
Aldosterone, Microvascular Function and Salt-sensitivity
Abdominal ObesityMetabolic Syndrome3 moreCurrently, the incidence of obesity and obesity-related disorders is reaching epidemic proportions, which entails an increasing burden for health care systems. The association of obesity with other risk factors for type 2 diabetes mellitus and cardiovascular disease, such as insulin resistance and hypertension, is often referred to as the metabolic syndrome. During recent years, salt-sensitivity of blood pressure has emerged as an additional cardiovascular risk factor that is related to obesity and other key components of the metabolic syndrome. The underlying pathophysiological mechanisms of these interrelationships are complex and incompletely elucidated. Microvascular dysfunction has been proposed as a link between insulin resistance and hypertension in obese individuals. In addition, impairment of microvascular function was found to be associated with salt-sensitivity of blood pressure. Increased aldosterone levels, as observed in obese individuals, might be a cause of microvascular dysfunction-induced salt-sensitivity and insulin resistance. Aldosterone not only gives rise to sodium-retention in the distal tubule of the kidney, but was also found to impair endothelial function and thus lower NO-availability, which is characteristic of microvascular dysfunction. In addition, elevated aldosterone levels are associated with both hypertension and insulin resistance, which is illustrated in patients with primary aldosteronism, but also in the general population. The investigators hypothesize that increased aldosterone levels in obese individuals lead to impairment of microvascular function through reduction of NO-availability. This microvascular dysfunction is suggested to play a central role in the pathogenesis of salt-sensitive hypertension and insulin resistance.

Air Pollution and Allergens - Attenuation of Health Effects Particle Reduction
AllergiesThe study probes the effects of combined exposures to diesel exhaust and allergens on lung function and on the immune system, specifically focusing on the ability of a particle depletion technique to attenuate effects we and others have seen previously. Individuals are exposed to either filtered air (FA), carefully controlled levels of diesel exhaust (DE) or particle-depleted diesel exhaust (PDDE) in our exposure chamber, after which the investigators will administer an inhaled allergen challenge. 48h later, a procedure called bronchoscopy is used to collect samples from the lungs. After 1 month, the entire procedure is to be repeated with one of the alternate exposures. This will be repeated 4 times (4 exposures; 2 filtered air, 1 diesel exhaust, 1 particle-depleted diesel exhaust)

Sensitive Periods in Human Flavor Learning
DevelopmentThe goals of the proposed research are to specify the timing and consequences of the sensitive period for flavor learning in infants who are being breastfed or formula fed. The investigators will conduct a randomized within- and between-subject study of women and their infants during a 15-month window.

Assessment of LCZ696 and Valsartan in Asian Patients With Salt-sensitive Hypertension
Salt-sensitive HypertensionThis study will evaluate the effect of LCZ696 and valsartan on natriuresis, diuresis, and blood pressure in salt-sensitive Asian hypertensive patients.

Acute Effects of an Oral Fat Load on Skeletal Muscle and Hepatic Insulin Sensitivity
Insulin SensitivityThe development of type 2 diabetes is based on a combination of insulin resistance and beta cell dysfunction. In the last years, elevated FFA were recognized as a key players in the pathogenesis of insulin resistance and type 2 diabetes. The study compares the acute effects of an oral lipid bolus on insulin sensitivity and hepatic glucose metabolism in healthy humans.

Modulation of Insulin Sensitivity by Betaine Upregulation of FGF21
Insulin SensitivityPeople with poor insulin sensitivity do not respond normally to elevations in blood sugar. This may increase their risk of developing diabetes in the future. The purpose of this research study is to determine if the nutrient betaine, found in beets, spinach and wheat products, can enhance the production of fetal growth factor 21 (FGF21), a molecule that is believed to promote insulin sensitivity.

Obesity, Sleep Apnea, and Insulin Resistance
Insulin SensitivityObstructive Sleep ApneaObstructive sleep apnea (OSA) and type 2 diabetes confer increasing economic, social, and public health burdens in the United States. That these diseases appear to co-exist and together increase one's risk of cardiovascular disease renders investigation into their shared pathophysiology even more urgent. Investigators will assess prevalence of insulin resistance, a precursor to diabetes, among overweight patients with OSA. Among those at highest risk of diabetes, investigators will randomize participants to pioglitazone or placebo to see the efficacy of the intervention on improving OSA, insulin resistance, and/or insulin secretion. In a separate intervention, investigators will evaluate the cardiometabolic benefits of continuous positive airway pressure (CPAP) for 12 weeks in patients with OSA. Investigators will also study subjects from the community without known sleep apnea, and assess whether insulin-resistant individuals are at risk for sleep apnea using clinical screening questionnaires.

Fatty Acid Metabolism and Insulin Sensitivity: the Role of Endurance Exercise
Insulin Resistance and Type 2 DiabetesClearly the effects of diet and exercise are beneficial for obese persons, but the underlying mechanisms for the improvements in metabolic health are not completely clear. Although mounting evidence suggests that alterations in lipid metabolism in persons with abdominal obesity are associated with a several medical complications, including diabetes, little is known about the factors responsible for this effect. The project in this application is designed to examine how the addition of endurance exercise training to a weight-loss program alters whole-body fatty acid availability, uptake, and oxidation as well as the expression of cellular factors that regulate these processes. In addition, we will evaluate whether these alterations are associated with improvements in insulin sensitivity. In the end, these experiments will provide insight into the cellular and whole-body adaptations in fatty acid metabolism in response to weight-loss and exercise training that may lead to enhancement of insulin sensitivity. Identifying relationships between gene expression, whole-body fatty acid metabolism and clinical outcome measurements, such as insulin sensitivity, may lead to improvements in the therapeutic and/or the preventative approach to obesity and its co-morbidities.

Testosterone and Lipolysis, Insulin Sensitivity and Protein Metabolism
HypogonadismTestosterone(T) has known effects on many organ systems, although many of its metabolic actions are unrevealed. T is an anabolic hormone stimulating protein synthesis but this effect has barely been investigated in controlled studies. It also has lipolytic actions influencing body composition, but little is known of its regional impact on fat tissue. T affects insulin sensitivity. There is an increased incidence of hypogonadism in type 2 diabetes, and among patients with hypogonadism there is an increased incidence of type 2 diabetes. The actions of testosterone on glucose metabolism are unknown. The purpose of this study is therefore to: Investigate the lipolytic effect of testosterone on muscle and fat tissue. To gain insight in the intracellular mechanisms of testosterone on lipolysis and investigate possible regional differences in lipolysis and changes in body composition. Finally to investigate the effect of short term experimental hypogonadism and acute testosterone substitution on cytokines, insulin sensitivity and protein metabolism. The trial is a randomised double blinded cross-over study of 4 x 2 days with an interval of 1 month in between. 12 healthy young men will receive GnRH treatment over a 3 month period and examined on 4 occasions with various degrees of T substitution and placebo . The examinations take place at the Research Lab within the Medical Department M. The investigations are deemed relevant to the understanding of the interrelationship between male hypogonadism and type 2 diabetes. The hypothesis is that T has beneficial effects on carbohydrate, fat and protein metabolism. The generated knowledge would therefore hopefully improve prophylaxis, screening and early treatment of both group of patients.

A Study of the Relief of Tooth Sensitivity of an Experimental Mouthrinse Device
Dentin SensitivityThis study is for people with sensitive teeth and involves going to the dentist for 4 visits over 6 weeks. During the first 2 weeks, you will just brush your teeth two times a day with the fluoride toothpaste provided. Then you will be assigned to a group if you qualify to continue in the study. All groups will get a marketed toothpaste and one group will also get a mouthwash with an experimental ingredient. You will have an equal chance of being assigned to any one of the three groups. For the next 4 weeks, you will brush with your assigned toothpaste and rinse with your assigned mouthwash if assigned to the mouthwash group. A dentist will look at your mouth, teeth, tongue and gums and check for sensitive teeth. The investigators will see if the mouthwash helps to reduce tooth sensitivity during the study.