Clinical Trials

7 studies in Healthy Volunteers

1. Pulsatile Feedback Actions of Cortisol on ACTH Release in Men and Women: Signaling via Glucocorticoid and Mineralocorticoid Receptor-Dependent Mechanisms Rochester, MN View Summary
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   Pulsatile Feedback Actions of Cortisol on ACTH Release in Men and Women: Signaling via Glucocorticoid and Mineralocorticoid Receptor-Dependent Mechanisms

   Location:

   Rochester, MN

   Trial status:

   Open for Enrollment

   Why is this study being done?

   This research study is designed to help us better understand how the body controls the secretion of adrenocorticotropic hormone (ACTH) in young men and women.
   
   ACTH is a hormone (a chemical that circulates in the blood and influences a person's health) that is made in and released by the pituitary gland in the brain. ACTH increases the production of cortisol by the adrenal gland.
   
   Cortisol is a hormone which allows the body to respond to stress. Thus, ACTH and cortisol are called stress hormones.
   
   Their levels differ in men and women, but doctors do not know why. This study will test how testosterone (male sex hormone) in men and estrogen (female sex hormone) in women control the stress hormones.
   
   This question is important, because sex hormones increase in puberty and decrease with aging.
   

   IRB Number:

   09-007226

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   Who can I contact for additional information about this study?

   Please contact Jean Wigham 507-293-1188

2. Mitochondrial Dysfunction in Diabetes Scottsdale and Phoenix, AZ View Summary
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   Mitochondrial Dysfunction in Diabetes

   Location:

   Scottsdale and Phoenix, AZ

   Trial status:

   Open for Enrollment

   Why is this study being done?

   The investigators' prior research has focused on defining the changes in expression of nuclear encoded mitochondrial genes that predict changes in insulin sensitivity in skeletal muscle, with the goal of defining the molecular mechanisms underlying the connection between mitochondrial dysfunction and insulin resistance in skeletal muscle. Three groups of subjects will be studied: lean, healthy control subjects (n=12) obese non-diabetic subjects (n=12) and patients with type 2 Diabetes Mellitus (n=12) for a total of 36 subjects. Twenty subjects have completed the study at Arizona State University; the remaining 16 subjects will be accrued at the Mayo Clinic in Arizona. Subjects will come to the Mayo Clinic 4 times. On Study Day 1 Subjects will be screened with a medical history & physical and a 75 g oral glucose tolerance test to determine if they are eligible for the study. On Study Day 2, subjects will report to the clinic after an overnight fast, undergo a euglycemic clamp (using deuterated glucose) to determine insulin sensitivity, and in addition have a muscle biopsy (basal biopsy for comparison). On Study Day 3, subjects will report to the clinic after an overnight fast, and undergo a Volume Oxygen Maximum (VO_2 max) determination. On Study Day 4, subjects will report to the clinic after an overnight fast to perform an exercise bout with muscle biopsy 30 minutes after the end of exercise. This will be followed by an overnight fast, and an additional muscle biopsy at 24 hours post exercise.

   NCT ID:

   NCT01724502

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   Who can I contact for additional information about this study?

   
   Scottsdale: Roxane McLaughlin, RN 480-301-4142
                       
   
   

3. PGC-1 and Mitochondrial Dysfunction in Diabetes Scottsdale and Phoenix, AZ View Summary
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   PGC-1 and Mitochondrial Dysfunction in Diabetes

   Location:

   Scottsdale and Phoenix, AZ

   Trial status:

   Open for Enrollment

   Why is this study being done?

   The investigators' prior research has focused on defining the changes in expression of nuclear encoded mitochondrial genes that predict changes in insulin sensitivity in skeletal muscle, with the goal of defining the molecular mechanisms underlying the connection between mitochondrial dysfunction and insulin resistance in skeletal muscle. The purpose of this study is to determine whether experimental lipid oversupply decreases mitochondrial respiratory function. We will use mitochondrial respiration studies in vitro and mass spectrometry and proteomics analysis to test the hypothesis that experimental lipid oversupply: 1. Decreases mitochondrial respiration in response to lipid fuels. 2. Reduces abundance of mitochondrial proteins. 3. Alters phosphorylation of proteins in the electron transport chain. Three groups of subjects will be studied: lean, healthy control subjects (n=12), obese non-diabetic subjects (n=12) and patients with type 2 Diabetes Mellitus (n=12) for a total of 36 subjects. Twenty subjects have completed the study at Arizona State University; the remaining 16 subjects will be accrued at the Mayo Clinic in Arizona. Subjects will come to the Mayo Clinic 2 times. On study Day 1 subjects will be screened with a medical history and physical exam, and a 75 g oral glucose tolerance test, measure body fat percentage, and an electrocardiogram (EKG). On Study Day 2, subjects will report to the clinic after an overnight fast. Female subjects will take a urine pregnancy test. A muscle biopsy will be performed to take a small sample from one thigh. A lipid infusion will be performed for 5 hours (60 ml/hr), with blood samples taken at 8 intervals during the infusion. At the end of the 5 hour period, a second muscle biopsy will be taken from the other thigh. The fat infusion will stop, subjects will be given lunch and allowed to leave the clinic.

   NCT ID:

   NCT01724515

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   Who can I contact for additional information about this study?

   
   Scottsdale: Roxanne McLaughlin, RN 480-301-4142
                       
   
   

4. Does Class of Dietary Fat Affect Insulin Resistance? Rochester, MN View Summary
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   Does Class of Dietary Fat Affect Insulin Resistance?

   Location:

   Rochester, MN

   Trial status:

   Open for Enrollment

   Why is this study being done?

   Type 2 Diabetes and cardiovascular disease are closely linked. A common abnormality in both conditions is insulin resistance. The primary cause of insulin resistance in not known. A significant question is what dietary components contribute to the development of insulin resistance. Based on epidemiologic data, it seems that the type of dietary fat is a significant contributor to the development of insulin resistance. However, some researchers argue that the main determinant is total amount of fat, not the composition. This study is intended to determine if the main types of fat (saturated, monounsaturated and polyunsaturated) ingested over a short time can cause insulin resistance in lean, healthy people. It has been demonstrated that 6 hours of intravenous fat infused into lean, healthy subjects can result in insulin resistance, as well as blood pressure elevation and endothelial dysfunction. Whether this is so with oral fat is not known. The question is important because there is debate about whether the type of fat is as important as the quantity of fat in a person's daily diet. Settling this debate will enhance the ability of health care personnel to determine the optimal dietary recommendations. This study will make use of a high fat diet consisting of vegetable oils high in the 3 main fatty acids in plasma (palmitate, oleate and linoleate). Because large fat loads can cause intestinal discomfort, a feeding tube will be used to bypass the stomach. The 3 oils will be assigned randomly following a base line study with saline 2 weeks prior to the intervention. Our primary endpoint is insulin resistance, which will be measured by a euglycemic, hyperinsulinemic clamp. Secondary measures will include changes in blood pressure and in vascular reactivity as measured by ultrasound after brief occlusion of a forearm vessel. The changes will be compared to baseline and to the other 2 groups.

   NCT ID:

   NCT01541592

   IRB Number:

   11-000179

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   Who can I contact for additional information about this study?

   Rochester: Tamera Roberson 507-255-8621
                       Almira Smailovic 507-255-7536
   
   
   

5. Effects of Aging and Aerobic Exercise Training on Brain Glucose Metabolism Rochester, MN View Summary
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   Effects of Aging and Aerobic Exercise Training on Brain Glucose Metabolism

   Location:

   Rochester, MN

   Trial status:

   Open for Enrollment

   Why is this study being done?

   Aging is associated with a loss of brain function and conditions such as dementia and Alzheimer's disease. It is likely that decreased brain metabolism is contributing to the progression of age related degenerative diseases. Aerobic exercise training can increase brain volumes and is associated with decreased risk for degenerative brain conditions. However, little is know about the changes that occur to brain metabolism with aerobic training and aging.

   NCT ID:

   NCT01738568

   IRB Number:

   12-003357

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   Who can I contact for additional information about this study?

   Rochester: Robinson, PhD 507-255-9610
                       
   
   
   

6. The Effect of Mixed Exercise and Metabolic Stress in Relationship to Age in Healthy Men Rochester, MN View Summary
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   The Effect of Mixed Exercise and Metabolic Stress in Relationship to Age in Healthy Men

   Location:

   Rochester, MN

   Trial status:

   Open for Enrollment

   Why is this study being done?

   Aging in men reduces the amount of luteinizing hormone (LH) and testosterone (Te) secreted in each burst. Stress-associated mechanisms introduced by acute illness and chronic disease decrease LH and Te secretion further. A major unresolved issue is whether the aging process heightens the negative effects of a stressor (whether physical or metabolic) upon LH and Te secretion. This study will assess LH and Te secretion in response to a physical stressor (maximal exercise) and a common metabolic stressor (hyperglycemia) as a function of age in healthy men ages 18-80 yr.

   NCT ID:

   NCT01800370

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   Who can I contact for additional information about this study?

   Rochester: Jean Wigham, BSN 507-293-1188
                       Sue Weist, BSN 507-255-1294
   
   
   

7. The Contribution of Incretin Hormones to Post-prandial Glucose Metabolism After Roux-en-Y Gastric Bypass Rochester, MN View Summary
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   The Contribution of Incretin Hormones to Post-prandial Glucose Metabolism After Roux-en-Y Gastric Bypass

   Location:

   Rochester, MN

   Trial status:

   Open for Enrollment

   Why is this study being done?

   The study is being undertaken to understand how the Roux-en-Y Gastric Bypass procedure can affect insulin secretion after meals. The hypothesis of this study is the Disposition Index is decreased in subjects who had previously undergone Roux-en-Y Gastric Bypass by glucagon-like peptide-1 (GLP-1) receptor blockade.

   NCT ID:

   NCT01843881

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   Who can I contact for additional information about this study?

   Rochester: Paula Giesler, R.N. 507-255-8345