~3 spots leftby Nov 2025

Sympathetic Vasoconstriction Blockade for Obesity

Age: 18 - 65
Sex: Any
Travel: May Be Covered
Time Reimbursement: Varies
Trial Phase: Phase 1
Waitlist Available
Sponsor: Vanderbilt University Medical Center

Trial Summary

What is the purpose of this trial?

The purpose of this study is to better understand the contribution of sympathetic vasoconstriction to impaired insulin-mediated vasodilation and subsequently insulin-mediated glucose uptake. The investigators will test the hypothesis that removal of sympathetic vasoconstriction can result in improvement in insulin-mediated vasodilation and subsequently sensitivity to insulin-mediated glucose uptake.

Eligibility Criteria

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.

Inclusion Criteria

I am between 18 and 60 years old.
I have insulin resistance or am a well-controlled type 2 diabetic on metformin.
Able and willing to provide informed consent
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Exclusion Criteria

Other factors which in the investigator's opinion would prevent the subject from completing the protocol (i.e., clinically significant abnormalities on clinical, mental examination or laboratory testing or inability to comply with protocol)
Previous allergic reaction to study medications
You have a history of alcohol or drug abuse.
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Treatment Details

Interventions

  • Phentolamine (Alpha Blocker)
  • Saline (Other)
  • Sodium Nitroprusside (Vasodilator)
Trial OverviewThe 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).
Participant Groups
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

Phentolamine is already approved in Canada for the following indications:

🇨🇦
Approved in Canada as Phentolamine for:
  • Hypertension
  • Pheochromocytoma

Find a Clinic Near You

Who Is Running the Clinical Trial?

Vanderbilt University Medical Center

Lead Sponsor

Trials
922
Recruited
939,000+