
Effect of Varying Testosterone Levels on Insulin Sensitivity in Normal and IHH Men
HypogonadismType 2 diabetes is one of the most common metabolic disorders in the U.S, estimated to affect 16 million Americans. Established risk factors for this disease include obesity, increased waist/hip ratio, high insulin levels in the blood, and insulin resistance. Testosterone may play a role in developing or preventing diabetes, but we do not yet know for sure. The purpose of this research study is to determine if changing testosterone levels in men will result in changes in insulin sensitivity. Information learned form this research study may have important public health implications and may point to new strategies for treating or preventing diabetes.

Ghrelin Decreases Insulin Sensitivity
Healthy SubjectsGhrelin administration increases appetite and, in rodents, induces weight gain. The aim of this study is to investigate the effect of short term ghrelin administration to humans on metabolism.

The Effect of Taurine on Morbidity and Mortality in the Elderly Hip Fracture Patient
Insulin ResistanceElderly Patient1 moreThe purpose of this study is to reduce the postoperative morbidity and mortality in the elderly hip fracture patient, by giving them taurine peri-operatively.

Effect of Salsalate on Bed Rest-Induced Vascular Dysfunction
Insulin ResistancePhysical inactivity induces vascular dysfunction and glucose intolerance during five days of bed rest. This study will investigate the effects of salsalate on these responses. Subjects will be randomized to treatment with salsalate or placebo for four days prior to initiation of bed rest. Vascular function in the brachial artery will be determined by ultrasound prior to treatment and before and after the 5-day bed rest protocol. We hypothesize that treatment with salsalate will be associated with protection again the development of glucose intolerance and vascular dysfunction in this setting.

Mechanisms Underlying Metabolic Syndrome in Obesity
Metabolic SyndromeInsulin Resistance1 moreThe purpose of this study is to better understand the link between obesity and diabetes or pre-diabetes.

Insulin Resistance and Substrate Metabolism After Acute Erythropoietin (EPO) Administration
Insulin SensitivityRecently EPO receptors have been found in human muscle tissue, but what is still not known is the physiological role of these receptors. In this study the researchers want to investigate if there is any effect of a acute administration of EPO on insulin resistance and/or substrate metabolism in muscle tissue.

Effect of Endoplasmic Reticulum Stress on Metabolic Function
Insulin ResistanceDiabetes1 moreNormally, the hormone insulin works to help keep blood sugar normal. However, as a person gains weight, insulin does not work as well and blood sugar tends to be a little higher than normal. This is called "insulin resistance". Two investigational drugs (not approved by the Food and Drug Administration) for the treatment of high lipid levels or insulin resistance are being examined in this study: one drug is called tauroursodeoxycholic acid (TUDCA), the other is called sodium phenylbutyrate (PBA). This study is designed to test if TUDCA and/or PBA is effective in people who are obese with insulin resistance and high lipids. We hypothesize that pharmacologically-induced decreases in ER stress will improve insulin action and hepatic lipid metabolism in obese subjects.

Fatty Acid Quality and Overweight (FO-study)
Weight Reduction and Insulin SensitivityThe purpose of this study is to study the health effects of fatty acid quality in healthy, overweight individuals.

Exploratory Study of the Relationships Between the Biomarkers of Inflammation, Lipidome and Insulin...
LipodystrophyDunnigan SyndromeThe objective of this work is to identify biomarkers of interest in patients with insulin resistance leading to early disorders of glycemic regulation. For this the investigators want to assay the insulin resistance marker Insulin Regulated Amino Peptidase serique (IRAPs), the plasma lipidome and inflammation markers in 2 populations of insulin-resistant subjects due to Dunnigan's inherited lipodystrophy or overweight/obesity and insulin-sensitive subjects with or without a glycemic regulation disorder objectified during an Oral induced hyperglycemia. The results of the IRAPs, lipidome and inflammation assays will be compared in insulin-resistant subjects, between normoglycemic, prediabetic and diabetic subjects. Correlations will be made between these markers and the deterioration of glycemic regulation as well as with known insulin resistance parameters (HOmeostasis Assessment Model (HOMA), Quantitative Insulin-sensitivity Check Index (QUICKI),Insulin Sensitivity Index (Isi) MATSUDA).

Impact of Plasma Lipids on β Cell Function and Insulin Sensitivity
HypertriglyceridemiaGlucose IntoleranceThe investigators aim to evaluate whether and to what extent glucose tolerance, beta cell function, insulin clearance, and glucose metabolic fluxes change in response to an acute increase in plasma triglycerides during lipid infusion, independently of free fatty acid (FFA) levels, in nondiabetic subjects.