6 Clinical Trials for Various Conditions
The overall goal of this study is to develop a new and practical way to prevent the development of Hypoglycemia Associated Autonomic Failure (HAAF), which is unawareness of hypoglycemia (low blood sugar) in individuals with diabetes. Previous studies suggest that two medications, naloxone and diazoxide, may increase the body's ability to respond to episodes of low blood sugar and prevent the development of HAAF (or hypoglycemia unawareness). Only healthy subjects are being recruited for this study. The study has three distinct phases. In the first phase, healthy, non-diabetic individuals who are susceptible to developing HAAF are identified. Only these individuals will be studied in the second and third phases. The second phase of this study evaluates the effect of using a naloxone nasal spray versus a placebo nasal spray in improving the body's response to episodes of low blood sugar and in preventing the development of HAAF. The third phase of this study evaluates the effect of using naloxone nasal spray and diazoxide in combination, compared to naloxone nasal spray plus a placebo (for diazoxide) or diazoxide plus a placebo (for naloxone) in improving the body's response to episodes of low blood sugar and in preventing the development of HAAF.
Exercise is a cornerstone of diabetes management. It helps reduce blood pressure, promote weight loss, lower insulin resistance and improve glucose and lipid (triglyceride and HDL-cholesterol) profiles. Unfortunately, the benefits of exercise are often not embraced by diabetic individuals because of the fear of low blood sugar (hypoglycemia). My laboratory has demonstrated that Autonomic nervous system (ANS) counterregulatory failure plays an important role in exercise associated hypoglycemia in Type 1 DM. ANS responses are significantly reduced in Type 1 DM and are further blunted by antecedent episodes of hypoglycemia. Furthermore, there is a large sexual dimorphism of reduced ANS responses during submaximal exercise in both Type 1 DM and healthy individuals that is unexplained. Accumulating data are demonstrating that serotonergic pathways can regulate ANS discharge. Generally, serotonergic pathways are inhibitory but both single and longer term administration of selective serotonin reuptake inhibitors (SSRI's) such as Prozac has been demonstrated to increase basal epinephrine levels and enhance baroreflex control of Sympathetic nervous system (SNS) activity. What is unknown is whether fluoxetine can also enhance SNS responses and also override the large ANS sexual dimorphism present during sub maximal exercise. Therefore, the purpose of this study is to determine if the SSRI fluoxetine (Prozac) can improve SNS responses during exercise.
Intensive glucose control in type 1 diabetes mellitus (T1DM) is associated with clear health benefits (1). However, despite development of insulin analogs, pump/multi-dose treatment and continuous glucose monitoring, maintaining near-normal glycemia remains an elusive goal for most patients, in large part owing to the risk of hypoglycemia. T1DM patients are susceptible to hypoglycemia due to defective counterregulatory responses (CR) characterized by: 1) deficient glucagon release during impending/early hypoglycemia; 2) additional hypoglycemia-associated autonomic failure (HAAF) and exercise-associated autonomic failure (EAAF) that blunt the sympathoadrenal responses to hypoglycemia following repeated episodes of hypoglycemia or exercise as well as degrading other CR; and 3) hypoglycemia unawareness (HU), lowering the threshold for symptoms that trigger behavioral responses (e.g. eating). Thus, the risk of hypoglycemia in T1DM impedes ideal insulin treatment and leads to defaulting to suboptimal glycemic control (2). There are two approaches that could resolve this important clinical problem: 1) perfection of glucose sensing and insulin and glucagon delivery approaches (bioengineered or cell-based) that mimic normal islet function and precisely regulate glucose continuously, or 2) a drug to enhance or normalize the pattern of CR to hypoglycemia. Despite much research and important advances in the field, neither islet transplantation nor biosensor devices have emerged as viable long-term solutions for the majority of patients (3, 4). Over the past several years, our lab has explored the approach of enhancing CR by examining mechanisms responsible for HAAF/EAAF and searching for potential pharmacological methods to modulate the CR to hypoglycemia (5-11). Our work has led to a paradigm shift in the field of hypoglycemia, exemplified by the novel hypothesis and published experimental data supporting a role for opioid signaling that resulted in the initiation of exploratory clinical trials by other research groups.
Elevations of plasma cortisol, a stress hormone, during prior episodes of low blood sugar (hypoglycemia) appear to be responsible for the deficient responses during subsequent hypoglycemia. Our specific aim is to determine if dehydroepiandrosterone (DHEA), a hormone with anti-corticosteroid actions, can prevent hypoglycemia associated autonomic failure in type 1 diabetic volunteers.
It is unclear what effect selective serotonin reuptake inhibitors (SSRIs) have on hypoglycemia. Thus, the American Hospital Formulary Service recommends careful monitoring of blood glucose levels in all patients with diabetes initiating or discontinuing SSRIs (Katz et al., 1996). Because of the increased prevalence of depression in those with diabetes, it is critical to discover what affect the antidepressant therapy may have on counterregulatory responses to hypoglycemia. This study hypothesizes that chronic administration of SSRIs may result in a blunted counterregulatory response to hypoglycemia, thereby leaving individuals more susceptible to hypoglycemia.
Alprazolam (Xanax) will blunt the body's ability to defend itself from low blood sugar.