He Purongo Mo Nga Kai Hei Arai i Te Matehuka - Dietary Diabetes Prevention Study for Maori
Insulin ResistanceHigh 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.
The Metabolic Effects of Almond Consumption in Adults With Pre-Diabetes
PrediabetesInsulin Resistance1 moreStudy Hypothesis: Daily consumption of almonds over 16 weeks will produce a decrease in hemoglobin A1c (HbA1c) levels in adults with pre-diabetes. Lay Summary: Persons developing type 2 diabetes mellitus (T2DM) will typically first have a condition called pre-diabetes. Lifestyle is a major factor that determines whether pre-diabetes becomes full T2DM. Lifestyle includes dietary habits and physical activity. Many people develop T2DM because of poor dietary habits and a sedentary lifestyle. Moreover, eating a high-fat, high-sugar diet can damage the blood vessels and increase the risk of strokes and heart attacks. A person's diet may produce substances in the blood that can interfere with the production of insulin in the pancreas. Sometimes, these changes in the insulin producing cells are serious and can eventually interfere with how the cells in the body use blood sugar, which causes T2DM. Techniques are available to measure circulating substances in the blood of persons with pre-diabetes that may be associated with the development of T2DM. Laboratory research has shown that almonds contain high levels of important compounds that may influence the onset of heart disease and T2DM. A meal plan that includes almonds daily will be given to half of the study participants and the other participants will be given a meal plan that is "nut-free". Because of the potential to delay the onset of heart disease and T2DM in some persons with pre-diabetes, this 16-week study will collect and analyze blood samples for changes that may make the person with pre-diabetes more likely to develop heart disease and T2DM. Blood samples will be collected at weeks 0, 8 and 16 to measure compounds that may be influenced by consuming almonds daily. This study will also attempt to understand other possible causes of heart disease and T2DM in persons with pre-diabetes; particularly those that might be related to body weight and body composition. Body composition techniques using very small amounts of electrical current are available to study body fat. Body weight, waist and hip measurements, blood pressure and body composition testing will be performed at the start of the study and every 4 weeks during the study. Lastly, these other possible causes of heart disease and T2DM will be investigated to look at relationships with the substances in the blood.
Rosiglitazone to Reverse Metabolic Defects in Diabetes
Diabetes MellitusType II1 moreThis study will examine whether the anti-diabetes medicine rosiglitazone can safely and effectively reverse the early problems of type 2 diabetes and delay the onset of disease in people with pre-diabetes. The underlying problem in people with diabetes or pre-diabetes is insulin resistance (lowered sensitivity to insulin) resulting in poor glucose (sugar) regulation. Rosiglitazone improves the body's sensitivity to insulin. Patients 21 years of age and older who have type 2 diabetes or who are pre-diabetic (glucose intolerant/insulin resistant) may be eligible for this study. Candidates are screened with a medical history, physical examination, blood tests, echocardiography (heart ultrasound), exercise test, brachial artery reactivity test (see below), and possibly a muscle biopsy. Participants take one rosiglitazone tablet daily by mouth for 2 weeks. The dose is then increased to two tablets daily for another 2 weeks and then to 4 tablets daily for the remainder of the 12-week treatment period. In addition to treatment, patients undergo the following tests and procedures: Resting and exercise metabolic testing: The amount of oxygen taken in and carbon dioxide exhaled during breathing is measured while the patient rests in a chair and then while he or she exercises on a stationary bicycle or treadmill. Both at rest and during exercise, the patient wears a facemask that measures the amount of oxygen used. During exercise, heart rate is monitored with electrodes on the chest, arms, and thighs. The exercise test is repeated three times, once to become familiar with the test, again the next day to measure exercise capacity, and again 3 days later. The third test is less strenuous and is optional. Muscle biopsy (optional): A small area of skin over a calf muscle is numbed with a local anesthetic and a 1-inch incision is made over the muscle. A small amount of muscle tissue is taken and the incision is closed with stitches. Brachial reactivity study: This ultrasound study tests how well the patient's arteries widen. The subject rests on a bed for 30 minutes. An ultrasound measuring device is placed over the artery just above the elbow. The size of the artery and blood flow through it are measured before and after inflating a pressure cuff around the forearm. The pressure cuff stops the flow of blood to the arm for a few minutes. After a 15-minute rest, a nitroglycerin tablet (medicine that causes blood vessels to relax) is placed under the patient's tongue. Before and 3 minutes after the nitroglycerin is given, the size of the artery and blood flow through it are measured again. Blood samples: Blood samples are collected at the beginning and end of the study and at study visits in between. Study visits: Patients come to the Clinical Center biweekly or monthly for a follow-up history, physical examination, and blood tests. At the end of the3-month treatment period, they receive recommendations about possible treatment modifications to best maintain glucose tolerance. Their physicians are informed of how their blood sugar was controlled. Six months after completing the study, patients undergo a final study evaluation and blood tests, and are then invited to return for yearly checkups after that.
Ginkgo Biloba Extract and the Insulin Resistance Syndrome
Type 2 Diabetes MellitusThe purpose of this study is to examine whether the ingestion of the herbal dietary supplement Ginkgo biloba extract has any effect on the efficacy of three classes of diabetic medications - (Glucotrol, Glucophage and Actose). Additionally, the study will examine the effect of Ginkgo biloba extract on pancreatic insulin production in non-diabetic subjects between the ages of 20 and 75 years old.
Effects of Oral Glucosamine on Insulin and Blood Vessel Activity in Normal and Obese People
ObesityInsulin ResistanceThis study will examine whether glucosamine affects the way the body responds to insulin. Insulin is a hormone that causes the body to use glucose (sugar). Insulin does not work as well in overweight people, causing a condition called insulin resistance. Insulin also increases the flow of blood into muscle by opening inactive blood vessels. This study will test whether glucosamine, a nutritional supplement that many people take to treat arthritis, can cause or worsen insulin resistance or change how blood vessels react to insulin in normal weight and overweight people. Healthy normal weight and overweight volunteers between 21 and 65 years of age may be eligible for this study. Candidates will be screened with a brief physical examination, medical history, and blood and urine tests. After screening, participants will have three additional outpatient clinic visits for the following procedures: Visit 1 Glucose clamp test to measure the body's response to insulin: For this procedure, a needle is placed in a vein of each arm, one for drawing blood samples, and one for infusing glucose and a potassium solution. The glucose is infused continuously during this 4-hour test and blood is drawn frequently to monitor glucose and insulin levels. After the test, blood glucose levels are monitored for another 2 hours to make sure they remain at an adequate level to prevent hypoglycemia (low blood sugar). Blood flow measurement: Blood flow in the brachial artery of the arm is measured to assess how many capillaries (very small blood vessels) are being used to supply nutrients and oxygen to the muscle in the forearm. This test is done at the same time as the glucose clamp test. Blood flow is measured using a technique called contrast ultrasound. A small amount of contrast agent consisting of gas-filled bubbles the size of red blood cells is infused over 10 minutes through one of the catheters placed in the vein for the glucose clamp test. The contrast agent is infused twice, once at the beginning of the glucose clamp test and once at the end of the test. The contrast material creates a signal in response to ultrasound that provides information about the distribution of capillaries in the forearm. Assignment to medication group: Participants are randomly assigned to take either glucosamine or placebo three times a day by mouth for 6 weeks. At the end of the 6 weeks, no study drug is taken for 1 week, and then participants "cross-over" medications, those who took glucosamine for the first 6 weeks take placebo for the next 6 weeks and vice versa. Visits 2 and 3 For these visits, the glucose clamp test and blood flow measurements are repeated. Visit 2 is scheduled at the end of the first 6-week treatment period, and Visit 3 is scheduled at the end of the second 6-week treatment period.
Effect of Metformin and Rosiglitazone Over no Diabetic With Metabolic Syndrome Patients.
Insulin ResistanceTo compare the effect of insulin sensitizing drugs (metformin and rosiglitazone) over glucose homeostasis (GH) in no diabetic metabolic syndrome individuals. A randomized blinded clinical trial did in patients with metabolic syndrome (n=30), without diabetes. Prior to detailed information and signature of informed consent by patients were done three treatment groups by randomized technique; a) Placebo, b) Metformin (850 mg/day), c) Rosiglitazone (4 mg/day), treatment was administered for 8 weeks. GH was measured before and after treatment using oral glucose tolerance test (OGTT), and IR-index (Homeostatic Model). Determination was performed on weight, size, body mass index, plicometry, blood pressure, fasting glucose levels, triglycerides, HDL-cholesterol and insulin.
Diagnostic Interest of the IRAP Protein (Insulin Regulated Amino Peptidase) in Insulin Resistance...
Insulin Resistance SyndromeThere is currently no reliable, diagnostic tests of insulin resistance other than the hyperinsulinemic euglycemic clamp which, due to its constraints and cost, is reserved for research. The insulin-Regulated aminopeptidase (IRAP) protein is a direct marker of insulin-dependent glucose cell capture and thus it blood concentration seems to be a good diagnostic test of insulin resistance. The purpose of this study is to assess a plasma essay of IRAP protein for evaluation of insulin resistance during an oral glucose tolerance test (OGTT).
Effects of a Plant-Based Diet on Insulin Requirements and Obesity Markers in Obese Adults With T2DM...
Diabetes MellitusType 23 moreThis is a crossover study utilizing a Dietary Approaches to Stop Hypertension (DASH) diet and a whole-food, plant-based diet among subjects with type 2 diabetes who require insulin. Outcomes are short-term changes in insulin requirements and changes in various biomarkers.
Study of Semaglutide for Non-Alcoholic Fatty Liver Disease (NAFLD), a Metabolic Syndrome With Insulin...
HIV InfectionsNon-Alcoholic Fatty Liver DiseaseThe purpose of this study is to evaluate the effects of semaglutide on intra-hepatic triglyceride (IHTG) content in people living with HIV (PLWH), central adiposity, insulin resistance or pre-diabetes, and hepatic steatosis.
Acute Hyperbaric Oxygen Treatment Increases Hepatic Insulin Sensitivity and Muscle Reactive Oxygen...
Type 2-diabetesDiabetes mellitus type 2 (T2D) is characterized by insulin resistance of liver and skeletal muscle, which is at least partly due to impaired muscle mitochondrial function. Long-term HBO therapy, as applied for treating the diabetic foot syndrome, has been shown to improve blood glucose concentrations. To study the underlying mechanisms, we want to examin the short-term effect of HBO treatment on insulin sensitivity and mitochondrial oxidative capacity and production of reactive oxygen species (ROS) in a randomized, double blinded, placebo-controlled cross-over trial.