Type1diabetesEarly Phase 1NCT03079921
Adrenergic System in Islet Transplantation
A Early Phase 1 study testing Phentolamine and Propranolol in people with Type1diabetes and Hypoglycemia, run by University of Pennsylvania at 1 site in United States.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 21 to 65 years
- Conditions the study is for
- Type1diabetes, Hypoglycemia, Hypoglycemia Unawareness
- What is being tested?
- Phentolamine and Propranolol
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 9 participants
- Where
- 1 siteUnited States
- Study dates
- 20 Jan 2017to 31 Dec 2025
- Phase
- Early Phase 1
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 21 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- GROUP 1
- Male and female subjects age 21 to 65 years of age.
- Subjects who are able to provide written informed consent and to comply with the procedures of the study protocol.
- Clinical history compatible with type 1 diabetes with onset of disease at < 40 years of age and insulin-dependent for > 10 years at the time of islet transplantation > 6 months before study.
- Stable islet graft function defined by C-peptide > 0.5 ng/ml and insulin-independent or insulin-dependent with daily insulin requirement < 0.2 units/kg•d to maintain HbA1c < 7.0%.
- Use of standard immunosuppression consisting of tacrolimus with or without sirolimus or mycophenolic acid. Substitutions of tacrolimus with cyclosporine, and of sirolimus or mycophenolic acid with azathioprine are permissible if stable for over 3 months. Prednisone is allowable if no more than 5 mg daily.
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- Male and female subjects age 21 to 65 years of age.
- Subjects who are able to provide written informed consent and to comply with the procedures of the study protocol.
- Clinical history compatible with type 1 diabetes with onset of disease at < 40 years of age and insulin-dependent for > 10 years at the time of islet transplantation > 6 months before study.
- Stable islet graft function defined by C-peptide > 0.5 ng/ml and insulin-independent or insulin-dependent with daily insulin requirement < 0.2 units/kg•d to maintain HbA1c < 7.0%.
- Use of standard immunosuppression consisting of tacrolimus with or without sirolimus or mycophenolic acid. Substitutions of tacrolimus with cyclosporine, and of sirolimus or mycophenolic acid with azathioprine are permissible if stable for over 3 months. Prednisone is allowable if no more than 5 mg daily.
- Patients who meet all of the following criteria are eligible for participation in Group 3 of this study:
- Male and female subjects age 21 to 65 years of age.
- Subjects who are able to provide written informed consent and to comply with the procedures of the study protocol.
- Clinical history compatible with total pancreatectomy and autologous islet transplantation > 6 months before study.
- Stable islet graft function defined by C-peptide > 0.5 ng/ml and insulin-independent or insulin-dependent with daily insulin requirement < 0.2 units/kg•d to maintain HbA1c < 7.0%.
Who cannot join
- GROUP 1
- BMI ≥ 30 kg/m2.
- Insulin requirement of ≥ 0.2 units/kg•day.
- HbA1c ≥ 7.0%.
- Uncontrolled hypertension: systolic blood pressure > 160 mmHg or diastolic blood pressure > 100 mmHg.
- History of cardiovascular disease, including coronary artery, cerebrovascular or peripheral vascular disease, or current use of β-blocker therapy.
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- Bronchial asthma.
- Abnormal kidney function: Estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m2.
- Abnormal liver function: persistent elevation of liver function tests > 1.5 times the upper limit of normal.
- Untreated hypothyroidism, Addison's disease, or Celiac disease.
- Anemia: baseline hemoglobin concentration < 11 g/dl in women and < 12 g/dl in men.
- Presence of a seizure disorder not related to prior severe hypoglycemia.
- Use of glucocorticoids greater than 5 mg of prednisone daily, or an equivalent physiologic dose of hydrocortisone.
- For female participants of child-bearing potential: Positive pregnancy test, presently breast-feeding, or unwillingness to use effective contraceptive measures for the duration of study participation. Oral contraceptives, intra-uterine devices, Norplant®, Depo-Provera®, and barrier devices with spermicide are acceptable contraceptive methods; condoms used alone are not acceptable.
- Treatment with any anti-diabetic medication other than insulin within 4 weeks of enrollment.
- Use of any investigational agents within 4 weeks of enrollment.
- Any medical condition that, in the opinion of the PI, will interfere with the safe completion of the study
- GROUP 2
- BMI ≥ 30 kg/m2.
- Insulin requirement of ≥ 0.2 units/kg•day.
- HbA1c ≥ 7.0%.
- Uncontrolled hypertension: systolic blood pressure > 160 mmHg or diastolic blood pressure > 100 mmHg.
- Active cardiovascular disease, including coronary artery, cerebrovascular or peripheral vascular disease.
- Abnormal kidney function: eGFR < 60 ml/min/1.73 m2.
- Abnormal liver function: persistent elevation of liver function tests > 1.5 times the upper limit of normal.
- Untreated hypothyroidism, Addison's disease, or Celiac disease.
- Anemia: baseline hemoglobin concentration < 11 g/dl in women and < 12 g/dl in men.
- Presence of a seizure disorder not related to prior severe hypoglycemia.
- Use of glucocorticoids greater than 5 mg of prednisone daily, or an equivalent physiologic dose of hydrocortisone.
- For female participants of child-bearing potential: Positive pregnancy test, presently breast-feeding, or unwillingness to use effective contraceptive measures for the duration of study participation. Oral contraceptives, intra-uterine devices, Norplant®, Depo-Provera®, and barrier devices with spermicide are acceptable contraceptive methods; condoms used alone are not acceptable.
- Treatment with any anti-diabetic medication other than insulin within 4 weeks of enrollment.
- Use of any investigational agents within 4 weeks of enrollment.
- Any medical condition that, in the opinion of the PI, will interfere with the safe completion of the study
- GROUP 3
- BMI ≥ 30 kg/m2.
- Insulin requirement of ≥ 0.2 units/kg•day.
- HbA1c ≥ 7.0%.
- Uncontrolled hypertension: systolic blood pressure > 160 mmHg or diastolic blood pressure > 100 mmHg.
- Active cardiovascular disease, including coronary artery, cerebrovascular or peripheral vascular disease.
- Abnormal kidney function: eGFR < 60 ml/min/1.73 m2.
- Abnormal liver function: persistent elevation of liver function tests > 1.5 times the upper limit of normal.
- Anemia: baseline hemoglobin concentration < 11 g/dl in women and < 12 g/dl in men.
- Presence of a seizure disorder not related to prior severe hypoglycemia.
- Use of glucocorticoids greater than 5 mg of prednisone daily, or an equivalent physiologic dose of hydrocortisone.
- For female participants of child-bearing potential: Positive pregnancy test, presently breast-feeding, or unwillingness to use effective contraceptive measures for the duration of study participation. Oral contraceptives, intra-uterine devices, Norplant®, Depo-Provera®, and barrier devices with spermicide are acceptable contraceptive methods; condoms used alone are not acceptable.
- Treatment with any anti-diabetic medication other than insulin within 4 weeks of enrollment.
- Use of any investigational agents within 4 weeks of enrollment.
- Any medical condition that, in the opinion of the PI, will interfere with the safe completion of the study
Trial locations and contacts
1 site in 1 country.
United States1 site
University of Pennsylvania - Institute for Diabetes, Obesity and Metabolism
Philadelphia, Pennsylvania, 19104
About this study
Official title: Adrenergic Contribution to Glucose Counterregulation 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.
Read the detailed description
This study is designed to test the hypothesis that α-adrenergic (neural) blockade will abolish insulin-mediated suppression of C-peptide, attenuating α-cell glucagon secretion during hypoglycemia, and that β-adrenergic (hormonal) blockade 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 islets.
Glucose counterregulation has not been studied in type 1 diabetic recipients of extrahepatic islet transplantation. Comparison of glucose counterregulatory responses measured during hyperinsulinemic euglycemic-hypoglycemic clamps will be compared to those obtained from type 1 diabetic recipients of intrahepatic islet transplantation studied under the placebo condition above.
Glucose counterregulation has not been directly compared between recipients of intrahepatic auto- and allo-islet transplantation. Direct comparison of glucose counterregulatory responses under the same experimental conditions is required to understand whether mechanisms other than the glucagon response may be important to the reported hypoglycemia affecting pancreatectomized recipients of islet auto-transplantation.
- Being tested
- Phentolamine, Propranolol, Placebo
- Keywords
- Islet Graft Function, Islet Cell transplantation, Auto-islet transplantation, Intra-hepatic islets, Extra-hepatic islets
- Medical subject headings
- Hypoglycemia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PhentolamineDrug
Also called Regitine
Physiologic receptor blockade (α1-receptor).
PropranololDrug
Also called Inderal
Physiologic receptor blockade (β2-receptor).
PlaceboDrug
Also called Saline, Sodium Chloride Solution
100mL bag of Normal Saline Solution (NSS).
| Study group | Role | What they receive |
|---|---|---|
| Group 1-Propranolol Intra-hepatic islet | Active comparator | The dose of propranolol will be 0.48 μg/kilogram•minute, which will provide a total dose of 0.10 mg/kg. It will be administered 1 x only via intravenous infusion over 3.5 hours, starting 30 min before conduct of a hyperinsulinemic euglycemic (90 min) followed by hypoglycemia (90 min) clamp. Receives: Drug: Propranolol |
| Group 1-Phentolamine Intra-hepatic islet | Active comparator | The dose of phentolamine will be 0.95 μg/kg•min, which will provide a total dose of 0.20 mg/kg. It will be administered 1 x only via intravenous infusion over 3.5 hours, starting 30 min before conduct of a hyperinsulinemic euglycemic (90 min) followed by hypoglycemia (90 min) clamp. Receives: Drug: Phentolamine |
| Group 1- Placebo Intra-hepatic islet | Placebo comparator | Placebo in 100mL NSS. Infuse Intravenously at 0.0095 ML/KG/MIN. 1 x only via intravenous infusion over 3.5 hours, starting 30 min before conduct of a hyperinsulinemic euglycemic (90 min) followed by hypoglycemia (90 min) clamp. Receives: Drug: Placebo |
| Group 2 - Extra-hepatic islet | No intervention | Hyperinsulinemic euglycemic (90 min) followed by hypoglycemia (90 min) clamp only. |
| Group 3 - Intra-hepatic auto islet | No intervention | Hyperinsulinemic euglycemic (90 min) followed by hypoglycemia (90 min) clamp only. |
What is being measured
The primary outcome is the main question the study is designed to answer.
C-PEPTIDE Suppression During Hyperinsulinemia Euglycemia.
The primary outcome measures will be the levels of C-peptide during hyperinsulinemia euglycemia.
Measured: For C-peptide at the 60-90 minute time-point during the hyperinsulinemic euglycemic-hypoglycemic clamp.
GLUCAGON Activation During Hyperinsulinemia Hypoglycemia.
The primary outcome measures will be the levels of glucagon during hyperinsulinemia hypoglycemia.
Measured: For Glucagon at the 150-180 minute time-point during the hyperinsulinemic euglycemic-hypoglycemic clamp.
Secondary outcomes (3)
EPINEPHRINE During Hyperinsulinemia Hypoglycemia.
Secondary outcome measures will include levels of epinephrine during hyperinsulinemia hypoglycemia.
Measured: During metabolic testing in the 150-180 minute time-point of the hyperinsulinemic euglycemic-hypoglycemic clamp.
Rates of ENDOGENOUS GLUCOSE PRODUCTION During Hyperinsulinemia Hypoglycemia.
Secondary outcome measures will include rates of endogenous glucose production during hyperinsulinemia hypoglycemia
Measured: During metabolic testing in the 150-180 minute time-point of the hyperinsulinemic euglycemic-hypoglycemic clamp.
AUTONOMIC SYMPTOMS During Hyperinsulinemia Hypoglycemia
A questionnaire was administered every 15-30 min during the study to quantitate autonomic symptoms as the sum of scores ranging from 0 (none) to 5 (severe) for each of the following symptoms: anxiety, palpitations, sweating, tremor, hunger, and tingling. (6 symptoms)
Total scores range 0 - 30, where higher scores indicate greater autonomic symptoms.
Measured: The autonomic symptom score was calculated as the mean of scores at the two hypoglycemic time points during the clamp (165 and 180 minutes).
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Mar 2017
- Study start20 Jan 2017
- Primary completion30 Apr 2019
- Study completion31 Dec 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for Type1diabetesStudies of the same condition, open and under way.
- More trials run by University of PennsylvaniaThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Early Phase 1
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Factorial
- Model description
- This study is a within subject and across group mechanistic design. Islet cell hormonal responses to a hyperinsulinemic euglycemic-hypoglycemic clamp will be assessed in "Group 1" on three occasions with randomized, double-blind administration of the α-adrenergic blocker phentolamine, the β-adrenergic blocker propranolol, or placebo. Responses in "Group 1" under the placebo condition will be used for comparison to those obtained from hyperinsulinemic euglycemic-hypoglycemic clamp testing on one occasion in subjects in each of "Group 2" and "Group 3".
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 9 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Pennsylvania
- Sponsor type
- University, hospital or other
- Collaborators
- National Institutes of Health (NIH), National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
- Responsible party
- Principal investigator, Michael R. Rickels, MD, MS, University of Pennsylvania
- Investigators
- Michael R Rickels, MD., MS, Principal investigator, Division of Endocrinology, Diabetes & Metabolism, Perelman School of Medicine
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03079921
- Sponsor's protocol ID
- 826386
- Other IDs
- 2R01DK091331-06
- Status last verified
- Apr 2026
- First submitted
- 28 Feb 2017
- Last updated
- 27 Apr 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No: It is not yet known if there will be any further plan to make IPD available besides the Informed Consent.
Study at a glance
From the registry record, last updated by the sponsor on 27 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Adrenergic Contribution to Glucose Counterregulation in Islet Transplantation
- ClinicalTrials.gov ID
- NCT03079921
- Acronym / sponsor ID
- 826386
- Keywords
- Islet Graft Function, Islet Cell transplantation, Auto-islet transplantation, Intra-hepatic islets, Extra-hepatic islets
- Phase
- Early Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 9 participants (actual)
- Lead sponsor
- University of PennsylvaniaUniversity, hospital or other
- Collaborators
- National Institutes of Health (NIH), National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
- Study start
- 20 Jan 2017 (actual)
- Primary completion
- 30 Apr 2019 (actual)
- Study completion
- 31 Dec 2025 (actual)
- First posted
- 15 Mar 2017 (actual)
- Results
- Posted 27 Apr 2026
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
This study is designed to test the hypothesis that α-adrenergic (neural) blockade will abolish insulin-mediated suppression of C-peptide, attenuating α-cell glucagon secretion during hypoglycemia, and that β-adrenergic (hormonal) blockade 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 islets.
Glucose counterregulation has not been studied in type 1 diabetic recipients of extrahepatic islet transplantation. Comparison of glucose counterregulatory responses measured during hyperinsulinemic euglycemic-hypoglycemic clamps will be compared to those obtained from type 1 diabetic recipients of intrahepatic islet transplantation studied under the placebo condition above.
Glucose counterregulation has not been directly compared between recipients of intrahepatic auto- and allo-islet transplantation. Direct comparison of glucose counterregulatory responses under the same experimental conditions is required to understand whether mechanisms other than the glucagon response may be important to the reported hypoglycemia affecting pancreatectomized recipients of islet auto-transplantation.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Factorial
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 5
- Model description
- This study is a within subject and across group mechanistic design. Islet cell hormonal responses to a hyperinsulinemic euglycemic-hypoglycemic clamp will be assessed in "Group 1" on three occasions with randomized, double-blind administration of the α-adrenergic blocker phentolamine, the β-adrenergic blocker propranolol, or placebo. Responses in "Group 1" under the placebo condition will be used for comparison to those obtained from hyperinsulinemic euglycemic-hypoglycemic clamp testing on one occasion in subjects in each of "Group 2" and "Group 3".
| Arm | Type | Receives |
|---|---|---|
| Group 1-Propranolol Intra-hepatic islet | Active comparator | Drug: PropranololThe dose of propranolol will be 0.48 μg/kilogram•minute, which will provide a total dose of 0.10 mg/kg. It will be administered 1 x only via intravenous infusion over 3.5 hours, starting 30 min before conduct of a hyperinsulinemic euglycemic (90 min) followed by hypoglycemia (90 min) clamp. |
| Group 1-Phentolamine Intra-hepatic islet | Active comparator | Drug: PhentolamineThe dose of phentolamine will be 0.95 μg/kg•min, which will provide a total dose of 0.20 mg/kg. It will be administered 1 x only via intravenous infusion over 3.5 hours, starting 30 min before conduct of a hyperinsulinemic euglycemic (90 min) followed by hypoglycemia (90 min) clamp. |
| Group 1- Placebo Intra-hepatic islet | Placebo comparator | Drug: PlaceboPlacebo in 100mL NSS. Infuse Intravenously at 0.0095 ML/KG/MIN. 1 x only via intravenous infusion over 3.5 hours, starting 30 min before conduct of a hyperinsulinemic euglycemic (90 min) followed by hypoglycemia (90 min) clamp. |
| Group 2 - Extra-hepatic islet | No intervention | –Hyperinsulinemic euglycemic (90 min) followed by hypoglycemia (90 min) clamp only. |
| Group 3 - Intra-hepatic auto islet | No intervention | –Hyperinsulinemic euglycemic (90 min) followed by hypoglycemia (90 min) clamp only. |
Who may qualify
- Ages
- 21 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (16 listed)
- GROUP 1
- Male and female subjects age 21 to 65 years of age.
- Subjects who are able to provide written informed consent and to comply with the procedures of the study protocol.
- Clinical history compatible with type 1 diabetes with onset of disease at < 40 years of age and insulin-dependent for > 10 years at the time of islet transplantation > 6 months before study.
- Stable islet graft function defined by C-peptide > 0.5 ng/ml and insulin-independent or insulin-dependent with daily insulin requirement < 0.2 units/kg•d to maintain HbA1c < 7.0%.
Key exclusion criteria (48 listed)
- GROUP 1
- BMI ≥ 30 kg/m2.
- Insulin requirement of ≥ 0.2 units/kg•day.
- HbA1c ≥ 7.0%.
- Uncontrolled hypertension: systolic blood pressure > 160 mmHg or diastolic blood pressure > 100 mmHg.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| PhentolamineAlso: RegitinePhysiologic receptor blockade (α1-receptor). | Drug | Group 1-Phentolamine Intra-hepatic islet |
| PropranololAlso: InderalPhysiologic receptor blockade (β2-receptor). | Drug | Group 1-Propranolol Intra-hepatic islet |
| PlaceboAlso: Saline, Sodium Chloride Solution100mL bag of Normal Saline Solution (NSS). | Drug | Group 1- Placebo Intra-hepatic islet |
Primary outcome
C-PEPTIDE Suppression During Hyperinsulinemia Euglycemia.
Time frame: For C-peptide at the 60-90 minute time-point during the hyperinsulinemic euglycemic-hypoglycemic clamp.
The primary outcome measures will be the levels of C-peptide during hyperinsulinemia euglycemia.
GLUCAGON Activation During Hyperinsulinemia Hypoglycemia.
Time frame: For Glucagon at the 150-180 minute time-point during the hyperinsulinemic euglycemic-hypoglycemic clamp.
The primary outcome measures will be the levels of glucagon during hyperinsulinemia hypoglycemia.
3 secondary outcomes
EPINEPHRINE During Hyperinsulinemia Hypoglycemia.
Time frame: During metabolic testing in the 150-180 minute time-point of the hyperinsulinemic euglycemic-hypoglycemic clamp.
Rates of ENDOGENOUS GLUCOSE PRODUCTION During Hyperinsulinemia Hypoglycemia.
Time frame: During metabolic testing in the 150-180 minute time-point of the hyperinsulinemic euglycemic-hypoglycemic clamp.
AUTONOMIC SYMPTOMS During Hyperinsulinemia Hypoglycemia
Time frame: The autonomic symptom score was calculated as the mean of scores at the two hypoglycemic time points during the clamp (165 and 180 minutes).
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 27 Apr 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Perelman School of Medicine / Faculty Search /Michael Rickels, M.D., M.S.Link provided by the sponsor.
- Research Studies at the University of PennsylvaniaLink provided by the sponsor.
- Institute for Diabetes, Obesity and Metabolism Research StudiesLink provided by the sponsor.
- Individual participant dataSharing planned: No. It is not yet known if there will be any further plan to make IPD available besides the Informed Consent.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Michael R Rickels, MD., MS principal investigator
Division of Endocrinology, Diabetes & Metabolism, Perelman School of Medicine
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Early Phase 1 study testing Phentolamine and Propranolol in people with Type1diabetes and Hypoglycemia, run by University of Pennsylvania at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 16 inclusion and 48 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 27 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Early Phase 1 (sometimes called Phase 0) studies give a very small amount of a treatment to a few people, mainly to see how the body handles it.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Yes. Results are posted in the registry (first posted 27 Apr 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
C-PEPTIDE Suppression During Hyperinsulinemia Euglycemia. (time frame: For C-peptide at the 60-90 minute time-point during the hyperinsulinemic euglycemic-hypoglycemic clamp.). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 27 Apr 2026.