Clinical Research Directory

Effect of Insulin Lowering on Lipogenesis

The goal of this clinical trial is to compare a one-week course of diazoxide (2 mg/kg per dose x 14 doses) and placebo in people with obesity and insulin resistance (IR) with metabolic dysfunction-associated steatotic liver disease (MASLD). The main question it aims to answer are how mitigation of compensatory hyperinsulinemia with diazoxide affects hepatic de novo lipogenesis, a major contributor to MASLD pathophysiology. Participants will: * Take 14 doses of placebo over 7 days, followed 4-12 weeks later by either 14 doses of diazoxide (at 2 mg per kg of body weight per dose \[mpk\]) or another 14 doses of placebo, over 7 days * Take 18 doses of heavy (deuterated) water (50 mL each) over 7 days, twice * Have blood drawn and saliva collected after an overnight fast on four mornings over the course of the study * Undergo insulin suppression tests (IST) to assess the degree of insulin resistance at the end of each 1-week study period * Consume their total calculated daily caloric needs as divided into three meals per day Researchers will compare blood tests at the beginning and end of each 1-week study period in participants randomized (like the flip of a coin) to receive either placebo followed by diazoxide or placebo followed by placebo, to see how the drug treatment affects de novo lipogenesis, serum insulin, plasma glucose, and other serum lipid parameters (triglycerides, free fatty acids), among others.

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 overnight, while participants are asleep and fasting (not eating or drinking other than water) and while consuming a standardized diet of nutritional beverages during the following day. The objective is to evaluate the effect of lowering insulin levels, while maintaining constant mild hyperglycemia, on plasma glucose and lipid levels.

Wake Forest Alzheimer's Disease Clinical Core

Efforts to find treatments for AD have yielded only modest benefits, likely because longstanding AD pathological processes induce irreversible neurological compromise. These processes begin years before the onset of clinical symptoms. This possibility has been incorporated into a model describing stages of AD development, articulated by the NIA/Alzheimer's Association preclinical workgroup of which the Co-Director of the Kulynych Alzheimer's Research Center, Dr. Suzanne Craft, was a member. According to this model, the best hope for countermanding the effects of AD lies in intervening at the earliest possible point in the pathological cascade. There are several important ongoing efforts in adults with preclinical AD that directly target amyloid aggregation. Although this strategy addresses an important aspect of the AD pathological cascade, we believe that addressing metabolic dysfunction affecting glucose and insulin regulation offers a complementary approach, in that it may reduce amyloid burden and toxicity, while also directly enhancing synaptic health, brain metabolism, tau regulation and neurovascular function. The purpose of the ADCC is to identify and characterize early risk factors that predict cognitive decline and dementia in asymptomatic adults and adults with early signs of cognitive impairment. The data obtained from this study, collected at enrollment and follow-up will allow us to examine disease trajectory in individuals with and without prediabetes and other measures of glucoregulatory dysfunction in this process. The enrollees, who will be well-characterized with regard to cognitive and metabolic status through ADCC assessments, will provide an important resource for other local (institution) and national investigations. Data collected from participants enrolled in the ADCC will be stored indefinitely for future investigations.

Enhancing Mental and Physical Health of Women Veterans

Women Veterans are the fastest growing segment of VA users. This dramatic growth has created challenges for VA to ensure that appropriate services are available to meet women Veterans' needs, and that they will want and be able to use those services. The EMPOWER QUERI 2.0 Program is a cluster randomized type 3 hybrid implementation-effectiveness trial testing two strategies designed to support implementation and sustainment of evidence-based practices for women Veterans in at least 20 VA facilities from 4 regions.

Human Models of Selective Insulin Resistance: Pancreatic Clamp

This is a single-center, prospective, randomized, controlled (crossover) clinical study designed to investigate the impact of lowering insulin levels on hepatic glucose production (HGP) vs de novo lipogenesis (DNL) in people with insulin resistance. The investigators will recruit participants with a history of overweight/obesity and evidence of insulin resistance (i.e., fasting hyperinsulinemia plus prediabetes and/or impaired fasting glucose and/or Homeostasis Model Assessment of Insulin Resistance \[HOMA-IR\] score \>=2.73), and with evidence of metabolic dysfunction-associated steatotic liver disease (MASLD). Participants will undergo two pancreatic clamp procedures -- one in which serum insulin levels are maintained near hyperinsulinemic baseline (Maintenance Hyperinsulinemia or "MH" Protocol) and the other in which serum insulin levels are lowered by 50% (Reduction toward Euinsulinemia or "RE" Protocol). In both clamps the investigators will use stable-isotope tracers to monitor hepatic glucose and triglyceride metabolism. The primary outcome will be the impact of steady-state clamp insulinemia on HGP vs DNL.

Effects of Sweetener Consumption on Risk Factors for Heart Disease in Prediabetic Subjects

The aim of this prospective interventional study is to investigate the metabolic effects of consuming artificial and natural sweeteners in persons with prediabetes. Prediabetes is a condition characterized by blood sugar levels that are elevated above normal but not yet meeting the criteria for type 2 diabetes. This condition markedly increases the risk of progressing to type 2 diabetes, which in turn can lead to complications including cardiovascular diseases. Artificial sweeteners such as saccharin and sucralose, as well as natural sugar substitutes like erythritol, are increasingly used as alternatives to sugar and are recommended for individuals at cardiometabolic risk - including overweight individuals, patients with prediabetes, or diabetics - to help reduce caloric intake. Recent literature has reported possible negative associations between artificial sweeteners and blood sugar regulation in healthy subjects (1). Additionally, effects on various blood cells have been observed. For example, erythritol has been shown to alter platelet function leading to increased reactivity in healthy study participants following consumption (2). However, the impact of alternative sweeteners on metabolic processes and their effects on blood coagulation in patients with prediabetes-a population at increased risk-has not been systematically studied. In this planned interventional study, 80 patients meeting laboratory criteria for prediabetes will be randomly assigned to one of four groups, each receiving a different intervention for two weeks: saccharin, sucralose, erythritol, or a control group receiving water. The doses reflect the acceptable daily intake or known doses that are considered safe. After enrollment, participants will visit the study center 2 times: before starting the intervention and after completing the intervention. During these visits, biological samples such as blood, urine, and stool will be collected to study metabolism, gut bacteria, immune and blood cell function. Tests will include an oral glucose tolerance test, coagulation tests, and additional blood analyses. Additionally, participants will wear a glucose monitor to track blood sugar fluctuations during the intervention. The investigators hypothesize that consumption of alternative sweeteners negatively affects blood sugar regulation and insulin sensitivity in patients with prediabetes. Furthermore, this study will explore how the candidate sweeteners influence the gut microbiome, blood cells and other metabolic factors in this population.

Use of Empagliflozin to Treat Prediabetes

The overall purpose of this study is to identify how empagliflozin (a drug commonly used to treat type 2 diabetes) impacts skeletal muscle metabolic health among adults with prediabetes. Our aims are to: 1) Test the ability of empagliflozin to improve regulation of glucose metabolism (i.e., blood sugar) among overweight and obese individuals at risk for diabetes, and 2) Identify mechanisms to explain how empagliflozin may improve skeletal muscle glucose metabolism. We hypothesize empagliflozin will improve regulation of glucose metabolism due to changes in whole-body and skeletal muscle metabolism (e.g., increased rates of whole-body fat oxidation, evidence of impaired skeletal muscle mitochondrial respiratory function and increased energetic stress, lower accumulation of skeletal muscle lipids and improved skeletal muscle insulin signaling compared with placebo treatment).

Enhancing Mental and Physical Health of Women Veterans 3.0

Women Veterans are the fastest growing segment of VA users, with most users in midlife. This dramatic growth has created challenges for VA to ensure that appropriate services are available to meet women Veterans' needs, and that they will want and be able to use those services. Furthermore, few VA improvement efforts have focused on women Veterans' health and health care in midlife. The EMPOWER QUERI 3.0 Program is a cluster randomized type 3 hybrid implementation-effectiveness trial testing two strategies designed to support implementation and sustainment of evidence-based practices for women Veterans in at least 18 VA facilities from 4 regions.

Feasibility of a Nutrition Intervention for Patients With Prediabetes at a Federally Qualified Health Center

The purpose of the study is to assess the feasibility and acceptability of incorporating hands-on nutritional demonstrations to enhance the Diabetes Prevention Program (DPP) curriculum among patients who are at-risk for prediabetes

Investigation of Metformin in Pre-Diabetes on Atherosclerotic Cardiovascular OuTcomes

This research will help us to learn if the medicine called metformin reduces the risk of death, heart attacks, and/or strokes in Veterans who have pre-diabetes and heart or blood vessel problems.

Sleep for Health Study on the Effects of Cognitive Behavioral Therapy for Insomnia on Diabetes Risk

This study tests whether providing cognitive behavioral therapy for insomnia (CBT-I) to people with prediabetes results in a reduction in glucose levels compared to a patient education control program.

Role of Aging and Individual Variation in Exercise Training Responsiveness

The primary purpose of this study is to assess the effects of aging on markers of physical reserve and exercise-induced adaptations in resilience in older adults who completed a structured exercise program within the last 15 years (Parent trial: STRRIDE-PD; NCT00962962). This feasibility pilot study will enroll up to 26 participants to complete a 6-month aerobic exercise intervention.

Time-restricted Eating, Window Timing, Type 2 Diabetes Status and Sex on Glycemic Control

This study will evaluate the effectiveness of time-restricted eating (TRE), which is a form of intermittent fasting. When performing TRE, individuals consume all of their calories within a specific time window and then only consume water or other no calorie drinks the rest of the day. TRE is performed each day. There is no restriction on the quality or amount of food that people can consume during their eating window (ad libitum eating) with TRE, which can last anywhere from 4 to 12 hours. We are comparing three different 9-hour eating windows to determine whether the start and stop time of the eating window impact blood sugar control in individuals with obesity who also have or are at risk for type 2 diabetes. We also aim to determine if there are differences in the effects of the timing of eating window between males and females.

OXXYNEA® GS: Study for Glycaemia Management

The aim of this study is to develop a proof of concept establishing a causal relationship between glycemia improvement through combination of polyphenols-rich botanical extracts or polyphenols-rich botanical extracts associated with white kidney bean extract and chromimum picolinate + zinc bisglycinate with chronic supplementation. Chronic glycemia improvement will be assessed by following the evolution of HbA1c, postprandial glucose and insulin kinetics, and questionnaires. The study design is double blinded randomized with 3 arms and 29 volunteers per arm.

Heat and Exercise in Aging as Therapy (HEAT)

The main goal of this two-phase clinical trial is to learn whether local heat therapy, using heat pads applied to the legs, can enhance skeletal muscle health, physical function, and blood sugar control in a manner comparable to exercise, specifically High-Intensity Interval Training (HIIT), in older individuals with prediabetes. The study aims to answer the following questions: 1. Does local heat therapy improve muscle architecture (e.g., muscle cross-sectional area, capillary density, mitochondrial content), glucose tolerance, and frailty indicators similarly to HIIT in older individuals with prediabetes? 2. Does local heat therapy as a pre-conditioning method enhance the skeletal muscle response to HIIT in older individuals with prediabetes?

Restoring 24-hour Substrate Rhythmicity to Improve Glycemic Control by Timing of Lifestyle Factors

Exercise is well-known to improve skeletal muscle energy metabolism and is an established intervention to improve muscle insulin sensitivity and to counter the development of type 2 diabetes (T2D). However, given the 24h rhythmicity in substrate metabolism previously observed in healthy, lean men and the lack of such rhythmicity in men with insulin-resistance, the investigator hypothesize that appropriate timing of exercise training can maximize the metabolic health effects of exercise. Indeed, a preliminary study in humans revealed that afternoon high-intensity interval training (HIIT) exercise was more effective than morning exercise in improving 24h blood glucose levels in men with T2D. Another recent study in mice showed that the time of day is a critical factor in augmenting the beneficial effects of exercise on the skeletal muscle metabolome as well as on whole-body energy homeostasis. However, human studies that specifically target the impact of timing of exercise training on glucose homeostasis and metabolic health are scarce and the potential underlying mechanisms largely unknown. The overarching goals of this project is to improve 24-hour rhythmicity of metabolism in men and women with prediabtes by appropriate timing of exercise and to assess its effect on metabolic health and immune response. Acute and prolonged exercise interventions timed in the morning vs late afternoon will be carried out in individuals with prediabetes to determine whether acute exercise in the afternoon and prolonged exercise training in the afternoon can improve peripheral insulin sensitivity, compared to exercise in the morning, and positively affect adipose tissue dietary fatty acid storage and partitioning of dietary fatty acids in skeletal muscles.

PreventT2 Together: Examining the Efficacy of Couple-based Lifestyle Intervention to Prevent Type 2 Diabetes

Nearly half of adults in the United States have or are at risk of developing type 2 diabetes. The overall goal of this community-engaged research is to examine the efficacy of an innovative couple-based lifestyle intervention to prevent type 2 diabetes that is applicable to a broad range of partnered adults in the United States. By simultaneously targeting lifestyle and perceived support from romantic partners, there is a high likelihood of creating lasting changes in both

Effect of Zinc on Glucose Homeostasis

The purpose of this investigation is to evaluate the impact of zinc supplementation on fasting glucose levels, hemoglobin A1c (HbA1c), and other indices of glucose homeostasis in individuals with prediabetes. The investigators hypothesize that prediabetic subjects receiving zinc will demonstrate a greater decrease in HbA1c and blood glucose compared to prediabetic subjects receiving placebo. Specific Aim: Conduct a prospective, double-blind randomized clinical trial comparing the effects of 12 months of zinc supplementation (zinc gluconate 30 milligram \[mg\] per day) versus placebo on glucose homeostasis. Based upon expected effect size and power calculations, and anticipating a 20% drop-out rate, the investigators will study 200 prediabetic subjects (100 per group) using a 1:1 randomization design. HbA1c, fasting plasma glucose, and other measures will be obtained at 0, 6, and 12 months and will be compared between zinc supplementation and placebo groups.

Exercise Training and Fat Metabolism in Postmenopausal Women

Adipose tissue turnover plays a critical role in body weight maintenance, and obesity is underscored by the dysregulated balance between fat breakdown and synthesis. Although there are clear health-related benefits of physical activity, little is known about how resistance exercise, as opposed to endurance exercise, can reduce the risk of metabolic disorders, particularly in women. The goal of the proposed study is to investigate the effectiveness of resistance training to improve basal and stimulated fat metabolism in postmenopausal women with obesity and pre-diabetes, potentially serving as a viable and practical approach to prevent the onset of type 2 diabetes.

Genetics of the Acute Response to Oral Semaglutide

The study aims to investigate the genetic basis of the response to short-term (3 months) orally administered semaglutide treatment, in terms of improving metabolic parameters, including the hormonal response to a standardized meal, and changes in body composition and liver steatosis. In the study, parameters such as fasting and 2-hour glucose during OGTT, HbA1c, body fat mass, body weight, total cholesterol, HDL and LDL, triglycerides, HOMA-IR, Matsuda Index and liver steatosis will be assessed. All the patients will undergo genome-wide genotyping. Moreover, in a subset of participants, muscle and fat biopsies will be performed, before and after the treatment, and liver, muscle and pancreas fat content will be assessed using MRI.

Effectiveness of the Brazilian Diabetes Prevention Program

The aim of this multicenter, randomized controlled trial is to assess the effectiveness of the Brazilian Diabetes Prevention Program (delivered face-to-face or via e-health) in preventing type 2 diabetes (T2D) in at least 1,590 adults at high risk of T2D over a 3-year follow-up period. Our outcomes include the incidence of T2D, body weight (kg), BMI, glycemic biomarkers, use of antidiabetic drugs, the proportion of individuals achieving controlled glycemia or HbA1c levels without medication, diet quality, moderate-to-vigorous physical activity (min/week), prevalence of physical inactivity, sleep quality, perceived stress, alcohol consumption, smoking, and quality of life. In addition, social, cultural, educational, and geographical factors at the community level will be analyzed throughout the follow-up to determine their association with the incidence of T2D.

Antidiabetic Effect of Olive Pomace Oil

This clinical trial aims at assessing whether consumption of olive pomace oil in the diet may benefit persons with type 2 diabetes mellitus or persons at risk of developing the disease (prediabetic persons). The main questions the study aims to answer are: * May olive pomace oil prevent a high increase of blood glucose levels when consumed in a meal together with carbohydrates in diabetic/prediabetic patients? * May olive pomace oil decrease fasting blood glucose levels of diabetic/prediabetic patients after consuming it daily? * May daily consumption of olive pomace oil improve glucose homeostasis and other alterations like elevated blood lipids or inflammation, which also affect persons with diabetes or prediabetes? Researchers will compare the effect of consuming olive pomace oil to the effects of a comparison oil (high-oleic acid sunflower oil). Participants will: In different days, they will consume white bread alone or the oils (olive pomace oil, high-oleic acid sunflower oil or extra virgin olive oil) spread on white bread and blood will be collected at different times during 2 h. This study to observe the increase of blood glucose after a carbohydrate-rich breakfast will be part of the so-called "postprandial" study, and will be conducted during 3 weeks, during which participants will consume corn oil on a daily basis. Participants will also take part in the "chronic" study, that will last 22 weeks in total. During this study, they will firstly "wash" the effects of the oil they normally consume in their diets by consuming corn oil during 3 weeks. It is during these weeks when they will attend the Human Nutrition Unit (HNU) of ICTAN to carry on the "postprandial" study described in the previous paragraph. After the initial 3 weeks, participants will consume olive pomace oil as the only oil in their diets during 8 weeks, "wash" its effects again by consuming corn oil during 3 weeks and then change to consume the other oil (high-oleic acid sunflower oil) during 8 weeks. During the chronic study, they will visit the clinic once every 4 weeks for checkups and tests. They will refrain from eating other oils or specific fat-rich foods. Participants will also attend our phone calls to ask them what they ate the day before on different weeks during the study, and wear an accelerometer during 1 week to record their physical activity. They will keep a diary of the doses of insulin/metformin used and the blood glucose levels they measured at home.

Efficacy of High-intensity Exercise in Women With Prediabetes

About 382 million of adults in the world have Diabetes type 2 (DT2), and it is foreseen that this number will increase to 592 million in 2035. International Diabetes Federation (IDF) (2017) established that 352 million adults around 20 and 79 years old (which is 7,3% of that population), could be classified as prediabetes. This last is characterized by the resistance to insulin of skeletal muscle, of the liver and/ or adipose tissue, provoking the excessive e insulin secretion of β cells and pancreatic exhaustion which produce severe hyperglycemia. The High-intensity interval training (HIIT) can increase the oxidation ability, relating directly to insulin sensibility.

Plant Sterols on Cardiovascular Markers, Microbiota and Sterol Metabolism (Cardiofoodsterol)

Potential cholesterol-lowering effect of a regular intake of a plant sterol (PS)-containing food supplement, in overweight/obese type 1 or 2, normoglycemic/pre-diabetic, with LDL-cholesterol values \> 115 mg/dl and not pharmacologically treated participants treated with the PS-containing food supplement or placebo supplement.