Clinical Research Directory

Understanding Metabolism and Inflammation Risks for Diabetes in Adolescents

This research study collects health-related information and blood samples to better understand how body composition, lifestyle habits, and diet influence meta-inflammatory monocytes (MiMos) in adolescents. The hypothesis of this study is that adolescents at risk for metabolic disease have enhanced MiMo related activities leading to insulin resistance.

Interplay of Central and Peripheral Vascular Effects of Insulin in Obesity

Determine the impact of obesity with insulin resistance on the neurovascular response to brain insulin stimulation.

Peripheral Vascular Effects of Insulin in Obesity

Successful completion of this project will advance our understanding of the role sympathetic nervous system overactivity plays in driving skeletal muscle malperfusion during hyperinsulinemia and consequently impaired glucose uptake in obesity.

Trial of the Combination of Alpha-Lipoic Acid and Mirabegron in Women and in Men With Obesity

Background: Obesity and related illnesses cause at least 2.8 million deaths each year worldwide. Few treatments exist for obesity that are safe and widely available. A study drug (mirabegron \[MG\]) combined with a supplement (alpha-lipoic acid \[ALA\]) may help. Objective: To learn how MG and ALA can help the body process food. Eligibility: People aged 18 to 65 years with a body mass index between 30 and 45 kg/m2. Design: Participants will be screened. They will have a physical exam. They will have blood and urine tests and a test of their heart function. They will speak with a dietician. The study has two phases. Each phase begins with a 2-day stay in the clinic; then the participant will take the study drugs at home for about 4 weeks, followed by another 2-day stay in the clinic. They will also have outpatient visits about 2 weeks after each clinic stay. During the clinic stays, participants will undergo many tests: They will have a plastic tube (catheter) inserted into a vein in each arm. These will be used to draw blood and to infuse glucose (sugar) and insulin. They will have imaging scans. They will have a clear hard plastic shield placed over their head to measure oxygen and carbon dioxide as they breathe. Participants will take the study drugs at home. Both MG and ALA are taken by mouth with water. During one phase, participants will take MG plus a placebo. A placebo looks like the study drug but doesn t contain medicine....

Cross-Sectional and Longitudinal Studies of "Pre-Diabetes" in the Pima Indians

Insulin resistance and a defect in early insulin secretion are risk factors for the development of type 2 diabetes mellitus. A recent longitudinal analysis which tracked the development of diabetes demonstrated that both insulin action and early insulin secretion deteriorate as individuals progress from normal to impaired glucose tolerance and then to diabetes. These results suggest that both inherent (apparent in normal glucose tolerant subjects who progress to diabetes and likely to have a genetic basis) and acquired (evident as individuals progress from NGT to IGT to diabetes and possibly environmental in origin) defects in insulin action and secretion contribute to the pathogenesis of type 2 diabetes. To identify the genetic and environmental determinants of diabetes we are continuing to determine: (1) if there are genes that segregate with metabolic risk factors for diabetes which might therefore be genetic markers for type 2 diabetes and (2) the mechanisms mediating genetic and environmental determinants of insulin resistance and impaired insulin secretion. \<TAB\> Volunteers for this study will be admitted to the clinical research ward where they will undergo several tests to determine body composition, oral and intravenous glucose tolerance and in vivo insulin action. In addition, in selected subjects, adipose and/or skeletal muscle tissue will be obtained by percutaneous biopsy for in vitro studies of gene expression and insulin action in these tissues. A transformed lymphocyte cell line will be established for each subject as a permanent source of DNA for genetic studies. Genetic markers for type 2 diabetes and insulin resistance will be sought by typing each individual at positional and functional candidate loci in the hopes of finding an association between these loci and obesity, insulin secretion, insulin resistance and/or type 2 diabetes. ...

Monounsaturated Fatty Acid Supplementation for Overweight and Obese Individuals With Prediabetes

The purpose of this study is to understand and determine whether Palmitoleic acid (POA), monounsaturated omega-7 fatty acid (exists in regular diet), improves insulin sensitivity and decreases liver fat accumulation in humans. Unlike others, the study will use POA as a dietary supplement, rather than complex oils, which contain a significant amount of saturated fat palmitic acid. Palmitic acid has known harmful effects on the body. Hence, eliminating palmitic acid from supplementation of POA might increase its benefits. This trial stems from the preclinical discoveries that POA acting as a fat hormone, has beneficial effects on the liver, muscle, vessels, and fat tissue. Supporting this, higher POA levels in humans have been shown to be correlated with a reduced risk of developing type-2 diabetes and cardiovascular diseases such as heart attacks. In animals, it has been observed that POA improves sugar metabolism in a number of mechanisms related to the liver and muscle. Based on these findings, the design of this study is a double-blind placebo-controlled trial that tests the effects of POA on insulin sensitivity of overweight and obese adult individuals with pre-diabetes.

Dietary Strategies for Remission of Type 2 Diabetes

In this project, the investigators will perform a multicenter randomised controlled trial to determine whether advice to consume a moderate, whole food-based low-carbohydrate high-fat (LCHF) ad libitum diet (CarbCount program) can produce and maintain equal remission rates of type 2 diabetes (T2D) as a nutritionally complete very-low-calorie formula diet followed by a energy-restrictive (i.e., calorie counting) diet (DiRECT principles). Within the principles of each approach, the dietary goals and change will be adjusted according to individual needs/capabilities conducive to long-term adherence. Furthermore, the investigators aim to determine whether the rate of diet-induced remission is reflected in/can be predicted by baseline or diet-induced changes in glucose variability (e.g., time-in-range measured by continuous glucose monitoring) and other factors such as anthropometric changes and genetic susceptibility. Each center will also conduct locally-lead standalone mechanistic research, including analyses of intra-abdominal/hepatic fat accumulation, adipose tissue biopsies and/or measurements of energy metabolism. Additionally, changes in medication use, nutritional status, cardiovascular disease risk, as well as adverse events, will be monitored.

Effect of Daily Erythritol Versus Sucrose Intake Over 5 Weeks on Glucose Tolerance in Adolescents

This trial is divided into different parts: Part A the EryAdo trial and Part B the EryClot trial. Part A EryAdo Trial: Childhood and adolescence are crucial periods for prevention of obesity, as obese children are five times more likely to be obese at adulthood than lean children. To this purpose, sugar consumption should be reduced. The sugar alcohol erythritol is increasingly popular as sugar substitute in the food industry and is also recommended to diabetic patients. The substance is freely available. Recent acute studies show that erythritol has a positive influence on satiation and gastric emptying without affecting insulin and plasma glucose. In this trial, the investigators aim to assess the effect of a chronic intake of erythritol versus sucrose on insulin resistance in healthy adolescents. Part B EryClot Trial: In recently published studies, a prothrombotic effect of erythritol and xylitol was described. Therefore, within a pilot study the investigators examined whether erythritol is detectable in the blood after administration of erythritol and conventional sweeteners (glucose and fructose). Also the effect on blood clotting was investigated. These preliminary tests served to clarify the data situation so that further studies can be based on them. The preliminary results of the pilot study indicated that there appears to be no measurable effect of erythritol on thrombocyte aggregation. This implicated that there is a discrepancy between our results and the results reported in a recent published study. This is why we need to assess the effects of erythritol in more detail (thrombocyte aggregation, and markers of platelet activation, endothelial activation and coagulation) in more subjects. Due to a study published in 2024 describing similar prothrombotic effects for xylitol, this substance needs to be investigated as well. Thus, the participants will receive erythritol, xylitol, or water in a randomized order. In addition to the EryClot ex vivo experiments, we will conduct in vitro experiments incubating platelet-rich plasma from healthy donors with increasing concentrations erythritol or xylitol followed by measurement of platelet aggregation by aggreegometry assay.

DIabetes GLycemic Assessment in Newly Confirmed Episodes

This is a prospective, open-label, randomized controlled trial involving 80 adult patients with newly diagnosed T2DM (diagnosed within the last 3 months) recruited at the Bogomolets National Medical University. Participants may be lifestyle-controlled or receiving stable non-insulin anti-diabetic medications. Participants will be randomized in a 1:1 ratio to either the Real-Time Continuous Glucose Monitoring group (CGM group) or the control group (standard Self-Monitoring of Blood Glucose \[SMBG\] using conventional glucometers). The gathered data will help determine whether the real-time visual feedback provided by CGM systems superiorly improves glycemic variability, optimizes metabolic parameters, and enhances patient adherence to lifestyle interventions and pharmacological treatment compared to conventional SMBG methods in the early stages of T2D.

Effects of Antipsychotics on Brain Insulin Action in Females

Females treated with antipsychotics have higher rates of comorbid metabolic syndrome than males. Despite this, females have historically been excluded from many mechanistic studies due to confounding effects of menstrual cycles. Recent evidence suggests that brain insulin resistance may be an underlying mechanism through which antipsychotics may exert their metabolic side effects. This study seeks to investigate how brain insulin action differs in females according to their menstrual cycle phase, and how a high metabolic liability agent such as olanzapine might interrupt these differential insulin effects. Young healthy females will be given olanzapine and intranasal insulin to test how these treatment combinations change brain processes. Participants will be tested during both the first half of their menstrual cycle (follicular phase) and the second half of their cycle (luteal phase). The investigators predict that intranasal insulin will change MRI-based measures in females, in a comparable way to males, in the follicular phase only. Adding olanzapine will block these effects of insulin in females in the follicular phase. This investigation has the potential to generate new knowledge in an area of significant unmet need. Demonstrating that antipsychotics disrupt brain insulin action, evidenced by inhibition of recognized effects of insulin on neuroimaging measures, will provide novel insights into currently poorly understood mechanisms.

Metabolic and Hormonal Parameters in Women With Polyendocrine Metabolic Ovarian Syndrome

Polyendocrine Metabolic Ovarian Syndrome (PMOS) is a common endocrine and metabolic disorder associated with insulin resistance, hyperandrogenism, and an increased risk of long-term metabolic complications. Fetuin-A and resistin are adipokines implicated in insulin resistance and chronic inflammation and may serve as potential biomarkers for metabolic dysfunction in women with PMOS. This prospective observational case-control study aims to compare serum and salivary Fetuin-A and resistin levels between women with PMOS and healthy controls. The study will evaluate the correlation between serum and salivary biomarker concentrations and investigate their associations with insulin resistance, lipid profile, and hormonal parameters. The findings may help determine whether salivary measurements can serve as reliable non-invasive biomarkers for the diagnosis and metabolic assessment of PMOS.

Pulmonary Arterial Hypertension Improvement With Nutrition and Exercise (PHINE)

The purpose of this study is to investigate the extent to which diet and exercise may improve PAH through the modulation of insulin sensitivity. The central hypothesis is that dysregulated glucose metabolism elicits a response in PAH patients that can be modified by exercise and diet, thereby leading to improvements in pulmonary vascular disease.

Insomnia and Insulin Resistance

Insomnia symptoms are linked to metabolic syndrome (MetS), which includes abnormal glucose metabolism, insulin resistance (IR), and incidence of diabetes. Chronic sleep deficit is a major predictor of disease and early mortality. Further, insomnia is the most common sleep disorder in the United States. The recommended first line of treatment for insomnia is Cognitive Behavioral Therapy for Insomnia (CBT-I). CBT-I is a multidimensional treatment that targets the thoughts and behaviors that perpetuate insomnia symptoms over time. This study will explore CBT-I effects on MetS outcomes (ie. blood pressure, triglycerides, etc.) and provide preliminary evidence that CBT-I impacts IR and fasting glucose concentrations within this population. 20 subjects with insomnia will be recruited. They will be randomly assigned to either CBT-i or sleep hygiene. The intervention is 5 wks. Pre and post intervention, the investigator will have participants fill out a number of questionnaires, a daily sleep diary, 2 weeks of actigraphy measuring sleep and physical activity and there will be a single blood draw at the beginning and the end of the study.

Study of the Effect of Innate on the Inflammatory Response to Endotoxin

Background: \- Innate immunity is the process by which white blood cells and other parts of the immune system sense and respond to potential infections by causing an inflammation. Researchers are interested in studying how the body responds to certain environmental factors, and whether the body s response can contribute to chronic illnesses or diseases such as asthma and certain types of cancers. Objectives: \- To examine how specific genes and proteins in blood cells respond to environmental exposures. Eligibility: \- Healthy volunteers between 18 and 45 years of age. Design: * The study will involve one visit of 45 to 60 minutes. * Participants will be screened with a brief physical examination and finger stick to determine if they are eligible to donate blood for the study, and will complete a questionnaire about any medications or other drugs (e.g., cigarettes) they may be taking. * Participants will provide a blood sample for research purposes.

Sleep Loss and Circadian Misalignment - Mechanisms of Insulin Resistance

The purpose of this study is to examine the impact of timed cortisol release or differently timed cortisol rhythms on insulin resistance in both men and women undergoing sleep restriction. Chronic sleep loss is highly prevalent, affecting 1 in 3 adults in the US. Chronic sleep loss causes stress which induces insulin resistance and leads to obesity and type 2 diabetes. Many factors contribute to sleep loss including shift work, environmental disturbances, sleep/circadian disorders and comorbid medical and mental health conditions. Sleep loss increases the stress hormone cortisol in the evening and decreases daytime testosterone. Examining these hormones in a controlled laboratory environment under different sleep schedules may help researchers find solutions for adults experiencing negative health consequences related to chronic sleep loss.

Graded Insulin Suppression Test P&F

The goal of this study is to learn about how the hormone insulin controls blood sugar in a variety of people. The main question it aims to answer is about how much insulin the body actually needs to maintain a normal blood sugar level. Participants will be asked to come in for a one-day study visit in which they will undergo a "graded insulin suppression test" ("GIST"). The GIST involves intravenous (into the vein) infusions of octreotide, a medication that turns off the body's own production of insulin, as well as replacement of insulin at two different levels (low and high), with or without replacement of glucagon, and glucose (sugar). The study investigators will check blood sugar levels every few minutes during the procedure to determine the effect of the two different insulin levels. This study will evaluate the GIST in both healthy volunteers and those at higher risk for type 2 diabetes.

Everolimus Aging Study

The objective of this project is to determine if mTORC1 inhibition by 24 weeks of daily (0.5 mg/day) or weekly (5 mg/week) everolimus can safely improve physiological and molecular hallmarks of aging in humans. Participants who are 55-80 years old and insulin resistant or prediabetic will be randomized to treatment and can expect to be on study for up to approximately 38 weeks. Participants aged 18-35 will not receive the intervention and can expect to be on study for up to approximately 8 weeks.

Prenatal Exercise and Glucose Regulation

Gestational diabetes mellitus (GDM) is the most common disease during pregnancy and is characterized by an inability to regulate blood glucose (sugar) levels because of resistance to the hormone, insulin, which is responsible for getting glucose out of the blood. Aerobic training (AT, "cardio," for example: walking) is commonly used to regulate blood glucose levels in similar populations, like diabetics, but another form of exercise known as resistance training (RT, for example: weightlifting), has shown to be just as effective. Further, exercise intensity, regardless of the type, is directly proportional to blood glucose control. However, no study has compared AT and RT exercise modalities or intensity on blood glucose regulation in GDM, even though women with GDM share a similar insulin resistant phenotype as diabetics. Therefore, long-term objective of this study is to compare the effects of exercise type and intensity on glucose regulation and insulin sensitivity after four acute exercise sessions: low intensity RT (LOW-RT), low intensity AT (LOW-AT), moderate intensity RT (MOD-RT), moderate intensity AT (MOD-AT). Researchers will address the following aims: Specific Aim 1: Determine the impact of exercise type and intensity on glucose regulation using continuous glucose monitoring during- and for 24 hours after four acute exercise sessions: LOW-RT, LOW-AT, MODRT, and MOD-AT. Researchers hypothesize that RT and moderate intensity will elicit better glucose control compared to AT and low intensity, respectively. Specific Aim 2: Determine the impact of exercise type and intensity on insulin sensitivity by quantifying the quantitative insulin-sensitivity check index (QUICKI) before and after four acute exercise sessions: LOWRT, LOW-AT, MOD-RT, and MOD-AT. Researchers hypothesize that RT and moderate intensity will elicit greater insulin sensitivity compared to AT and low intensity, respectively.

Mindfulness-Based Intervention for Depression and Insulin Resistance in Adolescents

Rates of type 2 diabetes (T2D) in adolescents have escalated. Adolescent-onset is associated with greater health comorbidities and shorter life expectancy than adult-onset T2D. T2D is preventable by decreasing insulin resistance, a physiological precursor to T2D. T2D prevention standard-of-care is lifestyle intervention to decrease insulin resistance through weight loss; yet, this approach is insufficiently effective in adolescents. Adolescents at risk for T2D frequently experience depression, which predicts worsening insulin resistance and T2D onset, even after accounting for obesity. Mindfulness-based intervention (MBI) may offer a targeted, integrative health approach to decrease depression, and thereby, ameliorate insulin resistance in adolescents at risk for T2D. In a single-site, pilot randomized controlled trial (RCT), we established initial feasibility/acceptability of a 6-week group MBI program, Learning to BREATHE, in adolescents at risk for T2D. We demonstrated feasible single-site recruitment, randomization, retention, protocol adherence, and MBI acceptability/credibility in the target population. Our preliminary data also suggest MBI may lead to greater reductions in stress-related behavior, vs. CBT and a didactic/health education (HealthEd) control group. The current study is multisite, pilot RCT to test multisite fidelity, feasibility, and acceptability in preparation for a future multisite efficacy trial that will have strong external validity, timely recruitment, and long-term follow-up. Adolescents (N=120) at risk for T2D will be randomized to MBI vs. CBT vs. HealthEd and followed for 1-year. Specific aims are to: (1) test multisite fidelity of training and implementation of 6-week group MBI, CBT, and HealthEd, to teens at risk for T2D; (2) evaluate multisite feasibility/acceptability of recruitment, retention, and adherence for an RCT of 6-week group MBI, CBT, HealthEd with 6-week and 1-year follow-up; and (3) modify intervention training/implementation and protocol procedures in preparation for a future, fully-powered multisite efficacy RCT.

Identifying Risk for Diabetes and Heart Disease in Women

Background: \- Rates of diabetes and heart disease in women are increasing. Early recognition of risk could help women live longer and healthier lives. Race and ethnicity may affect the best kinds of tests to use to screen for these conditions. Researchers want to compare risk factors for diabetes and heart disease in African, African-American, and white women. Doing so may help identify the most effective screening test for each group. This study will look at healthy African, African-American, and white women who are federal employees and contractors. Objectives: \- To study risk factors for diabetes and heart disease in African, African-American, and white women. Eligibility: * Healthy African, African-American, and white women between 30 and 65 years of age who are federal employees or contractors. * For this study, African women must be born in Africa and have immigrated to the United States, and report that both parents are Africans. African-American women must self-identify as African-Americans, born in the United States, and have parents who both self-identify as African-American born in the United States. White women must self-identify as white and have parents who also self-identify as white. Design: * Participants will have four visits to study their risk factors for diabetes and heart disease. * The first visit is a screening visit. Participants will be screened with a physical exam and medical history. Blood and urine samples will be collected. They will also have an EKG test. Participants will also be shown how to fill out a 3-Day Food Record and wear an activity monitor called an accelerometer. The food record will keep track of how much participants eat for 3 consecutive days, including 1 non-working day. The accelerometer device will be worn for 3 days to monitor movement. * At the second visit, participants will have blood tests, an oral glucose tolerance test, and body fat measurements. They will also fill out questionnaires, review the food record, and have two imaging studies. * At the third visit, participants will have a longer glucose tolerance test. During the test, participants will receive both glucose and insulin and blood samples will be collected over several hours. Participants will receive lunch at the clinical center after the test. * At the fourth visit, participants will have a meal test. They will fast for 12 hours before the test. Participants will eat a specific meal and have blood samples taken during and after they eat. * Participants will discuss the results of these tests with the study doctors.

Understanding Dose Related Effects of Strawberry

The proposed research is designed to extend previous research findings building on the knowledge of strawberries as fruits that support a healthy immune and vascular system. The proposed research leverages a recently funded proposal by the USDA to study in greater depth inflammation, glucoregulation and oxidative stress defense and their relation to improving endothelial function and insulin sensitivity. Before and after strawberry intake, blood samples will be collected for monocyte (immune cells and source of inflammatory cytokines) isolation and activation via changes in cellular NF-κB and Nrf-2 (key transcription factors of inflammation/oxidative stress defense) status along with products of their activation (ie., plasma cytokines). Because inflammation and oxidative stress impairs endothelial function and insulin sensitivity, acutely and chronically, investigators will also study changes in vascular and insulin sensitivity status, assessing changes in vascular adhesion molecules, endothelial responsiveness through flow mediated vasodilation (ie., FMD) and insulin sensitivity using the Liquid Meal Tolerance (LMTT) if intravenous glucose tolerance test (IVGTT) method cannot be used due to supply chain issues of sterile Dextrose. Glucoregulation will be assessed by placing a Continuous Glucose monitoring (CGM) machine (Dexcom-6) to participants for 10 days at the beginning and at the end of the study period of intervention. The study will be a randomized, double-blinded, 3-arm parallel, 4-week, dose-response study. Individuals with chronic low grade inflammation will be sought to test the anti-inflammation - vaso-relaxing - insulin sensitivity effects of strawberry.

Human Models of Selective Insulin Resistance: Alpelisib, Part I

The goal of this clinical trial is to understand how the blood sugar-lowering hormone insulin works in healthy adults versus those who are at risk for type 2 diabetes. The study will use a drug called alpelisib, which interferes with insulin's actions in the body, to answer the study's main question: does the liver continue to respond to insulin's stimulation of fat production even when it loses the ability to stop making glucose (sugar) in response to insulin. Researchers will compare the impact of single doses of both alpelisib and placebo (inert non-drug) in random order (like flipping a coin) in study participants. Participants will be asked to stay twice overnight in the hospital, take single doses of alpelisib and placebo (one or the other on each of the two hospital stays), and receive intravenous (into the vein) infusions of non-radioactive "tracer" molecules that allow researchers to measure the production of glucose (sugar) and fats by the liver. Measurements will be done both while participants are fasting (not eating or drinking other than water) and while consuming a standardized diet of nutritional beverages. The objective is to evaluate the effect of lowering insulin levels, while maintaining constant mild hyperglycemia, on plasma glucose and lipid levels.

Dietary Macronutrients and Metabolic Markers

This prospective 12-week dietary intervention study evaluated the effects of a ketogenic diet on thyroid function and glucose-insulin metabolism in premenopausal women aged 30-50 years across different adiposity categories. Participants followed an individualized low-carbohydrate ketogenic diet designed to induce and maintain nutritional ketosis. Thyroid-related outcomes included thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4). Glucose-insulin metabolism was assessed using fasting glucose, fasting insulin, glycated hemoglobin (HbA1c), and the homeostatic model assessment of insulin resistance (HOMA-IR). Changes in body mass and anthropometric parameters were also evaluated. Outcomes were assessed before and after the 12-week intervention and compared according to baseline BMI categories.

The Effects of Cognitive Behavioral Therapy on Insulin Resistance in People With HIV

The goal of this clinical trial is to learn if depression treatment improves insulin resistance, or how the body uses insulin to lower blood sugar, in people with HIV on HIV treatment. Researchers will compare an internet-based (online) depression treatment program called cognitive behavioral therapy with depression education. In the online group, participants will undergo 9 weekly treatment sessions. The education group will receive learning materials about depression and will be monitored every month. All participants will have 4 study visits over 12 months.