View clinical trials related to Insulin Resistance.
Filter by:This investigation is being carried out to learn more about research findings from a study that was completed last year. Those findings revealed that within the skeletal muscle cells of individuals with type 2 diabetes, there was often damage to the mitochondria (the muscle cell's power source or the machinery of the muscle cell that produces energy). In individuals with type 2 diabetes, the liver continues to release sugar even when sugar levels are normal; the pancreas is not able to produce and release insulin normally; and the muscle and fat cells no longer respond as effectively to insulin. These defects lead to an abnormal rise of sugar in the blood. In this study, we want both to look more closely at the mitochondria and see if there is potential for improving mitochondrial functioning (improving the machinery of the muscle cell that produces energy) and reversing mitochondrial damage through a weight loss or a combined exercise/weight loss program. The program you get assigned to will be determined by a process called randomization (like a flip of a coin).
The purpose of this study is to examine the effects of treating insulin resistance on memory and attention, brain glucose utilization, and proteins in spinal fluid.
High protein diets are popular among Maori, especially on the East Coast of the North Island. The purpose of this study was to compare the metabolic effects of a moderate carbohydrate, high protein diet (MCHP) with a high carbohydrate-high fibre (HCHF) diet on insulin sensitivity in Maori at increased risk of developing diabetes and cardiovascular disease.
Obesity is a multinational epidemic. There is evidence that despite educational measures and increased public awareness, the number of obese individuals continues to increase. Of the numerous obesity-related comorbidities, type 2 diabetes remains one of the most significant in terms of mortality and health care costs. Gastric Bypass Surgery (GBS) not only offers an effective form of therapy for morbid obesity, but also amelioration of type 2 diabetes mellitus. The normalization of glucose levels in GBS patients occurs within days after surgery and has been shown in surgical literature to be independent of the weight loss after surgery. The proximal gut, the site of release of certain incretins, may play a role in glucose homeostasis in obese individuals with type 2 diabetes mellitus. One such incretin is GIP, which when released into the circulation during the immediate postprandial period, accentuates the insulin response to a glucose meal. It is hypothesized that overactivity of this enteroinsular axis in obese individuals produces cell resistance to insulin and subsequent type 2 diabetes mellitus. A previous study reported elevated fasting GIP levels, as well as an exaggerated GIP response to a glucose meal, in obese subjects, which was significantly reduced months after GBS following weight loss. This pilot study of obese patients scheduled for GBS will compare the serum levels of certain peptides, including GIP, following a glucose meal before and after GBS, before weight loss has occured. In order to reproduce the preoperative state, and therefore to demonstrate the physiologic change, a small group of subjects who undergo open surgery will undergo the same measurements after surgery, but using a model in which the meal traverses the stomach, duodenum and jejunum with the aid of a gastrostomy tube.
Oral contraceptives (OCs) are the most widely used method of reversible birth control. However, the long-term cardiovascular safety of the widely used low-dose OCs (ethinyl-estradiol < 50 mcg) is still debated. Although cardiovascular events are rare in young women whether they use OCs or not, the risks of myocardial infarction and ischemic stroke are increased among users of OCs who have conventional cardiovascular risk factors such as use of tobacco, diabetes or hypercholesterolemia. However, the risk of cardiovascular events in OC users with emerging cardiovascular risk factors (such as obesity and the metabolic syndrome) have not been investigated. Recently, the metabolic syndrome has been linked with the risk of cardiovascular disease. The syndrome is a clustering of risk factors in a single individual, and its underlying cause may be insulin resistance. Whether the metabolic syndrome predicts a higher cardiovascular risk in OC users has not been studied. This is a critical problem because the metabolic syndrome is prevalent in 24% of adults. Until the cardiovascular risks in users of OC are clearly defined, the appropriate use of OC with the least harm would not be possible. The investigator's long-term goal is to understand the best way to prevent and treat cardiovascular disease in women. The objective of this particular project is to obtain pilot data on the extent to which the metabolic syndrome and obesity affects glucose metabolism and cardiovascular risks in women taking OCs. The researchers hypothesize that women with metabolic syndrome and obese women will have worsened glucose metabolism and elevated cardiovascular risks associated with OC use, when compared to normal weight women without the metabolic syndrome. Results of this study will clarify the risk factors for cardiovascular events in women taking OCs, and will serve as pilot data for a National Institutes of Health (NIH) proposal. Once the cardiovascular risk factors of OC users are understood, clinicians can make better informed decisions about contraceptive choices for their patients.
To investigate the separate effects of the amount of exercise and exercise intensity on cardiovascular risk factors in overweight men and women with mild to moderate dyslipidemia.
Fluid management study in patients with insulin resistance.
A prolonged elevation of plasma free fatty acids (FFA) impairs glucose stimulated insulin secretion. The concept of fatty acid impairment of glucose stimulated insulin secretion (lipotoxicity) has now been well accepted. Increased free fatty acid flux from adipose tissue to non-adipose tissue, resulting from abnormalities of fat metabolism, participates in and amplifies many of the metabolic derangements that are characteristic of insulin resistance syndrome and type 2 diabetes. Lipotoxicity is also likely to play an important role in the progression from normal glucose tolerance to fasting hyperglycemia and conversion to frank type 2 diabetes in insulin resistant individuals. This area of research is now focused on determining the mechanisms whereby FFAs impair b-cell function. There is some evidence to suggest that lipotoxicity could be mediated through induction of reactive oxygen species (ROS). N-acetylcysteine (NAC) is a known potent antioxidant and has been used experimentally in a number of medical conditions in humans for its protective antioxidant effects. The investigators now plan to administer NAC orally to humans for 48 hours to examine the effects of antioxidant therapy in ameliorating the deleterious effects of FFAs on pancreatic beta cell function. NAC is currently approved for the treatment of acetaminophen overdose and is also used as a mucolytic agent. The investigators are now using NAC as an antioxidant to determine whether it protects the pancreatic beta cell against the toxic effects of FFAs, as outlined in the detailed study protocol. This is a proof-of-principle study and is not designed to develop n-acetylcysteine for therapeutic use.
The literature suggests that there may be an association between hepatitis C and type 2 diabetes mellitus independent of the presence of cirrhosis, the likely mechanism for which is insulin resistance. The prevalence of insulin resistance in patients with hepatitis C is unknown. Furthermore, there are no studies that indicate an increased prevalence of insulin resistance in patients with hepatitis C compared to other etiologies of liver disease. The role that hepatitis C may have in the development of insulin resistance is unclear. The effect of antiviral therapy for hepatitis C virus on insulin resistance has not been addressed. The long-term consequence of insulin resistance is type 2 diabetes mellitus. There is significant morbidity and mortality from type 2 diabetes mellitus in the general population, and similar complications would be expected in patients with hepatitis C and insulin resistance particularly if they develop type 2 diabetes mellitus. Our hypothesis: The prevalence of insulin resistance is increased in patients with chronic hepatitis C compared to chronic hepatitis B. Secondarily, insulin resistance when present in patients with chronic hepatitis C improves with successful antiviral therapy. This study has two phases. The first phase of our study will be to estimate the prevalence of insulin resistance in individuals with chronic hepatitis C without cirrhosis compared to patients with chronic hepatitis B without cirrhosis. The second phase of the study will be restricted to those patients with hepatitis C found to be insulin resistant from phase 1, in the absence of known risk factors for insulin resistance (cirrhosis, diabetes). The effect on insulin resistance of anti-viral therapy to eradicate hepatitis C will be assessed.
Approximately 1/4 of the US population has insulin resistance and the associated risk factors such as elevated lipid levels -triglycerides (type of fat from what we eat and what the liver produces and low HDL cholesterol which is the good cholesterol helping to protect against heart disease. Currently one known treatment for this a medication called fenofibrate, another medication that can improve insulin resistance is rosiglitazone, a third treatment known to improve insulin resistance an decrease triglycerides is weight loss. In this study insulin resistant individuals with elevated triglycerides and or a ratio of triglycerides to HDL cholesterol of 3:1 or greater will be randomized (selected by chance) to receive one of these treatments and results of insulin sensitivity and cardiac risk profiles will be compared at the end of the study.