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Alpha Blocker

Sympathetic Vasoconstriction Blockade for Obesity

Phase 1
Recruiting
Research Sponsored by Vanderbilt University Medical Center
Eligibility Criteria Checklist
Specific guidelines that determine who can or cannot participate in a clinical trial
Must have
Insulin resistance defined as homeostasis model assessment 2 insulin resistance (HOMA2-IR) score >1.6 (never diagnosed or treated type 2 diabetic), or being a well-controlled type 2 diabetic on metformin only.
Insulin resistance defined as homeostasis model assessment 2 insulin resistance (HOMA2-IR) score >1.6 (never diagnosed or treated type 2 diabetic), or being a well-controlled type 2 diabetic on metformin only
Timeline
Screening 3 weeks
Treatment Varies
Follow Up before clamp and 15 minutes after clamp
Awards & highlights

Study Summary

This trial is testing whether removing sympathetic vasoconstriction can improve insulin-mediated vasodilation and sensitivity to insulin-mediated glucose uptake.

Who is the study for?
This trial is for adults aged 18-60 with obesity (BMI between 30-40) and insulin resistance, but not severe diabetes. Participants can be well-controlled type 2 diabetics on metformin. Exclusions include those on anticoagulants, with morbid obesity or cardiovascular disease, drug abuse history, heavy smokers, or certain medication users.Check my eligibility
What is being tested?
The study tests if blocking sympathetic vasoconstriction improves insulin-induced vasodilation and glucose uptake in obese individuals. It involves administering Phentolamine (blocks adrenaline effects), Saline (a placebo), and Sodium Nitroprusside (enhances blood flow).See study design
What are the potential side effects?
Potential side effects may include low blood pressure, dizziness, headache from Phentolamine; irritation at the infusion site from Saline; and possible rapid heartbeat or changes in blood oxygen levels from Sodium Nitroprusside.

Eligibility Criteria

Inclusion Criteria

You may be eligible if you check “Yes” for the criteria below
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I have insulin resistance or am a well-controlled type 2 diabetic on metformin.
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I have insulin resistance or am a well-controlled type 2 diabetic on metformin.
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My BMI is between 30 and 40.

Timeline

Screening ~ 3 weeks
Treatment ~ Varies
Follow Up ~before clamp and 15 minutes after clamp
This trial's timeline: 3 weeks for screening, Varies for treatment, and before clamp and 15 minutes after clamp for reporting.

Treatment Details

Study Objectives

Outcome measures can provide a clearer picture of what you can expect from a treatment.
Primary outcome measures
Contrast Enhanced-Ultrasonography (CEU)

Trial Design

3Treatment groups
Experimental Treatment
Active Control
Placebo Group
Group I: Blocked DayExperimental Treatment1 Intervention
Phentolamine
Group II: Vasodilator ComparisonActive Control1 Intervention
Sodium Nitroprusside
Group III: Intact DayPlacebo Group1 Intervention
Saline

Find a Location

Logistics

Participation is compensated

You will be compensated for participating in this trial.

Who is running the clinical trial?

Vanderbilt University Medical CenterLead Sponsor
857 Previous Clinical Trials
672,157 Total Patients Enrolled
10 Trials studying Insulin Resistance
861 Patients Enrolled for Insulin Resistance

Media Library

Insulin Resistance Research Study Groups: Intact Day, Blocked Day, Vasodilator Comparison
Insulin Resistance Clinical Trial 2023: Phentolamine Highlights & Side Effects. Trial Name: NCT03318094 — Phase 1
Phentolamine (Alpha Blocker) 2023 Treatment Timeline for Medical Study. Trial Name: NCT03318094 — Phase 1
Insulin Resistance Patient Testimony for trial: Trial Name: NCT03318094 — Phase 1

Frequently Asked Questions

These questions and answers are submitted by anonymous patients, and have not been verified by our internal team.

Could you please provide a synopsis of other research pertaining to Phentolamine?

"Currently, 8 clinical trials are ongoing that center around Phentolamine with none of them having entered Phase 3. Most of these studies are located in Salt Lake City; however, other sites across the US have been selected for research on this drug."

Answered by AI

What medical symptoms is Phentolamine most commonly prescribed to address?

"Phentolamine can effectively address intraoperative blood loss, anesthesia reversal, and the prophylaxis of necrosis caused by administration site extravasation."

Answered by AI

What is the current participant count of this clinical experiment?

"Affirmative, the information accessible on clinicaltrials.gov demonstrates that this research endeavour is in pursuit of participants. This trial was initially posted on October 24th 2017 and most recently updated August 24th 2022. There are 36 persons being sought from a single location."

Answered by AI

Are enlistees being accepted for this medical trial presently?

"Affirmative, the data hosted on clinicaltrials.gov attests to this experiment's ongoing recruitment efforts, which were first launched on October 24th 2017. The project is currently seeking 36 individuals at a single site for participation."

Answered by AI

Does this clinical trial permit the inclusion of individuals under 40 years old?

"This clinical trial has established the age criteria of 18 to 60 years old. There are 268 trials that have a minimum age lower than this and 1029 with an upper limit higher than the one set in place by this study."

Answered by AI

Can I become a participant of this research endeavor?

"This clinical trial seeks 36 participants aged 18 to 60 with insulin resistance, who must also meet the following conditions: Male and Female of any race BMI ranging from 30-40 kg/m2 HOMA2-IR score >1.6 (undiagnosed or treated type 2 diabetes) Be well controlled on just Metformin Willingly provide informed consent."

Answered by AI

What risks do individuals face when taking Phentolamine?

"Our team of experts has assigned Phentolamine a score of 1 because it is only in the early stages of clinical trials, and there is limited data indicating its safety or efficacy."

Answered by AI

Who else is applying?

What state do they live in?
Ohio
Colorado
How old are they?
18 - 65
What portion of applicants met pre-screening criteria?
Did not meet criteria
Met criteria
What site did they apply to?
Autonomic Dysfunction Center
How many prior treatments have patients received?
0

Why did patients apply to this trial?

Compensation and side money as well as to help find treatment for others.
PatientReceived 1 prior treatment
Recent research and studies
clinicaltrials.govStudy
Role of Sympathetic Vasoconstriction on Insulin-Mediated Microvascular Recruitment and Glucose Uptake in Obesity
Italo Biaggioni 2017. "Role of Sympathetic Vasoconstriction on Insulin-Mediated Microvascular Recruitment and Glucose Uptake in Obesity". ClinicalTrials.gov. https://clinicaltrials.gov/ct2/show/NCT03318094.
All > Obesity
~7 spots leftby Nov 2025
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