Active clinical trials for "Insulin Resistance"

Prospective, randomized and placebo-controlled 6-month trial of vitamin D supplementation in 130 Caucasian and vitamin D-deficient men and women aged 25 years and over. Participants will have abdominal obesity and at least one factor associated with insulin resistance. Participants will be randomized by sex, BMI and age. The primary aim is to compare the effect of daily vitamin D3 (cholecalciferol, 5000 IU) vs. placebo for 6 mo on insulin sensitivity (M-value by the gold standard method, the euglycemic hyperinsulinemic clamp). Secondary aims are to evaluate the effects of vitamin D3 vs. placebo on other indices of glucose metabolism, the lipid profile, blood pressure and anthropometric measurements. Questionnaires on physical activity and sunlight exposure, and a food frequency questionnaire will be administered at 0 and 6 mo to adjust for confounding factors. At 0 and 6 mo, changes in serum 25(OH)D will be correlated with changes in blood markers associated with insulin sensitivity [hs-CRP, inflammatory cytokines (IL-6 and TNF-alpha), adiponectin, leptin, total and undercarboxylated osteocalcin]. This research project intends to test 2 major hypotheses: (1) that vitamin D deficiency plays a causal role in the pathogenesis of insulin resistance in humans; and (2) that vitamin D increases insulin sensitivity.

Rationale: It is well established that increased intake of saturated fatty acids (SFA) is associated with incidence of cardiovascular heart disease (CHD). This effect is mediated by dietary saturated fat's impact on fasting plasma cholesterol levels. Research is needed to clarify the association between dietary fatty acids and metabolic risk markers beyond lipid profile. World Health Organisation (WHO) has recommended reduced intake of SFA with energy replacement from monounsaturated fatty acids (MUFA) or carbohydrates (CARB). However, limited evidence is available on the effects of dietary fatty acids on insulin sensitivity and secretion. The current study is designed to investigate the effects of SFA versus MUFA versus CARB on insulinemic response and lipid metabolism in healthy individuals with central obesity. Study design: A randomized, crossover, single blind design study was carried out. The subjects consumed controlled diets for 6 weeks each. They were provided 3 meals per day during weekdays in which SFA, MUFA and CARB diet was assigned to them randomly. Protein content was standardised at 14% energy. The SFA and MUFA diets each provided 31.5% energy intake from fat, with 69% of the total fats replaced by test fats (approximately 49 g/d based on a 2000 kcal basic diet). Each individual fatty acid provided approximately 7% of the total energy intake. The CARB diet provided approximately 34 g/day experimental fat based on a 2000 kcal basic diet. The CARB diet replaced 7 % energy of carbohydrate from total fat with the exchange from oleic acid (C18:1). Hypothesis: Changing energy from dietary fat (SFA and MUFA) to carbohydrate will influence insulin sensitivity, endothelial and vascular function, pro-inflammatory markers and lipid metabolism differently in individuals with metabolic syndrome. SFA (palm olein) may be comparable with MUFA (high oleic sunflower oil) with regards to its effects on insulin sensitivity, endothelial and vascular function and inflammation

The primary objective of this pilot study will be to examine the effects of consuming whole grains, differing in the degree of processing, on insulin sensitivity and other cardiometabolic risk factors. The overall aim will be to assess feasibility of the test diets and to generate preliminary data.

Physical activity is a powerful lifestyle factor that on average reduces risk for development of diabetes and cardiovascular disease. Nevertheless, investigators have demonstrated that following supervised endurance exercise training, 20% of subjects show no change in fitness and 30% demonstrate no improvement in insulin sensitivity. Our concept is that by using molecular profiling of blood/muscle samples investigators will develop personalised lifestyle intervention tools. Further, revealing the biological basis for a variable metabolic or cardiovascular response to exercise will enable us to propose new targets and biomarkers for drug discovery efforts directly in humans. Using our established OMICS approaches (RNA, DNA and Metabo-) investigators will generate classifiers that predict the responses to exercise-therapy (fitness and insulin sensitivity). Classifier generation is a statistical strategy for diagnosis or prognosis. Critically, investigators have a large human tissue biobank, including subjects with insulin-resistance; young to elderly males and females, as well as twins. Our SME partner has significant intellectual property and capacity in the field of bio-prediction, with a proven track-record of collaboration with the team and product development. Investigators will add to the diversity of our biobank by carrying-out an exercise intervention study using a novel time-efficient strategy that investigators have recently proven to be effective in reducing insulin resistance in sedentary young people and in middle aged obese subjects. A time-efficient protocol is a critical as lack-of-time is a key reason for not maintaining physical activity levels. Finally, investigators have a novel out-bred rodent model that replicates high and low exercise training responses and investigators will establish its suitability for future drug screening purposes. Because of these substantial pre-existing resources investigators believe that our project has a very high probability of delivering on its goals of improving the healthcare of European citizens.

Insulin resistance, characterised by a depressed cellular sensitivity to insulin in insulin-sensitive organs, is a central feature of the metabolic syndrome. In people with no diabetes mellitus, the presence of metabolic syndrome leads to an increase of mortality, whatever the cause, but, as a majority, cardiovascular diseases. In patients with type 2 diabetes mellitus, the presence of a metabolic syndrome leads to an increase in major adverse cardiovascular events. The prevalence of metabolic syndrome is led to grow in a near future, because of the increase of diabetes mellitus and obesity prevalence. Actually, there is no simple tool to measure insulin resistance. The gold standard technique remains the hyperinsulinemic euglycemic clamp. However, the complexity and length of this technique render it unsuitable for routine clinical use. Many methods or index have been proposed to assess insulin resistance in human, but none have shown enough relevance to be used in clinical use. Within the investigators U877 INSERM team, the investigators previously performed in vivo biodistribution studies with 6-DIG (6-deoxy-6-iodo-D-glucose), a new tracer of glucose transport, radiolabelled with123 iodine, with and without insulin, on the one hand in genetically diabetic mice (db/db), consequently having a severe insulin resistance and in the other hand in rats with acquired insulin resistance after a "fructose diet". The investigators have demonstrated that 6-DIG is able to identify in vivo slight glucose transport variations in insulin sensible organs. Then, the investigators developed a fast and simple imaging protocol with a small animal gamma camera, which allows the obtaining of an insulin resistance index for each organ, directly transferable to human. The investigators project is to transfer to human this measurement technique, perfectly validated in animal. The main goal of this monocentric phase I-II study is to evaluate the tolerance to the insulin resistance measurement technique with 6DIG scintigraphy, in healthy volunteers and in diabetic patients. The investigators plan to enrol 6 healthy volunteers and 6 type 2 diabetic patients. The investigators secondary goals will be to evaluate feasibility and reproducibility of the measurement technique, to follow pharmacokinetic and to assess efficacy of 6-DIG to measure insulin resistance.

The primary objective of this study is to determine the influence of insulin resistance on drug metabolism and response in obese subjects. The investigators hypothesize that expression of adiponectin (a hormone secreted by fat tissue), and specific variants in the adiponectin gene can predict the insulin resistance and drug response among obese subjects.

Food products derived from cereal grains constitute a major part of the daily diet of many Americans . For example, a typical Chinese American eats rice about 9.5 times a week on an average. However, most of these foods are derived from refined grain. During the refining process grains are stripped of their bran and germ which results in depletion of several biologically active constituents including fiber, anti-oxidants, phytoestrogens and minerals. From observational studies there is evidence for a protective effect of whole-grain foods with regard to the development of type 2 diabetes. More recently, higher intake of whole grains was also associated with decreases in insulin resistance - a risk factor related to the development of type 2 diabetes. In this randomized study the investigators plan to replicate this beneficial effect of improving insulin sensitivity in patients with pre-diabetes and go a step further by exploring the potential mechanisms by which this benefit may occur. The investigators will assess the effect of consuming a whole-grain-rich diet on levels of advanced glycation endproducts (AGE), RAGE (receptor for AGE) and markers of inflammation and oxidative stress - all of which have been shown to play an important role in the pathogenesis of diabetes mellitus. The investigators will also look for correlations between the levels of these markers with insulin sensitivity to identify potential mechanisms of pathogenesis.

The main purpose of this study is to assess the efficacy of metformin in abrogating androgen deprivation therapy (ADT) induced insulin resistance as measured by homeostasis model assessment (HOMAIR) in men with non-metastatic prostate cancer.

The purpose of this study is to investigate the mechanisms by which physical inactivity and obesity alter skeletal muscle insulin signaling to cause insulin resistance and increase the development of impaired glucose tolerance (IGT).

Employees in developed societies are becoming increasingly sedentary at work and at home due to technological advances. Physical inactivity coupled with excess intake of calorie-rich foods are responsible for the epidemic of obesity. In population cohorts, physical inactivity and obesity increase the risk of cardiovascular disease and death. Because of the impact on productivity and health care costs, many businesses and other organizations have initiated "wellness" programs, often with facilities at the work site to encourage exercise. Although these programs have often resulted in improved fitness for participants, weight loss has been more difficult to achieve. In this regard, in our initial study of NIH employees participating in NHLBI's Keep the Beat program--two-thirds of whom were overweight or obese--we found improved exercise fitness after 3 months of participation, with exercise averaging 20 minutes each work day, but no significant weight loss. Associated with greater fitness in our participants was improvement in endothelial function, an important biomarker of cardiovascular risk. Because level of fitness is a strong predictor of cardiovascular (and total) mortality in population studies, some investigators and thought leaders have proposed that it is acceptable to be "fat and fit." We found in our study, however, that exercise alone has little effect on insulin sensitivity and other biomarkers of risk, including C-reactive protein, which could limit further improvement in endothelial function and even greater risk reduction. We propose to test in this protocol whether weight loss through supervised nutritional counseling and daily exercise at worksite facilities confers health benefits beyond those achieved with improved fitness alone, such as improvement in endothelial function, arterial compliance, insulin sensitivity, markers of inflammation in blood and high-density lipoprotein (HDL) structure and function. Because obesity in a sedentary workforce environment is especially prevalent among women, with additional contribution of menopause to obesity, our study will be restricted to overweight and obese women to allow appropriate analysis in a cohort of manageable size for our testing resources. The primary endpoint will be differential improvement in endothelial function, as determined by brachial artery reactivity to shear stress, from baseline to 6 months in participants randomized to exercise coupled with weight-loss intervention versus subjects randomized to exercise alone. Secondary analyses will include comparisons of adiposity, arterial stiffness, insulin sensitivity, HDL subparticles and function, and markers of inflammation and adipokines in blood, with exploratory analyses of minorities and age/hormonal interactions. Demonstration of improved vascular function and other biomarkers of cardiovascular risk with improved fitness combined with weight loss may serve as an incentive for greater participation in organization-initiated wellness programs with emphasis both on exercise and on personalized nutritional counseling.