Active clinical trials for "Insulin Resistance"

At the Thrombophilia Clinic of the Hospital Federal dos Servidores do Estado do Rio de Janeiro there is a high prevalence of acute psychotic episodes, which allows the investigators to raise the suspicion that the thrombotic tendency or hypofibrinolysis play a role in the onset of the disease. It is striking that most of these patients, after some time on anticoagulants, no longer need to take psychiatric medication.

CD163 is a membrane bound receptor primary expressed in monocytes and macrophages. A soluble variant of CD163 (sCD163) is present in plasma and is elevated in pathological condition activating the monocyte-macrophage system. Recently sCD163 is associated with various inflammatory conditions, ex. adipose tissue inflammation and very recently to be a rather strong predictor of the development of type 2-diabetes. Only a subset of obese individuals develops insulin resistance, type 2-diabetes and related diseases. These healthy obese subjects are characterized of less adipose tissue inflammation and less insulin resistance as compared to unhealthy obese individuals. Consequently it would be of great importance to develop markers that could discriminate between healthy and unhealthy obese subjects. Aim: To investigate whether macrophage CD163 is involved in adipose tissue inflammation in obesity and thereby to the metabolic complications of metabolic syndrome. To investigate how sCD163 is regulated by metabolic factors such as obesity, fat distribution, weight loss and diet. Methods: Intervention study. 45 morbidly obese subject approved to gastric by-pass. Blood samples, MR-spectroscopy, DXA, weight control and fat biopsy are taken before and 12 month after surgery. Correlations studies: to investigate the influence of diet and weight loss on CD163 and sCD163. Perspective: To study the role of macrophages infiltration and activation for adipose tissue inflammation and to determine whether the macrophage marker, s-CD163, together with other markers will be able better to identify obese individuals who are at increased risk for developing complications such as diabetes

Background: Skeletal muscle wasting or decrease in muscle mass occurs as a result of alteration in the body's mechanisms to make or break muscle protein. In animal models, the pathway termed as 'ubiquitin-proteasome pathway' (UPP) is primarily responsible for the regulation of skeletal muscle protein loss in wasting conditions and during infection(sepsis). Skeletal muscle wasting is noticed in patients having major surgery due to the inflammatory reaction triggered by special group of proteins called cytokines (inflammatory proteins), resulting in reduced muscle strength, impaired capacity to fight infections, change in bowel function, increased clinical complications and prolonged recovery. Major surgery also leads to decreased sensitivity to hormone known as insulin, resulting in 'diabeteslike'state. We hypothesize that susceptibility of patients undergoing major abdominal surgery, to skeletal muscle wasting and insulin resistance, is determined by stress response to surgery over time, leading to changes in the pathways that make or break muscle protein, namely the Akt/Foxo signalling and UPP. Therefore, the aim of this study is to establish the underlying mechanisms of skeletal muscle wasting and insulin resistance in patients undergoing major abdominal surgery.

The purposes of the study are to evaluate the relative contributions of insulin resistance and renin-angiotensin-aldosterone system to blood pressure (BP) in subjects with prehypertension. This is a cross-sectional study. Anthropometric and BP measurements will be performed in 50 prehypertensive subjects. The subjects will receive a 75-g oral glucose tolerance test and a postural stimulation test for the measurements of insulin resistance, plasma rennin concentration and aldosterone level. Log (ISI0,120), an insulin sensitivity index from the oral glucose tolerance test, will be calculated. Statistical analyses will be performed to compare the degree to which aldosterone and Log (ISI0,120) predicted systolic and diastolic BP in these prehypertensive subjects.

Insulin resistance is a common condition that can lead to type 2 diabetes. One of the commonly prescribed diabetes medications, called rosiglitazone, works by decreasing insulin resistance. Rosiglitazone appears to work on fat cells. Animal studies suggest that rosiglitazone may work by increasing blood vessel growth in fat cells. The purpose of this research is to see if rosiglitazone also increases blood vessel growth in human fat cells. The investigators will compare results from before and after being on rosiglitazone for 6 weeks.

The purpose of this study is to investigate the effects of chronic elevated growth hormone on metabolism and insulin sensitivity by studying acromegalic patients before and after treatment.

Type II diabetes mellitus is rapidly becoming a global pandemic with a deleterious impact on cardiovascular morbidity and mortality. Understanding its pathophysiology is important for the development of future therapeutic interventions. Emerging evidence suggests interplay between mitochondrial dysfunction and the development of insulin resistance. Interestingly, mitochondrial dysfunction in skeletal muscle and adipose tissue are early events in the development of type II diabetes mellitus and are proposed to play a role in exacerbating insulin resistance. Although it has been demonstrated that skeletal muscle of insulin-resistant individuals has reduced mitochondria and mitochondrial dysfunction, whether this disruption of mitochondrial function is more widespread has not been explored. We hypothesize that this disruption of mitochondrial function is more systemic and thereby may contribute to the development of peripheral insulin resistance and possibly promote the myriad of complications associated with diabetes. To test these assumptions, we propose an initial proof of concept study to evaluate mitochondrial biology in human platelets in normal volunteers, pre-diabetic and diabetic subjects to assess whether mitochondrial disruption/dysfunction evolves with the progression to type II diabetes. In parallel, proteomic analysis will be performed to evaluate whether the development of insulin resistance and diabetes confers a specific modulation in the biological signature of human platelets with disease progression. To delineate these concepts, we will evaluate study subject's glucose tolerance and insulin sensitivity and draw blood in parallel to study their platelets. Biological readouts will include: 1) the quantification of the mitochondrial proteome and electron transfer chain content; 2) the evaluation of platelet mitochondrial respiratory function and 3) to determine the mitochondrial reactive oxygen species capacity and defenses. If this hypothesis is validated, this study will show that the mitochondrial disruption/dysfunction is a more generalized finding in type II diabetes. Additionally, it would propose the use of platelets as potential biomarkers for early detection of mitochondrial function and assessment of disease. Finally, this would establish a peripheral blood readout of the modification of mitochondrial function as a novel approach to monitor the prevention and/or reversal of insulin resistance and diabetes in response to therapeutic strategies.

This study, conducted at Stanford University in Palo Alto, California, will examine how insulin metabolism and cardiovascular risk are altered in response to weight loss. Insulin is a natural hormone that causes cells to remove glucose (sugar) from the blood. People who are insulin-sensitive remove glucose efficiently. People who are insulin-resistant require more insulin to remove glucose from the blood. Adult volunteers will be recruited for this study through advertisements in local newspapers in communities around Stanford University. Participants will undergo the following tests and procedures: Insulin sensitivity testing: Before beginning the study, participants will be tested for insulin sensitivity. For the test, two small catheters (plastic tubes) are placed into two veins - one for infusing glucose, insulin, and sandostatin (a drug that blocks insulin secretion from the pancreas), and one for drawing blood samples. The infusions are done over 3 hours. Blood samples are collected before, during, and at the end of the study to measure how well the cells remove glucose from the blood in response to insulin. Research diet: Participants are assigned to a low-calorie diet tailored to the individual's metabolic rate. The diets contain either 40 or 60 percent of total calories as carbohydrates, 40 or 20 percent as fat, and the rest as protein. People with type 2 diabetes who are taking diabetes medicine with have a diet of 45 to 50 percent carbohydrates, 35 to 40 percent fat, and the rest protein. Meal profile: Before beginning the diet and after 4 months on the diet, participants are tested for the effects of the various study diets on control of blood sugar and fats. On the day of each test, participants have a physical examination and provide a medical history. Then, a small catheter is placed in a vein. Blood samples are drawn before breakfast and then hourly for up to 8 hours. Participants who are diabetic are randomly assigned to take one of three diabetes medications - rosiglitazone, glucophage, or a sulfonylurea compound - to help control blood glucose levels. Magnetic resonance imaging: This diagnostic test uses a strong magnetic field and radio waves to show structural and chemical changes in tissues. During the scan, the participant lies on a table in a narrow cylinder containing a magnetic field, wearing ear plugs to muffle loud knocking and thumping sounds that occur during the scanning process. He or she can speak with a staff member via an intercom system at all times during the procedure. In addition to these procedures, patients may be asked to have a fat cell biopsy. This is done to determine whether insulin-resistant people have fewer fat cells but more fat per cell than insulin-sensitive people. For this test, a small piece of fat tissue is surgically removed, under local anesthetic, from an area of the lower abdomen. With the participant's consent, genetic testing may be done on the fat tissue sample to look for genes that may link central obesity to insulin resistance. Some participants may be asked to be followed for an additional 3 months after completion of the study for a continued weight loss program. The follow-up includes weekly visits for weight measurements and a review of food records.

The purpose of this study is to find out if androgen deprivation therapy affects insulin, cardiac risk factors such as cholesterol level, and body fat and muscle.

To define the relation of insulin resistance during childhood and adolescence to the development of the insulin resistance syndrome in young adulthood.