Dietary Polyphenols and Lipid Oxidation
ObesityInsulin Sensitivity1 moreThere are strong indications that (combinations of) polyphenols may be attractive candidates in the prevention of the metabolic syndrome and diabetes through modulation of pathways of fatty acid metabolism and mitochondrial function. We hypothesize that the combination of specific polyphenols, with partly distinct mechanisms of action, may have physiologically significant effects on fat oxidation through additive or synergistic effects, thereby improving body composition, insulin sensitivity and preventing type 2 diabetes. The following objective will be addressed in the current study: (1) to test short term (3 day) effects of combinations of polyphenols (supplements of EGCG either in combination with resveratrol or with resveratrol and genistein) to affect systemic lipolysis and fat oxidation during overnight fasted conditions and after ingestion of a high fat meal in overweight subjects
Clinical, Metabolic and Endocrine Effects of the Treatment With Drospirenone and Ethinyl Estradiol...
PCOSPolycystic Ovary SyndromePolycystic ovary syndrome (PCOS) is a heterogeneous syndrome with a variety of metabolic and endocrine abnormalities and clinical symptoms. The primary defect in PCOS consists of an abnormal androgen synthesis and secretion, particularly by ovarian theca cells. Insulin resistance and obesity may act as triggers, explaining the frequent association of PCOS with these metabolic conditions. Hyperinsulinaemia, which results from insulin resistance, stimulates both ovarian and adrenal androgen secretion and suppresses sex hormone-binding globulin synthesis from the liver. It results in an increase in free, biologically active androgens which are related to clinical signs such as hirsutism, acne, seborrhea, and alopecia. Combined oral contraceptive (COC) therapy is a common treatment for PCOS and it was widely used in this group of patients providing clinical improvement in the areas of excessive hair growth, unpredictable menses, acne, and weight gain. More recent studies outlined a deficiency in myo-inositol in women with PCOS and insulin-resistance. Myo-inositol is a precursor for many inositol-containing compounds and it plays critical and diverse roles in signal transduction, membrane biogenesis, vesicle trafficking, and chromatin remodeling. It is a precursor in the synthesis of phosphatidylinositol polyphosphates (PIPs) that are a source of several second messengers. It has been reported that the administration of myo-inositol reduces serum insulin, decreases serum testosterone and enhances ovulation. Due to the different beneficial actions, the aim of the present study is to evaluate the clinical, metabolic and endocrine effects of treatment with COC (drospirenone and ethinyl estradiol)alone or in combination with myo-inositol, in young women with PCOS and insulin resistance.
The Effect of Lowered Physical Activity on Insulin Sensitivity and Lipid and Glucose Metabolism...
Insulin SensitivityThe purpose of this study is to investigate the effects of lowered physical activity (resulting in decreased muscle mitochondrial oxidative capacity) alone and together with increased plasma free fatty acid availability (by infusion of a clinically widely used lipid emulsion (Intralipid)) on insulin sensitivity and glucose and lipid metabolism. To this end, we will compare skeletal muscle insulin sensitivity and glucose and lipid metabolism (within one subject) after 9 days of immobilization of one leg (unilateral lower limb suspension(ULLS))(decreased muscle mitochondrial oxidative capacity) versus an active control leg (unchanged muscle mitochondrial oxidative capacity). Further, changes in IMCL and fatty acid intermediates will be investigated in the immobilized vs the control leg, and this will be related to insulin sensitivity. The effectiveness of the ULLS intervention will be tested by measuring muscle mitochondrial oxidative capacity in both the immobilized and the control leg. All measurements will be performed both in the immobilized and control leg after 9 days of ULLS.
Sleep Loss and Glucose Metabolism in People With Family History of Type 2 Diabetes.
SleepSleep Deprivation2 moreThe use of sugar and starch-like foods for energy (carbohydrate metabolism) changes when people sleep. However, it is still not known if differences in the amount of nighttime sleep have an effect on the carbohydrate metabolism of people who have a relative with type 2 diabetes (parent, sibling, or grandparent). This study is being done to test the hypothesis that the carbohydrate metabolism of people who have a history of type 2 diabetes in their family will be different after they have slept short hours for 10 days in comparison to when they have slept longer hours for 10 days.
Exercise and Inflammation in the Elderly
InflammationInsulin SensitivityPersistent low-grade inflammation and impaired fibrinolysis, are independent predictors of several chronic diseases highly prevalent in the older Veteran population including cardiovascular disease (CVD), stroke, and diabetes. Inflammation is likely to be a causative underlying mechanism of insulin resistance. Lifestyle changes such as weight loss and physical activity are advocated for the treatment of these chronic diseases and endpoints, and data are emerging which suggest that these treatments may be beneficial, in part, due to their anti-inflammatory effects. Identification of effective therapies that reduce chronic inflammation for Veterans is important given the widespread adverse health effects of a chronically elevated inflammatory state.
Study of Vitamin D and Effect on Heart Disease and Insulin Resistance
Human Immunodeficiency Virus (HIV)Vitamin D Deficiency1 moreThe purpose of this study is to evaluate how Vitamin D affects endothelial function, inflammation, lipids, insulin resistance, vitamin D levels, and parathyroid hormone (PTH).
The Effects of Spirulina Platensis on Insulin Resistance in HIV-infected Patients
Insulin ResistanceHIV/AIDSSpirulina, a widely used food supplement, improves the lipid profile and glycemic control in people living with diabetes, suggesting that it could have some effects on insulin sensitivity. Since HIV-infected patients develop metabolic abnormalities due to the virus and/or to antiretroviral (ARV) drugs, the investigators therefore proposed to evaluate the effect that spirulina can have on HIV/HAART-associated insulin resistance
Effect of Angiotensin Receptor Blockade on Insulin Resistance and Adipose Tissue Cytokines in Type...
Insulin ResistanceType 2 DiabetesThe study aims to investigate the effect of acute angiotensin receptor blockade on insulin action/insulin resistance and expressions of selected adipocytokines in subcutaneous adipose tissue in insulin-resistant subjects with type 2 diabetes and healthy controls. Hypothesis: Changes in adipocytokine concentrations and/or expressions and different reactions to acute in vivo induced hyperinsulinemia and angiotensin receptor blockade will be found in patients with type 2 diabetes compared to healthy subjects. A significant relationships between insulin sensitivity and selected adipokines and intracellular fat content and high energy phosphates in soleus muscle will be documented in healthy individuals, while no significant relation will be found in patients with type 2 diabetes.
Isocaloric Dietary Interventions for Insulin Resistance and the Metabolic Syndrome
ObesityIn recent decades, the prevalence of obesity has increased dramatically in the United States. Obesity has been associated with an increased risk of the metabolic syndrome, which is characterized by a cluster of metabolic derangements, including insulin resistance, high blood sugar, high triglycerides, low high density lipoprotein (HDL) cholesterol levels, high blood pressure, and inflammation. Lifestyle interventions, including dietary modification, physical activity, and weight loss, form the basis of treatment for individuals with the metabolic syndrome. However, the optimal composition of the diet is not known at this time. Furthermore, due to hormonal and metabolic changes that accompany weight loss, most people find it very difficult to maintain significant weight reductions over time. As a result, weight regain is exceedingly common.
Metabolic Effects of Subchronic Dopamine D2 Receptor Blockade by Antipsychotic Drugs in Healthy...
Insulin ResistanceDyslipidemiaWe hypothesized that short-term treatment with AP drugs induces insulin resistance through a mechanistic route that is independent of weight gain and that atypical drugs exert stronger effects than typical compounds in this respect. We therefore treated healthy non-obese men with olanzapine (atypical AP) or haloperidol (typical AP) for 8 days, and studied the impact of these interventions on glucose and lipid metabolism by hyperinsulinemic euglycemic clamp, isotope dilution technology and indirect calorimetry.