View clinical trials related to Insulin Resistance.
Filter by:The purpose of this study is to determine how a decline in physical activity acutely leads to a decrease in insulin sensitivity in skeletal muscle. The hypothesis is that the loss of insulin sensitivity following physical inactivity is caused by a rapid reduction in skeletal muscle mitochondrial oxidative capacity.
Resistance to the hypoglycemic action of insulin develops within 7 days of bedrest in young, healthy volunteers. We propose that the same event occurs in elderly individuals confined to bed, that alterations in lipid metabolism are, at least in part, responsible for the insulin resistance associated with bedrest, and that the accumulation of intracellular triglyceride (TG) in liver and muscle will play a role in impairing insulin action. Further, we propose that the PPARĪ± (Peroxisome Proliferator-Activated Receptor Alpha) agonist fenofibrate will increase tissue fatty acid disposal by activating mitochondrial oxidative capacity, thereby improving insulin sensitivity. We will investigate a series of specific hypotheses designed to examine the role of altered lipid metabolism in the development of insulin-resistance associated with bedrest. Further, since inactivity is likely a principal factor in the development of insulin resistance in the elderly, the response to the inactivity imposed by bedrest represents an acceleration of the normal development of insulin resistance in elderly individuals. Therefore, the results of this study will also be pertinent to the understanding of the mechanisms responsible for the natural development of insulin resistance in free-living elderly.
This study will examine whether epigallocatechin gallate (EGCG), a major component of green tea, affects how the body responds to insulin in healthy and obese people. Insulin is not as effective in people who are overweight, have high blood pressure or diabetes. This condition is known as insulin resistance. Laboratory studies suggest that green tea or EGCG treatment lowers blood pressure, lowers blood sugar and increases blood flow. This study will see if EGCG improves insulin resistance or insulin's effects on blood flow in people with insulin resistance. Healthy normal weight or overweight people between 21 and 65 years of age may be eligible for this study. Participants are randomly assigned to take EGCG or a placebo ( inactive dummy pill ) in two 4-week treatment phases with a 2-week period of no study medication before each treatment phase. After the first 4-week treatment, patients on placebo are switched to EGCG and those on EGCG are switched to placebo. In addition to treatment, participants undergo the following procedures during the study period: - Screening, including medical history, physical examination and blood and urine tests, and finger-stick blood sugar measurement for patients with diabetes - Complete a dietary and physical activity questionnaire and consult with a dietitian - Blood and urine tests - At-home and clinic blood pressure monitoring - Glucose clamp test to measure how the body responds to insulin. This test is done three times during the study. A needle is placed in a vein in each of the subject's arms, one for sampling blood and the other for infusing insulin, glucose and potassium. Glucose and insulin levels, electrolytes, lipids, fatty acids, cytokines and epicatechin are measured. - Forearm blood flow measurement with microbubbles and ultrasound. Before beginning the glucose clamp test, a test of how well the blood vessels relax is done. A device that measures the size of the artery in the upper arm is placed above the elbow. Blood flow in the muscle of the forearm is measured by ultrasound using a small infusion through a vein of microbubble contrast agent consisting of gas-filled bubbles the size of red blood cells. The contrast agent is infused over a 7- to 9-minute period at the beginning of the glucose clamp test and again 2 hours after the beginning of the test.
Patients with NYHA FC II-III heart failure will be randomized in a cross-over fashion to 8 weeks of bumetanide versus furosemide therapy (equipotent dose), to test whether bumetanide therapy has a superior effect on insulin resistance compared to furosemide. Patients will be subject to a frequently sampled intravenous glucose tolerance test (FSIGT) with minimal model (MINMOD) analysis to assess insulin resistance and to a 6-minute walk test (6MWT) to assess functional capacity; patient recruitment and retention success, as well as medication adherence, will also be assessed.
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.