Sex Disparities in Hypoxic Vasodilation and Impact of Obesity

May 22, 2025 updated by: Jacqueline K Limberg, PhD, University of Missouri-Columbia
The purpose of this project is to examine key mechanisms contributing to sex-differences in hypoxic vasodilation and the impact of obesity, with particular emphasis on the sympathetic nervous system.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Patients with sleep apnea are at increased risk of developing cardiovascular disease - with women at potentially greater risk than men. Contributing mechanisms are not well understood, but may be related to how women respond to low oxygen and, given over 70% of patients with sleep apnea are obese, the impact of obesity. This project seeks to increase our understanding of mechanisms that may contribute to sex differences in the cardiovascular response to low oxygen with the hope that this knowledge will improve the efficacy of current therapies and support the discovery of novel therapeutics.

Study Type

Interventional

Enrollment (Estimated)

72

Phase

  • Early Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • United States
    • Missouri
      • Columbia, Missouri, United States, 65211
        • Recruiting
        • University of Missouri
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 45 years (Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • BMI >18 kg/m2

Exclusion Criteria:

  • Pregnancy, breastfeeding
  • Diagnosed sleep apnea or AHI >10 events/hr
  • Current smoking/Nicotine use
  • Increased risk of bleeding, pro-coagulant disorders, clotting disorders, anticoagulation therapy
  • Nerve/neurologic disease
  • Cardiovascular, hepatic, renal, respiratory disease
  • Blood pressure ≥140/90 mmHg
  • Diabetes, Polycystic ovarian syndrome
  • Communication barriers
  • Prescription medications, Sensitivity to lidocaine

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: Hypoxia Exposure
Men and women will be exposed to isocapnic hypoxia. Participants will wear a mask and systemic oxygen levels will be titrated to attain hypoxemia as assessed by pulse oximetry.
Drug: Norepinephrine
Regional forearm infusion at 8 ng/dL/min via brachial artery catheter during normoxia and hypoxia exposures
Drug: Propranolol Hydrochloride
Regional forearm blockade of β-adrenergic receptors at 20 mcg/dL/min via brachial artery catheter during normoxia and hypoxia exposures
Drug: Isoproterenol
Dose response (1, 3, 6, and 12 ng/dL/min) regional infusion to assess β-adrenergic receptor responsiveness
Drug: Phentolamine Mesylate
This infusion will be for 10 min before baseline measurement (12 mcg/dL/min) and continue the infusion at a maintenance rate (5 mcg/dL/min).

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in forearm vascular conductance with intra-arterial drug infusion
Time Frame: Change from baseline to last 1-minute of drug infusion
Vascular conductance is an index of vascular tone and is measured using a technique called venous occlusion plethysmography.
Change from baseline to last 1-minute of drug infusion

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Missouri-Columbia

Investigators

  • Principal Investigator: Jacqueline Limberg, Ph.D., University of Missouri-Columbia

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

March 14, 2023

Primary Completion (Estimated)

June 30, 2026

Study Completion (Estimated)

June 30, 2026

Study Registration Dates

First Submitted

January 21, 2022

First Submitted That Met QC Criteria

January 21, 2022

First Posted (Actual)

February 2, 2022

Study Record Updates

Last Update Posted (Actual)

May 29, 2025

Last Update Submitted That Met QC Criteria

May 22, 2025

Last Verified

May 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2080504

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

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

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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