Clinical Research Directory

Diagnosing and Treating Low Blood Sugar Levels

Hypoglycemia is the term used to refer to lower than normal levels of blood sugar. This study will continue to research the causes of hypoglycemia. Patients involved in the study will be admitted to the Clinical Center of the National Institutes of Health and undergo tests for evaluating blood sugar. Patients will be required to refrain from eating for a set period of time and will undergo blood tests for insulin levels and several other specific diagnostic tests related to insulin secretion. The patients will be under supervision and will be provided with appropriate medical and surgical attention as needed.

A Study to Investigate Safety and Effectiveness of Porcine Pancreatic Cells (OPF-310) in Patients With Type 1 Diabetes Mellitus

This study is First In Human study for Encapsulated Porcine Islet Cells for Xenotransplantation (OPF-310). The purpose of this study to assess the safety, tolerability, and efficacy of OPF-310 transplantation and to define the recommended Phase 2 dose (RP2D) in adult subjects with unstable Type 1 Diabetes Mellitus (T1DM) and a level 3 (severe) hypoglycemic episode at least three times within the 1 year prior to enrollment despite treatment with a closed loop system (CLS) for at least 6 months.

FEAR of HYPOGLYCEMIA in PATIENTS WITH DIABETES

Fear of hypoglycemia has a significant impact on both medication and dietary adherence in individuals with diabetes. Through avoidance behaviors, it can disrupt metabolic control, prevent the achievement of glycemic targets, and increase the risk of long-term complications. Therefore, monitoring only biochemical parameters is insufficient in diabetes management. It is crucial for healthcare professionals to systematically assess the fear of hypoglycemia.

Effect of C-peptide on Hypoglycemic Counterregulation

Iatrogenic hypoglycemia is the most prominent barrier to the safe, effective management of blood sugar in people with type 1 diabetes due to periodic over-insulinization. During insulin-induced hypoglycemia, glucagon secretion is diminished in type 1 diabetes which, in turn, reduces hepatic glucose production and increases the depth and duration of hypoglycemic episodes. We have observed that the naturally occurring protein C-peptide increases glucagon secretion in dogs during insulin-induced hypoglycemia, which increases hepatic glucose production; the experiments in this application will shed light on the translation of this finding to the human.

Monitoring Exhaled Breath to Noninvasively Detect Glycemic Events

The purpose of this study is to determine whether an array of biosensors can noninvasively identify hyperglycemic or hypoglycemic events in persons diagnosed with diabetes through noninvasive detection of volatile organic compounds in exhaled breath.

Hypoglycemia and the Gut Microbiome

This study is designed to evaluate individuals who are currently experiencing symptoms of hypoglycemia, in order to discern correlations between microbiome composition and patterns of postprandial glycemia.

Mechanisms of Hypoglycemia in Patients Without Diabetes

The goal of this study is to identify physiologic and molecular mechanisms that underlie hypoglycemia in the absence of diabetes (or medications that can cause hypoglycemia) and to investigate potential genetic and microbiome differences which contribute to hypoglycemia. We will test the hypothesis that hypoglycemia in the absence of diabetes is linked to genetic variation or the microbiome, and identify whether additional medical history or diagnoses are enriched in the population of patients with hypoglycemia.

Glucagon Dose-Response in Patients With Post-Bariatric Hypoglycemia

The purpose of the study is to determine how blood sugar levels in individuals with and without hypoglycemia after bariatric surgery respond to different doses of glucagon, a hormone that is usually present in your body that regulates blood sugar levels. In this study, there will be 4 visits to the clinical research center. In the first visit, medical history and physical exam will be performed, and blood samples will be taken to assess overall health. During visit 2, a continuous glucose monitor will be placed under the skin. (This may be combined with visit 1, depending on the schedule of visits.) In visit 3, we will test the effect of a total of 4 different doses of glucagon, in increasing doses. In visit 4, we will test the effect of a total of 3 doses of glucagon, in decreasing doses. For both visit 3 and 4, we will infuse labeled stable glucose to allow us to measure how much glucose the body is making, and will measure levels of hormones which regulate glucose, such as insulin and glucagon.

Continuous Glucose Monitoring Devices in Hospitalized Veterans With Diabetes

More than 25% of the patients admitted in the general wards have a history of Diabetes Mellitus (DM). Up to 30% of the hospitalized diabetics develop hypoglycemia (low glucose values); a condition that is associated with seizures, cardiac arrhythmias, and even death. In Veterans, the prevalence is disproportionally higher. It is estimated that 40-50% of hospitalized Veterans are diabetics. In this clinical trial the investigators describe the development of a novel system, the Glucose Telemetry System (GTS), with which glucose values can be wirelessly transmitted from the patient's bedside to a monitor device at the nursing station. The goal of this work is to develop a more effective glucose surveillance system at the general wards, which can decrease hypoglycemia in the hospital and improve clinical outcomes.

"Sexual Activity and Hypoglycemia Risk in Adults With Type 1 or Type 2 Diabetes Using Insulin Therapy and Continuous Glucose Monitoring"

This observational study examines whether sexual activity influences the risk of hypoglycemia in adults with type 1 or type 2 diabetes treated with insulin therapy and using continuous glucose monitoring (CGM). Many patients report fear of hypoglycemia during or after sexual activity, which may affect their quality of life and willingness to engage in intimate relationships. However, no systematic research has been conducted on this topic, largely due to the sensitive nature of sexual health and the previous lack of tools to remotely monitor glucose profiles. The study uses CGM systems (LibreView or Dexcom Clarity) to evaluate glucose changes during and up to 6 hours after sexual activity. Participants will mark the start of sexual activity in their CGM application using a neutral symbol (such as a heart icon). Data will be collected remotely through secure, certified platforms without the need for discussing details of intimate life. Glucose profiles from days with and without sexual activity will be compared. Each participant will be observed for 3 months. The study will include 100 adults with type 1 or type 2 diabetes who use CGM and insulin therapy. By analyzing episodes of glucose levels below 70 mg/dL during or after sexual activity, the study aims to determine whether sexual activity is associated with an increased risk of hypoglycemia. Findings may help to better understand patient concerns, reduce unnecessary fear, and develop future clinical recommendations for safe sexual activity in individuals treated with insulin.

External Carotid Blood Flow in Individuals With Post-Bariatric Hypoglycemia

This is a pilot study (small-scale study) that aims to understand more about how blood flow changes in people who have low blood sugar after bariatric surgery (post-bariatric hypoglycemia) compared to those who have had surgery without hypoglycemia, those who have hypoglycemia without surgery, or those who do not experience low blood sugar. This study has two phases. This is the first phase, and the purpose is to test comfort and feasibility of a novel in-ear wearable device (Lumia Health) that measures blood flow changes to the head. Information from the study will help the investigators determine if the device is suitable to be used in the second phase of the study.

Frequency of Hypoglycemia in Children With Beta-blocker Treated Long QT-syndrome

The goal of this observational study is to investigate the frequency and characteristics of hypoglycemic episodes in children with long QT syndrome (LQTS) and beta-blocker treatment, specifically those receiving propranolol, compared to healthy controls. The study focuses on children under seven years with genetically confirmed LQTS and beta-blocker therapy, as well as healthy siblings as controls. The main questions it aims to answer are: * Does hypoglycemic episodes occur in children with LQTS who are treated with propranolol? * Are there asymptomatic episodes of low blood glucose that could affect well-being and neurological development? * Are there individual differences in susceptibility to hypoglycemia, and do genetic factors explain these differences? * What is the incidence of hypoglycemia leading to emergency visits or hospitalizations among LQTS patients compared to healthy controls? Researchers will compare children with LQTS on propranolol to healthy siblings to see if the frequency and severity of hypoglycemia differs between groups. Participants will: Have a Dexcom G7 continuous glucose monitor installed to record glucose profiles for ten days, both during an healthy episode and during an infection (when risk for hypoglycemia is increased). If differences in susceptibility to hypoglycemia are observed, genetic data from the Helsinki biopank will be analyzed to explore potential genetic factors underlying these differences. Visits to emergency clinic and hospitalizations due to hypoglycemia will be retrospectively reviewed for all LQTS patients under 16 years old and compared to healthy controls. Additional Details: The study is conducted at Helsinki University Hospital (HUH) Children and Adolescents and the New Children's Hospital clinical research unit. The study aims to recruit 20-40 LQTS patients and 10 healthy controls. The study is ethically justified, with no extra laboratory tests or costs for participants, and written consent will be obtained from parents and capable children. The results are expected to improve the safety of propranolol treatment in LQTS children by identifying risk factors for hypoglycemia and informing preventive strategies, such as dietary guidance, use of glucose monitoring devices during illness, or considering selective beta-blockers for high-risk patients.

Differing Levels of Hypoglycemia

Hypoglycemia can produce a spectrum of pro-inflammatory and pro-atherothrombotic changes. To date no studies appear to have investigated the effects of differing levels of hypoglycemia on the vasculature and pro-atherothrombotic balance during hypoglycemia in healthy man. The specific aim of our study will be to determine the effects of differing levels of hypoglycemia on in-vivo vascular biologic mechanisms in a healthy population.

Endoscopic Ultrasound-guided Large Diameter Lumen-apposing Metal Stent Gastro-gastrostomy for Bypass Reversal in Patients With Roux-en-y Gastric Bypass

The primary objective of this open-label pilot study is to investigate whether an endoscopically placed lumen apposing metal stent is an effective alternative to surgery in patients that have a clear indication for reversal of their gastric bypass.

Role of Neural and Hormonal Regulation Factors on Insulin Secretion After Gastric Bypass Surgery

RYGB (roux-en-y gastric bypass) has been reported to reverse type 2 diabetes (T2DM) immediately after surgery before any significant weight loss. In addition, a growing number of patients have been recognized with life-threatening hyperinsulinemic hypoglycemia several years following their surgery. While the mechanisms by which RYGB improves glucose metabolism or alters islet cell function in patients after RYGB are not understood, recent studies suggest that increased secretion of GI hormones, primarily glucagon-like peptide 1 (GLP-1), as well as alteration in neural activity may contribute to enhanced insulin secretion in general, and to a greater extent in patients with hypoglycemia. The proposed research is designed to address the role of RYGB on insulin secretion by evaluating the contribution of stimulatory factors (neural and GI hormone) on islet cell function and the islet cell responsiveness to the physiologic stimulatory factors, in RYGB patients with and without hypoglycemia and non-operated controls.

Diabetes Clinical Decision Support

The purpose of this study is to determine the impact of an electronic medical record clinical decision support tool on rates of dysglycemia in the hospital, and its clinical and economical outcomes. The study also evaluates the perspectives of providers regarding the tool's usefulness on disease management support, knowledge, and practice performance.

Evaluating Glial Acetate Metabolism as a Biomarker of Hypoglycemic Counterregulation

Hypoglycemic complications are a major impediment to the maintenance of healthy glucose levels in persons with diabetes. The investigators recently completed a clinical pilot and feasibility study (GLIMPSE, NCT02690168), which identified a novel biomarker, glial acetate metabolism, that appears to predict the susceptibility to hypoglycemia. By providing an assay to predict hypoglycemic events and therefore diabetic complications, the development of this biomarker could significantly improve the treatment of persons with diabetes. The goal of this study is to determine the efficacy of our biomarker for predicting susceptibility to insulin-induced hypoglycemia. In order to accomplish this goal the investigatiors will pair our 13C magnetic resonance spectroscopy procedure to assess glial acetate metabolism, developed in the GLIMPSE study, with a hyperinsulinemic-hypoglycemic clamp procedure, developed in the HYPOCLAMP study (NCT03839511). The two procedures will be separated by a three day interval. The investigators will then correlate the participants' rates of glial acetate metabolism with their neuroendocrine responses to the hypoglycemic clamp. This proof of concept study will test the hypothesis that glial acetate metabolism is inversely proportional to the neuroendocrine response to hypoglycemia, that is, as glial acetate metabolism increases the neuroendocrine response will decrease.

Enhancing Shared Decision-making to Guide Care for People With Dementia and Diabetes

Aim 1: Characterize shared decision-making and unmet patient-caregiver dyads needs for patients with diabetes and Alzheimer's Disease and related dementias (ADRD) while using a continuous glucose monitoring (CGM) device. Aim 2: Develop an interactive tool to enhance shared decision-making for diabetes management.

Safer Aging With Diabetes Monitoring

Older adults with type 2 diabetes are at higher risk for severe hypoglycemia and its related complications (including hospitalization and death) when taking insulin. This study proposes to evaluate, in a randomized clinical trial, a strategy of safe insulin prescribing based on an educational program that leverages continuous glucose monitoring to support older adults at high risk for hypoglycemia. If the aims of this project are achieved, this novel care strategy could be widely applied to reduce severe hypoglycemia episodes in older, high-risk adults with type 2 diabetes.

DiGESTnewborn Study

We wish to study the effect of a mothers sugar (glucose) control during pregnancy on her baby's sugar control after birth.

A Study of Glycemic Control in Left Ventricular Assist

The study is being conducted to understand if the hemoglobin A1c, a measurement of control of blood sugars over a 3-month time, is valid in patients with Left Ventricular Assist Devices (LVADs) in place. To understand whether it is an adequate measurement, the investigators will compare the A1c to results from a continuous glucose monitor (CGM) measurement of blood sugars. By monitoring blood sugars continuously, the investigators will also assess whether they can get better control of blood sugars with a CGM, including avoiding low blood sugars.

Adrenergic System in Islet Transplantation

To determine the effect of sympathetic neural and hormonal (epinephrine) input on islet cell hormonal responses to insulin-induced hypoglycemia in type 1 diabetic recipients of intrahepatic islet transplantation. We hypothesize that α-adrenergic (neural) blockage will abolish insulin-mediated suppression of C-peptide, attenuating α-cell glucagon secretion during hypoglycemia, and that β-adrenergic (hormonal) blockage will have no effect. Glucose counterregulatory responses will be measured during hyperinsulinemic euglycemic-hypoglycemic clamps on three occasions with randomized, double-blind administration of the α-adrenergic blocker phentolamine, the β-adrenergic blocker propranolol, or placebo. The demonstration of neural rather than hormonal regulation of the transplanted islet cell response to hypoglycemia is critical for understanding the mechanism for protection from hypoglycemia afforded by intrahepatically transplanted.

CGM-Assisted Management of PN

The purpose of this study is to learn more about changes in glucose levels in hospitalized infants with intestinal failure receiving parenteral nutrition or PN (nutrients delivered intravenously), as they transition from continuous PN (given 24 hours a day) to cycled PN (given less than 24 hours a day). There is an increased risk of glucose abnormalities with cycled PN, which can be harmful to infant growth and brain health. Continuous glucose monitors (CGM) will be used to measure interstitial glucose levels (in the tissue under the skin), which are similar to blood glucose levels. CGM is a small, minimally-invasive sensor worn on the thigh, which gives a glucose measurement every 5 minutes, and can help us understand changes in blood sugar levels without having to do a blood draw or fingerstick. CGM will be used during PN cycling for up to 30 days or until hospital discharge. If target GIR cycled PN is not reached following 3 sensor periods (up to 10 days per sensor), the parent/guardian will be approached to accept or decline participation in an optional extension phase. In the extension phase, the primary study will be repeated and CGM monitoring will continue until target GIR cycled PN is reached, up to an additional 3 sensor placements. CGM data will be hidden from the clinical team, there will be no change to routine clinical care. CGM may provide false low glucose readings when the tissue around the sensor is compressed (compression lows), such as when laying on the sensor during sleep. We will generate data during the study to help identify and filter the final dataset to remove likely compression lows. This study may help us understand how cycled PN affects glucose levels in infants with intestinal failure, which may help other children treated with cycled PN in the future.

Cardiac Arrhythmia in Patients with End-Stage Renal Disease

The study will examine the presence of cardiac arrhythmias in patients receiving hemodialysis and the role of diabetes, hypoglycemia and parameters related to uremia and the dialysis procedure. The study is designed as a prospective cohort study with 18 months follow-up. 70 patients receiving chronic hemodialysis will be recruited and equipped with implantable loop recorders (ILR): 35 patients with diabetes and 35 patients without diabetes. Data collection during the follow-up includes continuous monitoring of the heart rhythm by the ILR for the entire follow-up period, continuous glucose monitoring for 10 days every second month, and monthly collection of blood samples and dialytic parameters. After the initial 18-month follow-up, heart rhythm monitoring will continue until the ILR battery runs out for those participants who wish to continue.