Active clinical trials for "Glucose Intolerance"

Glucose-dependent insulinotropic polypeptide (GIP) is a hormone produced in the intestine. It is released immediately after meal ingestion and increases insulin release. This, in turn, helps reduce blood glucose levels. This circuit does not work properly in humans with type 2 diabetes mellitus (T2DM). We have previously shown that a peptide called xenin-25 can amplify the effects of GIP on insulin secretion in humans. However, xenin-25 no longer does this when humans develop T2DM. Thus, it is important to understand how xenin-25 works in humans without T2DM so we know why it does not work in humans with T2DM. Acetylcholine is molecule produced by specific types of nerves. The effects of acetylcholine can be blocked by a drug called atropine. We have previously shown in mice that atropine prevents the ability of xenin-25 to increase the effects of GIP on insulin release. The purpose of this clinical trial is to determine if atropine also blocks the effects of xenin-25 in humans without T2DM. If it does, then impaired acetylcholine signaling may be one of the reasons humans develop T2DM and it could be possible to develop drugs that bypass this defect and increase insulin release in humans with T2DM.

The study will determine if increasing the highs and lows of blood glucose levels (glycemic variability) impairs insulin secretion in people with impaired glucose tolerance and/or impaired fasting glucose who are at risk for developing type 2 diabetes. Furthermore, the study will determine whether changes in beta-cell function are associated with glycemic variability and whether they are mediated by oxidative stress. To decrease or increase glycemic variability the study will provide subjects with special diets containing either low or high glycemic index foods respectively for 4 weeks. To determine if oxidative stress is a mediator, subjects on the high glycemic index diet will take either placebo or the anti-oxidant N-acetylcysteine. The study will address the hypothesis that increased glycemic variability results in increased oxidative stress and thereby exacerbates beta-cell dysfunction in individuals with impaired glucose tolerance and/or impaired fasting glucose. The findings may have important implications for the development of effective strategies aimed at the prevention and treatment of type 2 diabetes. In addition, understanding the contribution of dietary glycemic index to beta-cell dysfunction in subjects with pre-diabetes may have a significant public health impact, including changes to dietary counseling and promotion of healthier eating patterns.

The incretin hormone glucagon-like peptide-1 (GLP-1) has known insulinotrophic and glucagonostatic properties. However, inpatients with type 2 diabetes mellitus (T2DM)it is shown, that the beta cell sensitivity towards GLP-1 is decreased, when comparing to healthy controls. Further, these patients have decreased GLP-1 response to a meal. The aim of this study is to elucidate if the diabetic hyperglucagonemia, seen in these patients both during fasting and in a postprandial condition, is coursed by a decreased sensitivity to GLP-1 in the diabetic alpha cell. Ten T2DM patients and ten matched healthy control subjects will be examined on two separate days. Day 1: increasing GLP-1 infusions and Day 2: saline. During both days plasma glucose (PG) will be clamped at fasting level (FPG). Patients with T2DM will be submitted til a Day 3, here PG will be normalized over-night by an adjustable insulin infusion, on the following day the GLP-1 infusion of Day 1 will be repeated. The hypothesis is that these patients have decreased alpha cell sensitivity to GLP-1 as is the case with the beta cell sensitivity. This decreased sensitivity, the investigators speculate, contributes the defect suppression og glucagon and thereby to the increased PG levels seen in T2DM. Further the investigators will elucidate if this sensitivity can be increased by normalizing the diabetic PG to a normal FPG level.

The purpose of this study is to examine whether there is a causal relationship between insulin resistance and/or glucose intolerance in the development of a defect incretin effect.

The purpose of this study was to compare the acute effects of 5g of Cassia cinnamon, 50 minutes of endurance exercise performed at 70% of the heart rate reserve (correlated to VO2max), and 5g of cellulose placebo on blood glucose, serum insulin and insulin sensitivity following an oral glucose tolerance test 3 hours after administration of each intervention.

The objective for this pilot project is to determine the feasibility and effectiveness of the Interactive Voice Response protocol (IVR) on physical activity and eating behaviors in a group men and women who have been identified by their physician as being pre-diabetic. We hypothesize that participants receiving the IVR follow-up will have greater positive changes in their physical activity and eating behaviors when compared to those who receive only the standard-care pre-diabetes class.

In this study, adults with pre-diabetes will be prospectively enrolled for data collection to design prediction models that integrate electronic health record data and patient-generated activity data. Patients will be randomized to receive either a waist-worn or wrist-worn wearable device for 6 months to capture patient-generated activity data.

This study will evaluate whether long-term consumption of the low calorie sweetener stevia affects glucose tolerance in healthy participants. With regard to this aim, we will recruit 2 study groups, the stevia group where participants will be required to add stevia drops twice daily in their habitual drinks and the control group where participants will be asked not to change anything in their diet and lifestyle.

Determine the effects of reducing whole-body iron stores in overweight/obese subjects (via one-time blood donation) on adipose tissue iron content, factors regulating iron homeostasis and lipolytic rate in adipose tissue, as well as measures of adipose tissue and whole-body insulin resistance. After a screening visit to determine eligibility, subjects will undergo a battery of tests for the determination of primary outcome measures at baseline. They will then donate 1 unit (~500 mL) of blood (at a local blood donation center) and return for a follow-up testing 4 weeks after blood donation. During the 4-week period between study trials, subjects will be required to maintain a stable body mass and not alter their dietary or physical activity habits.

Physical activity is a first line treatment for patients with type 2 diabetes (T2D), however, the vast majority of patients with T2D do not achieve satisfying glycemic control with physical activity alone, which is why pharmacological treatment with metformin is most often initiated. It is known that metformin and exercise both activates 5' adenosine monophosphate-activated protein kinase (AMPK) in skeletal muscle and liver, and the activation of AMPK results in many different metabolic effects, including improvements in glycemic control. Because of this similarity in mechanism of action, an interaction between metformin and exercise is plausible, but knowledge in the area is sparse. Thus, the aim of this study is to assess the effects of training with and without concomitant metformin treatment, in order to investigate whether an interaction between the two occur. Subjects with impaired glucose tolerance will all undergo 12 weeks of training but will be randomized (1:1) to concomitant metformin/placebo treatment in a double-blinded way. Experimental days will be performed before randomisation (before initiation of metformin/placebo treatment), before initiation of the training period and after the training period.