Clinical Research Directory

Pulses Consumption and Its Role in Managing Systemic Inflammation, Insulin Sensitivity and Gut Microbiome in Human

Objective 1: Characterize indices of systemic inflammation and gut microbiota composition and function after chronic (12 weeks) intake of pulses compared to control diet in human OW/OB-IR participants. Objective 2: Characterize dietary- and microbial-derived metabolite pools after regular intake of pulses (12 weeks) in human participants with OW/OB-IR compared to control diet. Objective 3: Characterize cognitive functioning after chronic (12 weeks) intake of pulses compared to control diet in human OW/OB-IR participants.

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.

Mechanisms of Ultrasound Neuromodulation Effects in Diabetes

This study aims to evaluate the effect of hepatic ultrasound treatment on changes from baseline in whole-body insulin sensitivity during a hyperinsulinemic, euglycemic clamp (HE Clamp).

Topical Insulin for Ocular Surface Interface in Dry Eye Disease

This is a parallel randomized controlled trial for the treatment of dry eye disease. The main objective is to investigate the efficacy and safety of the use of insulin eye drops in the control of moderate-severe dry eye disease. Topical insulin drops will be compared to artificial tears in improving the ocular surface interface in patients with dry eye disease over 1 year period.

Effect of Dairy Products on Insulin Resistance

The objective of the study is to determine the effect of dairy consumption on insulin sensitivity in overweight and obese adults with prediabetes. Men and women (30-65 y) will be recruited from the greater Montreal area. Upon screening, those with prediabetes will complete a 2-wk run-in period in which participants will consume 1 serving/d of reduced-fat dairy. Adherent participants will be randomized by sex into 1 of 3 groups: ≤1 serving/d of dairy (limited dairy) or 2-3 servings/d of reduced-fat or regular-fat dairy for 12 weeks. Participants will be instructed on how to incorporate foods into their diet in a manner that prevents changes in their body weight. The hyperinsulinemic-euglycemic clamp will be used before and after the intervention to document potential changes in insulin sensitivity as the primary outcome. In addition, glycemic variables, body composition, and cardiometabolic risk factors will be assessed as secondary outcomes. Serum lipidomic and global gene expression responses to the intervention in subcutaneous adipose tissue will be measured as exploratory variables. Adherence to intervention will be assessed at each visit by food diaries, a record of consumed dairy products, and serum proportion of 15:0, 17:0, and t16:1n7 fatty acids as objective biomarkers of dairy fat intake.

Exploring the Anti-inflammatory Properties of Cannabis and Their Relevance to Insulin Sensitivity

This study tests the effects of cannabinoid levels in blood on inflammation and insulin sensitivity both acutely and chronically in individuals across the weight spectrum. To that end, the study employs two observational designs: 1) A study of acute effects with intermittent cannabis users and 2) A study in which current cannabis users will select one of three cannabis strains for four weeks and are compared to a matched control group who do not use cannabis to study chronic effects. Blood levels of THC and CBD, inflammatory biomarkers, and insulin resistance will be measured in both studies.

Effect of Sleep Extension on Ceramides in People With Overweight and Obesity

The overall goal is to determine how a sleep extension intervention (increasing time in bed) in individuals who maintain less than 6.5 hours sleep per night affects their plasma ceramides and insulin sensitivity. Participants will undergo a randomized controlled trial, with sleep extension (intervention) and healthy lifestyle (control) groups. The sleep extension is designed to increase participant's time in bed by 2 hours per night. Alternatively, the control group will receive basic health information (e.g., physical activity, goal setting, and nutrition when eating out).

Circadian Intervention to Improve Cardiometabolic Health

The overall goal is to examine the efficacy of a circadian intervention in people with overweight and obesity and habitual short sleep duration (HSSD). Participants will undergo a randomized controlled trial, with circadian intervention and control (healthy lifestyle) groups. The circadian intervention is designed to reduce nighttime light exposure and after-dinner snack food intake. Alternatively, the control group will receive basic health information (e.g., physical activity, goal setting, and nutrition when eating out).

Aging Resilience Through Microbiota Optimization and Regulation

Sarcopenia, characterized by the progressive loss of muscle mass and strength in older adults, is a key factor in health deterioration. It affects 15% of people between 65 and 80 years old and over 50% of those over 80, compromising autonomy and increasing the risk of diseases. Sarcopenia not only impacts muscle function but also bone health, mobility, and is associated with cardiometabolic diseases and cognitive decline. It has been proposed that changes in the gut microbiota in aging individuals, known as gut dysbiosis, contribute to sarcopenia. Species diversity decreases, and bacterial representation is altered, which could impair muscle function through various pathways, such as mitochondrial dysfunction, chronic inflammation, and disruption of protein synthesis. Muscle function loss is strongly associated with cognitive and metabolic impairment in older adults. Recently, it has been demonstrated that fecal microbiota transplantation (FMT) is an effective procedure for modulating gut microbiota and has proven highly effective in managing cases of Clostridium difficile-associated chronic diarrhea. The main objective of this project is to carry out FMT from young, physically active donors to a cohort of older adults to evaluate its effect on muscle, cognitive, and metabolic function. Why donors who exercise? There is growing evidence that gut microbiota diversity is increased in young, physically active individuals. The FMT is planned to be administered through lyophilized microbiota capsules. By restoring microbial diversity, it is expected to improve the quality and function of skeletal muscles, leading to greater cognitive and metabolic resilience. This project has great potential to develop an innovative approach for treating highly debilitating diseases that affect older adults, based on the lyophilization and encapsulation of gut microbiota from young, trained donors, which can be easily stored in a conventional freezer. Due to the high percentage of older adults worldwide and the high prevalence of sarcopenia within this age group, the aim of the project is to address a significant public health issue with a large target population eager for options to promote muscle health, functional autonomy, as well as cognitive and metabolic well-being.

A Study to Evaluate the Effect of Retatrutide on Insulin Secretion and Insulin Sensitivity in Adult Participants With Type 2 Diabetes Mellitus

The primary objective of Study GZQG is to compare the effect of retatrutide and placebo on total clamp disposition index (cDI) after 28 weeks of treatment.

Antecedent Metabolic Health and Metformin Aging Study

Aging is the number one risk factor for the majority of chronic diseases. There are no pharmaceutical treatments to slow aging and prolong healthspan. The anti-diabetic drug metformin is considered a likely pharmaceutical candidate to slow aging. In this study, the investigators hypothesize that metformin treatment in subjects free of type 2 diabetes will improve insulin sensitivity and glucoregulation in insulin resistant individuals, but will decrease insulin sensitivity and glucoregulation in insulin sensitive subjects. Further, the investigators hypothesize that long-term metformin treatment will remodel mitochondria in a way that decreases mitochondrial function in subjects that are insulin sensitive, but improves mitochondrial function in subjects that are insulin resistant. The investigators will use a dual-site, 12- week drug intervention trial performed in a double-blind, placebo-controlled manner on 148 subjects recruited from two separate sites (Oklahoma Medical Research Foundation (OMRF) and University of Wisconsin-Madison (UWM)). After consent and initial subject screening for chronic disease, subjects will be stratified to insulin sensitive (IS) or insulin resistant (IR) groups. Over a 12- week intervention, half of each group will take metformin and half will take a placebo. Pre- and post--intervention, subjects will complete a series of procedures to assess insulin sensitivity, glucose regulation, and biomarkers of aging. The same subjects will provide a skeletal muscle biopsy pre-- and post-intervention to assess the change in mitochondrial function and mitochondrial remodeling with and without metformin treatment. By completion of this project, the investigators expect to provide evidence that helps further delineate who may benefit from metformin treatment to slow aging.

Effect of Endoscopic Sleeve Gastroplasty in Patients With Obesity and MASH: A Randomized Controlled Trial

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common chronic liver disease globally. While weight loss through lifestyle modification is the standard treatment, most patients regain weight limiting ultimate improvement in liver disease. On the other end of the spectrum, bariatric surgery has shown promise in the treatment of MASLD/metabolic dysfunction-associated steatohepatitis (MASH) due to its efficacy in inducing weight loss. Nevertheless, its adoption has been hindered by the perceived invasiveness of surgery. Over the past decade, endoscopic sleeve gastroplasty (ESG) has gained recognition as a promising minimally-invasive approach to weight loss. The procedure involves utilizing a Food and Drug Administration (FDA)-authorized endoscopic suturing device to reduce the gastric volume by 70%. Studies reveal that ESG is associated with approximately 18.2% weight loss at one year after the procedure, with sustained results for at least 10 years. Nevertheless, the effect of ESG on MASH remains unknown. In this study, the investigators will compare ESG + lifestyle modification versus lifestyle modification alone in treating histologic MASH. The study will randomize patients to one of two different treatment options: ESG + lifestyle modification or lifestyle modification alone.

Acute Microbial Switch

In this project the investigators will test if it is possible to measure changes in intestinal gas production after supplementation of a complex fiber mixture over a 36 hour period in both lean normoglycemic individuals and individuals with insulin resistance and/or prediabetes with overweight when compared with a placebo Changes in intestinal gas production will also be related to energy expenditure, substrate metabolism, microbial composition and related metabolites in feces, blood and urine.

Saccharin and Acesulfame Potassium Consumption and Glucose Homeostasis in Older Adults With Prediabetes

Animal and observational research in humans suggest that specific types of non-nutritive sweeteners (NNS) may impair glycemic control. However, whether NNS consumption impacts glucose homeostasis in middle-aged/older adults with prediabetes is unknown, and potential mechanisms by which this could occur have yet to be identified. The overall objective of this R21 proposal is to establish proof-of-concept for alterations in glucose homeostasis following intake of saccharin, but not acesulfame potassium, in middle-aged/older adults with prediabetes compared to a eucaloric diet with no NNS.

Evaluation of Molecular Hydrogen Supplementation to Enhance the Efficacy of Weight Loss Retreat in Overweight and Obese Adolescents

This randomized controlled trial evaluates whether molecular hydrogen supplementation enhances the effectiveness of a 4-week weight loss retreat in overweight and obese adolescents. Outcome measures include: body composition, physical status, blood samples (insulin sensitivity, lipid profiles, markers of oxidative stress and inflammation) and autonomic nervous system function.

Improving Sleep Health and Circadian Timing to Support Cardiometabolic Health in Adolescents

Many teenagers get too little and late timed sleep. High body weight and diabetes are increasing in teenagers as well. This study plans to learn more about whether improving sleep habits can help improve how the body regulates blood sugar and energy use in teenagers who have higher body weight. To answer this question, the investigators plan to enroll teenagers who get \<7 hours of sleep on school nights and measure changes in blood sugars and energy use after two weeks of typical sleep (sleeping on their normal school schedule) and two weeks of a sleep intervention that includes spending longer time in bed at night, melatonin, and morning light.

Effect of Weight Loss on Intermuscular Adipose Tissue (IMAT) Signaling

The goal of this intervention study is to learn about how weight loss impacts molecular signaling of intermuscular adipose tissue (IMAT) in individuals with obesity. The main question it aims to answer is how inflammatory molecules secreted by IMAT promote muscle insulin resistance and inflammation, and how these same molecules are diminished after weight loss. Following screening visits involving body composition measures, blood testing, strength testing, and a thigh muscle biopsy, participants will go through a 12-week dietary intervention for weight loss. After 12 weeks, this will be followed by the same testing and biopsies that were completed before the intervention. Researchers will then compare outcomes of individuals who lost weight to individuals who did not lose weight.

Adaptive Immune Response in Visceral and Subcutaneous Fat: Role in Human Insulin Resistance

The proposed study is designed to test the hypothesis that in human obesity, the balance of pro- and anti-inflammatory T cells in fat tissue is in fact related to macrophage phenotype and insulin resistance, and how it is related. This study is needed to confirm whether conclusions based on studies of visceral adipose tissue in mice are indeed applicable to humans. We also want to determine the relationship between insulin resistance/hyperinsulinemia and ability to lose weight in obese individuals.

Low Dose Fat-Induced Insulin Resistance

The primary goal of this study is to determine the dose of fatty acids that acutely induces mild insulin resistance in healthy volunteers. We hypothesize that a low-dose of fatty acid infusion (Intralipid/heparin) will cause a mild insulin resistance. The dose of fatty acid infusion that reliably causes mild insulin resistance will be selected for use in future studies.

Metabolic Adaptations to Weight Loss With and Without Exercise

Study Purpose: The combination of caloric restriction and exercise is the most common first-line treatment for obesity-related disorders, yet we know very little about how these two very different treatments work together. A deeper understanding about mechanisms underlying the health benefits of adding exercise to a weight loss program will not only aid efforts to optimize more effective lifestyle interventions, but it can also uncover novel targets for the treatment/prevention of obesity-related diseases. Although a reduction in body fat is the fundamental adaptation to weight loss, we know almost nothing about the effects that adding exercise has on structural and functional changes within fat tissue that may further enhance metabolic health. This is very important because many obesity-related metabolic health complications are tightly linked with abnormalities in abdominal fat tissue. We argue exercise-induced modifications in abdominal fat tissue will reveal persistent health benefits even if some weight is regained Study Summary: 10% Weight Loss Phase - Subject participation in the study will involve a series of metabolic tests before, at midpoint, and after undergoing a 10% weight loss program (with or without exercise training depending on group randomization). During this, subjects will be randomized into one of two different experimental groups: 1. Moderate Intensity Continuous Training (MICT) exercise group 2. No exercise (control) group Follow-up Phase: After completing the metabolic testing post-weight loss, all study-related diet and exercise supervision will end and subjects will be free to make their own choices regarding diet and exercise/physical activity behavior. Subjects will then be asked to complete follow-up testing at 2-, 4- and 6- months post-weight loss. Total involvement in the study for each subject will likely be about 10-13 months (4-7 months during weight loss phase, 6 months during follow-up phase).

The Importance of Insulin Action in the Brain for the Immune System During Physical Activity-Overweight

The goal of this clinical trial is to clarify the interaction of central insulin action and physical activity with the immune system. Therefore, participants will undergo bicycle spiroergometer tests. This approach will be compared between days with insulin delivery to the brain as nasal spray and days with placebo spray. In another trial (NCT06552130) lean participants already have been tested. Significant effects on circulating cytokines could be identified. In this amendment, overweight persons in which brain insulin resistance is expected will be tested.

The Effect of Colchicine, on Insulin Sensitivity in Individuals With Type 1 Diabetes and Systemic Low-grade Inflammation

The aim for this clinical trial is to evaluate if colchicine in addition to standard of care improves insulin sensitivity in individuals with type 1 diabetes, systemic low-grade inflammaiton and reduced insulin sensitivity. The insulin sensitivity will be evaluated by a hyperinsulinemic, euglycemic clamp.

The Sweet Kids Study (Stevia on Weight and Energy Effect Over Time)

This is an 8 to14-week three-arm randomized controlled in children 8 to 12 years old. The main purpose of the study is to evaluate if stevia has benefits for weight control and metabolic function relative to caloric sweeteners, and whether it provides benefits in this regard similar to water.

Impact of Circulating and Tissue-specific Lipids on Vascular Function and Insulin Sensitivity in Chronic Night Shift Workers

People who experience repeated bouts of circadian misalignment, such as shift workers, are at higher risk of cardiovascular disease (CVD) and Type 2 diabetes (T2D) compared to daytime workers. However, the mechanism(s) by which shift work and associated circadian misalignment increase CVD and T2D risk are unknown. This project will examine whether elevated plasma lipids are a mechanism by which circadian misalignment impairs vascular function, insulin sensitivity, glucose homeostasis and muscle lipid accumulation, which could be targeted to prevent and treat cardiometabolic disease in people who chronically experience circadian misalignment, which includes more than 20% of the US workforce.