Insulin Sensitivity/Resistance

About 6.5 million adults in the United States who are 65 or older have dementia. While the exact cause of dementia is not known, it may be due to changes in the brain. Further, risk may be higher when the brain does not respond to insulin. Indeed, brain insulin resistance has emerged as a pathologic factor affecting memory, executive function as well as systemic glucose control. Regular aerobic exercise may help reduce the risk of dementia by increased blood flow to the brain and help the brain respond better to insulin. In addition, giving insulin through a nose spray (called intranasal insulin) may also help with thinking and memory. However, it is unknown if using both exercise and intranasal insulin is best for the brain.

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.

Reward learning and decision-making processes, which operate largely outside of conscious control, shape food choices and eating behaviors. Excess adiposity is associated with differences in brain structure and functional connectivity underlying these processes, and insulin resistance, which commonly co-occurs with excess adiposity, has been linked with dopamine signaling that is crucial for these processes. However, whether and how excess adiposity and insulin resistance affect reward learning and decision-making remains poorly understood. This study will address that gap, examining the effects of excess adiposity and insulin resistance, and their interaction, on processes of reward learning and decision-making in food-specific and general contexts.

A recognized driver for cardiovascular complications of type 2 diabetes mellitus (T2DM) is impaired plasma glucose homeostasis as consequence of skeletal muscle insulin resistance. Insulin-mediated plasma glucose disposal in skeletal muscle comprises oxidative glucose disposal (cellular glucose uptake for oxidation) and non-oxidative glucose disposal (NOGD; cellular glucose uptake for storage as glycogen), both processes being impaired in T2DM patients. Excessive intrahepatic fat accumulation (particularly monounsaturated (MUFA) and saturated (SFA)) is commonly observed in T2DM patients and tightly associates with plasma glucose dysregulation. It has been hypothesized that skeletal muscle insulin resistance redistributes circulating glucose away from muscle which together with hyperinsulinemia promotes intrahepatic lipid accretion via de novo lipogenesis (DNL). As saturated lipids is the final product of DNL, improving skeletal muscle insulin sensitivity, next to enhance plasma glucose homeostasis, might lower intrahepatic lipid content particularly intrahepatic saturated lipids. Regular exercise is a cornerstone in the treatment of T2DM and to improve skeletal muscle insulin sensitivity. Interestingly, a conventional exercise program (aerobic-type combined with strength-type exercise) restores insulin-stimulated oxidative glucose disposal in T2DM patients to levels observed in age-matched normoglycemic subjects. Non-oxidative glucose disposal (NOGD), however, does not improve upon such conventional exercise programs. In this regard, for full restoration of compromised glucose disposal, it is pivotal to come up with effective training methods to target NOGD. High intensity interval training (HIIT) has the potential to expands the glycogen synthesis capacity in athletes by repetitive cycles of glycogen depletion/repletion, hence holds promise to improve NOGD in T2DM patients. Of note, HIIT also lowers the intrahepatic fat content in pre-diabetes individuals. Nevertheless, whether HIIT reduces the intrahepatic fat content and modifies its composition in T2DM patients is unknown. In this regard, it is hypothesized that HIIT expands the NOGD capacity in skeletal muscle of overweight/obese type 2 diabetes patients. By doing so, it is postulated that HIIT improves skeletal muscle insulin sensitivity and therefore benefits the 24 hours glycaemic profile in T2DM patients. In line, it is hypothesized that the HIIT-mediated improvements on NOGD and skeletal muscle insulin sensitivity coexist with the reduction of intrahepatic lipid content -particularly reduced saturated lipids- via lowering DNL.

Every 3 minutes a new case of diabetes is diagnosed in Canada, mostly type 2 diabetes (T2D) increasing the risk for heart disease. T2D and heart disease share many common risk factors such as aging, obesity and unhealthy lifestyle. Paradoxically however, while lowering blood LDL, commonly known as "bad cholesterol", is protective against heart disease, research over the past 10 years have shown that the lower is blood LDL, the higher is the chance of developing T2D. This phenomena is happening whether blood LDL is lowered by a common drug against heart disease called Statins, or by being born with certain variations in genes, some of which are very common (\~80% of people have them). To date, it is unclear why lowering blood LDL is associated with higher risk for diabetes, and whether this can be treated naturally with certain nutrients. Investigators believe that lowering blood LDL by forcing LDL entry into the body tissue through their receptors promotes T2D. This is because investigators have shown that LDL entry into human fat tissue induces fat tissue dysfunction, which would promote T2D especially in subjects with excess weight. On the other hand, investigators have shown that omega-3 fatty acids (omega-3) can directly treat the same defects induced by LDL entry into fat tissue. Omega-3 is a unique type of fat that is found mostly in fish oil. Thus the objectives of this clinical trial to be conducted in 48 subjects with normal blood LDL are to explore if: 1. Subjects with higher LDL receptors and LDL entry into fat tissue have higher risk factors for T2D compared to subjects with lower LDL receptors and LDL entry into fat tissue 2. 6-month supplementation of omega-3 from fish oil can treat subjects with higher LDL receptors and LDL entry into fat tissue reducing their risk for T2D. This study will thus explore and attempt to treat a new risk factor for T2D using an inexpensive and widely accessible nutraceutical, which would aid in preventing T2D in humans.

This study investigates the potential of vericiguat, a soluble guanylate cyclase stimulator, to improve cardiometabolic health in obese Black individuals with insulin resistance by directly enhancing cyclic guanosine monophosphate (cGMP) activity. Given that this population has been shown to have lower cGMP activity and the association of lower cGMP activity with increased cardiometabolic disease risk, the proposed study hypothesizes that augmenting cGMP activity in obese individuals will improve insulin sensitivity and energy expenditure. This study is a placebo-controlled randomized trial involving 200 Black obese participants with insulin resistance, assessing the effects of vericiguat on insulin sensitivity, resting, and exercise-induced energy expenditure over 12 weeks. Additionally, it will explore changes in brown adipose tissue and gene expression related to energy metabolism in white adipose tissue, aiming to provide insights into how increasing cGMP activity may improve cardiometabolic health in Black obese individuals.

The goal of this intervention study is to learn more about what causes insulin resistance in otherwise healthy adults, and how short-term changes in physical activity or diet may influence it. The study includes healthy male and female participants aged 25 to 55 years, who meet specific health criteria. The main questions it aims to answer are: Does the cause of insulin resistance vary between individuals due to their genes and lifestyle? Can the investigators identify different types (sub-phenotypes) of insulin resistance at the molecular level? Researchers will compare groups who either reduce their physical activity for 14 days or consume a high-fat diet for 3 days, to see how these changes affect insulin sensitivity and related biological markers. Participants will: * Complete a health screening and be assessed for eligibility * Undergo baseline testing to measure insulin sensitivity, physical activity, diet, and metabolic health * Be randomly assigned to one of two short-term interventions (14 days of reduced physical activity, or 3 days of a high-fat, high-calorie diet) * Repeat selected tests after the intervention to assess changes This study will help researchers better understand how lifestyle and biology interact in the development of insulin resistance, even in people who are otherwise healthy.

The goal of this clinical trial is to investigate the efficacy of semaglutide on body weight, insulin dose requirements and improvements in glucose control and safety aspects in regards to risk of hypoglycemia and diabetic ketoacidosis for patients with established Type 1 Diabetes.

Black individuals are more likely to have decreased insulin sensitivity which results in a high risk for the development of cardiometabolic disease. The reasons for this are incompletely understood. Natriuretic peptides (NPs) are hormones produced by the heart that play a role in regulating the metabolic health of an individual. Low circulating level of NPs is an important contributor to increased risk for diabetes. The NP levels are relatively lower among Black individuals thus affecting their metabolic health and putting them at a higher risk for diabetes. This study aims to test the hypothesis that by augmenting NP levels using sacubitril/valsartan, among Black Individuals one can improve their metabolic health (as measured by insulin sensitivity \& energy expenditure) and help establish the role of NPs in the underlying mechanism behind increased risk for cardiometabolic disease in these population.

This observational study will evaluate the effect of puberty suppression on insulin sensitivity, metabolic rate and vascular health among transgender female youth at baseline and 6 months after initiation of a gondoatropin releasing hormone agonist compared to matched cisgender male controls.

Incretin mimetics are widely used pharmacological treatments for weight loss, known for their high efficacy and favorable safety profile. As the most commonly prescribed drug in this class, semaglutide is effective in both diabetic and non-diabetic individuals. However, treatment responses vary significantly, with non-diabetic individuals typically experiencing better weight loss outcomes. Despite this, up to 10% of non-diabetic individuals show little or no response to treatment, and the reasons for this variability remain unclear. The TRIM-IR study aims to investigate the role of insulin resistance (IR) in weight loss outcomes among non-diabetic obese individuals receiving semaglutide. This single-center, observational study will assess the impact of IR on weight loss, body composition, and adipose tissue function during the first 16 weeks of semaglutide therapy. The study will also explore molecular markers of adipose tissue dysfunction, focusing on the transition from dysfunctional to healthy adipose tissue. The investigators hypothesize, that individuals with lower IR will experience greater weight loss than those with higher IR, and that the glucose infusion rate (GIR) during hyperinsulinemic euglycemic clamp testing will correlate with weight loss variability. Secondary objectives include comparing changes in fat and lean mass, reductions in visceral fat, and improvements in adipose tissue function before and after 16 weeks of treatment. Exploratory analyses will assess adipocyte subpopulations and their response to insulin sensitivity changes. A total of 40 participants, equally distributed by gender, will be enrolled to ensure statistical power for detecting clinically relevant differences. The study aims to optimize semaglutide use for personalized obesity treatment and provide insights into the relationship between obesity, insulin resistance, and adipose tissue plasticity, with implications for improving obesity management and cardiovascular health outcomes.

The aim of this study is to investigate the relationship between body fat distribution measured by CT scan and related risk factors with the risk of incident metabolic and cardiovascular disease in a prospective cohort study of Japanese men and women. The investigators will also investigate novel risk factors for metabolic and cardiovascular disease using molecular weight-based metallomics analysis.

Epidemiological studies have revealed that 60-80% of women with breast cancer (BC) develop metabolic disorders that are similar to those observed in conditions like type 2 diabetes. These metabolic disorders, including insulin resistance, obesity, hyperinsulinemia, and glucose intolerance, are associated with increased BC recurrence and mortality. Skeletal muscle is the major site of glucose uptake in humans. The aims of the present project are to 1) determine the involvement of insulin resistance in skeletal muscle in the metabolic disorders prevalent in BC survivors, 2) identify BC-and/or treatment-induced molecular changes in skeletal muscle from BC survivors .