7 Clinical Trials for Various Conditions
Background: - Changes in how a person's body burns energy or calories can affect their weight over time. The lowest level of energy the body needs to function is called basal metabolic rate. In the cold, we burn extra energy, even before we start to shiver. This is called non-shivering thermogenesis and it occurs in different types of tissue such as muscle and fat. Researchers want to learn more about this type of energy burning and how it is regulated. They hope this will help treat obesity in the future. Objectives: * Sub-study 1: to better understand how non-shivering thermogenesis works. * Sub-study 2: to measure the effects of anti-obesity drugs on basal metabolic rate. * Sub-study 3: to better understand the effects of mirabegron, a beta-3 adrenergic receptor agonist, on brown fat activity. Eligibility: - Healthy, lean adult males ages 18 to 35. Design: * Participants will be screened with medical history, physical exam, blood test, and EKG. * For sub-studies 1 and 2: * Participants will receive one X-ray scan. * Each day, all participants will: * Have height and weight measured, and have urine collected. * Spend 4 hours in a temperature-controlled room with furniture, toilet area, phone, and computer. They will wear small non-invasive devices to monitor activity, heart rate, temperature, and shivering. * Walk for 30 minutes. * For sub-study 3: * Participants will receive one DXA scan and up to 4 PET/CT scans and 4 MRIs * Each stay, all participants will: * Have height and weight measured, and have urine collected. * Spend 6 hours in a temperature-controlled room with furniture, toilet area, phone, and computer. They will wear small non-invasive devices to monitor activity, heart rate, temperature, and shivering. * Participants will be compensated for their time and participation at the end of the study
The primary purpose of this study is to expand research on the effects of physical activity on basal metabolic rate (BMR) in healthy postmenopausal women, and to further compare the effects of long-term habitual exercise to the results of a shorter-term (16 weeks) training program. The investigators will measure BMR by indirect calorimetry and normalize it across subjects for body size (fat free mass) and level of aerobic fitness (VO2MAX). Two groups will be compared: an intervention group (no previous participation in regular exercise, newly enrolled in this study's 16 week training program), and a long-term athlete group (have engaged in at least 5 hours of exercise per week for the past 10 years or longer). A secondary aim is to generate an equation for the prediction of BMR from fat free mass in physically active postmenopausal women, to be applied to hypotheses in biological anthropology. The investigators expect to find at baseline that, controlling for fat free mass and VO2MAX, the long-term group will have significantly higher BMR than the intervention group. At 16 weeks the investigators expect no change in BMR for the long-term group, while BMR will have increased in the intervention group. At the same time, the investigators expect to find that after completing the training regimen, the intervention group will have BMR similar to that of the long-term athletes.
The purpose of the study is to compare the effects of nebivolol and metoprolol on 24-hour ambulatory blood pressure characteristics and basal metabolic rates in patients with hypertension.
Obesity and hypertension are independent risks for congestive heart failure (CHF) and chronic kidney disease. In obesity induced hypertension, the most common cause of human essential hypertension, the potential importance of mineralocorticoid receptor blockade has not been widely investigated. We propose to test the hypothesis that eplerenone reduces metabolic demand, improves cardiac function and attenuates glomerular hyperfiltration and microalbuminuria in obese patients. Our specific aims are to assess changes in basal metabolic rate, cardiac and renal function in obese hypertensive subjects treated with eplerenone compared to amlodipine.
Purpose: To evaluate the effects of replacing breakfast with a high protein, high fat, high fiber meal replacement in overweight individuals, on body composition. Participants: Healthy, overweight and obese individuals (ages 18-45 yrs) with no history of disease. Procedures (methods): In a randomized control intervention, subjects will complete 5 different testing sessions (pre-screening, 2 baseline testing sessions, and 2 post testing sessions) as well as an 8 week intervention period. Pre-screening will include written informed consent, health history questionnaire, nutrition analysis, and baseline anthropometric measures. Baseline testing will be split into two sessions and include measurements of resting metabolic rate (RMR), body composition, blood and saliva hormones, mood, satiety, and health related quality of life questionnaires, and a cardiorespiratory fitness assessment. Subjects will be randomly assigned to treatment (8 week supplementation with meal replacement to be taken at breakfast) and control groups (continue normal eating habits) with 4 electronic correspondences throughout the supplementation period. All measures will be repeated in two post-testing sessions.
Denervation following spinal cord injury (SCI) limits beneficial application of neuromuscular electrical stimulation (NMES). SCI with denervation results in extensive muscle atrophy that is accompanied with several cardio-metabolic health risks. The current proposal provides a novel intervention by examining the effects of long pulse width stimulation (LPWS) and testosterone replacement therapy (TRT) on restoring muscle size and leg lean mass after denervation in persons with SCI. This intervention will be rewarding for Veterans and Civilians with SCI who do not benefit from exercising their lower extremity muscles because denervation has limited the response to standard surface NMES. The investigators will study the biochemical mechanisms that contribute to changes in muscle size following this novel training. Combing both pharmaceutical and physical-therapeutic interventions will optimize restoration of muscle size after SCI.
The purpose of this study is to determine whether subjects taking a supplement designed to increase metabolic rate will have a positive effect on body composition (fat mass, muscle mass, and bone density.)