Transduction of Sympathetic Neural Activity in Human Obesity Without Hypertension

October 1, 2024 updated by: University of Kansas Medical Center

Concomitantly Higher Resting Arterial Blood Pressure and Transduction of Sympathetic Neural Activity in Human Obesity Without Hypertension

In addition to chronically elevated MSNA, there is a growing recognition that hypertension in states of insulin resistance and obesity may also be attributed to an increased vascular sensitivity to MSNA (1, 2, 13, 36-38). To study this phenomenon, we quantify vascular sensitivity to MSNA using an innovative, moment-to-moment assessment of the blood pressure response following individual bursts of muscle sympathetic nerve activity (MSNA), (10, 11, 34, 37). This approach is termed 'sympathetic-vascular transduction (SVT).' We will examine the hypothesis that SVT is exaggerated in obesity and insulin resistance and is attenuated by suppression of oxidative stress. Oxidative stress is the overabundance of reactive oxygen species and is another hallmark of hypertension, obesity, and insulin resistance. Oxidative stress can be safely reduced via intravenous infusion of ascorbic acid (Vit C) (4, 28). Therefore, we will use a randomized, double-blinded, placebo-controlled approach to test the hypothesis that elevated SVT will be attenuated by suppression of oxidative stress via ascorbic acid I.V. infusion compared with saline I.V. infusion (placebo) in obese adults with insulin resistance. Our study will identify a unique mechanism that can be targeted to reduce the excessively high prevalence of hypertension and risk for CVD in obesity and insulin resistance.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

This is a randomized, double blind, placebo-controlled study. Eligible participants will have a total of 3 visits to the laboratory. At the first experimental visit individuals will be randomized in a double-blind fashion to either ascorbic acid or placebo and the alternative treatment will be given on the subsequent study visit. The KU Investigational Pharmacy will perform the blinded randomization.

  1. Week 1 Visit 1 Screening
  2. Week 2 Visit 2 Randomization and Experimental visit
  3. Week 5 Visit 3 Experimental visit

Study Type

Observational

Enrollment (Estimated)

60

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
    • Kansas
      • Kansas City, Kansas, United States, 66160
        • Recruiting
        • University of Kansas Medical Center
        • Contact:
          • Seth Holwerda

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

  • Adult
  • Older Adult

Accepts Healthy Volunteers

N/A

Sampling Method

Probability Sample

Study Population

Obese

Description

Inclusion criteria:

  1. Obese: BMI >25 m/kg2
  2. Elevated insulin resistance: HOMA-IR > 2.5 (calculation based on fasting glucose and insulin concentrations in blood)
  3. Middle-aged: 35-65 years
  4. Participants must be willing and able to discontinue taking any vitamin C or E supplements or omega-3 fatty acids beginning 2 weeks prior.
  5. Able and willing to provide written informed consent

Exclusion criteria:

  1. Currently taking a statin or antihypertension medication
  2. Hyperlipidemia: Fasting triglycerides < 250 mg/dL
  3. Hypertension: >130/80 mmHg
  4. History of heart disease (e.g., myocardial infarction, stent)
  5. History of vascular disease (e.g., bypass, stroke)

  6. Individuals with narrow angle glaucoma

    -

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

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Obese
Drug: ascorbic acid
ascorbic acid

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Sympathetic transduction
Time Frame: 2 hours
2 hours

Collaborators and Investigators

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

Sponsor

University of Kansas Medical Center

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)

August 1, 2022

Primary Completion (Estimated)

September 1, 2026

Study Completion (Estimated)

September 1, 2027

Study Registration Dates

First Submitted

October 1, 2024

First Submitted That Met QC Criteria

October 1, 2024

First Posted (Actual)

October 3, 2024

Study Record Updates

Last Update Posted (Actual)

October 3, 2024

Last Update Submitted That Met QC Criteria

October 1, 2024

Last Verified

October 1, 2024

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • VITAMINC

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.

Subscribe