View clinical trials related to Insulin Resistance.
Filter by:This study will examine whether the anti-diabetes medicine rosiglitazone can safely and effectively reverse the early problems of type 2 diabetes and delay the onset of disease in people with pre-diabetes. The underlying problem in people with diabetes or pre-diabetes is insulin resistance (lowered sensitivity to insulin) resulting in poor glucose (sugar) regulation. Rosiglitazone improves the body's sensitivity to insulin. Patients 21 years of age and older who have type 2 diabetes or who are pre-diabetic (glucose intolerant/insulin resistant) may be eligible for this study. Candidates are screened with a medical history, physical examination, blood tests, echocardiography (heart ultrasound), exercise test, brachial artery reactivity test (see below), and possibly a muscle biopsy. Participants take one rosiglitazone tablet daily by mouth for 2 weeks. The dose is then increased to two tablets daily for another 2 weeks and then to 4 tablets daily for the remainder of the 12-week treatment period. In addition to treatment, patients undergo the following tests and procedures: - Resting and exercise metabolic testing: The amount of oxygen taken in and carbon dioxide exhaled during breathing is measured while the patient rests in a chair and then while he or she exercises on a stationary bicycle or treadmill. Both at rest and during exercise, the patient wears a facemask that measures the amount of oxygen used. During exercise, heart rate is monitored with electrodes on the chest, arms, and thighs. The exercise test is repeated three times, once to become familiar with the test, again the next day to measure exercise capacity, and again 3 days later. The third test is less strenuous and is optional. - Muscle biopsy (optional): A small area of skin over a calf muscle is numbed with a local anesthetic and a 1-inch incision is made over the muscle. A small amount of muscle tissue is taken and the incision is closed with stitches. - Brachial reactivity study: This ultrasound study tests how well the patient's arteries widen. The subject rests on a bed for 30 minutes. An ultrasound measuring device is placed over the artery just above the elbow. The size of the artery and blood flow through it are measured before and after inflating a pressure cuff around the forearm. The pressure cuff stops the flow of blood to the arm for a few minutes. After a 15-minute rest, a nitroglycerin tablet (medicine that causes blood vessels to relax) is placed under the patient's tongue. Before and 3 minutes after the nitroglycerin is given, the size of the artery and blood flow through it are measured again. - Blood samples: Blood samples are collected at the beginning and end of the study and at study visits in between. - Study visits: Patients come to the Clinical Center biweekly or monthly for a follow-up history, physical examination, and blood tests. At the end of the3-month treatment period, they receive recommendations about possible treatment modifications to best maintain glucose tolerance. Their physicians are informed of how their blood sugar was controlled. Six months after completing the study, patients undergo a final study evaluation and blood tests, and are then invited to return for yearly checkups after that.
The purpose of this study is to determine if pioglitazone is effective in preventing future strokes or heart attacks among non-diabetic persons who have had a recent ischemic stroke.
Study Description: Patients with mutations of the insulin receptor have diabetes that is challenging to control with conventional therapies, leading to early morbidity and mortality. We hypothesize that recombinant leptin (metreleptin) in these patients will improve glycemia control. Objectives: Primary Objective: To determine if 1 year of metreleptin will improve glycemia control in patients with genetic defects of the insulin receptor. Secondary Objectives: To determine mechanisms by which metreleptin improves glycemia. Endpoints: Primary Endpoint: Hemoglobin A1c. Secondary Endpoints: fasting plasma glucose, fasting insulin/C-peptide, glucose/insulin/C-peptide area under the curve during oral glucose tolerance test. Study Population: 20 male or female patients with mutations of the insulin receptor, age (Bullet)5 years, at the NIH Clinical Center. Description of Sites/Facilities Enrolling Participants: Description of Study Intervention: NIH Clinical Center Open label study of metreleptin, 0.2 mg/kg/day (max dose 0.24 mg/kg/day).
To study the genetic basis of obstructive sleep apnea using a genealogical approach.
To identify the genes involved in the metabolic syndrome.
To examine the effects of psychological stress on the metabolic syndrome.
This is a pilot study to examine the prevalence of metabolic risk factors (impaired insulin release and impaired insulin sensitivity) for type 2 diabetes mellitus in children and adults from a population that is at high risk for this disease. We hypothesize that at least one of these pre-diabetic traits will be evident in a large proportion of relatives of known type 2 diabetic children as compared to a control group of subjects without a family history of type 2 diabetes. By isolating these traits, it will be possible to determine the relative contributions of genes and environment to each trait and to identify those at risk for subsequent development of type 2 diabetes by virtue of having one trait. Ultimately, those individuals at risk, especially those with impaired insulin release, would hopefully benefit from intervention to prevent the weight gain that will 'unmask' their underlying pancreatic dysfunction and thus prevent or retard the development of type 2 diabetes.
The purpose of this study is to investigate the effects of Chromium on glucose tolerance and endothelial function in people at risk for type II diabetes.
This study will examine whether glucosamine affects the way the body responds to insulin. Insulin is a hormone that causes the body to use glucose (sugar). Insulin does not work as well in overweight people, causing a condition called insulin resistance. Insulin also increases the flow of blood into muscle by opening inactive blood vessels. This study will test whether glucosamine, a nutritional supplement that many people take to treat arthritis, can cause or worsen insulin resistance or change how blood vessels react to insulin in normal weight and overweight people. Healthy normal weight and overweight volunteers between 21 and 65 years of age may be eligible for this study. Candidates will be screened with a brief physical examination, medical history, and blood and urine tests. After screening, participants will have three additional outpatient clinic visits for the following procedures: Visit 1 - Glucose clamp test to measure the body's response to insulin: For this procedure, a needle is placed in a vein of each arm, one for drawing blood samples, and one for infusing glucose and a potassium solution. The glucose is infused continuously during this 4-hour test and blood is drawn frequently to monitor glucose and insulin levels. After the test, blood glucose levels are monitored for another 2 hours to make sure they remain at an adequate level to prevent hypoglycemia (low blood sugar). - Blood flow measurement: Blood flow in the brachial artery of the arm is measured to assess how many capillaries (very small blood vessels) are being used to supply nutrients and oxygen to the muscle in the forearm. This test is done at the same time as the glucose clamp test. Blood flow is measured using a technique called contrast ultrasound. A small amount of contrast agent consisting of gas-filled bubbles the size of red blood cells is infused over 10 minutes through one of the catheters placed in the vein for the glucose clamp test. The contrast agent is infused twice, once at the beginning of the glucose clamp test and once at the end of the test. The contrast material creates a signal in response to ultrasound that provides information about the distribution of capillaries in the forearm. - Assignment to medication group: Participants are randomly assigned to take either glucosamine or placebo three times a day by mouth for 6 weeks. At the end of the 6 weeks, no study drug is taken for 1 week, and then participants "cross-over" medications, those who took glucosamine for the first 6 weeks take placebo for the next 6 weeks and vice versa. Visits 2 and 3 For these visits, the glucose clamp test and blood flow measurements are repeated. Visit 2 is scheduled at the end of the first 6-week treatment period, and Visit 3 is scheduled at the end of the second 6-week treatment period.
To evaluate additional cardiovascular risk factors using data from the VA HDL Intervention Trial (VA-HIT).