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Carvedilol in Treating Hypoglycemia Unawareness

Primary Purpose

Hypoglycemia Unawareness

Status
Terminated
Phase
Phase 2
Locations
United States
Study Type
Interventional
Intervention
Carvedilol 3.125 mg
Carvedilol 2.5 mg
Placebo capsule
Sponsored by
Owen Chan, PhD
About
Eligibility
Locations
Arms
Outcomes
Full info

About this trial

This is an interventional treatment trial for Hypoglycemia Unawareness focused on measuring Type 1 Diabetes Mellitus, β-blocker

Eligibility Criteria

18 Years - undefined (Adult, Older Adult)All SexesDoes not accept healthy volunteers

Inclusion Criteria:

  • History of Type 1 diabetes mellitus for more than 5 years
  • Age > 18 years
  • Presence of impaired hypoglycemia awareness/unawareness
  • Intensive insulin treatment as defined by multiple daily insulin injections (3 or more) or insulin pump therapy
  • Negative pregnancy test
  • Able to provide informed consent and willing to sign an approved consent form that conforms to federal and institutional guidelines

Exclusion Criteria:

  • Major medical disorders (including liver disease, cardiovascular disease, kidney disease, chronic obstructive pulmonary disease, asthma, active malignancy or HIV)
  • Overt diabetes complications (neuropathy, nephropathy, retinopathy)
  • Presence of anemia
  • Current or recent use of beta-blocker therapy
  • Use of diuretics
  • Allergies or contraindications to beta-blockers or heparin
  • Use of benzodiazepines
  • Alcohol, drug or medication abuse
  • Frequent use of acetaminophen

Sites / Locations

  • University of Utah

Arms of the Study

Arm 1

Arm 2

Arm 3

Arm Type

Experimental

Experimental

Placebo Comparator

Arm Label

Carvedilol 3.125 mg

Carvedilol 2.5 mg

Placebo capsule

Arm Description

After enrollment, participants will be placed on continuous glucose monitoring (CGM). One week after CGM placement, participants will undergo the first hypoglycemic clamp study to obtain baseline measures of hypoglycemia frequency, hypoglycemia awareness scores and hormone responses. Following the initial clamp procedure, participants will receive 4 weeks of low-dose carvedilol treatment. After 4 weeks of treatment, the participants will undergo a second hypoglycemic clamp session.

After enrollment, participants will be placed on continuous glucose monitoring (CGM). One week after CGM placement, participants will undergo the first hypoglycemic clamp study to obtain baseline measures of hypoglycemia frequency, hypoglycemia awareness scores and hormone responses. Following the initial clamp procedure, participants will receive 4 weeks of low-dose carvedilol treatment. After 4 weeks of treatment, the participants will undergo a second hypoglycemic clamp session.

After enrollment, participants will be placed on continuous glucose monitoring (CGM). One week after CGM placement, participants will undergo the first hypoglycemic clamp study to obtain baseline measures of hypoglycemia frequency, hypoglycemia awareness scores and hormone responses. Following the initial clamp procedure, participants will receive 4 weeks of placebo treatment. After 4 weeks of treatment, the participants will undergo a second hypoglycemic clamp session.

Outcomes

Primary Outcome Measures

Change in Hypoglycemia Symptom Score
Participants will complete the Edinburgh Hypoglycemia Symptom questionnaire at baseline and after the 4-week treatment period. The average change in hypoglycemia symptom score will be compared between the carvedilol and placebo groups.

Secondary Outcome Measures

Change in Blood Glucagon
Blood samples will be drawn from study participants at baseline and after the 4-week treatment period during the clamp procedure. The average change in blood glucagon level will be compared between the carvedilol and placebo groups.
Change in Blood Epinephrine
Blood samples will be drawn from study participants at baseline and after the 4-week treatment period during the clamp procedure. The average change in blood epinephrine level will be compared between the carvedilol and placebo groups.
Change in Blood Norepinephrine
Blood samples will be drawn from study participants at baseline and after the 4-week treatment period during the clamp procedure. The average change in blood norepinephrine level will be compared between the carvedilol and placebo groups.
Change in Blood Cortisol
Blood samples will be drawn from study participants at baseline and after the 4-week treatment period during the clamp procedure. The average change in blood cortisol level will be compared between the carvedilol and placebo groups.
Change in Blood Growth Hormone
Blood samples will be drawn from study participants at baseline and after the 4-week treatment period during the clamp procedure. The average change in blood growth hormone level will be compared between the carvedilol and placebo groups.
Frequency of CGM-Determined Hypoglycemic Episodes
The number of hypoglycemic episodes as determined by CGM will be determined during the 4-week treatment period and compared to the 1-week pre-study baseline period.

Full Information

First Posted
May 15, 2018
Last Updated
November 10, 2020
Sponsor
Owen Chan, PhD
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1. Study Identification

Unique Protocol Identification Number
NCT03538015
Brief Title
Carvedilol in Treating Hypoglycemia Unawareness
Official Title
The Use of Low-Dose Carvedilol to Improve Hypoglycemia Awareness in Patients With Type 1 Diabetes Mellitus
Study Type
Interventional

2. Study Status

Record Verification Date
November 2020
Overall Recruitment Status
Terminated
Why Stopped
Sponsor was impacted by COVID-19 and did not have sufficient funds to continue.
Study Start Date
April 22, 2019 (Actual)
Primary Completion Date
August 10, 2020 (Actual)
Study Completion Date
August 10, 2020 (Actual)

3. Sponsor/Collaborators

Responsible Party, by Official Title
Sponsor-Investigator
Name of the Sponsor
Owen Chan, PhD

4. Oversight

Studies a U.S. FDA-regulated Drug Product
Yes
Studies a U.S. FDA-regulated Device Product
No
Product Manufactured in and Exported from the U.S.
No
Data Monitoring Committee
No

5. Study Description

Brief Summary
Type 1 diabetes mellitus (T1DM) can lead to cardiovascular, renal and neurological complications if left poorly-controlled over prolonged periods of time. However, lowering glycemic goals for diabetic patients increases their risk for hypoglycemia exposure. Hypoglycemia is associated with symptoms such as heart palpitations, fatigue, shakiness, anxiety, confusion, and blurred vision. Recurrent hypoglycemia leads to impairment of the body's autonomic and symptomatic responses to this condition, and can result in loss of awareness in the patient of the hypoglycemic state. Repeated incidences of hypoglycemia from loss of this awareness can result in even more hypoglycemic episodes and more severe outcomes, such as loss of consciousness, accidents, hospitalization and even death if left untreated. The aim of this study is to investigate whether adrenergic blockade through the use of low-dose carvedilol treatment can improve hypoglycemia awareness and the counterregulatory hormone responses to hypoglycemia in T1DM patients with impaired awareness of hypoglycemia.
Detailed Description
Hypoglycemia elicits a multifaceted hormonal response that helps restore glycemic levels to normal. As blood glucose levels start to fall, insulin secretion ceases. At the top of this hierarchy of counterregulatory responses are glucagon and epinephrine which are the two principal hormones that act rapidly to increase glucose production and inhibit glucose utilization to raise plasma glucose levels back to normal. In cases of prolonged and/or more severe hypoglycemia, growth hormone and cortisol are mobilized to stimulate the synthesis of gluconeogenic enzymes and inhibit glucose utilization. In non-diabetic individuals, glucagon and epinephrine are usually very effective and the latter responses are rarely required in the acute situation. In contrast, impaired glucose counterregulation presents itself in longstanding diabetes and with antecedent hypoglycemia. Within the first five years after the onset of T1DM, the primary defense against hypoglycemia, the release of glucagon, either becomes significantly attenuated or is completely absent in diabetic patients and this impairment appears to be specific for the stimulus of hypoglycemia. Hence, patients with diabetes primarily depend on the release of epinephrine as their main defense against hypoglycemia. Unfortunately, with longer duration of diabetes and especially with poor glycemic control, epinephrine secretion is also compromised, making these patients even more vulnerable to the threat of hypoglycemia. In patients with diabetes, hypoglycemia arises from the interplay of a relative excess of exogenous insulin and defective glucose counterregulation and it remains a limiting factor in attaining proper glycemic management. Both the Diabetes Control and Complications Trial (DCCT) conducted in Type 1 patients and the United Kingdom Prospective Diabetes Study (UKPDS) conducted in Type 2 patients, have established the importance of maintaining good glucose control over a lifetime of diabetes to avoid cardiovascular, renal and neurological complications. However, lowering glycemic goals for diabetic patients increases their risk for hypoglycemia exposure. According to the DCCT, T1DM patients put on intensive insulin therapy, though having improved outcomes for diabetic complications, are at a 3-fold higher risk of experiencing severe hypoglycemia compared to those on conventional insulin therapy. Moreover, recent antecedent hypoglycemia reduces autonomic (epinephrine) and symptomatic (which normally prompts behavioral defenses such as eating) responses to subsequent bouts of hypoglycemia. Thus begins the vicious cycle of recurrent hypoglycemia (RH) where hypoglycemia leads to further impairment of counterregulatory responses which tin turn, begets more hypoglycemia and so forth. Because of the imperfections of current insulin therapies, those patients attempting to achieve glycemic control suffer an untold number of asymptomatic hypoglycemic episodes. Current estimates of symptomatic hypoglycemic episodes range form 2-3 incidences per week on average and severe, debilitating episodes occur one or twice each year. Therefore, developing therapies to prevent or eliminate hypoglycemia is of great importance. Sensors that detect changes in blood glucose levels and initiate glucose counterregulatory responses have been identified in both the periphery and within the brain. These sensors have been localized to the hepatic portal vein, the carotid body and the brain. In the brain, the dominant sensors are located in the hypothalamus. While peripheral glucose sensors may play a role in mediating the immediate counterregulatory responses to hypoglycemia, it is thought that glucosensors located within the brain may have a redundant regulatory and/or modulatory role in regulating glucose counterregulatory responses. It is well established that brain glucose sensors are crucial for detecting falling blood glucose levels and for initiating counterregulatory responses. These sensors are located in the hindbrain, the lateral hypothalamus, the paraventricular nucleus, the dorsal hypothalamus and the ventromedial hypothalamus (VMH). The neurons within the VMH contain much of the same glucose sensing machinery as the pancreatic β-cells. To date, two main types of glucose sensing neurons have been identified in the brain - those that increase their firing rate in response to increases in glucose levels, the "glucose-excited" (GE) neurons and those that decrease their firing rate in response to increases in glucose levels, the "glucose-inhibited" (GI) neurons. The mechanism by which GE neurons sense changes in blood glucose concentrations is believed to be similar to that used by pancreatic β-cells whereas GI neurons respond to decreases in ambient glucose levels through activation of the metabolic fuel sensor, AMP kinase (AMPK), and closure of chloride channels that result in increased activity of GI neurons. Although many of these sensing components have been identified, it is still not entirely clear how glucose sensing neurons regulate counterregulatory hormone release. It has been proposed that alterations in the firing rates of VMH glucose sensing neurons in response to glucose or fuel deficits can inhibit (as is the case for GE neurons) or stimulate (as is the case for GI neurons) the exocytosis of vesicles containing neurotransmitters that can modulate the counterregulatory hormone response. The inhibitory neurotransmitter, GABA, and the stimulatory neurotransmitters, glutamate and norepinephrine (NE), act within the VMH to suppress or stimulate the counterregulatory responses to hypoglycemia, respectively. In response to an initial bout of hypoglycemia, VMH GABA levels decrease while glutamate and NE levels increase, allowing for activation of the counterregulatory hormone responses. While these studies underscore the importance of VMH neurotransmitter signaling in regulating glucose homeostatic mechanisms, to date, the mechanisms that lead to their dysregulation in models of counterregulatory failure are not entirely clear. Recent evidence suggests that lactate, which serves as an alternate fuel substrate in the brain, plays an important role in precipitating the defects noted above. Lactate produced from neighboring astrocytes can supplement higher energy requirements during periods of increased neuronal activity or when glucose supply is limited. If this is the case, then lactate can be used in place of glucose as a fuel for VMH glucose sensing neurons, preventing them from detecting a fall in glucose levels, causing (inhibitory) GABA tone to be enhanced and (stimulatory) glutamate output to be reduced. Together, these actions ultimately suppress the release of counterregulatory hormones. In recent years, it has been shown that lactate levels are sensed by the brain and more specifically, can act in the hypothalamus to regulate glucose homeostasis, appetite and body weight. Lactate prevents the activation of hypothalamic neurons during glucose deprivation and more pertinent to this application, attenuates glucose counterregulatory responses to hypoglycemia when locally administered into the VMH. Data from the investigator's research group revealed VMH extracellular lactate concentrations are elevated in RH and diabetic animals and in particular, these conditions also increase expression of the lactate transporter in the VMH. When VMH lactate uptake is pharmacologically inhibited, neurotransmitter and counterregulatory responses improve in both RH and diabetic animals, suggesting lactate plays an important role in dysregulating neurotransmitter systems in the VMH, which in turn, impairs counterregulatory responses. Preliminary data suggests that therapeutic strategies that can reduce brain lactate levels, may help restore hypothalamic glucose sensing mechanisms and the counterregulatory response to hypoglycemia. Hence, identifying the mechanisms that increase VMH lactate levels may lead to suitable therapeutic strategies to prevent hypoglycemia. Norepinephrine can enhance lactate production from astrocytes and it can also increase the uptake of lactate into neurons through the activation of β2-adrenergic receptors (β2AR), potentially helping to coordinate both the supply and uptake of lactate into neurons. Normally, in response to an acute bout of hypoglycemia, VMH NE levels rise and act through β2ARs to enhance the sympathoadrenal response. Although activation of VMH β2ARs augments the counterregulatory response during acute bouts of hypoglycemia, less is known about the effects of RH on this neurotransmitter system. It has been reported that VMH NE levels are not altered by successive bouts of hypoglycemia, suggesting activation of the VMH NE system is not dampened by RH and that its suppressive effects on counterregulatory hormone release may lie downstream of NE release. In support of this finding, adrenergic blockade during antecedent bouts of hypoglycemia was shown to prevent counterregulatory failure in healthy human subjects. Therefore, while acute activation of VMH adrenergic receptors may be beneficial in its capacity to enhance the counterregulatory response, repeated activation of this neurotransmitter system may contribute to counterregulatory failure, but the mechanisms by which this occurs have not been fully identified. To evaluate whether repeated activation of the VMH NE system contributes to counterregulatory failure, NE was microinjected into the VMH of non-diabetic, hypoglycemia-naive rats for 3 hours/day for 3 consecutive days before subjecting the animals to a hypoglycemic glucose clamp on day 4. Repeated activation of the VMH NE system in the absence of hypoglycemia, increased VMH lactate levels and more importantly, blunted the counterregulatory hormone responses to hypoglycemia. This phenomenon was recapitulated with microinjection of salbutamol, a short-acting β2AR agonist, into the VMH using the same protocol as for NE, suggesting the suppressive effects of NE are mediated through VMH β2ARs. In a subgroup of animals treated with NE, uptake of lactate into neurons was blocked immediately prior to the hypoglycemic clamp. In this group, the suppressive effects of NE treatment on glucose counterregulation were completely abolished. Hence, preliminary data suggests that repeated activation of the VMH NE system plays a role in the development of counterregulatory failure, in part by enhancing central lactate production and therefore, the use of β-adrenergic blockers may be a promising treatment to preserve the responses to hypoglycemia. Preliminary data show that RH rats treated with low doses of the non-specific β-blocker, carvedilol, during the induction of RH, required less exogenous glucose during the hypoglycemic clamp compared to RH animals treated with vehicle. More importantly, reductions in VMH lactate levels and significant improvements in the counterregulatory hormone responses to hypoglycemia in the carvedilol-treated RH animals were observed. Carvedilol is a third generation non-selective, vasodilating β-blocker, which is FDA-approved for the treatment of congestive heart failure and hypertension. Carvedilol mainly blocks β2- and β1-adrenergic receptors and some α1-adrenergic receptors. Due to its lipophilic nature, carvedilol readily crosses the blood-brain barrier. As the brain is the primary target, this beneficial pharmacokinetic property of carvedilol improves central nervous system bioavailability, allowing lower doses to be used to deliver treatment to the brain. With lower doses, the potential for side effects stemming from unnecessary exposure of peripheral tissues to high levels of β-adrenergic blockade can be reduced. This study is designed to evaluate the effectiveness of low-dose carvedilol treatment for 4 weeks as a treatment for restoring the counterregulatory hormone responses to hypoglycemia and improve hypoglycemia awareness in T1DM patients.

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Hypoglycemia Unawareness
Keywords
Type 1 Diabetes Mellitus, β-blocker

7. Study Design

Primary Purpose
Treatment
Study Phase
Phase 2
Interventional Study Model
Parallel Assignment
Model Description
Double-blinded, randomized, placebo-controlled study in patients with Type 1 diabetes mellitus and hypoglycemia unawareness
Masking
ParticipantInvestigator
Allocation
Randomized
Enrollment
1 (Actual)

8. Arms, Groups, and Interventions

Arm Title
Carvedilol 3.125 mg
Arm Type
Experimental
Arm Description
After enrollment, participants will be placed on continuous glucose monitoring (CGM). One week after CGM placement, participants will undergo the first hypoglycemic clamp study to obtain baseline measures of hypoglycemia frequency, hypoglycemia awareness scores and hormone responses. Following the initial clamp procedure, participants will receive 4 weeks of low-dose carvedilol treatment. After 4 weeks of treatment, the participants will undergo a second hypoglycemic clamp session.
Arm Title
Carvedilol 2.5 mg
Arm Type
Experimental
Arm Description
After enrollment, participants will be placed on continuous glucose monitoring (CGM). One week after CGM placement, participants will undergo the first hypoglycemic clamp study to obtain baseline measures of hypoglycemia frequency, hypoglycemia awareness scores and hormone responses. Following the initial clamp procedure, participants will receive 4 weeks of low-dose carvedilol treatment. After 4 weeks of treatment, the participants will undergo a second hypoglycemic clamp session.
Arm Title
Placebo capsule
Arm Type
Placebo Comparator
Arm Description
After enrollment, participants will be placed on continuous glucose monitoring (CGM). One week after CGM placement, participants will undergo the first hypoglycemic clamp study to obtain baseline measures of hypoglycemia frequency, hypoglycemia awareness scores and hormone responses. Following the initial clamp procedure, participants will receive 4 weeks of placebo treatment. After 4 weeks of treatment, the participants will undergo a second hypoglycemic clamp session.
Intervention Type
Drug
Intervention Name(s)
Carvedilol 3.125 mg
Other Intervention Name(s)
Coreg
Intervention Description
Participants will receive a 3.125 mg oral dose of carvedilol twice daily during the 4-week treatment period
Intervention Type
Drug
Intervention Name(s)
Carvedilol 2.5 mg
Other Intervention Name(s)
Coreg
Intervention Description
Participants will receive a 2.5 mg oral dose of carvedilol twice daily during the 4-week treatment period
Intervention Type
Drug
Intervention Name(s)
Placebo capsule
Intervention Description
Participants will receive a matching oral dose of placebo capsule twice daily during the 4-week treatment period
Primary Outcome Measure Information:
Title
Change in Hypoglycemia Symptom Score
Description
Participants will complete the Edinburgh Hypoglycemia Symptom questionnaire at baseline and after the 4-week treatment period. The average change in hypoglycemia symptom score will be compared between the carvedilol and placebo groups.
Time Frame
Baseline and 4 Weeks
Secondary Outcome Measure Information:
Title
Change in Blood Glucagon
Description
Blood samples will be drawn from study participants at baseline and after the 4-week treatment period during the clamp procedure. The average change in blood glucagon level will be compared between the carvedilol and placebo groups.
Time Frame
Baseline and 4 Weeks
Title
Change in Blood Epinephrine
Description
Blood samples will be drawn from study participants at baseline and after the 4-week treatment period during the clamp procedure. The average change in blood epinephrine level will be compared between the carvedilol and placebo groups.
Time Frame
Baseline and 4 Weeks
Title
Change in Blood Norepinephrine
Description
Blood samples will be drawn from study participants at baseline and after the 4-week treatment period during the clamp procedure. The average change in blood norepinephrine level will be compared between the carvedilol and placebo groups.
Time Frame
Baseline and 4 Weeks
Title
Change in Blood Cortisol
Description
Blood samples will be drawn from study participants at baseline and after the 4-week treatment period during the clamp procedure. The average change in blood cortisol level will be compared between the carvedilol and placebo groups.
Time Frame
Baseline and 4 Weeks
Title
Change in Blood Growth Hormone
Description
Blood samples will be drawn from study participants at baseline and after the 4-week treatment period during the clamp procedure. The average change in blood growth hormone level will be compared between the carvedilol and placebo groups.
Time Frame
Baseline and 4 Weeks
Title
Frequency of CGM-Determined Hypoglycemic Episodes
Description
The number of hypoglycemic episodes as determined by CGM will be determined during the 4-week treatment period and compared to the 1-week pre-study baseline period.
Time Frame
5 Weeks

10. Eligibility

Sex
All
Minimum Age & Unit of Time
18 Years
Accepts Healthy Volunteers
No
Eligibility Criteria
Inclusion Criteria: History of Type 1 diabetes mellitus for more than 5 years Age > 18 years Presence of impaired hypoglycemia awareness/unawareness Intensive insulin treatment as defined by multiple daily insulin injections (3 or more) or insulin pump therapy Negative pregnancy test Able to provide informed consent and willing to sign an approved consent form that conforms to federal and institutional guidelines Exclusion Criteria: Major medical disorders (including liver disease, cardiovascular disease, kidney disease, chronic obstructive pulmonary disease, asthma, active malignancy or HIV) Overt diabetes complications (neuropathy, nephropathy, retinopathy) Presence of anemia Current or recent use of beta-blocker therapy Use of diuretics Allergies or contraindications to beta-blockers or heparin Use of benzodiazepines Alcohol, drug or medication abuse Frequent use of acetaminophen
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Owen Chan, Ph.D.
Organizational Affiliation
University of Utah
Official's Role
Principal Investigator
Facility Information:
Facility Name
University of Utah
City
Salt Lake City
State/Province
Utah
ZIP/Postal Code
84132
Country
United States

12. IPD Sharing Statement

Plan to Share IPD
No

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Carvedilol in Treating Hypoglycemia Unawareness

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