View clinical trials related to Insulin Resistance.
Filter by:Propionic acid (PA) is used as a preservative in foods such as cheeses, baked goods, or additive for artificial fruit flavors. The U.S. Environmental Protection Agency considers it safe and therefore, has no limitation on its use. Since PA has been shown before to serve as a substrate for glucose production in the liver, the purpose of this study is to find out if PA intake causes changes in levels of glucose, insulin and other important hormones following a meal. This research study will compare PA to placebo. The placebo looks exactly like the active substance, but it does not contain any active agent (PA). Placebos are used in research studies to see if the results are due to the study drug or to other reasons. The investigators plan to have 20 subjects take part in this study at the Brigham and Women's Hospital (BWH).
In people with the metabolic syndrome, the investigators hypothesize that administration of a single 300 mg dose of a grape seed extract (GSE) will reduce insulin resistance (how well cells in the body can take up and use glucose), oxidative stress, and the amount of oxidized LDL in the blood during a 24 hour period. These measurements will be assessed at hourly intervals during the 24 hour study day protocol. Additionally, the investigators hypothesize that daily administration of 300 mg of GSE for 30 days will decrease baseline insulin resistance, oxidative stress, and the level of oxidized LDL in the blood.
The prevalence of obesity and obesity-related complications is currently taking epidemic proportions. These complications increase the risk of type 2 diabetes and cardiovascular disease, which are important causes of morbidity and mortality worldwide. It is important to gain insight in the mechanisms underlying obesity-related complications, because this may lead to the development of directed therapeutic strategies. Currently, there is significant evidence that the cause of both insulin resistance and hypertension must be sought at the level of the microcirculation. Over activity of the renin-angiotensin-aldosterone system is a potential cause of microvascular dysfunction. Angiotensin II was indeed found to be implicated in the pathogenesis of obesity-associated hypertension and insulin resistance, possibly through interference with the vascular effects of insulin. Increased aldosterone levels have also been associated with resistant hypertension and insulin resistance, which is illustrated in patients with primary aldosteronism. Furthermore, aldosterone is known to exert several detrimental effects on the vasculature, some of which are offset by mineralocorticoid receptor antagonists. In obese individuals, plasma aldosterone concentrations are increased as well. We hypothesize that increased aldosterone levels in adipose persons induce microvascular dysfunction, which contributes to the development of insulin resistance and hypertension, and mineralocorticoid receptor antagonism results in improved insulin sensitivity and decreased blood pressure by counteracting the adverse effects of aldosterone on the microvasculature.
The focus of this proposal is to define the mechanism by which bariatric surgery acutely improves insulin sensitivity. Our central hypothesis is that drastically reduced caloric intake early after Bariatric surgery improves the pro-inflammatory profile of macrophages, which in turn improves insulin sensitivity and glucose homeostasis.
The effects of physical inactivity on variations in blood glucose and vascular health are not fully understood. The purpose of this study is to determine if an acute transition from physical activity to inactivity alters vascular health. Specifically, the investigators wish to examine in healthy, lean physically active individuals (obtaining greater than 10,000 steps/day) if decreasing physical activity (obtaining less than 5,000 steps/day) will alter blood flow following a meal a marker of vascular health. Furthermore, the investigators wish to examine if a one day return to physical activity (obtaining >10,000 steps/day) can restore the detrimental effects on blood flow following a meal.
Childhood obesity is perhaps the most significant public health problem in the most developed countries and is rapidly becoming so in developing countries. National Health and Nutrition Examination Survey data shows a 3-fold increase in the prevalence of obesity in childhood, over past few decades. Furthermore, childhood obesity has markedly contributed to the prevalence of the metabolic syndrome and type 2 diabetes in U.S. children. Alarmingly, there is increasing evidence that atherosclerosis develops silently during childhood in obese children. In the Bogalusa Heart Study, pediatric autopsy studies showed a clear relationship between the number and severity of risk factors, principally obesity, with atherosclerosis in both the aorta and coronary arteries. Increased intimal medial thickness (IMT) was not present among obese adults who had been normal weight as children, emphasizing the cumulative effects of childhood obesity persisting into adulthood. Thus, the need for primary prevention of cardiovascular disease beginning in childhood is strongly suggested.
Rates of cardiovascular disease and diabetes are more than 2-fold greater in HIV infected people than the general population. Protease inhibitor booster antiretroviral therapy (PI-ART) which is used by ~50% of HIV infected people in the USA is an established risk factor for diabetes. Tauroursodeoxycholic acid (TUDCA), a naturally occurring bile salt, improves insulin sensitivity in HIV uninfected subjects, although the mechanisms for these benefits are unclear. This study will explore the hypothesis that TUDCA will improve insulin action in people with HIV who are receiving PI-ART. Further, this project will clarify the molecular mechanisms responsible for these improvements potentially benefiting society, irrespective of HIV status.
The role of Helicobacter pylori(HP)in the pathogenesis of non-alcoholic fatty liver disease (NAFLD) is controversial.
The purpose of this study is to look at how a reduction in oxygen levels (hypoxia) influences insulin sensitivity and carbohydrate metabolism. It is expected that 10 nights of exposure to moderate hypoxia (~ 15% O2, similar to conditions at an altitude of ~7500 feet) will improve glucose metabolism.
Background: - Some people who are obese may have decreased muscle strength. They may have greater muscle mass shown in scans, but they show poor results in exercise tests. Poor muscle strength might cause some of the difficulty with exercise performance. Researchers want to test muscle strength in the arms and legs of overweight women. They will also see how insulin resistance affects muscle strength in these women. Objectives: - To test muscle strength in overweight women. - To see if insulin resistance affects muscle strength. Eligibility: - Women at least 18 years of age who are overweight (body mass index greater than 25 kg/m2). Design: - Participants will be asked to fast before having an initial blood test to measure glucose and insulin levels. - On a different day, they will have the strength testing. The first test will measure leg muscle strength by testing the quadriceps and the hamstrings. The second test will measure arm muscle strength by testing the biceps and triceps. The final test will measure hand muscle (grip) strength. - All the tests should take about an hour.