Active clinical trials for "Insulin Resistance"

The overall hypothesis of these studies is that circulating triglycerides, coming primarily from fat in the diet, are an important source of free fatty acids. Free fatty acids are the major fat fuel in the body, and when they are elevated in the blood they are thought to raise the risk of cardiovascular disease by causing insulin resistance (in some cases leading to diabetes), raising blood pressure, and other effects. The investigator will use sophisticated methods for tracing triglycerides and free fatty acids in the blood. These methods involve the administration of low doses of radioactive and stable isotopes of naturally occurring fats. The studies will determine the contribution of triglycerides to free fatty acids in normal people and also in people with diabetes.

This study will characterize risk factors associated with breast cancer development in some patients. In particular, it will examine the role of insulin in breast cancer in patients with and without a family history of the disease. Women 30 to 70 years old who have been diagnosed with breast cancer and matched control healthy subjects with and without a family history of breast cancer may be eligible for this study. Participants undergo the following procedures: Cancer-genetic counseling session, including family history, risk assessment, genetic testing for BRCA1 and BRCA2 (if criteria is met), interpretation of results and management options Medical history, including questions about symptoms or diseases, reproductive history, use of oral contraceptives, body weight, exercise, lifestyle, and demographic issues Drawing of family tree Examination of medical records Blood drawing for genetic and other tests CT scan of the abdomen (approximate time < 1 minute) Filling out questionnaires

Medications like olanzapine have been associated with the development of weight gain and diabetes in some patients. It is not known if the increased risk of developing diabetes is a direct effect on insulin or simply related to weight gain. We hope to learn in this study whether or not olanzapine directly slows down insulin secretion from the pancreas, thereby increasing the risk of developing diabetes.

The purpose of this project is to determine if hyperinsulinemia attenuates sympathetic nervous system-mediated vasoconstriction in the human leg.

Hypothesis: Oral Supplementation of Vitamin D can Reduce Hypersecretion of Parathyroid Hormone and Insulin Resistance in Obese Chinese Males. Protocol: Weekly oral supplementation of 50,000 IU vitamin D (cholecalciferol) or eight weeks to the obese males compared with the normal-weight males. Index measures were conducted at baseline and endpoint.

The purpose of this study is to investigate the effect of an exercise training intervention on the ability of African American males to use insulin properly. Insulin is a hormone that helps the body use glucose.

The average American diet consumed by a significant proportion of the adult population, supplies excessive calories and large amounts of saturated fat. Saturated fats can be cleared and used in skeletal muscle, but in obese individuals, biomarkers of saturated fat are found in the blood, along with markers of poor muscle metabolism. Both fats and amino acids are processed by the same metabolic pathways in muscle, and the investigators hypothesize that meals with greater amounts of saturated fat slow muscle metabolism. A better understanding of the interaction of these to metabolites will allow for the development of future medications to treat muscle loss in sick individuals and the elderly.

Obesity has become an epidemic worldwide. Data from our laboratory and others demonstrate that most of the excess morbidity from obesity is related to insulin resistance (IR). While total adiposity correlates with insulin resistance, not all obese individuals are IR. When obese IR individuals lose weight in response to caloric restriction, even moderate loss of body fat results in improved insulin sensitivity (IS). With massive weight loss, either dietary or surgical, even the most IR individuals can completely reverse their insulin resistance. But why is one individual IR at a BMI of 26 and another IS at a BMI of 35? There must be differences in the manner in which adipose cells/tissue respond to caloric excess and weight gain. One potentially unifying hypothesis with regard to obesity-associated insulin resistance is that those individuals who fail to respond to caloric excess/obesity with adequate adipocyte differentiation and expanded subcutaneous fat storage capacity develop increased circulating FFAs, ectopic fat deposition, stress on adipocytes, triggering localized and systemic inflammation and ultimately insulin resistance in skeletal muscle. Clearly, the best way to examine the human response to obesity is to challenge overweight individuals with the need to store excess triglyceride in adipose tissue. Specific aims are: Test the hypothesis that impaired adipogenesis and fat storage capacity are associated with insulin resistance by comparing 1) cell size distribution; 2) gene markers of adipose cell differentiation; 3) differentiation of isolated preadipocytes in IR-prone vs IS individuals subjected to caloric excess. Determine if circulating (daylong FFA, two-stage Insulin Suppression Test) and ectopic fat (MRI liver, CT abdomen) are worsened to a greater degree in IR-prone vs IS individuals subjected to caloric excess. Determine whether differences in inflammation and/or innate or adaptive immune response are associated with insulin resistance by comparing differences in resident dendritic cells, macrophages and their activation profiles, changes in T-cell subpopulations, and other inflammatory mediators in IR-prone vs IS individuals who are subjected to caloric excess via overfeeding. Exploratory: Evaluate IR-prone vs IS individuals for evidence of hypoxia and insufficient angiogenic response in response to caloric excess.

The aim of this study is to investigate the markers of bone mineral metabolism in an unconfounded group of patients with hypogonadism and to search for a relationship between endothelial dysfunction and insulin resistance.

Obesity is a common problem in the Veteran population as at least 1 in 3 Veterans are obese. When obese people eat food they have less response in areas of the brain that sense pleasure (reward). Decreased pleasure response to food predicts future weight gain. It is not known if this poor brain response is reversible or why obese people's brains respond this way. Insulin in the brain regulates the brain's sensing of pleasure. As people gain weight the function of insulin becomes impaired. The investigators will study if impaired function of insulin is related to a poor brain response to food and if this brain response predicts voluntary intake of food and response to a diet. The investigators will also study if improving the function of insulin with weight loss improves the brain response. These studies will improve the understanding as to why weight loss is difficult and inform us if improving insulin signaling is a potential way to treat obesity.