68 Clinical Trials for Various Conditions
This study will investigate how different parts of the body lose body heat and will measure the heat released by specific areas such as the limbs and abdomen. Animal studies suggest that dissipation of body heat may affect energy expenditure, and therefore, body weight. This study will explore the relationship between obesity and heat in humans. Healthy people 18 years of age and older who are of normal weight or who are obese and who are not taking medications for obesity-related medical conditions may be eligible for this study. Candidates must have a body mass index (BMI) between 18 and 25 kg/m2 for normal weight subjects or a BMI greater than 30 kg/m2 for obese subjects. All candidates must weigh less than 300 pounds. Women must have a normal menstrual cycle or be postmenopausal. Participants undergo the following procedures in a single day on an outpatient basis: * Medical history, physical examination, blood and urine tests and electrocardiogram. * DEXA and MRI scans of the trunk and limbs to measure the amounts of muscle, bone and fat in the body. For the DEXA scan, the subject lies on a table while a very small dose of x-rays is passed through the body. For the MRI, the subject lies on a table that is moved into a steel cylinder. A magnetic field and radio waves produce images that are used to measure fat in the trunk of the body, thighs, and arms. * Infrared photography of hands, front of thigh, and abdomen. A special camera is used to measure the heat leaving the body. * Bicycle exercise test. The subject exercises on a stationary bicycle while the heart rate, heart rhythm, blood pressure and oxygen consumption are measured. The pedal resistance is increased gradually until the subject can no longer exercise and then the resistance is gradually decreased for cool-down. Participants who qualify for the second part of the study undergo the following procedures during a 5-day in-hospital stay: * Temperature measurements. Body temperature is measured in the ear canal. Skin temperature is measured with small round adhesive temperature-sensing patches placed on the abdomen and limbs for up to 5 days. * Measurement of body radiowaves. A remote sensing device is used to measure microwaves that are naturally released from the body. * Infrared photography of hands, front of thigh and abdomen is done several times during the study. * Application of mild coolness to hands, thigh and abdomen. The subject's hand is exposed to mild coolness first by immersion in cool water, then by a cool-water spray, then by a cooled pad placed on the hand, and finally, with a device applied to the hand that cools and has a gentle vacuum. The abdomen and thigh are similarly exposed. During each test, an infrared camera records how heat is released by the body. * Temperature effects of a "meal." The subject drinks lemon-flavored sugar water to measure the body's response. * Bicycle exercise test. The subject exercises on three different occasions. During or after some of the tests, mild cooling is applied to the abdomen, front of the thigh, or hands. * Measurement of exhaled air (indirect calorimetry). The subject wears a hood that collects and analyzes exhaled air for 15- to 30-minute periods. * Photography and videotaping. The subject is photographed and videotaped. The images do not include views of any private parts, and the subject's identity is protected.
This study is to investigate how adipocyte (fat cell) function and fat distribution differ between individuals with normal-weight type 2 diabetes (NWD) and normal-weight controls without diabetes (NWC). The study will assess whether adipocyte-directed therapies, specifically pioglitazone and tirzepatide, can improve insulin resistance, adipocyte function, and fat distribution in individuals with NWD. By analyzing the biological mechanisms underlying adipocyte dysfunction, the study aims to provide insights into novel treatment strategies for improving metabolic health in normal-weight individuals with type 2 diabetes.
Exercise acutely increases gut permeability and inflammation, even in healthy populations. However, whether this response differs in groups at-risk for CVD that present with low-grade inflammation (e.g., normal-weight obesity) has yet to be examined. The investigators aim to measure serum indicators of gut permeability in those with normal-weight obesity pre- and post-short, intense exercise and sustained, moderate exercise
The investigators are examining the extent gut permeability explains observed inflammation in normal-weight and metabolically healthy obesity (and potentially cardiovascular disease risk).
Investigators propose to study youth across the spectrum of body mass index (BMI) and dysglycemia. This approach will allow investigators to disentangle the relationship of key features of type 2 diabetes (T2D) risk (e.g. obesity) with intermediary physiologic changes (e.g. insulin resistance, inflammation, β-cell dysfunction and dysglycemia) that pose a risk for the brain. Investigators will determine which of these factors are most associated with differences in brain structure and function among groups, over time, and how these effects differ from normal neurodevelopment.
The purpose of this study is to identify early cardiovascular disease risk factors in those with "normal-weight obesity" (i.e., normal body, but high body fat percentage) that better track with their long-term cardiovascular disease risk.
This trial studies how well a lifestyle intervention works in reducing breast cancer risk through changing body composition and decreasing inflammation in normal weight women. This trial may help researchers learn more about diet and exercise programs designed to decrease body fat in postmenopausal women who are of normal weight but have an elevated risk of breast cancer because of excess body fat.
The aim of this study is to look at how the study medicine behaves in the participant's body and how it is removed from the participant's body. The study compares Japanese and Caucasian people who are normal weight, overweight or with obesity. The participants will either get NNC0174-0833 (a potential new medicine) or placebo (a "dummy" medicine similar to the study medicine but without active ingredients) - which treatment any participant gets is decided by chance. Participants will get 1 injection by a study nurse at the clinic. The injection will be with a needle in a skin fold in the participant's stomach area. The study will last for about 4 months, but duration of participation for any participant will last up to about 2 months. The participants will have 8 clinic visits with the study staff.
The Strength Training Regimen in Normal Weight Diabetics (STRONG-D) study will examine the effectiveness of different exercise regimen types in controlling diabetes for the normal weight type 2 diabetes population.
This trial is conducted in the United States of America (USA). The aim of this trial is to investigate the safety, tolerability and pharmacokinetics of single doses of NNC0174-0833 in normal weight, overweight to obese but otherwise healthy male subjects.
Patients undergoing Cesarean delivery (C-Section) with a body mass index of 30 or less will be given either 2 grams or 4 grams of an antibiotic before surgery. The antibiotic is intended to prevent infection from the surgery. It is unknown what the best dose for the usual medicine used for this purpose (an antibiotic medicine called cefazolin). Samples of the tissue just under the skin will be biopsied at the time the incision is made and at the time the cut is stitched or stapled closed. A sample of the muscle of the womb will be taken as the womb is stitched closed after the delivery. Blood tests will be done at the start and end of surgery to test the antibiotic level. A blood sample will be taken from the umbilical cord after the baby has been delivered and the umbilical cord has been cut. The umbilical cord blood sample will be tested for the antibiotic level. These tests will be used to find out if the usual dose of medicine is enough or if more medicine is needed to prevent infection in normal weight women undergoing c-sections.
The purpose of this study is to determine if there is a difference in the short term response in serum folate after a single dose of folic acid in normal weight and obese women of childbearing age.
This study examines youth's motivation for food or social rewards after a brief episode of simulated ostracism. The investigators hypothesize that youth who think about a friend after being ostracized will mediate their decision to resort to food, which is typically evidenced in socially isolated overweight youth.
The study is designed to evaluate the increment of serum 25 (OH) vitamin D levels in normal weight adolescents following a 12-week supplementation with Vitamin D3 2000 IU/day.
About 15 to 20 percent of individuals living in the United States have chronic abdominal pain, often of unknown origin, which is often difficult to diagnose and treat. One possible cause of chronic abdominal pain is an inflammation of the intestines, but it is not known whether the two are related. Furthermore, although overweight people tend to be more likely to have increased inflammation, it is not known whether there is a connection between increased body weight and chronic abdominal pain. This study will examine the relationship between symptoms of chronic abdominal pain and intestinal inflammation by comparing the medical test results of normal weight and overweight patients who have a history of chronic abdominal pain. This study will include 224 subjects, who must be men and women between the ages of 13 and 45. Half the subjects will be healthy participants, and half will have had chronic abdominal pain of unknown origin for longer than 6 months. Female participants must take a urine pregnancy test before starting the study, and will not be allowed to participate if the test is positive. During the study, patients will visit the NIH Clinical Center on two occasions for testing. On the first visit, patients will provide a medical history, including information about current medications or natural remedies and tobacco and alcohol use, and will also fill out questionnaires to provide information about symptoms, current levels of gastrointestinal pain, and general quality of life. The study researchers will conduct a physical examination, measure patients height and weight, and draw blood for testing. Patients will be asked to not eat or drink anything for 8 hours before the second visit, and will be asked to bring a bathing suit and a swim cap to the Clinical Center. On the day of the visit, patients will fill out questionnaires to provide information about symptoms, current levels of gastrointestinal pain, and general quality of life. Patients will also provide a blood sample for testing. Researchers will measure patients blood pressure and heart rate, height, weight, waist/hip circumference, and intra-abdominal measurement. Patients will also be asked to put on the bathing suit and swim cap to have their body fat measured using a machine called the BOD POD. To test the gastrointestinal system, patients will then be asked to drink a sugar-based test solution, and researchers will collect all voided urine for the next 5 to 6 hours. (Patients may drink water during this time.) On either Day 1 or Day 2 of the study, patients will sip, swish and spit an additional sweet taste solution. Patients will sip, swish, and spit different concentrations of this sweet taste solution, for a total of 25 tastings of this solution. Subjects will then complete questionnaires about their sweetness preferences related to these 25 tastings.
There are over 60 million women of reproductive age in the U.S. and a majority of these women qualify as overweight or obese. Evidence suggests that there is an association between increased body weight and decreased contraceptive efficacy. Studies with the combined hormonal contraceptive patch (Evra®) and the subdermal contraceptive implant (Norplant®) demonstrate higher failure rates in heavier versus lighter women. Weight related differences in the effectiveness of NuvaRing® need further study. A single secondary analysis of pooled data from Phase III clinical trials of NuvaRing® noted no difference in pregnancy rates among women in the highest weight decile (\>166#) versus the rest of the study population using the ring. (Westhoff, 2005) The finding of no difference, however, was influenced by too few obese subjects in the analysis which contributed to wide confidence limits. Additional studies are needed to explore how well the contraceptive ring functions to maintain effective serum steroid concentrations to suppress ovarian activity in obese women. This investigation focused on evaluating mean serum concentrations of hormones released in obese and normal weight women using the NuvaRing® . This study was a prospective clinical trial. Normal weight women are defined as women with a BMI 19-24.9 and obese women are those with a BMI 30-39.9. We recruited forty adult women interested in initiating the combined hormonal contraceptive ring to two months of use to complete analysis of at least 34 subjects (17 normal weight, 17 obese). We compared mean serum concentrations of ethinyl estradiol (E2) and etonogestrel (ENG) along with additional markers for ovarian suppression. These markers included sonographic evidence of follicular development and ovulation as well as circulating E2 levels which strongly correlate with follicular development and endometrial proliferation during the second month of NuvaRing® use. Assessment of these parameters will translated to understanding contraceptive-mediated suppression of ovarian function in these two groups. Subjects also logged patterns of ring use and bleeding patterns during the study period.
The overall objective of this project is to advance understanding of the causes of normal weight obesity (NWO) in men, namely the hormone profile and related potential mediating mechanisms, and the efficacy of different modes of exercise to restore body composition and cardiometabolic health in this population.
The objective of the proposed study is to investigate the effect of cinnamon on the postprandial glycemic response to a high glycemic index meal in normal and overweight/obese prediabetic subjects
The purpose of this study is to test how the brain responds when enjoyable foods such as chocolate are consumed. The investigators know that eating certain types of foods can make an individual want to keep eating even when he or she is full. The chemical in the brain that causes this is called dopamine. The investigators can measure this response by looking at changes to how an individual's eye responds to light.
An adaptation to a cold environment is a tendency to generate heat within our body. Some of this heat comes from our fat tissue. Although most fat tissue is "white fat", there are pockets deep within the body that are called "brown fat", which are specially adapted to burning fat and making heat. The investigator believes that our white fat, just underneath the surface of our skin, also has this property to burn fat and make heat, although not at the high level of brown fat. This study is to examine this fat-burning property of the white fat under the skin in response to seasons and to cold. Many such studies have been done in mice, but little has been done in humans. There are a number of factors, including age, weight, and medical history, that may make a person eligible or ineligible to participate in this study. Certain medications could make a person ineligible, but if these medications can be safely altered, the individual may become eligible.
The researchers will investigate blood and fecal responses in qualified study participants after eating walnuts for 4 weeks compared to not eating walnuts for 4 weeks. The two dietary interventions will be separated by a 4 week washout period. The order of diets will be random; study participants will complete both interventions. Dietary modifications will be part of the study protocol.
The purpose of this research is to investigate whether consuming two different kinds of olive oil will change risk factors related to cardiovascular disease, including levels of good and bad cholesterol, levels of inflammation, and levels of gene expression.
Blacks are at increased risk for obesity, type 2 diabetes mellitus and cardiovascular disease. A common pathogenetic link among these entities is insulin resistance/hyperinsulinemia. The specific aims of this project are: 1) to compare skeletal muscle lipid content (SMLC) in black vs white children by computed tomography (CT) scan of the mid-thigh, and assess the relationship to in vivo insulin sensitivity; 2) to test the hypothesis that free fatty acid (FFA) - induced insulin resistance is associated with larger increases in intramyocellular lipid (IMCL) in black vs white adolescents; 3) to examine if β-cell insulin secretion in prepubertal black children is more sensitive to the stimulatory effect of FFA than in whites; and 4) to test if the β-cell in black obese adolescents is more susceptible to the lipotoxic effect of FFA compared with whites. The methods to be used are: the well- established CT method as well as Magnetic Resonance Spectroscopy (1H-MRS) to assess SMLC and IMCL; intralipid infusion to elevate circulating FFA levels; the hyperinsulinemic-euglycemic clamp with stable isotopes and indirect calorimetry to measure insulin sensitivity and substrate turnover; the hyperglycemic clamp to assess insulin secretion; DEXA and whole body MRI for body composition assessments.
Ghrelin, a hormone produced in the stomach that stimulates hunger and food intake, declines immediately after weight loss surgery. Some studies suggest that ghrelin may worsen an individual's ability to respond to insulin. The purpose of this study is to determine if the decline in ghrelin levels after weight loss surgery contributes to the improvement of insulin sensitivity.
The overall hypothesis of this proposal is that nutrient sensing in the foregut regulates metabolic hormone secretion and nutrient metabolism via enteric neural signals, and these mechanisms might be defective in obesity.
This study tests whether different physical activity patterns are linked an individual's genes.
The purpose of this research is to test if playing games designed to improve an individual's executive function can change their views about the types of foods they eat. Executive function is a set of mental processes that people use every day to make decisions - such as what kinds of foods they choose to eat and when and where they eat those foods.
The purpose of this research is to understand how dietary fat is related to cardiovascular disease (CVD). This study tests the effect of different dietary fats on the level of fat in the blood and the particles that transport fat in the blood. The researchers want to know if these particles change after eating meals made with different fats.
The objective of this study is to determine the independent and combined effects of weight status and the level of dietary restraint on the relationship between package unit size and food intake.
Background: * Vitamin E is an antioxidant that reduces the damaging effects of oxygen in the body. Most American men (90%) and women (96%) do not get enough vitamin E from their diets; however, the amount of vitamin E needed by the body has been studied only in men, not women. In addition, it is unknown whether another antioxidant, vitamin C, helps vitamin E in protecting the body. Because vitamin E is a fat-soluble vitamin, how much body fat a person has could affect the amount of vitamin E needed for protection. Objectives: This study has three arms to examine vitamin E requirements: * To determine the amount of fat required to get the best vitamin E absorption from a meal. * To determine the amount (i.e., best dose) of vitamin E that must be consumed before it can be measured in the blood. * To examine how vitamin E and vitamin C work together in the body, in conjunction with diet and vitamin supplements. Eligibility: * Arms 1 and 2: Women between the ages of 18 and 40 years who have a normal weight and body mass index (BMI) of 27 or less. * Arm 3: Women between the ages of 18 and 40 years who have a normal weight (BMI 27), who are overweight (BMI \> 27), or who are overweight (BMI \> 27) and have non insulin-dependent diabetes. Design: * Arm 1: Five studies, each lasting 1 month with 1 month off between studies (total study = 10 months). Participants will take 500 1,000 mg of vitamin C twice daily for 2 weeks before admission to the clinical center for 1 week. * Study 1: Participants will eat breakfast containing a known amount of fat, after which they will take a vitamin E pill as well as receive an IV injection of vitamin E. Other foods contain only negligible amounts of vitamin E. Blood and urine samples will measure levels of vitamin E and other substances. * Studies 2 5: Outpatient visits will consist of the same tests as in Study 1; however, the amount of fat in the breakfast will range from 0% to 40% in random order. During one of the studies, an adipose tissue biopsy will be collected to determine how much vitamin E is in the tissues. * Arm 2: Five studies, each lasting 1 month with 1 month off between studies (total study = 10 months). Preparation for Arm 2 is the same as in Arm 1. The proportion of fat, muscle, and water in the body will also be measured. * Study 1: Participants will eat breakfast containing 30% fat, after which they will take a vitamin E pill as well as receive an IV injection of vitamin E. Conditions and procedures are the same as in Arm 1. * Studies 2 5: Outpatient visits will consist of the same tests as in Study 1; however, the amount of vitamin E in the breakfast will range from 2 to 30 mg in random order. * Arm 3: Outpatient (2 to 6 weeks) and inpatient studies (4 to 6 weeks). * Outpatient study: Participants will take 500 1,000 mg of vitamin C daily and provide blood and urine samples, as well as an adipose tissue sample. * Inpatient studies: Two vitamin E inpatient studies. Before these begin, participants vitamin C blood levels will be reduced by means of a diet low in vitamin C. Blood tests will determine how quickly vitamin C leaves the body. Once the vitamin C level is reduced, the first vitamin E study will begin. Study A: The procedure for this study is the same as in Arm 2, Study 1. Study B: The procedure for this study is the same as in Study A, except that the participants blood vitamin C levels will be higher.