with diabetes mellitus (gestational diabetes and pre-existing type 2 diabetes mellitus) compared to non-pregnant age matched controls. Given the adaptive tendency of the maternal body to use alternative energy sources such as ketones and free fatty acids rather than glucose and to shunt glucose and amino acids to the fetus, the investigators hypothesize that the amino acid and fatty acid profile will be reflective of this adaptive change and that maternal insulin resistance will result in alterations in this pattern in both the plasma and CSF. Furthermore, the investigators also hypothesize that maternal degrees of insulin resistance will also be reflected in CSF hormonal changes.
The E-MECHANIC Ancillary Study will measure changes in 24-hour energy expenditure and spontaneous physical activity in a subset of 60 obese individuals enrolled in the main study. We aim to determine if changes in energy metabolism might explain why people don't lose the expected amount of weight in an exercise program.
Background: - Researchers are studying how metabolism and hormone levels change in response to mild changes in environmental temperature. Changes in metabolism may lessen with time because of hormonal adaptations. If this increase in metabolism continues for a longer period, mild cold exposure may cause weight loss. It is unclear whether exposure to a warmer temperature may cause opposite changes in metabolism. Researchers want to see if longer exposure (1 month) to different temperatures can affect how the body uses energy. Objectives: - To test changes in energy metabolism in response to different room temperatures. Eligibility: - Healthy men between 18 and 40 years of age. Design: * The entire study will last for 4 months. It will involve a screening visit and a 4-month inpatient stay at the National Institutes of Health Clinical Center. The inpatient stay will be in a private room at the Metabolic Clinical Research unit. Study participants will be required to stay in the Metabolic Clinical Research unit during the night, but are free to leave during the day. * At the screening visit, participants will have a physical exam and medical history. Blood samples will be collected. A heart function test and diet questionnaire will also be given. * During the first month, the temperature of the private room will be set at to 75.2 degrees F. This will allow the body to become used to the testing environment. * During the second month, the temperature will be set to either a cool (66.2 degrees F) or a warm (80.6 degrees F) temperature. * During the third month, the temperature will return to 75.2 degrees F. * During the fourth month, the temperature will be altered to the opposite temperature to the one set in the second month. * Throughout stay, participants will have daily temperature monitoring and will keep a food diary. Once a week, they will collect all of their urine for 24 hours. Once a month, they will spend 24 hours in a metabolic suite to study their metabolism rate. * Throughout stay, the food will be provided as part of the study. * During the first and third month (75.2 degrees F) the participants will be allowed to leave the Metabolic Clinical Research unit during the weekends, while during the second and forth month (66.2 or 80.6 degrees F), the participants will be allowed to spend one weekend out of the Metabolic Clinical Research unit. * Other tests, such as body scans, fat tissue samples, and imaging studies, will be performed as needed.
This is a compassionate use study to allow patients already taking triheptanoin (C7) through previous studies to continue to receive the supplement. It will also allow triheptanoin supplementation in patients with qualifying disorders if they are failing conventional therapy.
The purpose of the study is to determine the effect of three weight loss surgeries compared to a low calorie diet with regard to energy expenditure, body composition, insulin sensitivity, and the response of gastrointestinal peptides to a standard meal. Baseline assessments will be conducted in all four groups and changes will be compared six and fifty-two weeks post-operatively.
The purpose of this study is to evaluate the effect of lorcaserin on energy metabolism and food intake in obese and overweight patients.
Participants 60 and older with and without Parkinson's disease who have mild cognitive decline will be randomized to either a standard higher carbohydrate diet or a carbohydrate-restricted ketogenic diet for 8 weeks. The main hypothesis is that nutritional ketosis will improve memory functioning. Pre and post-memory testing will be performed. Subjects will also provide blood samples and a subset of subjects with receive magnetic resonance brain imaging.
The use of energy from food changes when people sleep. However, it is still not known if differences in the amount of nighttime sleep have an effect on the amount of energy that people who have a relative with type 2 diabetes (parent, sibling, or grandparent) use to perform their daily activities. This study is being done to test the hypothesis that the daily use of energy in people who have a history of type 2 diabetes in their family will be different after they have slept short hours for 16 days in comparison to when they have slept longer hours for 16 days.
Postprandial thermogenesis, or thermic effect of food are terms that describe the increase in utilization of energy by the human body following a meal. The mechanisms involved in this process are believed to differ according to the type of food consumed, whether fat, protein or carbohydrate. The bile acids (BAs), unique substances secreted by the gall bladder into the gut after a meal, play an important role in the absorption of fat and the management of cholesterol stores in the body. Recent studies suggest that BAs may also serve as regulators of energy expenditure (consumption) in the cells of our body by increasing the production of T3, an active form of thyroid hormone. T3 in turn is believed to increase the efficiency with which our bodies burn calories thereby generating heat. Although this process has been shown to be effective in rodents who demonstrated weight loss after treatment, the role of BAs in humans is poorly understood. Thus we do not know whether endogenous (produced by the body) or exogenous (taken as medication) BAs play a significant role in the maintenance of body weight. We hypothesize that, similarly to rodents, humans will respond to BAs by increasing energy expenditure via the production of the active form of thyroid hormone. This randomized, cross-over study will look at changes in thyroid hormones and energy consumption in response to stimuli of endogenous BA secretion including dietary content, and to the intake of pharmacological doses of bile acids. Following a two-day period of equilibration diet, 30 healthy volunteers will be randomly assigned to receive either a high-fat or high-carbohydrate isocaloric meal followed by a 6-hour metabolic chamber stay; the next day they will be crossed-over to the alternate intervention. During the following three days, the study subjects will again be randomized to receive either an intravenous injection of sincalide (the C-terminal octapeptide fragment of cholecystokinin) 0.04 mcg/kg or placebo and P.O. placebo, or I.V. placebo and 15 mg/kg of BA (ursodiol) with similar metabolic chamber stays and cross-over design. The data gathered from this study will provide greater insight into the physiological and molecular mechanism(s) regulating the relation between endogenous bile acid secretion and energy metabolism in response to meals, as well as the role of BAs per se on energy metabolism.
The metabolic response to Crohn's disease, including increased proteolysis and lipolysis and changes in energy expenditure, plays a significant role in the resulting malnutrition from which these patients suffer. Tumor necrosis factor-alpha (TNF-alpha), a pro-inflammatory cytokine, has been found to be elevated in children with ulcerative colitis. TNF-alpha has been incriminated in the mechanism of weight loss in many different chronic diseases, and causes net protein and lipid catabolism. Anti-TNF-alpha antibody (infliximab) has been proven to be an effective therapy for ulcerative colitis. The purpose of this study is to compare changes in protein and lipid metabolism, as well as resting energy expenditure, before and after therapy with anti-TNF-alpha antibody (infliximab) or corticosteroids in children with recurrent Crohn's disease. Performing this study will better define the changes in nutrition status observed in these children following remission of active Crohn's disease, and potentially lead to changes in medical and nutritional management of these children.
This study will examine whether there are differences in energy (calories) losses in stool and urine between lean and obese people. People gain weight when the amount of calories in the food they eat is greater than the amount of calories their body uses to support its functions and activities. The balance between caloric intake and expenditure may be affected by the amount of calories from food that is not absorbed but is lost in stool and urine. This study will examine whether differences in food absorption are related to obesity. Healthy normal volunteers between 18 and 45 years of age with a body mass index (BMI) of 18-25 kg/m2 or less than 35 kg/m2 may be eligible for this 15-day study. Participants are admitted to the Clinical Research Unit at the Phoenix Indian Medical Center for the study. Participants undergo the following tests and procedures: * Experimental diets with dye marker: Subjects are fed a 2400-calorie diet and a 3400-calorie diet for 3 days each. On the first of the day of each diet, a blue dye marker is added to the breakfast meal. A red marker is added to the breakfast meal of the first day after the diet period. Urine is collected beginning after breakfast on the first day of the diet and until before breakfast on the last day of the diet. Stool samples are collected during the entire diet period, and until the appearance of the red dye in the stool. * 24-hour metabolic rate in the respiratory chamber: After the first diet period, subjects spend 24 hours in a respiratory chamber to measure the number of calories the body burns a day and to assess the energy balance between intake and expenditure. * Stool sample: Stool samples are collected on days 1 and 2 of the study to look for parasites or internal bleeding that may affect nutrient absorption. * DXA scanning: This scan uses a low dose of X-rays to measure body fat. * Oral glucose tolerance test: For this test for diabetes, an I.V. line (needle attached to a small plastic tube) is inserted into an arm vein. The subject drinks a sugar solution. Small blood samples are drawn from the I.V. before the subject drinks the solution and at five intervals during the 3 (Omega)-hour test period. * Fasting blood tests: On the first day of each diet and on the day after each diet is completed a blood sample is drawn before breakfast to measure hormones that may affect the ability to absorb food. At the end of the study, some participants may be asked to repeat the experimental diets and stool and urine collections. ...
Insulin resistance and hyperglycemia contribute to negative outcomes in burned patients. We will assess insulin sensitivity in traditional terms of glucose metabolism, and with regard to the responsiveness of both muscle and liver protein metabolism, in severely burned patients. Plasma free fatty acid (FFA) and tissue TG levels will be manipulated via inhibition of peripheral lipolysis with nicotinic acid or activation of plasma lipoprotein lipase activity with heparin, stimulation of tissue fatty acid oxidation and thus reduction of tissue TG with the peroxisome proliferate-activated receptor (PPAR) alpha agonist fenofibrate. Methodological approaches will include stable isotope tracer techniques to quantify kinetic responses of protein, glucose and lipid metabolism in vivo, quantification of intracellular stores of TG and glycogen by means of magnetic resonance spectroscopy (MRS), as well as quantitative analysis of tissue levels of active products of fatty acids, key intermediates of the insulin signaling pathway, glycogen, the enzyme activities of citrate synthase and glycogen synthase and the activity of the muscle mitochondria. These studies will clarify the physiological and clinical significance of the alterations of tissue lipid metabolism that occur after burn injury, thereby forming the basis for new therapeutic approaches not only in this specific clinical condition but in other clinical circumstances in which hepatic and/or muscle TG is elevated. We will investigate the general hypothesis that the accumulation of intracellular TG in liver and muscle either directly causes insulin resistance in those tissues or serves as an indictor of the intracellular accumulation of active fatty acid products, such as fatty acyl CoA and diacylglycerol, which in turn disrupt insulin action. The following specific hypotheses will be investigated: 1. Intracellular TG is elevated in both muscle and liver in severely burned patients. The reduction of the fat in the liver and the insulin resistance will improve clinical outcomes, glucose and protein metabolism. 2. The insulin signaling pathway, as reflected by phosphoinositol-3-kinase (PI3K) and PKC activity, is impaired in tissues with elevated TG. 3. Fatty acids, or their active intracellular products, are the direct inhibitors of insulin action, rather than the tissue TG itself.
This study will evaluate changes in brain energy metabolism due to treatment with escitalopram in people with major depressive disorder.
This study will examine how two thyroid preparations-levothyroxine (T4) and liothyronine (T3)-affect fat and cholesterol metabolism, blood sugar regulation, and thyrotropin secretion in patients who have had their thyroid gland removed. Results of the study may help in the development of better therapies to optimize blood sugar and cholesterol levels in some patients. Patients 18 years of age or older who have had most or all of their thyroid gland removed and are taking long-term thyroid hormone medication may be eligible for this study after screening.
This a randomized, double blind, placebo controlled, crossover design study which measures the effect of an available thermogenic dietary supplement on resting energy expenditure (REE), blood pressure and heart rate, and mood changes in moderate caffeine consumers. Participants will complete baseline measurements then ingest one of three pills. Once the pill is ingested, subjects will complete four REEs along with heart rate and blood pressure and appropriate questionnaires. Participants will return two more times, each after a one week washout period, and complete the same protocol with the remaining supplements.
Comparison of Capsimax™ 2mg and 4mg of capsicum extract vs. placebo on metabolic rate and satiety.
The primary purpose of this study is to test different methods of measuring energy balance, including food intake and energy expenditure. Another primary purpose of this study is to see if energy expenditure predicts weight and change after a weight loss diet. A secondary aim will be to test the reliability and validity of the Actical accelerometer, SenseWear Armbands, and the Intelligent Device for Energy Expenditure and Activity (IDEAA) monitors at measuring activity energy expenditure (AEE) and total daily energy expenditure (TEE) against the gold standard, doubly-labeled water (DLW). Similarly, we will test whether the estimated energy expenditure or posture allocation from the 3 devices is associated with weight change during and following a low calorie diet (LCD).
The investigators are developing two new medical instruments: 1. the Intelligent Sensor Belt (ISB), and 2. the Body Composition and Hydration Status Analyzer (BC-HS-A). ISB serves the purpose of measuring calorie/ energy consumption of the human body during physical activity. The BC-HS-A measures the body composition, i.e. the fat and lean body mass and the hydration status i.e the amount of water inside and outside of the body cells. The goal of this pilot study is to obtain data from the investigators prototype medical instruments: 1. ISB, and 2. BC-HS-A during physical exercise and compare those results with readings of other commercially available instruments or exercise equipments. The investigators would be testing for technical feasibility and, through comparison with existing measuring devices, the reliability of the investigators prototype.
The purpose of this study is to validate previously developed physical function-clustered specific machine-learned accelerometer algorithms to estimate total daily energy expenditure (TDEE) in individuals with general movement and functional limitations.